Abstract
To assess the circulation of Oropouche, Mayaro, West Nile, and St. Louis encephalitis viruses, we tested samples from 824 patients with acute febrile illness, 3,484 mosquitoes, and 113 nonhuman primates from northern Minas Gerais, Brazil. All samples were negative for dengue, Chikungunya, and Zika virus. One imported Oropouche virus infection was detected.
Source: Emerging Infectious Diseases Journal, https://doi.org/10.3201/eid3212.260870
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I am an Italian blogger, active since 2005 with main focus on emerging infectious diseases such as avian influenza, SARS, antibiotics resistance, and many other global Health issues. Other fields of interest are: climate change, global warming, geological and biological sciences. My activity consists mainly in collection and analysis of news, public services updates, confronting sources and making decision about what are the 'signals' of an impending crisis (an outbreak, for example). When a signal is detected, I follow traces during the entire course of an event. I started in 2005 my blog ''A TIME'S MEMORY'', now with more than 40,000 posts and 3 millions of web interactions. Subsequently I added an Italian Language blog, then discontinued because of very low traffic and interest. I contributed for seven years to a public forum (FluTrackers.com) in the midst of the Ebola epidemic in West Africa in 2014, I left the site to continue alone my data tracking job.
• New human cases {2}:
° From 7 September to 7 October 2026, based on reporting date, detections of influenza A(H5N1) in one human, influenza A(H9N2) in four humans and influenza A(H1N1) variant (A(H1N1)v) in one human were officially reported.
• 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} Additionally, low pathogenicity avian influenza viruses as well as swine influenza viruses continue to circulate in animal populations.
• Risk assessment {5}:
° There have been no reports of sustained human-to-human transmission associated with the above-mentioned human infection events. Based on information available at the time of this update, the overall public health risk from currently known influenza A viruses detected at the human-animal interface has not changed and, at present, these viruses are not thought to be capable of sustained human-to-human transmission, although this could change as they evolve. Whilst human infections with viruses of animal origin are infrequent, they are not unexpected at the human-animal interface.
• Risk management:
° Candidate vaccine viruses (CVVs) for zoonotic influenza viruses intended for pandemic preparedness purposes, were reviewed and updated at the September 2026 WHO consultation on influenza vaccine composition for use in the Southern Hemisphere 2027 influenza season. A detailed summary of zoonotic influenza viruses characterized since February 2026 is published and updated CVVs lists are published.
• 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
° A(H5N1), Cambodia
§ On 27 September 2026, Cambodia notified WHO of a laboratory- confirmed human infection with an avian influenza A(H5N1) virus in an adult male, from Oddar Meanchey Province. He developed a runny nose on 24 September, and respiratory swabs collected that day tested positive for influenza A(H5N1) at the National Institute of Public Health on 26 September. Institut Pasteur du Cambodge, a WHO H5 Reference Laboratory, confirmed the result on 27 September. The patient was admitted to a referral Hospital for isolation, clinical monitoring and oseltamivir treatment. Genomic sequencing of the virus from this case could not be done due to a low viral load.
§ The national and provincial Rapid Response Teams, in collaboration with animal health and local authorities, are conducting epidemiological, environmental and animal health investigations. The patient frequently visited a family member’s poultry farm. At the farm, chickens began becoming ill and dying around 13 September. Poultry specimens collected from remaining birds on 22 September tested positive for avian influenza.
§ Additional specimens were collected for testing from five direct contacts with the case and three persons with poultry exposure and all were negative for influenza A(H5N1). All identified contacts are being monitored for symptoms 14 days.
§ This is the sixth case reported in Cambodia in 2026.
§ 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, Europe and Oceania. 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(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 infections so far have been reported in people exposed to A(H5N1) 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 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(H5N1) 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.
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
§ Between 9 and 30 September 2026, China notified WHO of four laboratory-confirmed human cases of A(H9N2) virus infection.
[Age - Province - Symptom onset]
1} < 5-year-old - Henan - 30 August 2026
2} < 5-year-old - Guangdong - 7 September 2026
3} Adult - Henan - 17 September 2026
4)} < 5-year-old - Guizhou - 20 September 2026
§ Three of the cases with mild symptoms were detected in influenza-like illness surveillance and have recovered. The adult has underlying chronic conditions and was still in hospital at the time of reporting.
§ All cases had direct or indirect exposure to poultry and/or local live bird markets. Samples from environments associated with the likely area of exposure of some of the cases tested positive for A(H9) viruses.
§ No further cases were detected among contacts of these 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, additional human cases associated with exposure to infected poultry or contaminated environments are expected but remain unusual. The impact to public health if additional sporadic cases are detected is minimal. The overall global public health risk is low.
2. What is the likelihood of sustained human-to-human transmission of avian influenza A(H9N2) viruses related to these events?
§ 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.
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. Swine influenza viruses in humans
° Influenza A(H1N1)v, Brazil
§ On 30 September 2026, Brazil notified PAHO/WHO of a laboratory- confirmed human infection with an influenza A(H1N1)v virus in an adult woman, with pre-existing chronic conditions, residing in the state of Santa Catarina. She developed symptoms of influenza-like illness on 16 July 2026 and sought medical attention on 20 July. Her husband and three adult children, who live in the same household, also experienced symptoms of an influenza-like illness; at that time, all were diagnosed, based solely on clinical examination, with a viral infection and received treatment. The woman, however, did not recover. On 27 July, the patient was hospitalized due to worsening respiratory symptoms. She received treatment, including the antiviral oseltamivir, and required intensive care, including ventilatory support. Despite intensive care, the patient passed away on 28 August.
§ A nasopharyngeal sample, collected on 29 July, tested positive for influenza A on 30 July and was subsequently subtyped as influenza A(H1N1) on 31 July. The sample was sent to the reference laboratory for respiratory viruses at the Oswaldo Cruz Institute (IOC/Fiocruz) in Rio de Janeiro for further characterization. On 4 September, genomic analysis identified an influenza A(H1N1)v virus.
§ According to information gathered during an epidemiological investigation conducted by municipal and state teams between 5 and 9 September, the patient had no history of travel or direct contact with swine. However, a possible indirect exposure to swine was identified through a neighbour who raises these animals for personal consumption.
§ Since 2015, twelve cases of human infection with swine-origin virus variants, including this one, have been detected within Brazil’s respiratory virus surveillance workflow.
° Risk Assessment:
1. What is the public health risk of additional human cases of infection with swine influenza viruses?
§ Swine influenza viruses circulate in swine populations in many regions of the world. Depending on geographic location, the genetic characteristics of these viruses differ. Most human cases are exposed to swine influenza viruses through contact with infected animals or contaminated environments. Human infection tends to result in mild clinical illness in most cases. Since these viruses continue to be detected in swine populations, further human cases are expected but remain unusual. The impact for public health if additional cases are detected is minimal. The overall risk of additional human cases is low.
2. What is the likelihood of sustained human-to-human transmission of swine influenza viruses?
§ No sustained human-to-human transmission was identified associated with the event described above. Current evidence suggests that contemporary swine influenza viruses have not acquired 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 swine influenza viruses by travelers?
§ 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 suggest that these viruses have not acquired the ability to transmit easily among humans.
For more information on zoonotic influenza viruses, see the report from the WHO Consultation on the Composition of Influenza Virus Vaccines for Use in the Southern Hemisphere Influenza Season that was held on 21-24 September 2026 at this link.
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.
• 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. {7} 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 must be maintained at all times, including during a non- influenza emergency. To maximize the value of influenza surveillance platform for other respiratory threats, 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).{8,9} State Parties to the IHR (2005) are required to immediately notify WHO of any laboratory-confirmed {10} case of a recent human infection caused by an influenza A virus with the potential to cause a pandemic {11}. 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 {12} 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 risk elements. The results of TIPRA complement those of the risk assessment provided here, and those of prior TIPRA risk assessments are published at http://www.who.int/teams/global-influenza-programme/avianinfluenza/tool-for-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)
° Global framework to accelerate action on avian influenza https://iris.who.int/handle/10665/387613
° 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/
° WOAH/FAO Network of Expertise on Animal Influenza (OFFLU) http://www.offlu.org/
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{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} Avian influenza. Global situation. World Organisation for Animal Health (WOAH) (https://www.woah.org/en/disease/avian-influenza/#ui-id-2).
{4} Global Avian Influenza Viruses with Zoonotic Potential situation update. Food and Agriculture Organization of the United Nations (FAO) (https://www.fao.org/animal-health/situation-updates/global-aiv-with-zoonoticpotential).
{5} Rapid risk assessment of acute public health events. World Health Organization; 2012 (https://iris.who.int/handle/10665/70810).
{6} Case definitions for the four diseases requiring notification in all circumstances under the International Health Regulations (2005). World Health Organization; 2009 (https://www.who.int/publications/m/item/casedefinitions-for-the-four-diseases-requiring-notification-to-who-in-all-circumstances-under-the-ihr-(2005)).
{7} World Organisation for Animal Health. Statement on High Pathogenicity Avian Influenza in Cattle, 6 December 2024 (https://www.woah.org/en/high-pathogenicity-avian-influenza-hpai-in-cattle/).
{8} World Health Organization. International Health Regulations (2005), as amended through resolutions WHA67.13 (2014), WHA75.12 (2022), and WHA77.17 (2024) (https://apps.who.int/gb/bd/pdf_files/IHR_2014-2022-2024-en.pdf).
{9} World Health Organization. Case definitions for the four diseases requiring notification in all circumstances under the International Health Regulations (2005) (https://www.who.int/publications/m/item/casedefinitions-for-the-four-diseases-requiring-notification-to-who-in-all-circumstances-under-the-ihr-(2005)).
{10} World Health Organization. Manual for the laboratory diagnosis and virological surveillance of influenza (2011) (https://apps.who.int/iris/handle/10665/44518).
{11} World Health Organization. Pandemic influenza preparedness framework for the sharing of influenza viruses and access to vaccines and other benefits, 2nd edition (https://iris.who.int/handle/10665/341850).
{12} World Health Organization. Operational guidance on sharing influenza viruses with human pandemic potential (IVPP) under the Pandemic Influenza Preparedness (PIP) Framework (2017) (https://apps.who.int/iris/handle/10665/259402)
Source:
____
I am an Italian blogger, active since 2005 with main focus on emerging infectious diseases such as avian influenza, SARS, antibiotics resistance, and many other global Health issues. Other fields of interest are: climate change, global warming, geological and biological sciences. My activity consists mainly in collection and analysis of news, public services updates, confronting sources and making decision about what are the 'signals' of an impending crisis (an outbreak, for example). When a signal is detected, I follow traces during the entire course of an event. I started in 2005 my blog ''A TIME'S MEMORY'', now with more than 40,000 posts and 3 millions of web interactions. Subsequently I added an Italian Language blog, then discontinued because of very low traffic and interest. I contributed for seven years to a public forum (FluTrackers.com) in the midst of the Ebola epidemic in West Africa in 2014, I left the site to continue alone my data tracking job.
Summary
Background
Although adverse maternal and infant outcomes have been reported following Oropouche virus infection, the frequencies of these outcomes have not been compared with those in uninfected pregnancies. We followed up pregnant women from areas with Oropouche virus transmission in Rio de Janeiro state, Brazil, to evaluate potential adverse maternal and infant outcomes following Oropouche virus exposure.
Methods
In this prospective cohort study across the state of Rio de Janeiro, Brazil, we included pregnant women receiving prenatal care in municipalities with or at high risk of Oropouche virus outbreaks. Inclusion criteria were: ongoing risk of Oropouche virus infection at the time of prenatal visit; prenatal care at one of the participating sites; and willingness and ability to consent to and participate in the study. Exclusion criteria included infection with other arboviruses and fetal chromosomal abnormalities. Maternal blood, urine, and saliva were collected and tested for Oropouche virus by RT-PCR at enrolment and pregnancy endpoints. IgG and IgM serologies from maternal blood, placental tissue PCR, and immunohistochemistry were done. Confirmed infections were defined by: positive Oropouche virus PCR in blood, urine, saliva, or placenta; positive Oropouche virus placental immunohistochemistry; or Oropouche virus-specific IgM or IgG seroconversion. Possible infection was defined as one positive IgM result without a positive PCR. Negative results ruled out infection. Adverse maternal outcomes (reported by study investigators following up participants at study sites) were maternal death or disability, fetal loss, or haemorrhage; adverse infant outcomes were neonatal death or malformations. Relative risks adjusted for maternal age, other congenital infections, and use of tobacco, alcohol, and drugs during pregnancy for adverse maternal and infant outcomes were calculated.
Findings
Between Nov 29, 2024, and Oct 8, 2025, 544 participants were enrolled: 130 (24%) with confirmed, 143 (26%) with possible, and 271 (50%) with no Oropouche virus infection. The median cycle threshold value of RT-PCR was 29·7 (IQR 25·8–34·9). Among the 130 women with confirmed infection, 104 (80%) developed detectable IgG antibodies. Symptoms were present in 80 (62%) women with confirmed infection, not necessarily associated with adverse outcomes (adjusted relative risk [aRR] 0∙84 [95% credible interval 0∙51–1∙21]). By the end of follow-up, the pregnancies of 119 women with confirmed infection and 193 with no infection had resulted in livebirth, stillbirth, or miscarriage; 105 (88%) women with confirmed infection had livebirths and 187 (97%) women without infection had livebirths. Adverse maternal outcomes occurred in 21 (18%) women with confirmed infection and 14 (7%) women with no infection (aRR 2∙90 [1∙52–5∙35]). Fetal loss and haemorrhage risk were three times higher in women with confirmed infection than in those with no infection (aRR 3∙08 [1∙28–7∙29] for fetal loss and 2∙79 [1∙22–6∙21] for haemorrhage). The aRR for adverse infant outcomes was 9∙18 (1∙89–47∙88). CNS abnormalities occurred in eight (8%) infants of mothers with confirmed infection and in no infants of mothers with no infection.
Interpretation
Oropouche virus infection during pregnancy is associated with severe maternal and infant outcomes, including maternal haemorrhage, fetal loss, and infant CNS abnormalities.
Funding
The Carlos Chagas Filho Foundation for Research Support of the State of Rio de Janeiro (FAPERJ), the National Council for Scientific and Technological Development (CNPq), the Brazilian Ministry of Health, the Oswaldo Cruz Foundation (Fiocruz), and the European Health and Digital Executive Agency.
Translation
For the Portuguese translation of the abstract see Supplementary Materials section.
Source:
Link: https://doi.org/10.1016/S1473-3099(26)00493-7
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I am an Italian blogger, active since 2005 with main focus on emerging infectious diseases such as avian influenza, SARS, antibiotics resistance, and many other global Health issues. Other fields of interest are: climate change, global warming, geological and biological sciences. My activity consists mainly in collection and analysis of news, public services updates, confronting sources and making decision about what are the 'signals' of an impending crisis (an outbreak, for example). When a signal is detected, I follow traces during the entire course of an event. I started in 2005 my blog ''A TIME'S MEMORY'', now with more than 40,000 posts and 3 millions of web interactions. Subsequently I added an Italian Language blog, then discontinued because of very low traffic and interest. I contributed for seven years to a public forum (FluTrackers.com) in the midst of the Ebola epidemic in West Africa in 2014, I left the site to continue alone my data tracking job.
Abstract
We identified highly pathogenic avian influenza virus subtype H5 in stranded dolphins along the coastline of Brazil during 2023–2025. Infected animals included species classified as vulnerable or endangered. Our results highlight the need for ongoing surveillance of cetaceans susceptible to viral infections, which pose an additional threat to threatened species.
Source:
Link: https://doi.org/10.3201/eid3210.260051
____
I am an Italian blogger, active since 2005 with main focus on emerging infectious diseases such as avian influenza, SARS, antibiotics resistance, and many other global Health issues. Other fields of interest are: climate change, global warming, geological and biological sciences. My activity consists mainly in collection and analysis of news, public services updates, confronting sources and making decision about what are the 'signals' of an impending crisis (an outbreak, for example). When a signal is detected, I follow traces during the entire course of an event. I started in 2005 my blog ''A TIME'S MEMORY'', now with more than 40,000 posts and 3 millions of web interactions. Subsequently I added an Italian Language blog, then discontinued because of very low traffic and interest. I contributed for seven years to a public forum (FluTrackers.com) in the midst of the Ebola epidemic in West Africa in 2014, I left the site to continue alone my data tracking job.
Abstract
In 2025, we detected highly pathogenic avian influenza H5N1 virus in dead waterfowl at Ibirapuera Park, São Paulo, Brazil. Genomic characterization indicated a reassortant virus that emerged from locally circulating low pathogenicity avian influenza viruses and highly pathogenic North American lineages. Our results highlight cross-species transmission risk and underscore the need for enhanced surveillance.
Source:
Link: https://doi.org/10.3201/eid3210.260723
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I am an Italian blogger, active since 2005 with main focus on emerging infectious diseases such as avian influenza, SARS, antibiotics resistance, and many other global Health issues. Other fields of interest are: climate change, global warming, geological and biological sciences. My activity consists mainly in collection and analysis of news, public services updates, confronting sources and making decision about what are the 'signals' of an impending crisis (an outbreak, for example). When a signal is detected, I follow traces during the entire course of an event. I started in 2005 my blog ''A TIME'S MEMORY'', now with more than 40,000 posts and 3 millions of web interactions. Subsequently I added an Italian Language blog, then discontinued because of very low traffic and interest. I contributed for seven years to a public forum (FluTrackers.com) in the midst of the Ebola epidemic in West Africa in 2014, I left the site to continue alone my data tracking job.
Influenza at the human-animal interface - Summary and risk assessment, from 13 June to 7 July 2026 {1}
• New human cases {2}:
° From 13 June to 7 July 2026, based on reporting date, detections of influenza A(H5) in one human, influenza A(H9N2) in two humans, and an influenza A(H3N2) variant ((H3N2)v) virus in one human were officially reported.
• 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}
° Additionally, low pathogenicity avian influenza viruses as well as swine influenza viruses continue to circulate in animal populations.
• Risk assessment {5}:
° There have been no reports of sustained human-to-human transmission associated with the above-mentioned 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 - At present, these viruses are not thought to be capable of sustained human-to-human transmission, although this could change as they evolve.
° 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
A(H5), Bangladesh
° On 15 June 2026, Bangladesh notified WHO of one laboratory-confirmed human case of avian influenza A(H5) infection in Bangladesh in a child from Sylhet Division.
° The case was detected notified through the National Influenza Surveillance, Bangladesh (NISB) platform as an influenza likeillness (ILI) case.
° The patient developed respiratory symptoms on 17 May 2026, received outpatient healthcare on 20 May.
° A clinical sample was collected that day and was received by the Institute of Epidemiology, Disease Control and Research (IEDCR) on 4 June as part of routine surveillance.
° The sample tested positive for influenza A(H5) virus by real-time reverse transcription polymerase chain reaction (RTPCR) on 11 June.
° The patient is now in good health and reported no travel history and no history of exposure to poultry.
° However, poultry deaths were reported in the area surrounding the patient’s residence.
° The outbreak investigation team identified and followed close and possible contacts.
° Samples from some of the close contacts as well as animal and environmental samples were collected for testing for influenza.
° All contacts remained asymptomatic and all samples tested negative for influenza.
° This is the third laboratory-confirmed human case of avian influenza A(H5) reported in Bangladesh in 2026, and the 15th human case of avian influenza A(H5) reported to WHO from Bangladesh since 2008, including two fatal cases, one reported in 2013 and one in 2026.
Risk assessment for avian influenza A(H5) viruses:
° Between 12 and 23 June 2026, two laboratory-confirmed cases of A(H9N2) virus infection were detected in China.
° Both cases had mild illness and were hospitalized in isolation wards at the time of reporting.
{Click on Image to Enlarge}
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° Both cases had exposure to local live bird markets.
° Samples from environments associated with the likely area of exposure of the cases tested positive for A(H9) viruses.
° No further cases were detected among contacts of these cases.
Risk assessment for avian influenza A(H9N2):
Influenza A(H3N2)v, Brazil
° On 25 June 2026, Brazil notified PAHO/WHO of a laboratory-confirmed human infection with an influenza A(H3N2)v virus detected in a child in Santa Catarina state.
° The patient had symptom onset on 12 June 2026 and due to worsening respiratory symptoms, healthcare was sought on 16 June.
° The patient was referred for hospital admission with a diagnosis of Severe Acute Respiratory Infection (SARI).
° Upon admission, an antigen test confirmed influenza A and the patient was placed in a private respiratory isolation room and antiviral treatment was initiated.
° The patient was discharged on 19 June.
° A nasopharyngeal swab sample was collected on 16 June and sent to the State public health laboratory for real-time RT-PCR.
° On 18 June, a swine-origin influenza H3 variant was suspected, and the sample was sent to the Laboratory of Respiratory Viruses, Exanthems, Enteroviruses, and Viral Emergencies (LVRE) at the Oswaldo Cruz Institute (Fiocruz/Rio de Janeiro) on 19 June.
° Analyses confirmed the presence of an influenza A(H3N2)v virus via molecular testing and genomic sequencing.
° An investigation by the state and municipality epidemiological surveillance team found that all contacts were asymptomatic before, during and after the child’s illness.
° The child's grandfather worked at a swine nursery housing approximately 5,000 animals, though he noted that sanitary barriers were in place.
° The child frequently visited the grandfather's home and had contact with him several days a week.
° This is the first human A(H3N2)v infection detected in the Brazil in 2026 and the first case reported in the state of Santa Catarina.
Risk assessment for swine influenza viruses:
° 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.{7}
- 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).{8,9} State Parties to the IHR (2005) are required to immediately notify WHO of any laboratory-confirmed {10} case of a recent human infection caused by an influenza A virus with the potential to cause a pandemic {11}. 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 {12} 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 risk elements. The results of TIPRA complement those of the risk assessment provided here, and those of prior TIPRA risk assessments are published at http://www.who.int/teams/global-influenza-programme/avianinfluenza/tool-for-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/
° WOAH/FAO Network of Expertise on Animal Influenza (OFFLU) http://www.offlu.org/
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{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 four diseases requiring notification in all circumstances under the International Health Regulations (2005). Available at: https://www.who.int/publications/m/item/case-definitions-for-the-four-diseases-requiring-notification-towho-in-all-circumstances-under-the-ihr-(2005).
{7} World Organisation for Animal Health. Statement on High Pathogenicity Avian Influenza in Cattle, 6 December 2024 (https://www.woah.org/en/high-pathogenicity-avian-influenza-hpai-in-cattle/).
{8} World Health Organization. International Health Regulations (2005), as amended through resolutions WHA67.13 (2014), WHA75.12 (2022), and WHA77.17 (2024) (https://apps.who.int/gb/bd/pdf_files/IHR_20142022-2024-en.pdf).
{9} World Health Organization. Case definitions for the four diseases requiring notification in all circumstances under the International Health Regulations (2005) (https://www.who.int/publications/m/item/casedefinitions-for-the-four-diseases-requiring-notification-to-who-in-all-circumstances-under-the-ihr-(2005)).
{10} World Health Organization. Manual for the laboratory diagnosis and virological surveillance of influenza (2011) (https://apps.who.int/iris/handle/10665/44518).
{11} World Health Organization. Pandemic influenza preparedness framework for the sharing of influenza viruses and access to vaccines and other benefits, 2nd edition (https://iris.who.int/handle/10665/341850).
{12} World Health Organization. Operational guidance on sharing influenza viruses with human pandemic potential (IVPP) under the Pandemic Influenza Preparedness (PIP) Framework (2017) (https://apps.who.int/iris/handle/10665/259402).
Source:
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I am an Italian blogger, active since 2005 with main focus on emerging infectious diseases such as avian influenza, SARS, antibiotics resistance, and many other global Health issues. Other fields of interest are: climate change, global warming, geological and biological sciences. My activity consists mainly in collection and analysis of news, public services updates, confronting sources and making decision about what are the 'signals' of an impending crisis (an outbreak, for example). When a signal is detected, I follow traces during the entire course of an event. I started in 2005 my blog ''A TIME'S MEMORY'', now with more than 40,000 posts and 3 millions of web interactions. Subsequently I added an Italian Language blog, then discontinued because of very low traffic and interest. I contributed for seven years to a public forum (FluTrackers.com) in the midst of the Ebola epidemic in West Africa in 2014, I left the site to continue alone my data tracking job.
