#Evidence of #SARS-CoV-2 #Exposure in #Rodents from Rural Localities in the #Yucatan Peninsula, #Mexico

 

Abstract

Zoonotic diseases involve pathogen transmission between humans and animals, with most research focused on animal-to-human spillover. However, reverse zoonosis—the transmission of pathogens from humans to animals—remains understudied despite its potential ecological and epidemiological consequences. The SARS-CoV-2 pandemic highlights this risk, as human-associated viruses may sporadically infect wildlife species and generate novel exposure pathways. To assess evidence of SARS-CoV-2 exposure in wildlife, we analyzed serum and rectal swab samples from rodents collected in rural localities of the Yucatan Peninsula, Mexico, between 2021 and 2022. An indirect ELISA detected antibodies against SARS-CoV-2 in 23.1% of sampled rodents. Molecular analysis detected one positive sample with a pan-coronavirus RT-PCR, though all were negative for SARS-CoV-2–specific assays. This study provides serological evidence of SARS-CoV-2 exposure in rodent communities from rural areas of Mexico and is consistent with sporadic wildlife spillback events rather than sustained transmission. The observed exposure patterns may be influenced by human activities and frequent human–wildlife interactions in heterogeneous rural landscapes. Our results underscore the need for integrated serological and genomic surveillance to better understand the ecological context of reverse zoonosis and its implications for public health.

Source: 

Link: https://www.mdpi.com/1999-4915/18/4/435

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Novel #Reassortant #H5N2 Highly Pathogenic Avian #Influenza Viruses from Backyard #Poultry in #Mexico

 

Abstract

Highly pathogenic influenza A viruses of the H5 subtype continue to diversify worldwide through mutation and genetic reassortment, generating novel variants with unpredictable consequences under the One Health approach. Between 2024 and 2025, five outbreaks of avian influenza A viruses were detected in backyard poultry across Michoacán, Estado de México, and Ciudad de México. We conducted molecular and genetic characterization of five highly pathogenic H5N2 viruses isolated from these events. All cases tested positive for influenza A virus and the H5 hemagglutinin, exhibiting high pathogenicity with intravenous pathogenicity index values ranging from 2.88 to 3.0. Whole-genome sequencing revealed novel reassortants containing hemagglutinin from Eurasian H5N1 clade 2.3.4.4b and neuraminidase from the endemic Mexican H5N2 lineage. The viral genome of the isolate from Michoacán contained six segments derived from Eurasian H5N1 viruses introduced into North America in 2021–2022, while nucleoprotein and neuraminidase originated from Mexican H5N2 viruses. In contrast, viruses from Estado de México and Ciudad de México contained five H5N1-derived segments and incorporated polymerase basic protein 1, nucleoprotein, and neuraminidase from low-pathogenic H5N2 viruses circulating in 2024. Phylogenetic analyses confirmed the emergence of a distinct H5N2 Mexican sublineage, providing evidence of active viral reassortment and local evolutionary processes in Mexico.

Source: 

Link: https://www.mdpi.com/1999-4915/18/3/337

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A #Market-Based #Sentinel #Surveillance for an Early #Detection of Viral #Outbreaks

 

Abstract

Mexico has experienced recurrent viral epidemics of substantial intensity, including hyperendemic dengue, COVID-19, and recent reports of avian influenza A (H5N1) infections in birds, which pose an ongoing risk of zoonotic transmission. Mexico was also the location for the earliest detection of the pdmH1N1 virus during the 2009 influenza A pandemic. Under a One Health framework, markets represent a unique opportunity for low-cost virus monitoring at the human-animal interface. Under the hypothesis that these represent sentinel sites for an early virus detection, we implemented a pilot surveillance program at the central market of Merida city, Yucatan, Mexico, considered a regional hotspot for multiple and recent viral outbreaks. Longitudinal sampling was carried out over 11 months at 1-to-6-week intervals from April 2022 to February 2023. We used multi-type surveillance in mosquitoes, live poultry, and wastewater. All samples were screened using RT-qPCR. Positive samples for DENV, SARS-CoV-2 and avian influenza A were further sequenced and analysed under a phylogenetic and epidemiological approach. Through our entomological surveillance, we report the earliest detection of DENV-3 III-B3.2 (genotype III American II lineage, considered a major public health concern in Latin America) in Mexico, overlapping with the resurgence of DENV-3 as the predominant serotype driving the 2023 national epidemic, which showed an increased severity. Through wastewater surveillance, we consistently detect SARS-CoV-2 RNA in wastewater samples, coinciding with the two infection waves officially recorded at a city and state level. Finally, cloacal swabs taken from two juvenile birds at the market suggest that avian influenza A viruses circulated in live poultry sold at the market. These findings show that our market-based surveillance framework is effective for an early detection and monitoring of pathogenic viruses in urban settings, and could complement official epidemiological surveillance in low- and middle-income countries to strengthen early-outbreak warning systems.

Competing Interest Statement

The authors have declared no competing interest.

Funding Statement

This study was supported by the John Fell OUP Research Grant ATD00390 (M.E.Z and M.U.G.K), the Wellcome Infectious Disease Award ?317324/Z/24/Z (M.G.K, H.P.G and M.E.Z), the Secretaria de Ciencia, Humanidades, Tecnología e Inovación award (SECIHTI, Mexico) through the PRONACES Health grant (PRONAII project number 303002, G.S) and the Ciencia Básica y de Frontera programme (CBF2023-2024-3184, M.G.K), and the UKRI Innovation BSRC/EPSRC/NIHR 971557 grant (A.R.S). M.G.K is funded through a Sanger International Fellowship award. M.E.Z is funded by a UCL Rosetrees Excellence Fellowship UCL2024\2. P.M.D was funded through the doctoral program at ‘Posgrado en Ciencias de la Produccion y de la Salud Animal-UNAM’ through the SECIHTI doctoral scholarship. M.U.G.K. acknowledges funding from The Rockefeller Foundation (PC-2022-POP-005), Health AI Programme from Google.org, the Oxford Martin School Programmes in Pandemic Genomics & Digital Pandemic Preparedness, European Union's Horizon Europe programme projects MOOD (#874850) and E4Warning (#101086640), Wellcome Trust grants 303666/Z/23/Z, 226052/Z/22/Z & 228186/Z/23/Z, the United Kingdom Research and Innovation (#APP8583), the Medical Research Foundation (MRF- RG-ICCH-2022-100069), UK International Development (301542-403), the Bill & Melinda Gates Foundation (INV-063472) and Novo Nordisk Foundation (NNF24OC0094346). B.G is further funded by Wellcome Trust grants 303666/Z/23/Z, 226052/Z/22/Z & 228186/Z/23/Z. The contents of this publication are the sole responsibility of the authors and do not necessarily reflect the views of the European Commission or the other funders. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Source: 

Link: https://www.medrxiv.org/content/10.64898/2025.12.22.25342882v1

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Emergence of a novel #reassorted high pathogenicity avian #influenza #H5N2 virus associated with severe #pneumonia in a young #adult

 

Abstract

Background 

Infection of backyard and poultry with low pathogenicity avian influenza LPAI A(H5N2) viruses has occurred in Mexico since 1994, and the first human infection caused by this influenza virus was detected in 2024. Since its emergence in the Americas, frequent reassortments between high pathogenicity avian influenza HPAI A(H5N1) and LPAI viruses has occurred. In September 2025, the Instituto Nacional de Enfermedades Respiratorias of Mexico City identified an unsubtypeable influenza A virus infection in a young adult patient later determined to be a reassortant HPAI (H5N2) virus with a clade 2.3.4.4b HA. 

Methods 

We analyzed clinical and epidemiologic data from this patient. Respiratory samples were tested for influenza RT-qPCR assays. Genomic sequence and phylogenetics analyses were performed to provisionally assign a new genotype to the novel HPAI A(H5N2) reassortant virus. 

Results 

The patient presented with fever and tachypnea, later developed hemoptysis and thoracic pain, with oxygen saturation decreasing to 70%. CT scan showed bilateral ground-glass opacities consistent with diffuse alveolar hemorrhage and zones consistent with consolidation. Clinical improvement was observed and the patient was discharged. Through viral complete genome analysis, we identified an HPAI A(H5N2) virus with genes from both clade 2.3.4.4b A(H5N1) viruses similar to those detected in North America during 2022-2023 and genes from the LPAI A(H5N2) viruses detected in Mexico during 2024. 

Conclusions 

This is the first ever laboratory-confirmed human infection caused by an HPAI A(H5N2) virus infection, suggesting a new genotype provisionally classified as B3.14. The relationship of the virus with the severity of illness remains unknown.

Competing Interest Statement

Conflicts of Interest: The authors declare that they have no competing interests. The sponsors had no role in the design, execution, interpretation, or writing of the study. The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the Centers for Disease Control and Prevention or the Agency for Toxic Substances and Disease Registry.

Funding Statement

Funding: This work was financially supported by Secretaria de Ciencia, Humanidades, Tecnologia e Innovacion (SECIHTI), Grant CBF-2025-I-3693 to J.A.V.-P.

Source: 

Link: https://www.medrxiv.org/content/10.1101/2025.11.21.25340167v1

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#Influenza at the #human - #animal #interface - Summary and #risk #assessment, from 30 September to 5 November 2025 (#WHO)

 

• New human cases{1,2}: 

-- From 30 September to 5 November 2025, based on reporting date, the detection of influenza A(H5N1) in one human, A(H5N2) in one human and A(H9N2) in two humans were reported officially.  

• Circulation of influenza viruses with zoonotic potential in animals: 

-- High pathogenicity avian influenza (HPAI) events in poultry and non-poultry animal species 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 in the above human infection events. 

-- Based on information available at the time of this risk assessment update, the overall public health risk from currently known influenza A viruses detected at the human-animal interface has not changed and 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{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 29 September 2025, one laboratory-confirmed human case of A(H5N1) infection was detected in Cambodia, and one laboratory-confirmed human case of A(H5N2) virus infection was detected in Mexico. 

A(H5N1), Cambodia 

-- On 15 October 2025, Cambodia notified WHO of a laboratory-confirmed human infection with HPAI avian influenza A(H5N1) in a girl from Kampong Speu Province. 

- The case, with no known underlying medical conditions, had an onset of fever on 4 October and was admitted to hospital on 12 October. 

- Nasopharyngeal and oropharyngeal swabs collected on 13 October tested positive for avian influenza A(H5N1) at the Institut Pasteur du Cambodge (the National Influenza Centre (NIC) by reverse transcription-polymerase chain reaction (RT-PCR). 

- Laboratory results were confirmed at the National Institute of Public Health. 

- Treatment with oseltamivir was initiated on 14 October. 

- The case fully recovered and was discharged on 23 October. 

- Respiratory samples collected from 11 close contacts and one symptomatic villager tested negative for influenza A(H5N1) virus. 

- Field investigations revealed that backyard chickens had died in the weeks preceding the detection of the human case. 

- Although no clear history of direct exposure to sick or dead chickens was identified, it was reported that the case frequently played around the house and in the nearby backyard where the chickens had died.

- Seventeen human infections with A(H5N1) viruses have been confirmed in Cambodia in 2025 and eight of these have been fatal. 

- All these cases in 2025 had exposure to domestic birds or their environments. 

- In some cases, domestic birds were reported to be sick or dead. 

- 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(H5N2), Mexico 

- On 2 October 2025, Mexico notified PAHO/WHO a laboratory-confirmed case of avian influenza A(H5) virus infection detected in an adult, resident of Mexico City. 

- The case had an onset of respiratory symptoms on 14 September and was hospitalized on 28 September. 

- A bronchoalveolar lavage sample collected on 29 September tested positive for unsubtypable influenza A. 

- On 30 September, further testing by real-time RT-PCR confirmed the presence of influenza A(H5) virus. 

- The sample was subsequently sent to the National Influenza Centre, the National Institute of Epidemiological Diagnosis and Reference (InDRE), which confirmed avian influenza A(H5) through molecular diagnostics. 

- The neuraminidase was identified as N2. 

- The sample was sent to a WHO Collaborating Centre for influenza for further characterization.  

- Respiratory samples collected from close contacts including hospital contacts, tested negative for influenza viruses. 

- During the epidemiologic investigation, several animals (including birds) and bird droppings were found in the building where the case resides, in an area the case passes frequently. 

- A dog was identified as a pet at the case’s residence. 

- Samples collected from the animals tested positive for influenza A(H5). 

- Information on whether this virus was a high or low pathogenicity avian influenza virus (HPAI or LPAI) is pending further testing. 

- This is the third human case of avian influenza A(H5) in Mexico since 2024 and the first case in Mexico City. 

- In 2024, a human case of infection with an influenza A(H5N2) virus was detected in a resident of the state of Mexico. 

- In 2025, a human case of infection with an influenza A(H5N1) virus was detected in the state of Durango. 

- Ongoing outbreaks of A(H5) viruses in birds have been detected in multiple states in Mexico since 2022. 

- 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.{7} 

- A list of bird and mammalian species affected by HPAI A(H5) viruses is maintained by FAO.{8}

Risk Assessment for avian influenza A(H5) viruses:  

-- 1. What is the current global public health risk of additional human cases of infection with avian influenza A(H5) viruses?  

- Most human infections so far have been reported 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. As long as 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 remain unusual. The impact for public health if additional sporadic cases are detected is minimal. The current 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(H5) 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(H5) viruses. There has been no reported human-to-human 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(H5) viruses related to these events did not acquire the ability to efficiently transmit between people, therefore sustained human-to-human transmission is thus currently considered unlikely.  

-- 3. What is the likelihood of international spread of avian influenza A(H5) 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 29 September 2025, two cases of infection with influenza A(H9N2) were notified to WHO from China on 13 October 2025 in a child in Hunan province and an adult in Jiangxi province. The cases had onsets of symptoms in September 2025. Both had known exposure to backyard poultry. Both cases were detected through the influenza-like illness (ILI) surveillance system and have recovered. The adult case had underlying conditions and was hospitalized. No further cases were detected among contacts of these cases. 

-- A(H9) viruses were detected in environmental samples collected during the investigations around each case. 

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, further human cases associated with exposure to infected poultry are 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(H9N2) viruses related to this event?   

- At the present time, no sustained human-to-human transmission has been identified associated with the recently reported human infections with A(H9N2) viruses. Current evidence suggests that 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.   

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.{9} More guidance can be found from WOAH and FAO. 

• 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 communitybased 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 with 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).{10} State Parties to the IHR (2005) are required to immediately notify WHO of any laboratory-confirmed{11} case of a recent human infection caused by an influenza A virus with the potential to cause a pandemic{12}. Evidence of illness is not required for this report. 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 humans 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{13} 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} World Organisation for Animal Health (WOAH). Avian influenza. Global situation. Available at: https://www.woah.org/en/disease/avian-influenza/#ui-id-2. 

{8} 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. 

{9}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/. 

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

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

{12} 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. 

{13} 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/10665/259402. 

Source: World Health Organization, https://www.who.int/publications/m/item/influenza-at-the-human-animal-interface-summary-and-assessment--5-november-2025

____

#Cambodia notified two additional #human cases of infection with #influenza #H5N1, #Bangladesh one case of #H5, #China four cases of #H9N2 (HK CHP, Nov. 21 '25)

{Excerpt}

This Week:

[Date of report - Country - Province / Region District / City - Sex - Age - Condition at time of reporting  - Subtype of virus]

1) .../10/2025 - Cambodia - Takeo Province - F - 14 - Hospitalised - H5N1 

2) 16/10/2025 - Cambodia - Kampong Speu Province - F - 3 - Under intensive care - H5N1

(...)

[Place of occurrence - No. of cases  (No. of deaths) - Details]

-- Bangladesh - 1(0) 

- Avian influenza A(H5): 

1) Sylhet Division: A boy with onset on July 27, 2025. 

-- Chinese Mainland - 4(0) 

- Avian influenza A(H9N2): 

- Guangdong Province: 

1) An individual with onset in February 2025. The case was retrospectively reported. 

- Guangxi Zhuang Autonomous Region: 

2, 3) Two individuals with onset in February 2025. Both cases were retrospectively reported.  

- Tianjin Municipality: 

4) An individual with onset in February 2025. The case was retrospectively reported. 

-- Mexico - 1(0) 

- Avian influenza A(H5): 

1) Mexico City: A 23-year-old woman with onset on September 14, 2025. 

(...)

Source: Centre for Health Protection, Hong Kong PRC SAR, https://www.chp.gov.hk/files/pdf/2025_avian_influenza_report_vol21_wk42.pdf

____

#Genetic and Serological Analysis of #H7N3 Avian #Influenza Viruses in #Mexico for #Pandemic #Risk Assessment

 

Abstract

Avian influenza A viruses pose ongoing threats to human and animal health, with H7 subtypes causing outbreaks globally. In Mexico, highly pathogenic H7N3 viruses have circulated in poultry since 2012, causing sporadic human infections. Here we analyzed genetic markers in hemagglutinin sequences from Mexican H7N3 isolates and conducted serological assays on human populations with poultry exposure. Our results show conserved avian-like receptor binding sites, thus limiting human adaptation, alongside antigenic drift and acquisition of glycosylation sites likely driven by vaccination. Serological testing of 1103 individuals revealed no detectable antibodies against H7N3, indicating a naïve population. Phylogenetic analyses revealed multiple virus clades circulating regionally. These findings suggest that while current H7N3 viruses have limited capacity for sustained human transmission, the lack of population immunity underscores the importance of continued surveillance and risk assessment to mitigate potential pandemic threats.

Source: Viruses, https://www.mdpi.com/1999-4915/17/10/1376

____

First #Evidence of #Mammarenavirus in the Giant Fruit #Bat (Artibeus lituratus) in #Mexico

 

Abstract

Background: 

In Mexico, two Mammarenavirus genotypes have been identified: Real de Catorce virus and Ocozocoautla de Espinosa virus (OCEV), which are found in rodents (Neotoma leucodon and Peromyscus mexicanus). Mammarenaviruses from clade B cause mild to severe infectious diseases in humans, particularly in South America. A 1967 outbreak in Chiapas, Mexico, was potentially linked to the OCEV.

Materials and Methods: 

Between 2017 and 2020, we collected bats across southern/southeastern Mexico to identify Mammarenavirus reservoirs. We analyzed 81 liver samples from 14 bat species using nested PCR. For quality control, we synthesized and OCEV S-region fragment into an ampicillin-resistant pUC57 plasmid, cloned in One Shot Stbl3 chemically competent E. coli.

Results: 

Here, we report the first detection of a Mammarenavirus (OCEV) in an Artibeus lituratus bat from Sabancuy, Campeche, southeastern Mexico. This finding represents the third Mammarenavirus recorded in this bat species in the Americas, suggesting it may harbor multiple Mammarenavirus species (OCEV and Mammarenavirus tacaribeense).

Conclusions: 

While this represents the first documentation of OCEV in a bat, it remains unknown whether environmental stressors could facilitate potential transmission to humans, particularly given the close association between Artibeus bats and human populations.

Source: Vector-Borne and Zoonotic Diseases, https://www.liebertpub.com/doi/abs/10.1177/15303667251377563

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#Measles – Region of the #Americas (#WHO D.O.N., April 28 '25)

{Excerpt}

Situation at a glance

As of 18 April 2025, a total of 2318 measles cases, including three deaths, have been confirmed in six countries in the WHO Region of the Americas, an 11-fold increase compared to the same period in 2024. 

The majority of cases have occurred among people between 1 to 29 years, who are either unvaccinated or have an unknown vaccination status. 

Additionally, most cases are imported or linked to importation. 

Measles is a highly contagious, airborne viral disease that can lead to severe complications and death. 

Although it is preventable with two doses of the vaccine, over 22 million children worldwide did not receive their first dose of the vaccine in 2023. This has contributed to a global rise in measles cases in 2024, which heightens the risk of imported infections, particularly from unvaccinated travellers arriving from areas where the virus is actively circulating. 

WHO is working closely with countries in the WHO Region of the Americas to prevent the spread and reintroduction of measles. 

The regional risk is currently assessed as high, while the global risk remains moderate.

Description of the situation

From 1 January to 18 April 2025, a total of 2318 measles cases, including three deaths, were confirmed in the WHO Region of the Americas, an 11-fold increase compared to the 205 cases of measles reported in the same period in 2024. 

The cases have been reported from six countries: 

- Argentina (n= 21 cases), 

- Belize (n= 2 cases), 

- Brazil (n= 5 cases), 

- Canada (n=1069 cases), 

- Mexico (n= 421 cases including one death), and 

- the United States of America (n=800 cases, including two deaths).

(...)

Source: World Health Organization, https://www.who.int/emergencies/disease-outbreak-news/item/2025-DON565

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Serologic #Surveillance for #Orthoflaviviruses and #Chikungunya Virus in #Bats and #Opossums in #Chiapas, #Mexico

Abstract

We performed serologic surveillance for selected arthropod-borne viruses (arboviruses) in bats and opossums in the Lacandona Rainforest, Chiapas, Mexico, in 2023–2024. Sera were collected from 94 bats of at least 15 species and 43 opossums of three species. The sera were assayed by the plaque reduction neutralization test (PRNT) for antibodies to eight orthoflaviviruses (dengue viruses 1–4, St. Louis encephalitis virus, T’Ho virus, West Nile virus, and Zika virus) and one alphavirus (chikungunya virus; CHIKV). Twelve (12.8%) bats and 15 (34.9%) opossums contained orthoflavivirus-specific antibodies. One bat (a Jamaican fruit bat) was seropositive for Zika virus, and 11 bats contained antibodies to an undetermined orthoflavivirus, as did the 15 opossums. All bats and most opossums seropositive for an undetermined orthoflavivirus had low PRNT titers, possibly because they had been infected with another (perhaps unrecognized) orthoflavivirus not included in the PRNTs. Antibodies that neutralized CHIKV were detected in three (7.0%) opossums and none of the bats. The three opossums had low CHIKV PRNT titers, and therefore, another alphavirus may have been responsible for the infections. In summary, we report serologic evidence of arbovirus infections in bats and opossums in Chiapas, Mexico.

Source: Viruses, https://www.mdpi.com/1999-4915/17/5/590

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Avian #Influenza A(#H5N1) - #Mexico {#WHO D.O.N., April 17 '25}

 

Situation at a glance

On 2 April 2025, the International Health Regulations (IHR) National Focal Point (NFP) for Mexico notified the World Health Organization (WHO) of the country’s first laboratory-confirmed human infection with an avian influenza A(H5N1) virus in the state of Durango. 

In response, local and national health authorities have implemented a range of measures to monitor, prevent, and control the situation. 

There have been reports of A(H5N1) outbreaks in birds in Durango, although the exact source of infection in this case remains under investigation. 

To date, no further cases of human infection with influenza A(H5N1) linked to this case have been identified. 

In accordance with the IHR (2005), any human infection caused by a new influenza A virus subtype is considered a potentially significant public health event and is subject to mandatory notification to WHO. 

Based on the information currently available on this and previous cases, WHO assesses the risk to the general population posed by A(H5N1) viruses as low. 

For individuals with occupational exposure to these viruses, the risk of infection is considered low to moderate. 

The situation may change as more information is gathered and so WHO continues to closely monitor these viruses and the global epidemiological situation.

Description of the situation

On 2 April 2025, the Mexico IHR National Focal Point (NFP) notified the World Health Organization of a laboratory-confirmed human infection with an avian influenza A(H5N1) virus in the state of Durango.

This case represents the second reported human infection with avian influenza A(H5) in Mexico, and the first confirmed case of infection with an influenza A(H5N1) virus in the country.

The case is a child under the age of 10 years from the state of Durango who tested positive for influenza A(H5N1) at the Instituto de Diagnóstico y Referencia Epidemiológicos (InDRE, by its Spanish acronym). The case did not have any underlying medical conditions, had not received seasonal influenza vaccination, and had no history of travel.

Symptoms began on 7 March 2025 with fever, malaise, and vomiting. On 13 March, the case was admitted to hospital due to respiratory failure and antiviral treatment was initiated the next day. The case was transferred to a tertiary care hospital on 16 March and died on 8 April due to respiratory complications.

On 18 March, a nasopharyngeal swab was collected, and the sample was processed by real-time polymerase chain reaction (RT-PCR). The result was influenza A, non-subtypable. The sample was sent to the Centro de Investigación Biomédica del Noroeste (CIBIN, by its Spanish acronym), IMSS Monterrey, where the result was confirmed as influenza A, non-subtypeable, along with simultaneous detection of parainfluenza 3 virus. On 31 March, the sample was forwarded to the Laboratorio Central de Epidemiología (LCE, by its Spanish acronym) “La Raza,” where it was molecularly identified as influenza A(H5). On 1 April, the sample was received by InDRE, where the positive result for influenza A(H5N1) was confirmed by RT-PCR. The sample was further characterized as avian influenza A(H5N1) clade 2.3.4.4b genotype D1.1.

The source of infection remains under investigation. During contact tracing, 91 individuals were identified, including 21 household contacts, 60 healthcare workers, and 10 individuals from a childcare center. Pharyngeal and nasopharyngeal swab samples collected from 49 contacts tested negative for influenza A(H5N1). To date, no further cases of human infection with influenza A(H5N1) linked to this case have been identified.

According to information from the National Service for Agrifood Health, Safety and Quality (SENASICA per its acronym in Spanish), between January 2022 and August 2024, 75 outbreaks of A(H5N1) in poultry were reported across various regions of Mexico including: Aguascalientes (5), Baja California (4), Chiapas (1), Chihuahua (3), Guanajuato (2), Jalisco (17), México City (7), Michoacán (1), Nuevo León (1), Oaxaca (2), Puebla (2),  Sonora (8), Tamaulipas (1), Veracruz (1), Yucatán (20). 

At the end of January 2025, SENASICA confirmed a new case of high pathogenicity avian influenza (HPAI) A(H5N1) in a sick vulture at the Sahuatoba Zoo in Durango, the state where the case lived. 

Following this, the death of a Canada goose with neurological and hemorrhagic symptoms was reported at the Peña del Aguila dam in Durango. A total of 25 sick birds were reported, and the presence of HPAI A(H5) was confirmed at a laboratory in Gómez Palacio, in Durango. A positive case of avian influenza A(H5) was also recorded in a bird at Las Auras Park.

Epidemiology

Animal influenza viruses typically circulate within animal populations but some have the potential to infect humans. Human infections are predominantly acquired through direct contact with infected animals or exposure to contaminated environments. Based on the original host species, influenza A viruses can be categorized into subtypes such as avian influenza, swine influenza, and other animal-origin influenza subtypes.

Human infection with avian influenza viruses may result in a spectrum of illness, ranging from mild upper respiratory tract symptoms to severe, life-threatening conditions. Clinical manifestations include conjunctivitis, respiratory, gastrointestinal symptoms, encephalitis, and encephalopathy. In some cases, asymptomatic infections with the A(H5N1) virus have been detected in individuals with known exposure to infected animals and environments.

A definitive diagnosis of human avian influenza infection requires laboratory confirmation. WHO regularly updates its technical guidance on the detection of zoonotic influenza, utilizing molecular diagnostic methods such as RT-PCR. Clinical evidence indicates that certain antiviral agents, particularly neuraminidase inhibitors (e.g., oseltamivir, zanamivir), have been shown to shorten the duration of viral replication and improve patient outcomes in some cases.

From 2003 to 10 April 2025, 972 cases of human infections with avian influenza A(H5N1), including 470 deaths (CFR 48.4%), have been reported to WHO from 24 countries. Almost all of these cases have been linked to close contact with infected live or dead birds, or contaminated environments.

Public health response

In response to this detection, additional investigation and surveillance activities are underway, coordinated by local and national health authorities, with involvement from both the animal and environmental sectors. These activities include:

-- Conducting a comprehensive epidemiological investigation of the case and contacts, including the collection of respiratory samples from symptomatic household contacts and healthcare workers, alongside ongoing follow-up and monitoring of close contacts.

-- Strengthening surveillance of respiratory viruses (including influenza-like illness [ILI] and severe acute respiratory infection [SARI]), with a particular focus on influenza viruses, in order to identify and analyze any atypical respiratory patterns or trends in the region.

-- Activating the One Health approach, involving SENASICA and national environmental agencies (SEMARNAT and CONANP), to ensure inter-institutional coordination, assess potential animal health risks, evaluate possible exposures within the community and animal populations, and notify the National Epidemiological Surveillance Committee (CONAVE).

-- Undertaking regular reporting of HPAI incidence in poultry and wild birds to the World Organisation for Animal Health (WOAH). The latest update on 5 March 2025 reported active surveillance and timely outbreak notifications, with a recent detection in the State of Durango. Consequently, local poultry farmers have been urged to reinforce biosecurity measures on their farms and backyard operations, and to immediately report any observed anomalies in animal health to the relevant authorities. Ongoing epidemiological surveillance is being maintained in poultry production units, backyards, federally inspected slaughterhouses, municipal slaughterhouses, and through national-level monitoring of wild bird populations.

WHO risk assessment

This case represents the second documented case of human infection with avian influenza A(H5) in Mexico and the first confirmed case of infection with an A(H5N1) influenza virus. Ongoing investigations are focused on identifying the source of infection and monitoring contacts. To date, no additional human cases of A(H5N1) virus infection have been identified in relation to this case, nor have any been detected through routine influenza surveillance.

Outbreaks of HPAI A(H5) viruses, including A(H5N1), in poultry have been reported across multiple states in Mexico since January 2022, including in the state of Durango.

When avian influenza viruses circulate in poultry populations, there is an inherent risk of human infection through exposure to infected birds or contaminated environments. As such, sporadic human cases are expected.

Although limited human-to-human transmission of A(H5) viruses was observed in isolated events between 1997 and 2007, sustained human-to-human transmission of A(H5) viruses has not been documented. Available epidemiological and virological data suggest that A(H5) viruses from previous outbreaks have not acquired the capacity for sustained human-to-human transmission.

Based on current information, the WHO assesses the overall public health risk associated with A(H5) viruses as low. However, for individuals with occupational exposure, the risk of infection is considered low to moderate.

The risk assessment will be updated as new epidemiological or virological information emerges in relation to this event.

WHO advice

This event does not change the current WHO recommendations on public health measures and surveillance of influenza.

Given the dynamic and evolving nature of influenza viruses, WHO underscores the critical importance of robust global surveillance systems to detect and monitor virological, epidemiological, and clinical changes associated with emerging or circulating influenza strains with implications for human or animal health. Timely sharing of virus isolates remains essential to inform comprehensive risk assessments.

In instances where humans are exposed to outbreaks of influenza A viruses in domestic poultry, wild birds, or other animal species—or when a human case is confirmed or suspected—enhanced surveillance of potentially exposed populations should be promptly initiated.

Surveillance strategies should account for healthcare-seeking behaviors within the affected population and may include a combination of active and passive methods, such as intensified case finding through ILI/SARI sentinel systems, active hospital-based screening, and targeted surveillance among high-risk occupational groups. Additional data sources, including traditional healers, private healthcare providers, and non-governmental diagnostic laboratories, should also be integrated where applicable to enhance the comprehensiveness of surveillance.

Considering the widespread detection of avian influenza viruses among poultry, wild birds, and select mammalian species, the general public is advised to avoid direct contact with sick or deceased animals. Any suspected dead birds or mammals, as well as any requests for their removal, should be reported to the appropriate local veterinary or wildlife authorities to ensure safe handling and testing.

All poultry products, including eggs and meat, should be thoroughly cooked and handled with proper food safety precautions. Consumption of raw milk is discouraged due to potential health risks. WHO advises consuming pasteurized milk and if pasteurized milk is not available, heating raw milk until it boils to make it safer for consumption. 

In the event of a confirmed or suspected human infection with a novel influenza A virus of pandemic potential, including avian-origin strains, a comprehensive epidemiological investigation should be initiated. This should include detailed assessment of animal exposure history, travel history, and identification of close contacts, even prior to laboratory confirmation. The epidemiological investigation should also include early identification of unusual events that could signal person-to-person transmission of the novel virus. Clinical specimens from confirmed or suspected cases should be tested and referred to a WHO Collaborating Centre for further virological characterization. Additional samples should be collected from animals, the environment or any foods suspected to be sources of infection. 

Individuals working in poultry production and processing environments should take additional health precautions as they are at higher risk of exposure to avian influenza and other zoonotic diseases due to their close contact with birds and potentially contaminated environments.

Farm workers who have direct or close contact with animals or materials infected or contaminated with avian influenza A(H5) virus should wear appropriate personal protective equipment (PPE) to minimize their risk of exposure. 

Currently, there are several vaccines licensed for preventing influenza A(H5) virus infection in humans, although their availability is limited. Candidate vaccine viruses for pandemic preparedness have been selected to protect against A(H5) disease in humans based on circulating strains. 

Existing seasonal influenza vaccines are unlikely to provide protection against avian influenza A(H5) viruses, based on currently available data. However, it is important that individuals who may have frequent exposure to infected or potentially infected birds or other animals get a seasonal influenza vaccine, as it would contribute to decreasing the risk of co-infection and possible genomic recombination of avian and human viruses, which could result in new strains with pandemic potential. 

Close monitoring of the epidemiological, clinical and virological situation, further characterization of recent human, poultry, and other animal influenza viruses, and serological investigations remain essential for assessing risk and adjusting risk management measures as needed.

WHO advises travelers to regions experiencing animal influenza outbreaks to avoid contact with live animal markets, farms, slaughter sites, or any environments with potential contamination from animal excreta. Adherence to hand hygiene and safe food handling practices is strongly recommended. Should infected individuals travel internationally, detection may occur during travel or upon arrival through routine health screening. However, further community-level spread is considered unlikely, as this virus has not yet acquired the ability to transmit easily among humans.  

All human infections caused by a novel influenza A virus subtype are notifiable under the International Health Regulations (IHR 2005) and State Parties to the IHR are required to immediately notify WHO within 24 hours of any laboratory-confirmed case of a recent human infection caused by an influenza A virus due to the potential to cause a pandemic. Evidence of illness is not required for this report. WHO has updated the influenza A(H5) confirmed case definition on the WHO website.

WHO does not recommend special traveler screening at points of entry or other restrictions due to the current situation of influenza viruses at the human-animal interface.

Further information

1) WHO Global influenza programme, human-animal interface

2) World Health Organization. (‎2025)‎. Surveillance for human infections with avian influenza A(‎H5)‎ viruses: objectives, case definitions, testing and reporting.

3) WHO (12 September 2024). Clinical practice guidelines for influenza

4) WHO Risk assessments and summaries of influenza at the human-animal interface

5) Zoonotic influenza candidate vaccine viruses and potency testing reagents

6) WHO Practical interim guidance to reduce the risk of infection in people exposed to avian influenza viruses

7) Surveillance for respiratory viruses of epidemic and pandemic potential

8) Protocol to investigate non-seasonal influenza and other emerging acute respiratory diseases

9) WHO case definition for human infections with avian influenza A(H5) virus requiring notification under IHR (2005)

10) World Health Organization. Cumulative number of confirmed human cases of avian influenza A(H5N1) reported to WHO. Geneva: WHO; 2024

11) Centers for Disease Control and Prevention. Recommended composition of influenza virus vaccines for use in the southern hemisphere 2025 influenza season and development of candidate vaccine viruses for pandemic preparedness. Atlanta: CDC; 2025

12) Pan American Health Organization / World Health Organization. Epidemiological Alert - Human infections caused by avian influenza A(H5N1) in the Region of the Americas - 5 June 2024. Washington, D.C.: PAHO/WHO; 2024

13) Public Health Risk Assessment associated with the spread of zoonotic avian influenza A(H5N1) clade 2.3.4.4b in the Region of the Americas - 12 July 2024

14) World Health Organization. Mosaic Respiratory Surveillance Framework. Geneva: WHO; 2024

15) World Health Organization. Practical interim guidance to reduce the risk of infection in people exposed to avian influenza viruses. Geneva: WHO; 2024.

16) World Health Organization. WHO case definition for human infections with avian influenza A(H5) virus requiring notification under IHR (2005) Geneva: WHO; 2024

17) World Health Organization. Case definitions for the four diseases requiring notification in all circumstances under the International Health Regulations (2005). Geneva: WHO; 2024

18) WOAH report Mexico - Influenza A viruses of high pathogenicity (Inf. with) (non-poultry including wild birds) (2017-) - Follow up report 7

19) Pan American Health Organization / World Health Organization. Technical note: Laboratory Diagnosis of Human Infection with Influenza A/H5

20) Pan American Health Organization / World Health Organization. Samples from patients suspected of Influenza A/H5 LABORATORY TESTING ALGORITHM

21) Pan American Health Organization / World Health Organization. Technical note: Laboratory Diagnosis of Human Infection with Influenza A/H5

22) Current technical information including monthly risk assessments at the Human-Animal Interface

23) WHO. Zoonotic Influenza Outbreak Toolbox

24) WHO. International Health Regulations (2005)

25) Terms of Reference for National Influenza Centers of the Global Influenza Surveillance and Response System

26) Pan American Health Organization / World Health Organization. Epidemiological Update: Avian Influenza A(H5N1) in the Americas Region, 15 November 2024. Washington, D.C.: PAHO/WHO; 2024

27) Pan American Health Organization / World Health Organization. Report of the Regional Consultation for the Strengthening of Intersectoral Work in the Human-Animal Interface of Influenza. 22 March 2023. Washington, D.C.: PAHO/WHO; 2023

28) Pan American Health Organization / World Health Organization. Strengthening the intersectoral work for Influenza at the Human Animal Interface in the Region of the Americas: Technical Questions and Answers. 19 May 2023. Washington, D.C.: PAHO/WHO; 2023

29) Pan American Health Organization / World Organization. Epidemiological Update: Avian Influenza A(H5N1) in the Americas Region, 4 March 2025. Washington, D.C.: PAHO/WHO; 2025

Source: World Health Organization, https://www.who.int/emergencies/disease-outbreak-news/item/2025-DON564

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#Mexico: The Ministry of Health reports the #death of the first #human case of avian #influenza A (#H5N1)

{Automatic translation. Edited.} 

www.gob.mx/salud

The Ministry of Health reports the death of the first human case of avian influenza A (H5N1) in Mexico. 

It is reported that a three-year-old girl diagnosed with avian influenza A(H5N1) and a resident of Durango died today at 1:35 a.m. due to respiratory complications resulting from the infection. 

It is a viral disease that affects birds (wild and domestic), mammals and occasionally humans. 

Local, state, and federal health, environmental, and agricultural authorities continue prevention and control measures within the context of One Health. So far, 38 human contacts of the case have been sampled, all of which have tested negative. 

No additional human cases have been identified, and the risk of further cases is considered low. 

X:  @SSalud_mx  

Source: Ministry of Health, https://www.gob.mx/salud/prensa/secretaria-de-salud-informa-la-defuncion-del-primer-caso-humano-de-influenza-aviar-a-h5n1

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#Mexico: The Ministry of #Health reports the #detection of the first #human case of avian #influenza A (#H5N1)

{Auto translated}

www.gob.mx/salud

The Ministry of Health reports the detection of the first human case of avian influenza A (H5N1) in Mexico. 

The case occurred in a three-year-old girl residing in the state of Durango. On April 1, the Institute of Epidemiological Diagnosis and Reference (InDRE) confirmed the result of influenza A (H5N1). The patient initially received treatment with oseltamivir and is currently hospitalized in a tertiary care unit in the city of Torreón, where her condition is reported to be serious. 

Once the case was confirmed, the following actions were immediately implemented: 

-- Notification to the World Health Organization, in accordance with the protocol established for this purpose in the International Health Regulations. 

Health

-- Health personnel from the Durango and Coahuila Health Services were trained in relation to the National Guide for the preparation, prevention and response to a zoonotic influenza outbreak or event at the animal-human interface. 

-- Intentional search operations were initiated for cases suspected of viral respiratory illness. 

Semarnat - Conanp

-- Biological surveys and sampling of wild and synanthropic birds were carried out in the area of ​​influence surrounding the home of the positive case of avian influenza A (H5N1), and a permanent monitoring system was established for the timely detection of other similar cases in wildlife living in the area.

Agriculture - Senasica

-- The Ministry of Agriculture and Rural Development, through the National Service of Health, Safety, and Agrifood Quality (Senasica), reported that no commercial production units have been affected by avian influenza A (H5N1) in any region of the country. However, Senasica continues its active epidemiological surveillance efforts to promptly identify any potential cases. If so, the corresponding national and international protocols will be implemented.

The Ministry of Health informs the population:

-- The WHO considers the public health risk of this virus to the general population to be low, so eating well-cooked chicken or eggs does not pose a risk to human health. Zoonotic influenza is a disease that can be transmitted from birds or other animals to humans. To date, there is no evidence of sustained human-to-human transmission. 

-- The Ministry of Health has a strategic reserve of 40,000 oseltamivir treatments. 

-- The population is recommended to: 

- Wash your hands frequently with soap and water or 70 percent alcohol-based solutions. 

- Wear a face mask if you have respiratory symptoms and ventilate spaces. 

- Cover your mouth and nose when coughing or sneezing. 

- Wash your hands before handling cooked foods and after handling raw foods. 

- Cook chicken and eggs properly (over 70°C) 

- Do not use the same utensils to handle raw and cooked foods. 

- Avoid touching or approaching wild animals. 

- Do not handle or pick up dead animals. 

- Do not touch sick or dead birds or poultry due to unknown causes. 

- Wear gloves, face masks, and protective clothing if you work on farms or slaughterhouses and have contact with birds or other animals, their products, and waste. 

-- Monitor for signs of illness or abnormal death in farm or backyard animals and report them immediately to the authorities. 

- The Ministry of Health recommends seeking medical attention if you experience fever, conjunctivitis (burning, itching, redness of the eyes), cough, sore throat, runny nose, difficulty breathing, headache, vomiting, diarrhea, bleeding, or altered consciousness after contact with sick or dead birds or other animals. 

Source: Ministry of Health, https://www.gob.mx/salud/prensa/secretaria-de-salud-informa-la-deteccion-del-primer-caso-humano-de-influenza-aviar-a-h5n1

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#Mexico’s Laboratory-Confirmed #Human Case of #Infection with the #Influenza A(#H5N2) Virus

Abstract

In April 2024, the Instituto Nacional de Enfermedades Respiratorias of Mexico City identified a case of unsubtypeable Influenza A in a 58-year-old immunocompromised patient with renal failure due to diabetic nephropathy and bacterial peritonitis. Through sequencing the M, NS, NA, NP, and HA complete segments, we identified an H5N2 influenza virus with identity of 99% with avian influenza A(H5N2) from Texcoco, Mexico, in 2024. This case is the first reported with direct evidence of human infection caused by the H5N2 influenza virus; the relationship of the virus with the severity of his condition remains unknown.

Source: Viruses, https://www.mdpi.com/1999-4915/17/2/205

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