#India - High pathogenicity avian #influenza #H5N1 viruses (Inf. with) (#poultry) - Immediate notification

 

A poultry farm in the Maharashtra State.

Source: 

Link: https://wahis.woah.org/#/in-review/7469

____

#India - High pathogenicity avian #influenza #H5N1 viruses (Inf. with) (#poultry) - Immediate notification

 

A poultry farm in the Chhattisgarh Region.

Source: 

Link: https://wahis.woah.org/#/in-review/7453

____

#India - High pathogenicity avian #influenza #H5N1 viruses (Inf. with) (#poultry) - Immediate notification

 

A poultry farm in Bihar State.

Source: 

Link: https://wahis.woah.org/#/in-review/7319

____

#India - High pathogenicity avian #influenza #H5N1 viruses (Inf. with) (#poultry) - Immediate notification

 

Poultry farms in Andhra Pradesh State.

Source: 

Link: https://wahis.woah.org/#/in-review/7268

____

#India - #Influenza A #H5N1 viruses of high pathogenicity (Inf. with) (non-poultry including wild birds) (2017-) - Immediate notification

{By Pkspks - Own work, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=162556362}

___

More than 300 House Crows in Bihar: Darbhanga, Patna, Bhagalpur, Katihar, Pashchim Champaran Regions. 

Source: 

Link: https://wahis.woah.org/#/in-review/7269

____

#Nipah virus infection - #India (#WHO D.O.N., Jan. 30 '26)

 

Situation at a glance

On 26 January 2026, the National IHR Focal Point for India notified WHO of two laboratory‑confirmed cases of Nipah virus (NiV) infection in West Bengal State. 

Both are healthcare workers at the same private hospital in Barasat (North 24 Parganas district). 

NiV infection was confirmed at the National Institute of Virology in Pune on 13 January. 

One case remains on mechanical ventilation as of 21 January, the other case experienced severe neurological illness but has since improved. 

Authorities have identified and tested over 190 contacts, who all tested negative for NiV with support from a mobile BSL‑3 laboratory deployed by the National Institute of Virology, Pune. 

No further cases have been detected to date. 

This event represents the third NiV infection outbreak reported in West Bengal (previous outbreaks reported in Siliguri in 2001 and Nadia in 2007). 

Enhanced surveillance and infection prevention and control (IPC) measures are in place while investigations into the source of exposure are ongoing. 

NiV infection is a serious but rare zoonotic disease transmitted to humans through infected animals (such as bats), or food contaminated with saliva, urine, and excreta of infected animals. 

It can also be transmitted directly from person to person through close contact with an infected person. 

There are currently no licensed medicines or vaccines for NiV infection, however early supportive care can improve survival. 

WHO assesses the risk posed by Nipah to be moderate at the sub-national level, and low at the national, the regional and global levels.

Description of the situation

On 26 January 2026, the India IHR NFP notified WHO of two confirmed NiV infection cases that occurred in West Bengal State. 

Preliminary laboratory testing suggested NiV infection, and confirmation was received from the National Institute of Virology, Pune on 13 January 2026.

The cases were confirmed through Reverse Transcription Polymerase Chain Reaction (RT-PCR) and Enzyme-Linked Immunosorbent Assay (ELISA) testing.

The first case is a female nurse and the second case is a male nurse. 

Both cases were between 20 – 30 years old, from Barasat, North 24 Parganas district. 

Both cases developed symptoms typical of severe NiV infection in late December 2025 and were admitted to hospital in early January 2026. 

As of 21 January 2026, the second case showed clinical improvement, while the first case remained under critical care.

Following the two confirmed cases, Indian health authorities identified and tested over 190 contact persons, including health and care workers and community contacts. All samples from contact persons tested negative for NiV.

The Indian National Centre for Disease Control, announced on 27 January that no further confirmed cases have been detected in West Bengal from December 2025 to date.

Epidemiology

NiV infection is a zoonotic disease transmitted to humans through infected animals (such as bats), or food contaminated with saliva, urine, and excreta of infected animals. It can also be transmitted directly from person to person through close contact with an infected person. Fruit bats or flying foxes (Pteropus species) are the natural hosts for the virus.

The incubation period ranges from 3 to 14 days. In some rare cases incubation of up to 45 days has been reported. Laboratory diagnosis of a patient with a clinical history of NiV infection can be made during the acute and convalescent phases of the disease by using a combination of tests. The main tests used are RT-PCR from bodily fluids and antibody detection via ELISA.

Human infections range from asymptomatic infection to acute respiratory infection (mild, severe), and fatal encephalitis (brain swelling).

Infected people initially develop symptoms including fever, headaches, myalgia (muscle pain), vomiting and sore throat. This can be followed by dizziness, drowsiness, altered consciousness, and neurological signs that indicate acute encephalitis. Some people can also experience atypical pneumonia and severe respiratory problems, including acute respiratory distress. Encephalitis and seizures occur in severe cases, progressing to coma within 24 to 48 hours.

Further information about NiV infection can be found here.

The case fatality ratio (CFR) in outbreaks across Bangladesh, India, Malaysia, and Singapore range from 40% to 75%, depending on local capabilities for early detection and clinical management. There are currently no licensed medicines or vaccines specific for NiV infection. Intensive supportive care is recommended to treat severe respiratory and neurologic complications. Henipavirus nipahense (Nipah virus) is considered a priority pathogen for the acceleration of medical countermeasures (MCMs) to respond to epidemics and pandemics as part of the WHO R&D Blueprint for Epidemics. 

Public health response

Several public health measures have been implemented by local authorities, including:

-- The Government of India, in close coordination with the Government of West Bengal, initiated prompt and comprehensive public health measures in accordance with established protocols.

-- Investigations were conducted in collaboration with other sectors through a One Health coordinated approach.

-- Contact tracing has been carried out around the identified cases, with continuous follow-up.

-- Surveillance efforts have been strengthened and enhanced to ensure early case detection.

-- Health education and awareness campaigns, including community engagement and advocacy, are ongoing.

-- Clinicians have been sensitized and alerted to NiV. Infection prevention and control has been strengthened at health-care settings.

- Prompt sample collection, transportation, and testing were conducted at the reference laboratory teams.

The support provided by WHO includes:

-- Providing event communication support at national and international levels, including the submission of an official IHR notification.

-- Monitoring of the evolving outbreak situation, especially during the ongoing Nipah season, including support for assessment of epidemiological patterns, risk factors, and geographic spread.

WHO risk assessment

Nipah virus (Henipavirus nipahense) is a rare zoonotic pathogen with a high CFR (40-75%) and no licensed vaccine or treatment. 

Its reservoirs are fruit bats or flying foxes (bats in the Pteropus genus), which are distributed in the coastal regions and on several islands in the Indian ocean, India, south-east Asia and Oceania. 

The virus can be transmitted to humans from wild and domestic animals, however, as the disease can be transmitted by domesticated animals, secondary human-to-human transmissions are also possible. 

Cases of Nipah virus infection were first reported in 1998 and since then have been reported in Bangladesh, India, Malaysia, Philippines and Singapore. 

The virus is present in India, with seasonal outbreaks linked to bat activities and cultural practices such as the consumption of raw date palm sap. Seasonal outbreaks occur between December and May, coinciding with the harvesting of date palm sap.

This event represents the 13th Nipah outbreak documented in India and the third reported in West Bengal. 

Since 2001, India has reported 12 Nipah outbreaks prior to this event: 10 in the state of Kerala and two in the state of West Bengal. 

In West Bengal, previous outbreaks occurred in 2001 (Siliguri) and 2007 (Nadia district). 

Based on the current available information, WHO assesses the overall public health risk posed by NiV at the sub-national level to be moderate, taking into consideration no availability of specific drugs or vaccines for NiV infection and the difficulty of early diagnosis. 

Although sensitive and specific laboratory methods exist, the symptoms during the first phase are not specific and could potentially delay a timely diagnosis, outbreak detection and response. 

In addition, fruit bats (Pteropus spp.) are the natural reservoir of NiV, and they are present in India and repeated spillover of the virus from its reservoir to the human population has been demonstrated.

Human-to-human transmission has been documented in previous outbreaks, mostly reported in health-care settings and among family and caregivers of sick people through close contact with bodily fluids. 

Implementation of adequate infection prevention and control measures in health care facilities is critical to mitigate health care associated infection.

The yearly number of NiV infection cases reported in India has remained relatively low since 2001, except for 2001, when 66 cases were reported and 2018 when 18 cases were reported. 

Over the past 5 years, a dozen confirmed cases were reported in India, all in Kerala State. 

Strong public health measures are implemented in India to detect and control outbreaks, including established NiV surveillance, and the availability of Rapid Response Teams (RRT) at both the Central and State levels, along with the capacity to rapidly test samples.

For neighbouring countries, WHO assesses the public health risk posed by NiV at the regional level to be low. There have been no reports of cross‑border transmission, and the current outbreak remains geographically limited. 

Nevertheless, the risk of disease occurrence persists due to the shared ecological corridor of fruit bats and the history of human cases previously reported in the region. India has demonstrated strong capacity and experience in managing past NiV outbreaks.

WHO assesses the public health risk posed by NiV at the global level to be low, as there has been no confirmed spread of cases outside India.

WHO advice

In the absence of a licensed vaccine or specific therapeutic treatment for Nipah virus disease, reducing or preventing infection in people relies on raising awareness of the risk factors. 

This includes providing guidance on and reinforcing risk communication messages about the measures that people can take to reduce exposure to the Nipah virus. This is also important in the context of mass gatherings, where attendees come from different countries and may be unfamiliar with disease and its mode of transmission, as well as actions they can take to protect themselves. and case management should focus on delivering timely supportive care, supported by an effective laboratory system and adequate infection prevention and control measures in health facilities. Intensive supportive care is recommended for treatment of severe respiratory and neurologic complications. 

Public health educational messages should focus on:

-- Reducing the risk of bat-to-human transmission

- Efforts to prevent transmission should first focus on decreasing bat access to date palm sap and other fresh food products. Freshly collected date palm juice should be boiled, and fruits should be thoroughly washed and peeled before consumption. Fruits with signs of bat bites should be discarded. Areas where bats are known to roost should be avoided.

-- Reducing the risk of human-to-human transmission.

- Close unprotected physical contact with NiV-infected people should be avoided. Regular hand washing should be carried out after caring for or visiting sick people along other preventive measures.

-- People experiencing Nipah-like symptoms should be referred to a health facility, as early supportive care is key in the absence of treatment. Contact tracing and monitoring are also key to mitigate human-to-human transmission.

-- Controlling infection in health care settings

- Health and care workers caring for patients with suspected or confirmed infection, or handling specimens from them, should always implement standard precautions for infection prevention and control at all times, for all patients.

- When caring for patients with suspected or confirmed NiV, WHO advises the use of contact and droplet precautions including a well-fitting medical mask, eye protection, a fluid-resistant gown, and examination gloves. Airborne precautions should be implemented during aerosol-generating procedures, including placing the patient in an airborne-infection isolation room and the use of a fit-tested filtering facepiece respirator instead of a medical mask. Suspected or confirmed cases of NiV should be placed in a single-patient room.   For family members and caregivers visiting patients with suspected or confirmed Nipah virus, similar precautions should be applied.   

- Samples taken from people and animals with suspected NiV infection should be handled by trained staff working in suitably equipped laboratories.

Based on the currently available information, WHO does not recommend any travel and/or trade restrictions.

Further information

-- World Health Organization. Nipah virus [Fact sheet]. Geneva: WHO; 2026. Available from: https://www.who.int/news-room/fact-sheets/detail/nipah-virus

-- Ministry of Health and Family Welfare. Only Two Nipah Virus Disease Cases Reported in West Bengal Since Last December: NCDC. 196 Contacts Linked to Nipah Cases Traced and Found Asymptomatic; All Test Negative. https://www.pib.gov.in/PressReleasePage.aspx?PRID=2219219&reg=3&lang=1

-- News On AIR. West Bengal reports two suspected Nipah cases; Centre sends response team. New Delhi: Prasar Bharati; 13 January 2026. Available from: https://www.newsonair.gov.in/west-bengal-reports-two-suspected-nipah-cases-centre-sends-response-team/

-- News On AIR. Centre deploys National Joint Outbreak Response Team in West Bengal after suspected Nipah cases. New Delhi: Prasar Bharati; 12 January 2026. Available from: https://www.newsonair.gov.in/centre-deploys-national-joint-outbreak-response-team-in-west-bengal-after-suspected-nipah-cases/

-- Ministry of Health and Family Welfare (MoHFW). X (formerly Twitter). 11 Jan 2026. Available from: https://x.com/MoHFW_INDIA/status/2010751351232594216

-- World Health Organization, Regional Office for South-East Asia, Epidemiological Bulletin WHO Health Emergencies Programme, 2nd edition (2026), 28 January 2026 Reporting period: 12 to 25 Jan 2026: https://cdn.who.int/media/docs/default-source/searo/whe/wherepib/2026_02_searo_epi_bulletin.pdf

-- World Health Organization (6 August 2025). Disease Outbreak News; Nipah virus infection – India. Available at: https://www.who.int/emergencies/disease-outbreak-news/item/2025-DON577

-- https://www.who.int/news-room/fact-sheets/detail/nipah-virus

-- World Health Organization, Regional Office for South-East Asia. Regional strategy for the prevention and control of Nipah virus infection: 2023–2030. New Delhi: WHO SEARO; 2023. Available from: https://www.who.int/publications/i/item/9789290210849

-- World Health Organization. Technical brief: Enhancing readiness for a Nipah virus event in countries not reporting a Nipah virus event: interim document. Geneva: WHO; 2024 Feb. Available from: https://www.who.int/publications/i/item/9789290211273

-- Kumar SS, Maan S, Kumari M, Gupta P, Bhatia S, Maan NS. Nipah virus disease: epidemiological, clinical, diagnostic and legislative aspects of this unpredictable emerging zoonosis. Animals (Basel). 2023;13(1):159. doi:10.3390/ani13010159. Available from: https://www.mdpi.com/2076-2615/13/1/159

-- Thomas B, Chandran P, Lilabi MP, George B, Sivakumar CP, Jayadev VK, et al. Nipah virus infection in Kozhikode, Kerala, South India, in 2018: epidemiology of an outbreak of an emerging disease. Indian J Community Med. 2019;44(4):383–7. https://pubmed.ncbi.nlm.nih.gov/31802805

-- World Health Organization. Standard precautions for the prevention and control of infections: aide memoire. Geneva: WHO; 2022. Available from: https://www.who.int/publications/i/item/WHO-UHL-IHS-IPC-2022.1

-- Transmission-based precautions for the prevention and control of infections: aide memoire. Geneva: WHO; 2022. Available from: https://www.who.int/publications/i/item/WHO-UHL-IHS-IPC-2022.2

Source: 

Link: https://www.who.int/emergencies/disease-outbreak-news/item/2026-DON593

____

#Pathology of dose dependent inocula of #H5N8 avian #influenza viruses in experimentally infected #chicken

 

Abstract

In the present study, we assessed the pathogenicity of H5N8 avian influenza viruses belongs to the clade 2.3.4.4b in chicken. Birds of three different dose groups, 10 2 , 10 4 , and 10 6 EID 50 were used in the study. No mortality was observed in 10 2 EID0 group. Percent cumulative mortality of 10 4 and 10 6 EID 50 group was 66.67 and 100 %, respectively. Varying duration of MDT of 3.2 and 2 days was observed in 10 4 and 10 6 EID 50 group, respectively. The CID 50 of virus was found to be 10 4.5 EID 50 . High no. of viral RNA copies were found both in oropharyngeal and cloacal swabs and in various organs of birds infected in 10 4 and 10 6 EID 50 group. Significant gross and histological changes and presence of viral antigen in various organs were observed in 10 4 and 10 6 EID 50 group. So, the study concludes that Indian HPAI, H5N8 isolates are highly pathogenic in nature to chicken by affecting most organs systemically. CID 50 of this H5N8 virus indicates poor adaption in chicken and it implies poor transmission possibility of this virus for host species in field condition. Though this virus are highly pathogenic in nature as that of HPAI, H5N1 viruses, absence of endothelial staining in most organs attributes variation in replication process and pathogenesis from HPAI, H5N1 viruses. Hence, further studies need to be done to elucidate the pathobiology of this virus in various bird species.

Competing Interest Statement

The authors have declared no competing interest.

Funder Information Declared

Indian Council of Agricultural Research, https://ror.org/04fw54a43

Source: 

Link: https://www.biorxiv.org/content/10.64898/2026.01.27.700741v1

____

#HK, DH follows up on #Nipah virus #infection cluster in #India (Jan. 26 '26)

 

DH follows up on Nipah virus infection cluster in India

In light of reports indicating a cluster of a Nipah virus infection in a certain region of India, the Centre for Health Protection (CHP) of the Department of Health (DH) said today (January 26) that it has proactively sought further information from the World Health Organization (WHO) and Indian health authorities. 

The CHP is also conducting health screenings on inbound travellers from the affected area who exhibit suspected symptoms, with an aim of promptly referring suspected cases to hospitals for investigation. 

Currently, there are no imported or local cases of Nipah virus infection in Hong Kong.

Preliminary information indicated that a hospital in Kolkata, West Bengal, India, has recorded five confirmed cases of Nipah virus infection since mid-January of this year. 

The cluster was mainly due to nosocomial transmission and primarily involved healthcare workers, with no reported deaths or cross-border transmissions to date. 

Approximately 100 close contacts have been quarantined and tested in India. 

The CHP's current risk assessment indicates a low risk of importation of Nipah virus into Hong Kong.

Nipah virus was first identified during outbreaks in Malaysia and Singapore from 1998 to 1999, affecting pig farm workers and individuals with close contact with pigs. 

It can affect various animals, including pigs, horses, goats, sheep, cats and dogs. 

Over the past two decades, multiple outbreaks of human Nipah virus infections were recorded in Bangladesh and India, typically occurring between December and April. 

Transmission primarily occurs through the consumption of raw date palm sap contaminated by fruit bats. India's most recent outbreak occurred in Kerala in mid-2025, involving four cases.

"Nipah virus infection is an emerging zoonotic disease. Fruit bats are the natural host for the virus. The virus is mainly transmitted through direct contact with sick animals via their contaminated respiratory droplets, nasal secretions and tissues. It can also be transmitted via consuming food contaminated with urine, droppings or saliva from infected bats, usually fruits or fruit products (particularly raw date palm sap). Human-to-human transmission is also possible through close contact with contaminated secretions and excretions of infected persons. Such transmission has been reported in patients' household and healthcare settings," the Controller of the CHP, Dr Edwin Tsui, said.

Patients infected with Nipah virus can be asymptomatic. 

Early symptoms include flu-like symptoms, such as fever, headache, vomiting, sore throat and muscle aches. Other symptoms include dizziness, drowsiness and a decrease in consciousness. Severe cases may develop complications such as pneumonia, seizure, encephalitis, coma or even death. The case fatality rate ranges from approximately 40 per cent to 75 per cent. Among the patients who survive acute encephalitis, around 20 per cent of them may have persistent nerve problems. Currently, there is no specific treatment or medication for Nipah virus infection. The mainstay of treatment is limited to supportive care. Symptoms usually start to develop around four to 14 days after exposure, but onset may occur as late as 45 days.

"Hong Kong has the ability to detect infections of unknown causes and emerging infectious diseases at boundary control points and in hospitals. On the immigration level, the DH conducts medical assessments for sick travellers at all boundary control points and refers them to hospitals for medical examinations as needed. The CHP has a robust communicable disease surveillance and notification mechanism that enables medical professionals to report suspected cases. So far, no cases of Nipah virus infection have been recorded. Although there are no direct flights between Kolkata and Hong Kong, the CHP will step up health screenings for passengers arriving from India at the airport as a precautionary measure. Port Health staff have been arranged to carry out temperature screenings for travellers at relevant flight gates, perform medical assessments on symptomatic travellers and refer suspected cases with potential public health implications to hospitals for examination," said Dr Tsui.

Dr Tsui reminded the public to take the following measures to reduce infection risk if travel to Nipah virus-affected areas is unavoidable:

-- Avoid contact with wild animals or sick farm animals, especially bats, farmed pigs, horses, domestic and feral cats.

-- Avoid areas where bats are known to roost.

-- Observe good personal hygiene; wash hands frequently with liquid soap and water, especially after contact with animals or their droppings/secretions, and after taking caring of or visiting sick people.

-- Observe food hygiene by thoroughly washing and peeling fruits before consumption. Fruits with signs of bat bites or found on the ground should not be consumed. Avoid drinking raw date palm sap, toddy or other juice.

 The CHP will monitor the situation and implement appropriate prevention and control measures based on risk assessments to safeguard public health and the well-being of citizens.

 

Ends/Monday, January 26, 2026

Issued at HKT 19:45

Source: 

Link: https://www.info.gov.hk/gia/general/202601/26/P2026012600674.htm?fontSize=1

____

#India - High pathogenicity avian #influenza #H5N1 viruses (Inf. with) (#poultry) - Immediate notification

 

{Kerala}

1) The outbreak was detected in ducks within an integrated rice–duck farming system.

2) The outbreak was detected in ducks within an integrated rice–duck farming system.

3) The outbreak was detected in ducks within an integrated rice–duck farming system.

4) The outbreak was detected in ducks within an integrated rice–duck farming system.

5) The outbreak was detected in ducks within an integrated rice–duck farming system.

6) The outbreak was detected in ducks within an integrated rice–duck farming system.

7) The outbreak was detected in ducks within an integrated rice–duck farming system.

8, 9 & 10) Poultry farms.

Source: 

Link: https://wahis.woah.org/#/in-review/7161

____

#India - High pathogenicity avian #influenza #H5N1 viruses (#poultry) (Inf. with) - Immediate notification

Farmed and  Backyard poultry in Uttarakhand State.

Source: 

Link: https://wahis.woah.org/#/in-review/6804

____

#Kyasanur Forest #disease: an emerging #arboviral #threat

 

Summary

Kyasanur Forest disease is a neglected tick-borne viral haemorrhagic fever endemic to India's Western Ghats, caused by the Kyasanur Forest disease virus, a flavivirus transmitted by Haemaphysalis spinigera ticks. The virus circulates in a sylvatic cycle among monkeys, rodents, shrews, birds, and ixodid ticks, and is transmitted to humans incidentally via tick bites. Since its discovery in 1957 in Karnataka, Kyasanur Forest disease has spread to other Indian states, driven by deforestation, forest fragmentation, and increased human incursion into wildlife habitats. Clinically, the disease manifests in a biphasic pattern, with haemorrhagic and neurotropic presentations. Although a formalin-inactivated vaccine is available, its efficacy is not promising, and no antivirals have been approved to date. Field reports indicate that mortality in monkeys might serve as an early indicator of forthcoming human outbreaks. The transmission dynamics of Kyasanur Forest disease, diagnostic gap, and ecological complexities present substantial public health challenges. In this Review, we provide an update on Kyasanur Forest disease virus, covering its epidemiology, transmission dynamics, molecular virology, virus–host interactions, immunological responses, animal models, and potential antiviral therapies and vaccines.

Source: Lancet Infectious Diseases, https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(25)00589-4/abstract?rss=yes

____

#India - High pathogenicity avian #influenza #H5N1 viruses (#poultry) (Inf. with) - Immediate notification

{Several poultry farms in Uttar Pradesh State.}

HPAI (H5N1) was detected in a Live Bird Market from the environmental sample. Hence no cases were observed.

Source: WOAH, https://wahis.woah.org/#/in-review/6730

____

#India - #Influenza A #H5N1 viruses of high pathogenicity (Inf. with) (non-poultry including wild birds) (2017-) - Immediate notification

 

{By Charles J. Sharp - Own work, from Sharp Photography, sharpphotography.co.uk, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=116380120}

Nineteen captive Painted Storks in the National Zoological Park, Delhi.

Source: WOAH, https://wahis.woah.org/#/in-review/6803

____

#India - High pathogenicity avian #influenza #H5N1 viruses (#poultry) (Inf. with) - Immediate notification

 

Two Poultry Farms in the Odisha State.

Source: WOAH, https://wahis.woah.org/#/in-review/6694

____

#Nipah virus #infection - #India (#WHO D.O.N., August 6 '25)

Situation at a glance

Between 17 May and 12 July 2025, the Information and Public Relations Department, Government of Kerala informed through a series of official press releases about four confirmed cases, including two deaths, due to Nipah virus (NiV) infection in two districts of Kerala State. 

NiV infection is a bat-borne disease transmitted to humans through infected animals (such as bats or pigs), contaminated food or, less commonly, through close contact with infected individuals. 

Since 1998 NiV outbreaks have been reported in Bangladesh, India, Malaysia, the Philippines, and Singapore. 

In India, NiV infections have occurred multiple times since 2001 with outbreaks in West Bengal State in 2001 and 2007, and in Kerala State regularly since 2018. 

Since 2018, Kerala has reported a total of nine NiV outbreaks. While the state has a strong healthcare system and improved infection control measures since 2023, it is advisable to maintain strong preparedness and surveillance efforts while ensuring continued care for patients. 

At the same time, States that may be at risk should be encouraged to continue strengthen their detection systems and response capacities. 

With no licensed vaccine or treatment available, public health efforts should focus on raising awareness of risk factors and promoting preventive measures to reduce exposure to the virus, and on early case detection supported by adequate intensive supportive care. 

Currently, the risk of international disease spread is considered low. There is no evidence of human-to-human transmission of NiV internationally in this event.

Description of the situation

Between 17 May and 12 July 2025, the Information and Public Relations Department, Government of Kerala through a series of official press releases informed about four confirmed NiV cases, including two deaths, due to NiV infection from two districts of Kerala State. 

Of the four cases, two were reported from Malappuram and two from Palakkad district. 

This marks the first-ever outbreak in Palakkad District. 

Of the four cases, one case was reported in May (with symptom onset in April) and three in July with symptom onset June (two cases), and July (one case).

The first patient was an adult woman from Malappuram district with symptom onset on 25 April.  The patient was admitted in critical condition to a local hospital in Malappuram with fever, cough, and respiratory distress due to worsening of symptoms. She was transferred to intensive care on 2 May due to acute encephalitis syndrome. Samples were collected and tested positive for NiV at Calicut Medical College on 6 May. Confirmatory testing was conducted by the National Institute of Virology, Pune, and results confirmed on 8 May.

The second patient, also an adult woman from Malappuram district developed symptoms on 23 June and died on 1 July. She visited multiple healthcare facilities, before being transferred to a government medical facility, where clinical suspicion of NiV led to sample collection and laboratory testing. 

The third patient is an adult woman from Palakkad district who developed symptoms on 25 June. She sought care at several healthcare facilities, before being admitted to a multi-specialty hospital, where she remains in critical condition on ventilator support. This is the first confirmed NiV case in Palakkad district. 

The fourth case was an adult male also from Palakkad district, who developed symptoms on 6 July 2025. He sought initial medical care on the same day, was admitted to a private hospital on 10 July, and transferred to a multi-specialty hospital on 11 July. On 12 July, he died and was confirmed with NiV infection. This is the second confirmed case in Palakkad district.  

The sources of infection of the cases remain under investigation. 

None of these cases appear to be linked to each other, suggesting independent spillover events from the natural reservoir. 

A significant presence of fruit bats, the known reservoir for NiV has been observed in the affected areas.

Epidemiology

NiV infection is a bat-borne zoonotic disease transmitted to humans through infected animals (such as bats or pigs), or food contaminated with saliva, urine, and excreta of infected animals. It can also be transmitted directly from person to person through close contact with an infected person (although less common). Fruit bats or flying foxes (Pteropus species) are the natural hosts for the virus.

The incubation period ranges on average from 4 to 14 days. However, an incubation period of up to 45 days has been reported once. Laboratory diagnosis of a patient with a clinical history of NiV infection can be made during the acute and convalescent phases of the disease by using a combination of tests. The main tests used are Reverse Transcription Polymerase Chain Reaction (RT-PCR) from bodily fluids and antibody detection via enzyme-linked immunosorbent assay (ELISA).

Symptoms range from acute respiratory infection and fatal encephalitis. Further information about NiV infection can be found here.

The case-fatality rates in outbreaks across Bangladesh, India, Malaysia, and Singapore typically range from 40% to 100%, depending on local capabilities for early detection and clinical management. Although candidate products are in development, there are no licensed vaccines or therapeutics available for the prevention or treatment of NiV infection.

Public health response

Several public health measures have been implemented by local authorities including:

-- The Kerala state health minister chaired an emergency meeting to assess the situation and confirmed that preventive measures have been strengthened in accordance with the established NiV protocol.  

-- As of 17 July, contact tracing is intensively implemented. A total of 723 individuals have been identified as contacts of confirmed Nipah virus (NiV) cases across several districts: Palakkad (394), Malappuram (212), Kozhikode (114), Ernakulam (2), and Thrissur (1).  

-- Based on an in-depth investigation, Kerala health authorities have released route maps for the movement of three confirmed NiV cases reported in July, to trace potential community exposures.  

-- Alerts have been issued by health authorities in Kozhikode, Malappuram, and Palakkad districts. In response, 26 special teams were deployed to carry out contact tracing, monitor symptoms among contacts and inform the public. 

-- Additionally, a special alert has been issued to hospitals in Kannur, Kozhikode, Malappuram, Palakkad, Thrissur and Wayanad districts, instructing them to remain vigilant and promptly report any suspected cases with NiV symptoms.  

-- The public has been advised to avoid non-essential visits to healthcare facilities to minimize the risk of transmission.

-- WHO is closely coordinating with the National Centre for Disease Control on One Health and capacity building for high threat pathogens including NiV.

WHO risk assessment

As of July 2025, a total of nine NiV outbreaks have been reported in Kerala State. Recent case numbers reported in Kerala State are consistent with trends observed in previous years and are therefore not entirely unexpected. 

However, they continue to highlight a localized risk associated with NiV in that area. 

At this time, the overall risk to the broader national and regional population remains low.  

The first outbreak was reported in 2018 (23 cases including confirmed and probable; CFR: 91%), followed by subsequent outbreaks in 2019 (a single case who survived), 2021 (one case; CFR: 100%), 2023 (six cases including two deaths; CFR: 33%), 2024 (two cases; CFR 100%), and 2025. 

So far in 2025, four confirmed cases of NiV, have been reported, all from Kerala State, with the symptom onset in April (one case), June (two cases) and July (one case).  

These recurrent spillover events highlight the ongoing risk of NiV in Kerala. In addition, studies indicated that fruit bats tested positive for NiV antibodies in several other Indian states, suggesting that NiV infection may potentially emerge in other States.  

Kerala State has a robust healthcare system. While nosocomial transmission was confirmed during the 2023 outbreak, the Infection Prevention and Control (IPC), and waste management practices have since been strengthened and audited.  

The sources of infection for the 2025 cases are yet to be confirmed. 

WHO advice

In the absence of a vaccine or licensed treatment available for NiV disease, the only way to reduce or prevent infection in people is by raising awareness of the risk factors and supporting people with measures they can take to reduce exposure to the virus. 

Case management should focus on the delivery of timely, supportive care and be supported by a good laboratory system. Intensive supportive care is recommended to treat severe respiratory and neurologic complications.  

Public health educational messages should focus on:

-- Reducing the risk of bat-to-human transmission

-- Efforts to prevent transmission should first focus on decreasing bat access to date palm sap and other fresh food products. Freshly collected date palm juice should be boiled, and fruits should be thoroughly washed and peeled before consumption. Fruits with signs of bat bites should be discarded. Areas where bats are known to roost should be avoided.

-- Reducing the risk of human-to-human transmission.

-- Close unprotected physical contact with NiV-infected people should be avoided. Regular hand washing should be carried out after caring for or visiting sick people.

-- Controlling infection in health care settings

-- Health-care workers caring for patients with suspected or confirmed infection, or handling specimens from them, should implement standard infection control precautions at all times. 

-- As human-to-human transmission has been reported, in particular in health-care settings, contact and droplet precautions should be used in addition to standard precautions. Airborne precautions may be required in certain circumstances.

-- Samples taken from people and animals with suspected NiV infection should be handled by trained staff working in suitably equipped laboratories.

-- WHO does not recommend any travel and/or trade restrictions toward India based on the currently available information.

Further information

- Department of Public Relations, Government of Kerala. https://www.prd.kerala.gov.in/ml/node/307801

- Directorate of Health Services, Kerala. IDSP Daily Report 1 August 2025. Thiruvananthapuram: DHS Kerala; 2025. Available from: https://dhs.kerala.gov.in/wp-content/uploads/2025/08/IDSP-Daily-Report-01.08.2025.pdf

- Information & Public Relations Department, Government of Kerala 29 May 2025. Relief in Nipah: A total of 114 people tested negative after the quarantine period of all those on the contact list was over. Available from: https://prd.kerala.gov.in/index.php/ml/node/300946

- Public Relations Department, Government of Kerala. Nipah virus infection updated official report, May 2025. Thiruvananthapuram: Government of Kerala; 2025 [cited 2025 May 12]. Available from: https://prd.kerala.gov.in/ml/node/297643

- Public Relations Department, Government of Kerala. Nipah virus infection updated official report, May 2025. Thiruvananthapuram: Government of Kerala; 2025 [cited 2025 May 12]. Available from: https://prd.kerala.gov.in/ml/node/297971

- Department of Public Relations, Government of Kerala. Confirmed Nipah Cases in Malappuram and Palakkad Districts [press release]. Thiruvananthapuram: DPR Kerala; 4 July 2025. Available from: https://www.prd.kerala.gov.in/ml/node/307104. 

- Department of Public Relations, Government of Kerala. Nipah Virus Infection: Health Department Intensifies Surveillance and Containment Measures [press release]. Thiruvananthapuram: DPR Kerala; 2 July 2025. Available from: https://www.prd.kerala.gov.in/ml/node/306853. 

- Department of Public Relations, Government of Kerala. Health Department Issues Nipah Virus Alert in Palakkad and Malappuram [press release]. Thiruvananthapuram: DPR Kerala; 1 July 2025. Available from: https://www.prd.kerala.gov.in/ml/node/306653. 

- Department of Public Relations, Government of Kerala. A total of 499 people are on the Nipah contact list; 10 July. https://www.prd.kerala.gov.in/ml/node/307528 

- Department of Public Relations, Government of Kerala. A total of 609 people are on the Nipah contact list in the state; 14 July https://www.prd.kerala.gov.in/ml/node/307873 

- Department of Public Relations, Government of Kerala; 17 July: https://www.prd.kerala.gov.in/ml/node/308413

- Department of Public Relations, Government of Kerala. High-level meeting convened in connection with the spread of Nipah virus [press release]. Thiruvananthapuram: DPR Kerala; 11 July 2025. Available from: https://prd.kerala.gov.in/ml/node/307707 

- World Health Organization, Regional Office for South-East Asia. Regional strategy for the prevention and control of Nipah virus infection: 2023 2030. New Delhi: WHO SEARO; 2023. Available from: https://www.who.int/publications/i/item/9789290210849 

- World Health Organization. Technical brief: Enhancing readiness for a Nipah virus event in countries not reporting a Nipah virus event: interim document. Geneva: WHO; 2024 Feb. Available from: https://www.who.int/publications/i/item/9789290211273 

- World Health Organization. Nipah virus [Fact sheet]. Geneva: WHO; 2018. Available from: https://www.who.int/news-room/fact-sheets/detail/nipah-virus 

- 10th edition, Epidemiological Bulletin WHO Health Emergencies Programme WHO Regional Office for South-East Asia , 21 May 2025 Reporting period: 05 - 18 May 2025 Available from: https://www.who.int/southeastasia/publications/i/item/9789290220831

Citable reference: World Health Organization (6 August 2025). Disease Outbreak News; Nipah virus infection – India. Available at: https://www.who.int/emergencies/disease-outbreak-news/item/2025-DON577

Source: World Health Organization, https://www.who.int/emergencies/disease-outbreak-news/item/2025-DON577

____

#H1N1-associated acute #leukoencephalopathy: An unusual presentation in a young adult indian male

Abstract

The H1N1 virus commonly causes symptoms such as fever, cough, sore throat, which have a self-limited course in most cases. Neurological complications are rare, especially in adults. This case illustrates H1N1-associated acute leukoencephalopathy in a young adult with a favorable outcome and no lasting neurological deficits. The initial presentation included fever, sore throat, and myalgia, evolving into neurological symptoms, including dysarthria, nystagmus, and left-sided motor weakness. Comprehensive laboratory tests ruled out common bacterial, viral, or autoimmune causes, while MRI findings suggested acute leukoencephalopathy of infectious or toxic etiology. Although the urine toxicology screen showed traces of phenol, clinical evidence did not correlate with toxic exposure and pointed towards an infectious origin. A throat swab for Influenza/H1N1 PCR confirmed the diagnosis. Treatment with oseltamivir and methylprednisolone led to symptomatic improvement with no sequelae.

Source: IDCases, https://www.sciencedirect.com/science/article/pii/S2214250925001684?via%3Dihub

____

#Influenza at the #human - #animal #interface - #Summary and #risk #assessment, from 28 May to 1 July 2025 (#WHO)

 

New human cases{2}: 

-- From 28 May to 1 July 2025, based on reporting date, the detection of influenza A(H5N1) in nine humans, influenza A(H9N2) in three humans and influenza A(H10N3) in one human were reported officially. Additionally, one human case of infection with an influenza A(H5N1) virus was detected. 

Circulation of influenza viruses with zoonotic potential in animals: 

-- High pathogenicity avian influenza (HPAI) events in poultry and non-poultry continue to be reported to the World Organisation for Animal Health (WOAH).{3} The Food and Agriculture Organization of the United Nations (FAO) also provides a global update on avian influenza viruses with pandemic potential.{4} 

Risk assessment{5}: 

-- Sustained human to human transmission has not been reported from these events. 

-- Based on information available at the time of the risk assessment, the overall public health risk from currently known influenza viruses circulating at the human-animal interface has not changed remains low. 

-- The occurrence of sustained human-to-human transmission of these viruses is currently considered unlikely. 

-- Although human infections with viruses of animal origin are infrequent, they are not unexpected at the human-animal interface.  

IHR compliance: 

-- All human infections caused by a new influenza subtype are required to be reported under the International Health Regulations (IHR, 2005).{6} 

-- This includes any influenza A virus that has demonstrated the capacity to infect a human and its haemagglutinin (HA) gene (or protein) is not a mutated form of those, i.e. A(H1) or A(H3), circulating widely in the human population. 

-- Information from these notifications is critical to inform risk assessments for influenza at the human-animal interface.  

Avian influenza viruses in humans 

Current situation:  

Since the last risk assessment of 27 May 2025, single laboratory-confirmed human cases of A(H5N1) infection were detected in Bangladesh and India. Eight confirmed human cases of A(H5N1) infection were reported to WHO from Cambodia. 

-- A(H5N1), Bangladesh 

On 31 May 2025, Bangladesh notified WHO of one confirmed human case of avian influenza A(H5) in a child in Chittagong division detected through hospital-based surveillance. The patient was admitted to hospital on 21 May with diarrhea, fever and mild respiratory symptoms and a respiratory sample was collected on admission. On 28 May, the IEDCR confirmed infection with avian influenza A(H5) through RT-PCR. The N-type was later confirmed as N1. The patient has recovered, and exposure to backyard poultry was reported prior to symptom onset. No further cases were detected among the contacts of the case. This is the 11th human infection with influenza A(H5N1) notified to WHO from Bangladesh since the first case was reported in the Dhaka division in 2008 and the third confirmed case in 2025. 

-- A(H5N1), Cambodia 

Between 29 May and 1 July 2025, Cambodia notified WHO of eight laboratory-confirmed cases of A(H5N1) virus infection.  

(...)

All cases above had exposure to sick or dead backyard poultry. The most recent case was from a different village than the other three cases from Siem Reap. The 46-year-old female and the 16-yearold male cases are members of the same family and are neighbors of the first case detected in Siem Reap; they were sampled as part of active case finding during the response to the first case because they also handled sick and dead poultry from their own backyard. 

Rapid response teams from the public health and animal health sectors have been deployed to investigate and respond to the outbreak.  

Eleven human infections with A(H5N1) viruses have been confirmed in Cambodia in 2025 and six of these have been fatal. 

All these cases in 2025 had exposure to domestic birds or their environments. In some cases, the domestic birds were reported to be sick or dead. 

Influenza A(H5N1) viruses continue to be detected in domestic birds in Cambodia in 2025, including in areas where human cases have been detected.{7} 

Where the information is available, the genetic sequence data from the viruses from the human cases closely matches that from recent local animal viruses and are identified as clade 2.3.2.1e viruses. From the information available thus far on these recent human cases, there is no indication of human-to-human transmission of the A(H5N1) viruses.  

-- A(H5N1), India  

A human infection with an H5 clade 2.3.2.1a A(H5N1) virus was detected in a sample collected from a man in Khulna state in May 2025, who subsequently died. Genetic sequence data are available in GISAID (EPI_ISL_19893416; submission date 4 June 2025; ICMR-National Institute of Virology; Influenza). 

According to reports received by WOAH, various influenza A(H5) subtypes continue to be detected in wild and domestic birds in Africa, the Americas, Asia and Europe. 

Infections in non-human mammals are also reported, including in marine and land mammals.{8} A list of bird and mammalian species affected by HPAI A(H5) viruses is maintained by FAO.{9}    

Risk Assessment for avian influenza A(H5N1) viruses:  

1. What is the current global public health risk of additional human cases of infection with avian influenza A(H5N1) viruses?  

-- Most human cases so far have been infections in people exposed to A(H5) viruses, for example, through contact with infected poultry or contaminated environments, including live poultry markets, and occasionally infected mammals and contaminated environments. While the viruses continue to be detected in animals and related environments humans are exposed to, further human cases associated with such exposures are expected but unusual. The impact for public health if additional cases are detected is minimal. The current overall global public health risk of additional human cases is low. 

2. What is the likelihood of sustained human-to-human transmission of avian influenza A(H5N1) viruses related to the events above?  

No sustained human-to-human transmission has been identified associated with the recent reported human infections with avian influenza A(H5N1) viruses. There has been no reported human-tohuman transmission of A(H5N1) viruses since 2007, although there may be gaps in investigations. In 2007 and the years prior, small clusters of A(H5) virus infections in humans were reported, including some involving health care workers, where limited human-to-human transmission could not be excluded; however, sustained human-to-human transmission was not reported.  Current evidence suggests that influenza A(H5N1) viruses related to these events did not acquire the ability to efficiently transmit between people, therefore the likelihood of sustained human-tohuman transmission is thus currently considered unlikely.  

3. What is the likelihood of international spread of avian influenza A(H5N1) viruses by travellers?  

Should infected individuals from affected areas travel internationally, their infection may be detected in another country during travel or after arrival. If this were to occur, further community-level spread is considered unlikely as current evidence suggests these viruses have not acquired the ability to transmit easily among humans.  

-- A(H9N2), China

Since the last risk assessment of 27 May 2025, three human cases of infection with A(H9N2) influenza viruses were notified to WHO from China on 9 June 2025. The cases were detected in Henan, Hunan and Sichuan provinces. Two infections were detected in adults who were also hospitalized. The cases had symptom onset in May 2025 and have recovered. All cases had a known history of exposure to poultry prior to the onset of symptoms. No further cases were detected among contacts of these cases and there was no epidemiological link between the cases.   

Risk Assessment for avian influenza A(H9N2):   

1. What is the global public health risk of additional human cases of infection with avian influenza A(H9N2) viruses?   

Most human cases follow exposure to the A(H9N2) virus through contact with infected poultry or contaminated environments. Most human infections of A(H9N2) to date have resulted in mild clinical illness. Since the virus is endemic in poultry in multiple countries in Africa and Asia{11}, further human cases associated with exposure to infected poultry are expected but remain unusual. The impact to public health if additional cases are detected is minimal. The overall global public health risk of additional human cases is low.  

2. What is the likelihood of sustained human-to-human transmission of avian influenza A(H9N2) viruses related to this event?   

At the present time, no sustained human-to-human transmission has been identified associated with the recent reported human infections with A(H9N2) viruses. Current evidence suggests that influenza A(H9N2) viruses from these cases did not acquire the ability of sustained transmission among humans, therefore sustained human-to-human transmission is thus currently considered unlikely.   

3. What is the likelihood of international spread of avian influenza A(H9N2) virus by travellers?   

Should infected individuals from affected areas travel internationally, their infection may be detected in another country during travel or after arrival. If this were to occur, further community level spread is considered unlikely as current evidence suggests the A(H9N2) virus subtype has not acquired the ability to transmit easily among humans.   

-- A(H10N3), China  

On 9 June 2025, China notified the WHO of one confirmed case of human infection with avian influenza A(H10N3) virus in an adult from Shaanxi Province, with a history of asthma. Symptom onset occurred on 21 April, and the patient was admitted to hospital with pneumonia on 25 April. At the time of reporting, that patient was under treatment and improving.    According to the epidemiological investigation, a history of exposure to backyard poultry in Inner Mongolia was reported. The patient is a farmer and raises chickens and sheep. Environmental samples did not test positive for influenza A(H10) viruses. All close contacts tested negative for influenza A and remained asymptomatic during the monitoring period.    Since 2021, China has notified WHO of a total of six confirmed human cases of avian influenza A(H10N3) virus infection. 

Risk Assessment for avian influenza A(H10N3):   

1. What is the global public health risk of additional human cases of infection with avian influenza A(H10N3) viruses?   

Human infections with avian influenza A(H10) viruses have been detected and reported previously.   The circulation and epidemiology of these viruses in birds have been previously reported.{12} Avian influenza A(H10N3) viruses with different genetic characteristics have been detected previously in wild birds since the 1970s and more recently spilled over to poultry in some countries. As long as the virus continues to circulate in birds, further human cases can be expected but remain unusual. The impact to public health if additional sporadic cases are detected is minimal. The overall global public health risk of additional sporadic human cases is low.    

2. What is the likelihood of sustained human-to-human transmission of avian influenza A(H10N3) viruses related to this event?   

No sustained human-to-human transmission has been identified associated with the event described above or past events with human cases of influenza A(H10N3) viruses. Current epidemiologic and virologic evidence suggests that influenza A(H10N3) viruses related to this event did not acquire the ability of sustained transmission among humans, therefore sustained human-tohuman transmission is thus currently considered unlikely.    

3. What is the likelihood of international spread of avian influenza A(H10N3) virus by travellers?   

Should infected individuals from affected areas travel internationally, their infection may be   detected in another country during travel or after arrival. If this were to occur, further community   level spread is considered unlikely based on current limited evidence.   

Overall risk management recommendations: 

Surveillance and investigations 

• Due to the constantly evolving nature of influenza viruses, WHO continues to stress the importance of global strategic surveillance in animals and humans to detect virologic, epidemiologic and clinical changes associated with circulating influenza viruses that may affect human (or animal) health. Continued vigilance is needed within affected and neighbouring areas to detect infections in animals and humans. Close collaboration with the animal health and environment sectors is essential to understand the extent of the risk of human exposure and to prevent and control the spread of animal influenza. WHO has published guidance on surveillance for human infections with avian influenza A(H5) viruses. 

• As the extent of influenza virus circulation in animals is not clear, epidemiologic and virologic surveillance and the follow-up of suspected human cases should continue systematically. Guidance on investigation of non-seasonal influenza and other emerging acute respiratory diseases has been published on the WHO website. 

• Countries should increase avian influenza surveillance in domestic and wild birds, enhance surveillance for early detection in cattle populations in countries where HPAI is known to be circulating, include HPAI as a differential diagnosis in non-avian species, including cattle and other livestock populations, with high risk of exposure to HPAI viruses; monitor and investigate cases in non-avian species, including livestock, report cases of HPAI in all animal species, including unusual hosts, to WOAH and other international organizations, share genetic sequences of avian influenza viruses in publicly available databases, implement preventive and early response measures to break the HPAI transmission cycle among animals through movement restrictions of infected livestock holdings and strict biosecurity measures in all holdings, employ good production and hygiene practices when handing animal products, and protect persons in contact with suspected/infected animals.{10}  

• When there has been human exposure to a known outbreak of an influenza A virus in domestic poultry, wild birds or other animals – or when there has been an identified human case of infection with such a virus – enhanced surveillance in potentially exposed human populations becomes necessary. Enhanced surveillance should consider the health care seeking behaviour of the population, and could include a range of active and passive health care and/or community-based approaches, including: enhanced surveillance in local influenza-like illness (ILI)/SARI systems, active screening in hospitals and of groups that may be at higher occupational risk of exposure, and inclusion of other sources such as traditional healers, private practitioners and private diagnostic laboratories. 

• Vigilance for the emergence of novel influenza viruses of pandemic potential should be maintained at all times including during a non-influenza emergency. In the context of the cocirculation of SARS-CoV-2 and influenza viruses, WHO has updated and published practical guidance for integrated surveillance. 

Notifying WHO 

• All human infections caused by a new subtype of influenza virus are notifiable under the International Health Regulations (IHR, 2005).{11} State Parties to the IHR (2005) are required to immediately notify WHO of any laboratory-confirmed{12} case of a recent human infection caused by an influenza A virus with the potential to cause a pandemic{13}. Evidence of illness is not required for this report. 

• WHO published the case definition for human infections with avian influenza A(H5) virus requiring notification under IHR (2005): https://www.who.int/teams/global-influenzaprogramme/avian-influenza/case-definitions. 

Virus sharing and risk assessment 

• It is critical that these influenza viruses from animals or from people are fully characterized in appropriate animal or human health influenza reference laboratories. Under WHO’s Pandemic Influenza Preparedness (PIP) Framework, Member States are expected to share influenza viruses with pandemic potential on a timely basis{14} with a WHO Collaborating Centre for influenza of GISRS. The viruses are used by the public health laboratories to assess the risk of pandemic influenza and to develop candidate vaccine viruses.  

• The Tool for Influenza Pandemic Risk Assessment (TIPRA) provides an in-depth assessment of risk associated with some zoonotic influenza viruses – notably the likelihood of the virus gaining human-to-human transmissibility, and the impact should the virus gain such transmissibility. TIPRA maps relative risk amongst viruses assessed using multiple elements. The results of TIPRA complement those of the risk assessment provided here, and those of prior TIPRA analyses will be published at http://www.who.int/teams/global-influenza-programme/avian-influenza/toolfor-influenza-pandemic-risk-assessment-(tipra).  

Risk reduction 

• Given the observed extent and frequency of avian influenza in poultry, wild birds and some wild and domestic mammals, the public should avoid contact with animals that are sick or dead from unknown causes, including wild animals, and should report dead birds and mammals or request their removal by contacting local wildlife or veterinary authorities.  

• Eggs, poultry meat and other poultry food products should be properly cooked and properly handled during food preparation. Due to the potential health risks to consumers, raw milk should be avoided. WHO advises consuming pasteurized milk. If pasteurized milk isn’t available, heating raw milk until it boils makes it safer for consumption. 

WHO has published practical interim guidance to reduce the risk of infection in people exposed to avian influenza viruses. 

Trade and travellers 

• WHO advises that travellers to countries with known outbreaks of animal influenza should avoid farms, contact with animals in live animal markets, entering areas where animals may be slaughtered, or contact with any surfaces that appear to be contaminated with animal excreta. Travelers should also wash their hands often with soap and water. All individuals should follow good food safety and hygiene practices.  

• WHO does not advise special traveller screening at points of entry or restrictions with regards to the current situation of influenza viruses at the human-animal interface. For recommendations on safe trade in animals and related products from countries affected by these influenza viruses, refer to WOAH guidance.  

Links:  

-- WHO Human-Animal Interface web page https://www.who.int/teams/global-influenza-programme/avian-influenza 

-- WHO Influenza (Avian and other zoonotic) fact sheet https://www.who.int/news-room/fact-sheets/detail/influenza-(avian-and-other-zoonotic) 

-- WHO Protocol to investigate non-seasonal influenza and other emerging acute respiratory diseases https://www.who.int/publications/i/item/WHO-WHE-IHM-GIP-2018.2 

-- WHO Public health resource pack for countries experiencing outbreaks of influenza in animals:  https://www.who.int/publications/i/item/9789240076884 

-- Cumulative Number of Confirmed Human Cases of Avian Influenza A(H5N1) Reported to WHO  https://www.who.int/teams/global-influenza-programme/avian-influenza/avian-a-h5n1-virus 

-- Avian Influenza A(H7N9) Information https://www.who.int/teams/global-influenza-programme/avian-influenza/avian-influenza-a-(h7n9)virus 

-- World Organisation of Animal Health (WOAH) web page: Avian Influenza  https://www.woah.org/en/home/ 

-- Food and Agriculture Organization of the United Nations (FAO) webpage: Avian Influenza https://www.fao.org/animal-health/avian-flu-qa/en/ 

-- OFFLU http://www.offlu.org/ 

___

{1} This summary and assessment covers information confirmed during this period and may include information received outside of this period. 

{2} For epidemiological and virological features of human infections with animal influenza viruses not reported in this assessment, see the reports on human cases of influenza at the human-animal interface published in the Weekly Epidemiological Record here.  

{3} World Organisation for Animal Health (WOAH). Avian influenza. Global situation. Available at: https://www.woah.org/en/disease/avian-influenza/#ui-id-2. 

{4} Food and Agriculture Organization of the United Nations (FAO). Global Avian Influenza Viruses with Zoonotic Potential situation update. Available at: https://www.fao.org/animal-health/situation-updates/global-aiv-withzoonotic-potential. 

{5} World Health Organization (2012). Rapid risk assessment of acute public health events. World Health Organization. Available at: https://iris.who.int/handle/10665/70810. 

{6} World Health Organization. Case definitions for the 4 diseases requiring notification to WHO in all circumstances under the International Health Regulations (2005). Case definitions for the four diseases requiring notification in all circumstances under the International Health Regulations (2005).   

{7} https://wahis.woah.org/#/in-event/5754/dashboard 

{8} World Organisation for Animal Health (WOAH). Avian influenza. Global situation. Available at: https://www.woah.org/en/disease/avian-influenza/#ui-id-2. 

{9} Food and Agriculture Organization of the United Nations. Global Avian Influenza Viruses with Zoonotic Potential situation update. Available at: https://www.fao.org/animal-health/situation-updates/global-aiv-withzoonotic-potential/bird-species-affected-by-h5nx-hpai/en. 

{10} World Organisation for Animal Health. Statement on High Pathogenicity Avian Influenza in Cattle, 6 December 2024. Available at: https://www.woah.org/en/high-pathogenicity-avian-influenza-hpai-in-cattle/. 

{11} World Health Organization. Case definitions for the four diseases requiring notification in all circumstances under the International Health Regulations (2005).    

{12} World Health Organization. Manual for the laboratory diagnosis and virological surveillance of influenza (2011). Available at: https://apps.who.int/iris/handle/10665/44518 

{13} World Health Organization. Pandemic influenza preparedness framework for the sharing of influenza viruses and access to vaccines and other benefits, 2nd edition. Available at: https://iris.who.int/handle/10665/341850 

{14} World Health Organization. Operational guidance on sharing influenza viruses with human pandemic potential (IVPP) under the Pandemic Influenza Preparedness (PIP) Framework (2017). Available at: https://apps.who.int/iris/handle/10665/25940 

Source: World Health Organization, https://www.who.int/publications/m/item/influenza-at-the-human-animal-interface-summary-and-assessment--1-july-2025

____