#Bundibugyo Virus Disease #Outbreak - #DRC, #Kenya, #Nigeria - Sit. #Report No. 24, Data as of 1 Nov. '26 (WHO, summary): 10,532 cases & 5,126 deaths in DRC

  

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Event description

    The Bundibugyo virus disease (BVD) outbreak in the Democratic Republic  of the Congo passed 10 000 confirmed cases during the reporting period and  continues at a high, sustained level of transmission, driven increasingly by  Nord-Kivu while Ituri remains the largest contributor. 

    The importation events in Kenya and Nigeria have so far remained  contained: no new case has been reported in Kenya since 19 October and all  secondary cases occurred among contacts already in quarantine, while no  secondary case has been identified in Nigeria. 

    However, a one new death was reported in Kenya, bring the total number of  deaths to two. 

    In the Democratic Republic of the Congo, insecurity, health-worker strikes  in Bas-Uélé and Tshopo and the suspension of response activities in Bafwasende  Health Zone continue to constrain surveillance and response operations.

Democratic Republic of the Congo

    As of 1 November 2026, the BVD outbreak in the Democratic Republic of  the Congo has affected 67 health zones across eight provinces; Yakoma  Health Zone in Nord-Ubangi Province was added to the list of affected zones on 28  October.

    Since External Situation Report #23, an additional 895 confirmed cases and 480 confirmed deaths have been reported, bringing the cumulative total to  10 532 confirmed cases, including 5 126 confirmed deaths [crude case fatality  ratio (CFR) 48.7%]. 

    Transmission remains highly heterogeneous across affected areas. Ituri  continues to account for the largest proportion of cumulative confirmed cases  (70.6%), although its relative contribution is declining, while Nord-Kivu (23.9% of cumulative cases; CFR 55.4%) accounted for 60.0% of the cases reported on 1 November. 

    Transmission persists at lower levels in Haut-Uélé and Tshopo.

    National daily incidence rose steadily from May to its highest levels in late  July and mid-August, declined through late September and has fluctuated at  a high plateau since early October. 

    The seven-day moving average ranged between 67 and 76 confirmed  cases per day during the reporting period, peaking at 76 cases per day on 29–30  October before easing to 67 on 1 November, still below the mid-August peak of  94. 

    Provincial trends diverge. Ituri continues its gradual decline from the late- July peak (seven-day average of 31 cases per day on 1 November, down from 38  on 19 October), while Nord-Kivu is rising again (30 cases per day, up from 26)  and now reports almost as many cases as Ituri each day. HautUélé remains stable  at four to five cases per day, Tshopo shows low-level but sustained transmission,  and Nord-Ubangi reported its first cases in October. Bas-Uélé, Sud-Kivu and Sud-Ubangi have reported no case in the last 21 days (Figures 1 and 2).

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Trend Analysis (21-day comparison):

    During the most recent 21-day period (12 October – 1 November 2026), a  total of 1 466 confirmed cases were reported nationally, compared with 1 333  cases during the preceding 21 days (21 September – 11 October), representing  an increase of 133 cases (+10.0%). 

    Provincial trends remain heterogeneous. Cases in Ituri decreased slightly  from 748 to 736 (−1.6%), accounting for 50.2% of national cases during the  latest period. 

    In Nord-Kivu, cases increased from 486 to 607 (+24.9%), accounting for  41.4% of national cases, while in Haut-Uélé cases increased from 72 to 84  (+16.7%), accounting for 5.7% of national cases. Tshopo reported 33 cases  compared with 20 in the preceding period (+65.0%), and Nord-Ubangi reported  its first six cases. Bas-Uélé and Sud-Ubangi, which reported six and one cases  respectively in the preceding period, reported none.

    During the same period, a total of 745 confirmed deaths were reported  nationally, compared with 649 deaths during the preceding 21 days (21  September – 11 October), representing an increase of 96 deaths (+14.8%). 

    Deaths increased from 377 to 393 (+4.2%) in Ituri, from 230 to 303  (+31.7%) in Nord-Kivu and from 34 to 43 (+26.5%) in Haut-Uélé and decreased  from eight to five in Tshopo; Nord-Ubangi reported its first death. The rise in  deaths, concentrated in NordKivu, outpaced the rise in cases, reflecting a  worsening mortality burden in the province where transmission is now intensifying.

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    Transmission remained active in two-thirds of all health zones affected  since the start of the outbreak. Of the 67 health zones affected to date,  45 (67.2%) reported at least one new confirmed case during the most recent 21  days(12 October – 1 November 2026). 

    Case incidence increased in 26 health zones, decreased in 27 and was  unchanged in one when the two periods are compared. 

    

    The largest absolute increase occurred in Beni, Nord-Kivu (177 to 262  cases; +48.0%), followed by Mambasa, Ituri (22 to 62; +181.8%), Mandima,  Ituri (199 to 233; +17.1%), Mutwanga, Nord-Kivu (14 to 43; +207.1%), Oicha,  Nord-Kivu (28 to 51; +82.1%) and Wamba, Haut-Uélé (26 to 49; +88.5%).  Bafwasende in Tshopo (11 cases), Wapinda and Yakoma in Nord-Ubangi (three  cases each) and Damas and Mahagi in Ituri (one case each) reported cases after  none in the preceding period (Figure 4).

    There were also 22 health zones without a new case in the last 21 days.  These include Adja, Ariwara, Aungba, Boga, Drodro, Fataki, Gety, Kambala and  Logo in Ituri; Goma and Kayna in Nord-Kivu; Dungu and Gombari in Haut-Uélé;  Lubunga, Mangobo and Wanie-Rukula in Tshopo; Miti-Murhesa in Sud-Kivu; Buta, Dakwa, Ganga and Viadana in BasUélé; and Bulu in Sud-Ubangi.

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    Weekly confirmed deaths (Figure 6) rose to 286 during 19–25 October 2026,  the highest weekly total since late August, before declining by 16.4% to  239 during 26 October – 1 November. Community deaths decreased from 184 to  155 (−15.8%) and deaths in treatment facilities from 102 to 84 (−17.6%), so  that the proportion of deaths occurring in the community was essentially  unchanged at 64.9% (64.3% the previous week). 

    On 1 November alone, 20 of the 23 confirmed deaths (87.0%) occurred in  the community. Close to two-thirds of confirmed deaths continue to occur outside treatment facilities, highlighting persistent challenges in early case  detection, timely referral and access to treatment.

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Kenya

    Since the previous report, Kenya has reported no new confirmed case of BVD. The cumulative total remains nine confirmed cases, including two deaths (CFR 22.2%): the imported index case, who died on 5 October, and a  65-year-old family member who died on 23 October. All eight secondary cases  (four family members and four hospital staff) were epidemiologically linked to the  index case and were already under quarantine when they developed symptoms. 

    The last confirmed case was reported on 19 October 2026; the 42-day  countdown to the end of the outbreak will start once the last confirmed patient  has been discharged after two negative tests.

    Of the nine confirmed cases, seven were male and two were female, with  ages ranging from 24 to 65 years. Seven patients remain under treatment in  isolation at designated facilities, which have 211 isolation beds (scalable to 241), 

corresponding to a bed occupancy of 3.3%.

    A total of 135 contacts have been listed, comprising 46 airport staff, 45  hospital staff, 26 passengers, 14 relatives and four flight crew members. Of these,  eight (5.9%) tested positive for BVD during quarantine (four relatives and  four hospital staff), one of whom has died. 

    As of 28 October, 98 contacts remained  in quarantine in Kenya (41 hospital staff, 33 airport staff, 14 passengers  and 10 family members), all of whom were followed up in the  previous 24 hours (100%); 20 contacts (13 airport staff, four flight crew and three  passengers) had completed follow-up and been discharged from quarantine; and nine passengers who travelled outside Kenya are being  followed up through bilateral engagement with their Countries of destination.

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Nigeria

    Nigeria reported a single confirmed case of BVD, announced by the  Federal Ministry of Health on 20 October 2026 in the Federal Capital Territory,  Abuja. The case, a 42-year-old woman, arrived in Abuja from Uganda via Addis  Ababa on 3 October, developed symptoms on 7 October and was admitted to a  private health facility on 11October. 

    The patient was clinically stable and received supportive care before  being medically evacuated to Switzerland on 26 October 2026. 

    As of 31 October, no additional confirmed cases had been reported. As of  29 October, 62 contacts had been identified in Abuja Municipal Area Council, none  of whom had developed symptoms, and 18 samples had been tested, of which one  was positive. 

    No secondary transmission has been detected; the 12-day  interval  between symptom onset and notification, eight days of which were spent in  private-facility care, remains the main concern for undetected exposures.

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Situation interpretation

    The BVD outbreak remains at a critical juncture. In the Democratic  Republic of the Congo, transmission is not declining:  the cumulative count  passed 10 000 confirmed cases, the national seven-day average has held between  67 and 76 cases per day for three weeks, and the epicentre is shifting  towards Nord-Kivu, where cases rose by a quarter and deaths by a third over the  last 21-day period, where one in three patients is managed outside dedicated  treatment centres, and where contact follow-up and safe burial performance are  the weakest. 

    Health-worker strikes in Bas-Uélé and Tshopo, insecurity in Beni and Nizi and  the suspension of activities in Bafwasende further increase the risk of  undetected transmission. 

    The absence of new cases in Kenya since 19 October and of secondary  transmission in Nigeria is encouraging and indicates that the exported chains have  so far been contained, although continued surveillance is essential until the  end-of-outbreak criteria are met. 

    Priorities should focus on reinforcing response capacity in NordKivu,  particularly in Beni, Mutwanga, Oicha and Mabalako, restoring operational access  in insecure and strike-affected areas, improving the timeliness of isolation of  suspected cases and the completion of safe burials, and maintaining coordinated  cross-border surveillance and information sharing to prevent further international  spread.

Source: World Health Organization, https://www.afro.who.int/countries/nigeria/publication/bundibugyo-virus-disease-outbreak-democratic-republic-congo-kenya-nigeria-weekly-external-situation

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#Shamonda virus in #human - #France (#WHO D.O.N., November 5 '26)

 

Situation at a glance

    On 20 October 2026, the National IHR Focal Point (NFP) of France notified WHO regarding the first documented human infection with Shamonda virus (SHAV). 

    The case was an immunocompromised older man from eastern France with no travel history during the preceding year. 

    He developed severe neurological illness on 23 September 2026 and was diagnosed with severe encephalitis (brain inflammation). 

    The patient died on 8 October 2026. 

    SHAV is recognized primarily as an animal-associated virus, like the closely related Schmallenberg virus circulating in Europe, with no previously documented human infections. 

    SHAV was confirmed by metagenomic sequencing and reverse transcription polymerase chain reaction (RT-PCR), with high viral loads detected in tissue samples collected after death and other causes of encephalitis excluded. 

    There is currently widespread SHAV circulation in animals in Europe, including outbreaks across much of France. 

    The source and route of human infection remain unknown. 

    While vector-borne transmission is most likely, food-borne transmission is under investigation. 

    As this is the first documented laboratory confirmed human infection, WHO considers that the public health risk cannot yet be reliably assessed and recommends continued One Health surveillance and investigation.

Description of the situation

    On 20 October 2026, the National IHR Focal Point of France notified WHO of a laboratory-confirmed human infection with Shamonda virus. 

    The case was an immunocompromised older adult male who was hospitalized on 18 August 2026 for his underlying illness. 

    He developed neurological signs on 23 September, including visual disturbances, confusion, loss of consciousness and seizures. 

    A diagnosis of severe encephalitis was made on 25 September, and cerebrospinal fluid (CSF) samples were collected. He died on 8 October.

    Virological findings of SHAV were identified by metagenomics on the CSF samples from 25 September, and the French health authorities were notified on 7 October. 

    The sequence belonged to the SHAV-EU1 genotype and is 99% genomically identical to a virus circulating in neighbouring Switzerland, and the sequence retrieved covered approximately 90% of the genome. 

    Retrospective testing of serum samples collected in early July through October, as well as faecal, urine, saliva and respiratory samples, confirmed the presence of SHAV RNA by RT-PCR. 

    Post-mortem biopsies of the brain, liver and spleen showed very high viral genomic loads. 

    A wide panel of tests for other encephalitis pathogens returned negative results. 

    The patient lived in rural eastern France, where animal SHAV transmission has been documented since July 2026, and had not travelled in the preceding year. 

    The patient received multiple blood transfusions between February and October 2026 for his underlying illness.

    Testing performed by the French Blood Establishment (EFS) and the National Reference Center for Arboviruses (CNR) on blood donors linked to transfused red blood cell units was negative for Shamonda virus, making transfusion-associated transmission unlikely, although it cannot be completely excluded at this stage. 

    Epidemiological investigations around the case have not identified a specific source of exposure, although mosquito exposure was reported. 

    Serological investigations are also being conducted among close contacts of the patient.

    Although foodborne transmission is currently considered unlikely, investigations are ongoing to assess the potential excretion of Shamonda virus in the milk of infected cattle and to better characterize any potential implications for food safety. 

    In parallel, veterinary and entomological investigations are continuing to further clarify the vector(s), the ecology, transmission pathways, and public health significance of the virus.

    This is the first laboratory confirmed human case of Shamonda virus disease reported globally. 

    No additional human cases have been detected to date.

Epidemiology

    SHAV belongs to the family Peribunyaviridae, genus Orthobunyavirus, within the Simbu serogroup. It belongs to the same species as Schmallenberg virus (ie Orthobunyavirus schmallenbergense). It was first isolated from cattle in Nigeria in the 1960s and has subsequently been identified in animals in parts of Africa, Japan and Europe. 

    Until the recently reported human case, SHAV was recognized primarily as an animal-associated virus, like the closely related Schmallenberg virus circulating in Europe, with no documented human infections. 

    As this is the first confirmed human infection reported globally, there is currently insufficient evidence to assess the extent to which SHAV infects humans or causes disease.

    SHAV was detected for the first time in Europe during the summer of 2026 with confirmed or suspected infections reported in cattle, horses and alpacas in Belgium, France, Germany, the Netherlands and Switzerland. 

    As of 21 October 2026, additional European countries and territories have reported SHAV detections in animals: Austria, Ireland, Jersey, Liechtenstein, Portugal, Slovenia and Spain. 

    In metropolitan France, as of 20 October, the available reports indicate animal detections in 54 departments, predominantly in cattle.

    Two distinct variants of SHAV have been identified in animals in Europe: SHAV-EU1, reported in Germany, Austria, France and Switzerland, and SHAV-EU2, identified in Belgium, the Netherlands, northern Germany and northwestern France. 

    Based on current knowledge, SHAV is a vector-borne disease and it is not considered to spread directly between animals. 

    It appears to be transmitted primarily by biting midges of the genus Culicoides, although the main vector species remain unknown. 

    Culicoides (midges) are widespread, and climate change may alter their geographical distribution and abundance, potentially affecting the transmission of vector-borne pathogens in Europe, including Simbu serogroup orthobunyaviruses such as Schmallenberg virus, as well as orbiviruses like bluetongue and African horse sickness viruses. 

    Furthermore, wind-assisted dispersal of infected Culicoides over long distances may also contribute to the introduction and spread of midge-borne viruses into previously unaffected areas, although its role in SHAV transmission requires further investigation. Vertical transmission from mother to fetus during gestation in animals can also occur.  

    In cattle, reported signs include acute systemic illness, such as fever, diarrhoea, reduced activity or appetite, and reduced milk production. 

    Neurological disease has been observed in horses with SHAV-positive brain tissue. 

    Congenital malformations have occurred during gestational infection with related Simbu serogroup orthobunyaviruses in animals. However, the full effects of SHAV, including recently detected European strains, on pregnancy, reproduction and fetal development in animals require further investigation. 

    Given the concurrent circulation of bluetongue virus in Europe and the overlap in clinical signs, veterinary surveillance and laboratory-based differential diagnosis are important. 

    Laboratory confirmation relies on molecular methods, such as RT-PCR, with sequencing or further testing where indicated. 

    No specific antiviral treatment or vaccine is currently available for SHAV; animal-health prevention measures focus on reducing exposure to biting midges, livestock management practices and routine farm biosecurity. 

    Given the potential for overlapping neurological or systemic clinical presentations in animals with other viral infections, such as West Nile virus (WNV), retrospective investigations may be warranted among equine cases presenting with clinical signs compatible with SHAV infection that tested negative for WNV. 

    In addition, testing of samples from WNV-positive horses could help assess the occurrence of possible co-infections and better characterize the contribution of SHAV to equine disease. 

    Such investigations would support a more accurate assessment of the epidemiology, clinical impact and geographical distribution of SHAV in the European equine population.

    The emergence of SHAV in Europe warrants continued epidemiological surveillance and assessment by national veterinary authorities and the public health authorities in Europe using a coordinated One Health approach.  

    As of October 2026, SHAV was not included in the World Organisation for Animal Health (WOAH) list of reportable diseases; however, where SHAV meets the definition of an emerging disease, veterinary authorities are required to notify WOAH in accordance with Article 1.1.5 of the Terrestrial Health Code. 

Public health response

Notification by authorities to WHO and regional bodies.

    Clinical, biological and epidemiological investigations are continuing in conjunction with experts in human, animal and environmental health.

WHO risk assessment

    This first documented human infection with SHAV in 2026 demonstrates that human infection is possible. However, a single case is insufficient to assess the risk to the general population, including immunocompetent individuals, or to determine the frequency, clinical spectrum or severity of human infection. The route of infection and possible sources of exposure are unknown, though vector-borne transmission is a plausible hypothesis.

    Although transmission to humans by Culicoides has been documented for Oropouche virus, another orthobunyavirus, currently, there is no evidence that SHAV is transmitted to humans by this route. 

    Although widespread animal infections in Europe justify further investigation of potential human exposure, they do not establish the likelihood of human infection or sustained transmission. 

    Seasonal declines in Culicoides activity may reduce vector-borne transmission in the short term in northern climates, but do not exclude other routes or future exposure. 

    Given the very limited data regarding the zoonotic potential of SHAV, the public health risk remains uncertain and cannot yet be reliably assessed or quantified. 

    Continued surveillance, investigation of potential transmission routes and potential new human cases, assessment of clinical outcomes across different population groups and retrospective studies in animal populations are warranted. 

    The risk assessment should be updated as further evidence becomes available. 

WHO advice

    In view of the limited evidence on the zoonotic potential of SHAV, the following actions are recommended:

        ° Strengthened surveillance and information sharing. 

            § Continue animal surveillance for SHAV and other orthobunyavirus and consider appropriate human surveillance such as serosurveys, with timely information sharing between veterinary and public health authorities. 

            § Suspected human infections should be investigated in accordance with national procedures and available diagnostic capacity.

        ° Further investigation of the circumstances surrounding the reported case should seek to clarify the source of infection, including the potential contribution of vector exposure.

        ° Assessment of the potential for infection across different population groups. Further analysis of viral genotype and phenotype is required to better understand its potential for transmission to humans.

        ° Should additional human cases be identified, investigations should aim to characterize clinical presentation and outcomes, taking account of immune status and relevant underlying conditions or treatments.

        ° Improved diagnostic and epidemiological understanding, including laboratory investigation and characterization of any suspected cases.  

            § SHAV should be considered and tested for in people with relevant symptoms when occupational and/or environmental exposure may be compatible, until the risk to humans is better understood. 

            § Collaboration between human and animal health services can help identify possible epidemiological links and improve understanding of the virus's transmission pathways.

        ° Strengthened entomological investigations. 

            § Entomological studies should be enhanced to identify the Culicoides species and potentially other vectors involved in SHAV transmission and assess their geographical distribution, seasonal dynamics and vector competence. 

            § Improved understanding of the vectors involved would support both animal and public health risk assessments and help inform surveillance prevention and control strategies.

        ° Promoting One Health investigations to better characterize SHAV circulation. 

            § Investigations in animal populations, including species that may serve as sentinels of viral circulation, can provide valuable information on the geographical spread, transmission dynamics and clinical impact of SHAV. 

            § Improved understanding of animal infections may help identify areas of possible human exposure and support public health risk assessment.

        ° Maintaining proportionate risk communication. Communication should clearly distinguish the established circulation of SHAV in animals from the still-limited evidence of human infection.

        ° Review the risk assessment as evidence evolves. The assessment should be updated if additional human infections are identified, the route of transmission is clarified, or new evidence emerges regarding the clinical consequences of infection in immunocompromised or immunocompetent individuals. 

        ° Continued surveillance, targeted investigation and coordination between human and animal health authorities are warranted to address uncertainties and inform any subsequent adjustment of public health risk assessment and guidance. 

Further information

    • Ministry of Health, Families, Autonomy and Disability Affairs, France: https://sante.gouv.fr/actualites-presse/presse/communiques-de-presse/article/virus-shamonda-une-premiere-detection-chez-l-etre-humain   

    • Fatal encephalitis caused by Shamonda virus Europe 1 (SHAV-EU1) in a patient with a severely weakened immune system, France, 2026. https://www.eurosurveillance.org/content/10.2807/1560-7917.ES.2026.31.42.2600883   

    • Ministry of agriculture, agri-food and food sovereignty, France: Shamonda virus: a first detection in humans. https://agriculture.gouv.fr/virus-shamonda-une-premiere-detection-chez-letre-humain    

    • Ministry of agriculture, agri-food and food sovereignty, France: Cases of orthobunyavirus infection in dairy cows. https://agriculture.gouv.fr/cas-dinfections-de-vaches-laitieres-par-un-orthobunyavirus     

    • Public Health Agency (Santé publique France) France. https://www.santepubliquefrance.fr/les-actualites/virus-shamonda-un-premier-cas-humain-detecte-en-france-que-sait  

    • Health Food chain safety environment, Belgium: Shamonda-like virus: information and frequently asked questions. https://www.health.belgium.be/fr/outils/shamonda-virus-informations-questions-frequentes   

    • Swiss federal authorities, Institute of virology and immunology: Shamonda virus in Switzerland. https://www.ivi.admin.ch/en/neues-orthobunyavirus-der-simbu-serogruppe-bei-rindern-entdeckte    

    • USCDC: Emergence of Shamonda Orthobunyavirus, Central Europe, 2026. https://wwwnc.cdc.gov/eid/article/32/12/26-1496_article    

    • Plateforme ESA, France. https://plateforme-esa.fr/fr/un-nouveau-virus-apparente-au-virus-schmallenberg-agent-causal-potentiel-de-cas-epizootiques-de  

    • European Food Safety Authority (EFSA): Identification and mapping of potential and highly likely vectors for selected vector-borne diseases in the EU and neighbouring countries. https://efsa.onlinelibrary.wiley.com/doi/10.2903/j.efsa.2026.10061   

    • WOAH, Schmallenberg virus. https://www.woah.org/app/uploads/2021/03/a-schmallenberg-virus.pdf    

    • WOAH, Bunyaviral disease of animals. https://www.woah.org/fileadmin/Home/eng/Health_standards/tahm/3.10.01_BUNYAVIRAL_DISEASES.pdf  

Citable reference: World Health Organization (1 November 2026). Disease Outbreak News; Shamonda virus in human, France. Available at:  https://www/who.int/emergencies/disease-outbreak.news.item/2026-DON623     

Source: World Health Organization, https://www/who.int/emergencies/disease-outbreak.news.item/2026-DON623

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#WHO Rapid #Risk #Assessment -Yellow fever, WHO African Region v.1 (Oct. 31 '26)

{Summary}

Risk statement

    This rapid risk assessment was triggered by the recent increase in yellow fever activity in a limited number of countries in West and Central Africa, within the broader group of countries classified as high risk for  yellow fever in the WHO African Region. 

    It focuses primarily on the evolving situations in Burkina Faso, Cameroon, Côte d’Ivoire, Ghana and Liberia, while considering relevant  developments in other affected countries where necessary. 

    It assesses the public health risk associated with ongoing yellow fever  transmission in the WHO African Region during 2026, considering the impact on  human health, the potential for geographical spread, including cross-border  spread, and the risk of insufficient control capacity. 

    It builds on the Global Rapid Risk Assessment for yellow fever that was  finalized on 5 June 2026 and incorporates regional information available up to 12  October 2026.

    Between 1 January and 12 October 2026, 67 confirmed cases including 18 deaths were recorded in nine countries in the WHO African Region.

    However, the most recent cases were concentrated in Burkina Faso, Côte  d’Ivoire, Ghana and Liberia, particularly in districts near international borders. 

    Differences in reporting cut-off dates and case classifications across  available sources affect the comparability of regional epidemiological data.

    The likelihood of continued transmission and additional human cases is  considered likely. Several affected districts have previously identified immunity  gaps, including areas where preventive vaccination has not been implemented or  where population immunity remains insufficient despite past vaccination activities. 

    Unvaccinated and under-vaccinated populations remain at highest risk,  particularly among rural and forestedge communities, mobile and cross-border  populations, and people with occupational exposure in forested, agricultural and  mining environments.

    The concentration of outbreaks in border areas increases the potential for  further geographical spread. 

    Population mobility, frequent crossborder movement, trade, agricultural  activities, pastoral movements and mining operations may facilitate transmission  between affected and neighbouring countries. 

    Introduction into densely populated urban or peri-urban areas with  established Aedes aegypti populations and low population immunity could result  in larger outbreaks and place additional pressure on response capacities. 

    Environmental and seasonal factors, including rainfall, temperature and  vector abundance, may influence transmission dynamics. Evolving El Niño  conditions may further modify the environmental and operational context but  should not be considered a direct cause of the outbreaks.

    The region has important capacities, including established surveillance  systems, a regional laboratory network, routine and reactive vaccination mechanisms, outbreak-response experience, access to the  international emergency vaccine stockpile and activated response structures.

    However, persistent immunity gaps, surveillance and laboratory challenges,  delays in specimen referral and confirmation, insecurity, access constraints, operational challenges to reach unprotected at-risk  communities, funding constraints and competing public health emergencies continue to affect timely detection, investigation, and control. 

    The simultaneous occurrence of outbreaks and epidemic signals in  multiple countries increases demand for laboratory confirmation, vaccination  activities, outbreak investigations and cross-border coordination.

    Based on the likelihood of continued transmission, the risk of cross-border spread, documented immunity gaps and operational constraints affecting  outbreak control, the overall public health risk is assessed as moderate in the WHO African Region, with moderate confidence. 

    The global risk remains low, with high confidence, as transmission remains  concentrated in areas with a history of yellow fever circulation and established  international response mechanisms remain available. 

    Confidence in the regional assessment is moderate because reporting cut- off dates and case classifications vary across available sources, some laboratory  results remain pending, entomological information is limited, and cases may be  under detected in remote or insecure areas. 

    Confidence is high regarding the hazard and established transmission routes, but lower for the magnitude and geographical extent of current  transmission because of differences in national reporting cut-offs and case classifications, pending confirmatory testing, incomplete reconciliation of line  lists and laboratory results, limited entomological information, and possible under- detection in remote or insecure areas.

    The assessment will be updated as new epidemiological, laboratory and operational information becomes available

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Source: World Health Organization, https://www.who.int/publications/m/item/who-rapid-risk-assessment--yellow-fever--who-african-region-v.1

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#Influenza at #human - #animal #interface - #Summary and #risk #assessment, 7 Sept. - 7 Oct. '26 (WHO, Oct. 28 '26): 1 New H5N1 case in #Cambodia, 4 #H9N2 in #China, 1 #H1N1v in #Brazil

• 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: 

Link: https://www.who.int/publications/m/item/influenza-at-the-human-animal-interface-summary-and-assessment--7-october-2026

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