A lethal #human #H5N5 #influenza virus isolate exhibits low #pandemic #risk traits

 

Abstract

In fall of 2025, a fatal infection of highly pathogenic avian influenza (HPAI) virus H5N5 occurred. To define the risk of this emerging virus to humans, we performed a comprehensive analysis based on our established triage. Serological analysis revealed that humans across all birth years had no detectable neutralizing antibodies to this H5N5 isolate. Further characterization revealed a lack of phenotypic signatures associated with epidemiologically successful influenza viruses in humans, including reduced replication in human airway cells and an avian-like pH of inactivation. Additionally, assessment of H5N5 in ferrets revealed a lack of direct contact transmission and moderate disease severity. H5N5 infection in ferrets with prior immunity against the 2009 H1N1 pandemic strain resulted in fewer clinical signs and reduced viral shedding. Together our data suggest that the current H5N5 HPAI lineage poses a low pandemic risk.

Source: 

Link: https://www.biorxiv.org/content/10.64898/2026.07.20.739507v1

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#Ebola disease caused by #Bundibugyo virus, #DRC & #Uganda (WHO D.O.N., July 17 '26): 2124 cases & 828 deaths in DRC

 

Situation at a glance

    ° The Bundibugyo virus disease (BVD) outbreak in the Democratic Republic of the Congo remains active, with sustained transmission driving increases in reported cases and deaths. 

    ° As of 15 July 2026, a cumulative total of 2124 confirmed cases, including 828 deaths, have been reported from the Democratic Republic of the Congo. 

    ° On 13 July 2026, German authorities informed WHO of a laboratory-confirmed case of Ebola disease caused by Bundibugyo virus in a humanitarian worker from the United States of America who was medically evacuated from the Democratic Republic of the Congo. 

    ° This is the second United States citizen to be treated in Germany, reflecting the ongoing international response efforts. 

    ° In Uganda no new cases have been reported since 21 June 2026. The most recent case was discharged from the treatment centre on 16 July after two negative tests results. 

    ° The country has therefore begun the 42-day period of enhanced surveillance required before the end of the outbreak can be declared. 

    ° National authorities in Uganda and the Democratic Republic of the Congo, in collaboration with WHO and partners, continue to implement extensive response measures. 

    ° A regional preparedness and prioritization framework continues to guide readiness activities across the African Region.

Description of the situation

    ° Since the previous  Disease Outbreak News was published on 3 July 2026, the number of confirmed cases and deaths has increased substantially in the Democratic Republic of the Congo. 

    ° In total, 2145 confirmed cases have been reported:  2124 in the Democratic Republic of the Congo (including two cases with diagnosis in the Democratic Republic of the Congo and subsequent treatment in Germany), 20 in Uganda and one in France. 

    ° A total of 830 deaths has been reported, including two in Uganda.  

    ° To date, at least 410 patients have recovered, including 390 in the Democratic Republic of the Congo, 18 in Uganda, one in France, and one in Germany.  

(...)

Democratic Republic of the Congo

    ° Since 3 July 2026, an additional 664 confirmed cases, including 376 confirmed deaths, have been reported in the Democratic Republic of the Congo. 

    ° The increase is in part due to the scale-up of surveillance activities, testing, and diagnostic capacities. 

    ° As of 15 July 2026, a total of 2124 confirmed cases, including 828 deaths (crude case fatality ratio [CFR] 39%) have been reported in the Democratic Republic of Congo. 

    ° So far, 390 patients have recovered. 

    ° Cases have been reported from 46 health zones (HZ) across five provinces:  Ituri (27/36 HZ), North Kivu (11/34 HZ), South Kivu (1/34 HZ), Haut-Uele (4/13 HZ) and Tshopo (3/23 HZ).

    ° Of the 46 affected health zones, the outbreak remains active in 38 health zones, which have reported cases within the past 21 days. The remaining health zones have not reported any new cases during this period. In the past 21 days, 969 confirmed cases, including 524 confirmed deaths, have been reported.  

    ° Ituri  remains the most affected province, accounting for 89.6% (1904/2124) of all confirmed cases and 83.6% (692/828) of all reported deaths nationwide. Within the province, the highest number of confirmed cases have been reported from Bunia (570 cases), Rwampara (418 cases), Mongbwalu (347 cases), Nizi (148 cases), and Nyankunde (99 cases) health zones.  

    ° As of 15 July, 12 693 contacts have been identified and are under follow-up across Ituri (10 183), North Kivu (2360) and Tshopo (150). Of these, 10 195 contacts have been followed up, corresponding to follow-up rates of 78.1% in Ituri, 50.0% in Tshopo and 91.7% in North Kivu. Previously listed contacts in South Kivu have completed their 21-day followup. In addition, 107 contacts of the case reported in France have been listed and are under follow-up in Kinshasa.  

    ° Infections among health workers continued to increase, with 119 confirmed cases, 61 recoveries and 36 deaths reported among health workers, corresponding to a CFR of 30.3%. This highlights persistent occupational exposure risks, inadequate infection prevention and control (IPC) implementation in health facilities, and exposure risk in the community. 

    ° The outbreak continues in a complex humanitarian and conflict-affected environment, characterized by highly mobile and often displaced populations, many of whom have limited access to basic services, including food, clean water, shelter, health care and protection.  These conditions increase the risk of transmission, particularly in overcrowded sites for internally displaced people. 

    ° Security incidents affecting health facilities, have created additional operational challenges in affected provinces, including restricted access for response teams, disruption of surveillance and response activities and an increased risk of undetected transmission. These conditions underscore the need for response efforts to be led by local leaders and anchored in communities.  

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Figure 2: Number of confirmed cases (n = 2124), in the Democratic Republic of the Congo, by date of reporting and as of 15 July 2026 

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Figure 3: Number of deaths among confirmed cases (n = 828), in the Democratic Republic of the Congo, by date of reporting and as of 15 July 2026.  

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NB: Newly reported confirmed cases/deaths may be part of the backlog of samples and therefore not necessarily newly acquired infections.  

Uganda

    ° The last confirmed case was reported to be identified on 21 June 2026.  As of 14 July 2026, a cumulative total of 20 confirmed cases have been reported, including two deaths in imported cases (reported on 15 May and 5 June) and one probable case resulting in death. 

    ° Of the confirmed cases, 15 were imported cases and five were secondary cases among contacts and health workers linked to imported cases from the Democratic Republic of the Congo.  All cases were reported in Kampala District. To date, no community transmission has been in Uganda. Exposure risks have been associated with health-care settings and cross-border movements.  

    ° Following case reclassification, the number of affected healthcare workers was revised from five to four. In total, 18 recoveries have been reported. 

    ° Of the 831 contacts listed as of 28 June, 821 contacts have completed their 21-day follow-up period as of 14 July.  

    ° The most recent case was discharged from the treatment centre on 16 July after two negative tests results. This marks the start of the 42-day countdown period (twice the maximum incubation period) to ensure surveillance activities continue to be implemented and detect any cases that were missed before the declaration of the end of the outbreak. Given the ongoing outbreak in the Democratic Republic of the Congo, the risk of importation still exists.   

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Figure 4: Number of confirmed cases (n = 20), in Uganda by date of reporting and as of 17 July 2026 

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France

    ° No additional BVD cases have been reported in France since the previous update. 

    ° The imported confirmed BVD case reported on 24 June recovered and was discharged from the healthcare facility on 4 July after two negative PCR test results. No secondary transmission has been identified among the five low-risk flight contacts  placed under precautionary quarantine. These contacts  completed their follow-up period on 14 July. 

    ° French authorities have been monitoring  these individuals in coordination with relevant regional public health authorities as well as with the National IHR Focal Points of Belgium and the Netherlands who conducted an individual risk assessment. None of the contacts developed symptoms, and no addtional  at-risk individuals have been identified. 

Germany

    ° A  physician from the United States  working in the Democratic Republic of the Congo, was medically evacuated and treated in Germany in May 2026. The patient recovered and was discharged. No secondary cases were reported. 

    ° A second United States citizen, a humanitarian worker, tested positive for Bundibugyo virus in the Democratic Republic of Congo in July 2026 and was medically evacuated to a university hospital in Frankfurt/Main, Germany. The patient  is reported to be in stable condition.

Epidemiology

    ° Bundibugyo virus disease (BVD) is a severe Ebola disease caused by the Bundibugyo virus, one of the Orthoebolavirus species. It is a zoonotic disease, with fruit bats suspected to be the natural reservoir. 

    ° Human infection is thought to occur through close contact with the blood or secretions of infected wildlife, such as bats or non-human primates, and it subsequently spreads from person-to-person through direct contact with the blood, secretions, organs, or other bodily fluids of infected individuals or contaminated surfaces and materials. Transmission is particularly amplified in health-care settings when IPC measures are inadequate and during unsafe burial practices involving direct contact with deceased persons. 

    ° The incubation period for BVD ranges from 2 to 21 days, and infected individuals are not infectious until symptom onset. Early symptoms such as fever, fatigue, muscle pain, headache, and sore throat, are non-specific, which complicates clinical diagnosis and can delay detection. These symptoms then progress to gastrointestinal symptoms, organ dysfunction, and, in some cases, haemorrhagic manifestations. 

    ° CFRs in the past two BVD outbreaks, reported in Uganda and in the Democratic Republic of the Congo in 2007 and 2012 were 30% and 50%, respectively. 

    ° Differentiating BVD from other endemic febrile illnesses such as malaria is challenging without laboratory confirmation using PCR or antigen- or antibody-based assays. Outbreak control relies on rapid case identification, isolation and care, contact tracing, safe burials and strong community engagement, as no approved vaccines or specific treatments currently exist for BVD. 

Public health response

    ° Health authorities in the Democratic Republic of the Congo and Uganda, in collaboration with WHO and partners, continue to implement extensive public health measures, including implementing the continental response plan, engaging donors and mobilizing additional resources to address critical funding gaps and sustain response operations across affected and at-risk areas. 

    ° For further information about public health response actions by the respective Ministry of Health, WHO and partners, please refer to the latest situation reports published by the WHO Regional Office for Africa: Ebola Bundibugyo Virus Disease Outbreak Democratic Republic of the Congo | Uganda Weekly External Situation Report | WHO | Regional Office for Africa  

WHO risk assessment

    ° On 6 June 2026, WHO reassessed the risk of the outbreak of BVD to incorporate newly available information and align with the WHO Temporary Recommendations. The risk for countries sharing land borders with countries with documented Bundibugyo virus detection, the Democratic Republic of the Congo and Uganda at the time of assessment, has been separated from the risk for other countries in the African Region. 

    ° The risk in the Democratic Republic of the Congo remains assessed as very high due to ongoing transmission and the continued expansion of the outbreak into new health zones, increasing the potential for further national and regional spread. 

    ° The risk in Uganda is still assessed as high due to confirmed cross-border spread through imported cases and ongoing epidemiological links along the eastern Democratic Republic of the Congo–western Uganda corridor, which has historically been affected by Ebola outbreaks, including Bundibugyo virus and Sudan virus disease.  

    ° The risk for countries sharing land borders with countries reporting BDBV detection is assessed as high due to sustained population mobility linked to cross-border trade and mining activities, variation in capacities and experience of BVD response, and variable levels of readiness.  

    ° The risk for the rest of the African region and at the global level is assessed as low. 

    ° For further information, please see the WHO Rapid Risk Assessment – Ebola disease caused by Bundibugyo virus, Democratic Republic of the Congo, Uganda and countries with land borders adjoining countries with documented BDBV detection v3. 

(...)

Source: 

Link: https://www.who.int/emergencies/disease-outbreak-news/item/2026-DON613

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Pan-continental #spillover #risk: integrated spatiotemporal, transmissibility and #surveillance analysis of avian #influenza #H5N1 in #Africa

 

Abstract

Background: 

The HPAI H5N1 panzootic represents a critical threat to human health in Africa, where traditional poultry systems and dense human-animal interfaces facilitate frequent zoonotic spillover. While sporadic human cases raise pandemic concerns, continent-wide integration of spatial dynamics, transmissibility indicators, and surveillance performance has been lacking. This study quantifies avian influenza transmission over two decades across Africa, identifies geographical hotspots, and evaluates the responsiveness of current surveillance systems.

Methods: 

We analysed 8,037 avian influenza outbreak events and 369 laboratory-confirmed human cases, predominantly caused by HPAI H5N1 (2004–2025), using harmonised data from FAO (EMPRES-i+), WHO, and WOAH. A Bayesian Besag-York-Mollié (BYM) spatiotemporal model estimated residual transmission risks and Incidence Rate Ratios (IRR) by subtype. The basic reproduction number (R₀) was derived via an exponential growth model applied to human outbreak phases across infectious durations of 7–30 days. Surveillance responsiveness was assessed by quantifying notification delays between clinical observation and official reporting.

Results: 

Risk of infection in animals: HPAI H5N1 was the dominant strain, representing 87.8% of animal cases, with Egypt acting as the primary epidemiological epicentre (66% of total records). The spatiotemporal model revealed that H5N1 is associated with a significantly higher risk of animal infection (IRR = 8.37; 95% CI: 6.65–10.53). Although 71% of outbreaks were reported within 5 days of detection, significant delays (≥15 days) occurred in 12% of cases, with notable regional disparities. Risk of infection in human: H5N1 was associated with a 67-fold increase in the incidence of human cases compared to other subtypes (IRR = 66.78; 95% CI: 25.29–176.37). Sensitivity analyses yielded R0 estimates ranging from 1.05 (95% CI: 0.91–1.31) to 1.23 (95% CI: 0.60–2.33), indicating localised epidemic potential.

Conclusion: 

Our findings highlight a persistent and geographically heterogeneous H5N1 reservoir in Africa with high zoonotic affinity. Although sustained human-to-human transmission remains limited, the identification of dual poultry-human hotspots and localised R0 peaks underscores the urgent need for geographically targeted One Health interventions. Strengthening real-time reporting systems and improving biosecurity in high-risk poultry value chains are critical to mitigating future pandemic threats on the continent.

Source: 

Link: https://www.frontiersin.org/journals/epidemiology/articles/10.3389/fepid.2026.1813211/full

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Occupationally Exposed and General #Population #Antibody #Profiles to #Influenza A Viruses Circulating in #Swine as Indication of Zoonotic #Risk

 

Abstract

Persons with occupational exposure to swine might be at disproportionate risk for zoonotic swine influenza A virus. To evaluate human antibody responses, we tested serum or plasma from swine veterinarian, farm employee, and general population cohorts by hemagglutination inhibition assays against representative swine and human seasonal influenza vaccine strains. We analyzed hemagglutination inhibition data by antigenic cartography to assess strain relationships and reproduction number modeling to evaluate pandemic potential using age-stratified immunity profiles. Occupationally exposed groups had lower human seasonal vaccine uptake (45.5% vs. 70%) and lower odds of seropositivity to several H1 and H3 strains from swine than did general population cohorts. One swine strain exhibited significant antigenic drift (3.62 antigenic units) from its nearest vaccine strain. Multiple strains required lower reproduction number thresholds for pandemic spread (1.09–1.35) than recorded pandemic strains (1.46–1.80), demonstrating that population immunity gaps heighten zoonotic risk to circulating swine H1 and H3 strains.

Source: 

Link: https://wwwnc.cdc.gov/eid/article/32/8/25-1995_article

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#Bundibugyo Virus Disease #Outbreak, #DRC & #Uganda & #France - External #Situation Report 08, as of 05 July 2026 (WHO AFRO, edited): 1624 cases and 521 deaths in DRC

 

{Excerpts}

Key Figures at a Glance 

    ° 3 Countries Affected 

    ° 1 645 Confirmed Cases 

    ° 523 Confirmed Deaths 

    ° 31.8% CFR Confirmed 

    ° 12 417 Contacts to follow 

Summary 

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Event description

    ° The Bundibugyo virus disease (BVD) outbreak in the Democratic Republic of the Congo continues to intensify, driven by sustained transmission in hotspot health zones of Ituri and North Kivu provinces. 

    ° The outbreak is marked by growing numbers of community deaths, and the continued spread of infection into previously unaffected health zones. 

    ° While Uganda has not reported any new confirmed cases during the past week, and the imported case reported in France has fully recovered without evidence of secondary transmission among identified contacts, the ongoing epidemic in eastern Democratic Republic of the Congo continues to pose a significant regional and global public health threat.  

Democratic Republic of the Congo

    ° Compared with the previous update issued on 28 June 2026 (Situation Report #7), the epidemiological situation in the Democratic Republic of the Congo has deteriorated further. 

    ° An additional 317 confirmed cases and 144 confirmed deaths have been reported, representing increases of 24.3% and 38.2%, in cumulative cases and deaths respectively. 

    ° The crude case fatality ratio (CFR) rose from 28.8% to 32.1%. 

    ° Geographic spread continues as the first confirmed case was detected in Lolwa health zone in Ituri Province, increasing the total number of affected health zones to 36. 

Figure 1.  Weekly trends of confirmed cases of Bundibugyo virus disease in the Democratic Republic of the Congo by epidemiological week of report, epidemiological weeks 18 – 27, 2026 

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    ° Mabalako and Vuhovi health zones have now completed 21 consecutive days, without reporting a confirmed case and have been added to the list of areas with no recent transmission. 

    ° However, Rimba Health Zone, which had previously gone 25 days without reporting a case, has now reported a new confirmed case. 

    ° This brings the total number of previously affected health zones that have surpassed the 21-day threshold to eight. 

    ° These include MitiMurhesa in South Kivu Province (46 days); Gety (45 days), Mambasa (33 days), and Aru (31 days) in Ituri Province; and Kalunguta (42 days), Goma (41 days), Vuhovi (24 days), and Mabalako (22 days) in North Kivu Province.   

    ° The outbreak remains active in 28 health zones across Ituri and North Kivu provinces that have reported confirmed cases within the past 21 days. 

    ° During this period, 787 confirmed cases and 325 confirmed deaths were reported. 

    ° Ituri Province continues to bear the overwhelming burden of the outbreak, accounting for 710 cases (90.2%) and 282 deaths (86.8%) across 21 active health zones. 

    ° The remaining seven active health zones in North Kivu reported 77 cases (9.8%) and 43 deaths (13.2%). 

    ° The highest transmission was recorded in Bunia (237 cases), Rwampara (190 cases), Mongbwalu (103 cases), Nizi (62 cases), Nyankunde (51 cases), and Lita (24 cases) in Ituri Province. 

    ° In North Kivu Province, Katwa (27 cases) and Butembo (21 cases) remained the main areas of transmission. 

    ° Collectively, these health zones accounted for 90.9% of all confirmed cases reported during the past 21 days. 

    ° A similar pattern was observed for mortality. Bunia reported the highest number of deaths (101), followed by Mongbwalu (66), Rwampara (45), Katwa (22), Nizi (18), Nyankunde (15), Lita (12), Mangala (11), and Butembo (11). 

    ° Together, these health zones accounted for 92.6% of all confirmed deaths reported during the same period.  

    ° The crude CFR of the outbreak also increased over recent weeks. In Ituri Province, the CFR rose from 20.5% on 15 June to 29.7% on 05 July 2026, while North Kivu continued to record the highest provincial CFR, remaining above 56% throughout the reporting period. 

    ° The largest increase in CFR was observed in Lita Health Zone (+36.4 percentage points), followed by Komanda (+22.1 percentage points), Nizi (+18.1 percentage points), and Bunia (+17.6 percentage points). 

    ° These elevated CFRs likely reflect continued delays in case detection and healthcare-seeking behaviour, compounded by the persistently high proportion of deaths occurring in the community. 

(...)

    ° Since the beginning of the outbreak, the Democratic Republic of the Congo has reported 1624 confirmed cases, including 521 confirmed deaths (CFR 32.1%]. 

    ° Ituri Province remains the epicentre of the outbreak, accounting for 90.9% (1477) of all confirmed cases and 84.3% (439) of all reported deaths nationwide. 

    ° The most affected health zones are Bunia (452 cases, 121 deaths), Rwampara (349 cases, 72 deaths), Mongbwalu (288 cases, 149 deaths), Nyankunde (96 cases, 19 deaths), Nizi (78 cases, 19 deaths), Lita (33 cases, 12 deaths), and Mangala (33 cases, 14 deaths), all located in Ituri Province, as well as Katwa (52 cases, 38 deaths), Butembo (40 cases, 18 deaths), and Beni (29 cases, 17 deaths) in North Kivu Province. Together, these health zones account for nearly 89.3% of all confirmed cases and 91.9% of confirmed deaths reported nationally. 

(...)

    ° Investigation of 430 confirmed deaths as of 05 July 2026, showed that 397 (92.3%) occurred in the community or before admission to a treatment facility, highlighting persistent delays in case detection, referral, isolation, and access to clinical care. 

    ° Only 33 deaths (7.7%) occurred after patients had been admitted to treatment centres or healthcare facilities.  

    As of 05 July 2026, a total of 12412 contacts were under follow-up of whom 9624 (77.5%) were successfully seen within the previous 24 hours. 

    ° Ituri Province accounted for the majority of contacts under follow-up, with 9757 contacts, including 7574 (77.6%) seen during the reporting period. 

    ° In North Kivu, 2050 out of 2655 contacts (77.2%) were followed up, while all contacts in South Kivu had completed the required 21-day monitoring period.  

    ° Although contact tracing performance has improved overall, follow-up remains below optimal levels, leaving a significant proportion of contacts unreached and increasing the likelihood of undetected infections and continued transmission.  

    ° The proportion of new confirmed cases identified among registered contacts increased steadily as the outbreak progressed, exceeding 40% by late June 2026. 

    ° Overall, 32.4% of confirmed cases were detected through contact follow-up. However, a substantial number of infections continued to occur outside known contact lists, indicating ongoing gaps in surveillance. These gaps are likely driven by insecurity in affected areas, population displacement and mobility, delayed case detection, community resistance, incomplete epidemiological investigations, and the movement of suspected cases and deceased individuals across affected areas. 

(...)

Uganda  

    ° Uganda has not reported any new cases during the past two weeks. 

    ° The latest confirmed case was reported on 21 June 2026 and involved a truck driver travelling along the Democratic Republic of the Congo–Uganda international route. 

    ° The case became symptomatic on 15 June 2026, crossed into Uganda on 19 June, and was admitted to the treatment unit for isolation on 20 June 2026.  

    ° As of 5 July 2026, the outbreak had resulted in a total of 21 cases (20 confirmed and one probable). 

    ° Three deaths, including two confirmed and one probable, had been reported, while 16 patients had recovered and been discharged from care. 

    ° Two patients remained hospitalised. 

    ° Since the onset of the outbreak, health authorities had identified 831 contacts. 

    ° All contacts placed under follow-up have now completed the required 21-day monitoring period without any new linked cases being detected.  

Figure 5.  Weekly trends of confirmed cases of Bundibugyo virus disease in Uganda by epidemiological week of report, epidemiological weeks 18 – 27, 2026 

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France

    ° The imported laboratory-confirmed case of BVD, notified to WHO by the French authorities on 24 June 2026, has recovered and was discharged from hospital on 4 July after obtaining two consecutive negative laboratory test results. 

    ° The patient, a middle-aged male physician, had recently returned from a five-week deployment in Ituri Province, Democratic Republic of the Congo, where he provided clinical care to patients with BVD. 

    ° Upon arrival at Charles de Gaulle Airport in Paris on 23 June 2026, he voluntarily reported experiencing symptoms to airport health officials, prompting his immediate isolation and transfer to a designated high-containment treatment facility.  

    ° Contact tracing identified five passengers who had travelled on the same flight as the patient. These individuals were placed under quarantine in France and continue to be monitored. 

    ° None had become symptomatic as of 5 July 2026.   

Risk Assessment  

    ° The overall public health risk in the Democratic Republic of the Congo remains very high, driven by sustained and widespread transmission that continues to outpace the current response capacity. 

    ° The outbreak remains concentrated in the Bunia–Rwampara–Mongbwalu corridor, although transmission persists across multiple affected health zones. 

    ° The persistently elevated case fatality ratio in North Kivu suggests ongoing delays in case detection, diagnosis, and access to clinical care, while treatment capacity in Ituri Province is becoming increasingly strained. 

    ° Although contact follow-up and alert investigation have improved, performance remains insufficient to rapidly interrupt transmission.   

    ° In addition, reports of threatened strike action among frontline response workers have emerged in affected areas, reportedly linked to delays in payment and other operational constraints. 

    ° If not rapidly addressed by health authorities and partners, these challenges could further disrupt critical response activities and undermine ongoing outbreak control efforts.  

    ° Uganda continues to face a high risk of importation due to frequent population movement from eastern Democratic Republic of the Congo, including commercial trucking routes and possible informal cross-border crossings linked to border closures.  

    ° The imported case reported in France further demonstrates the continued risk of international spread and highlights the need to sustain enhanced surveillance, strengthen traveller awareness, and reinforce cross-border coordination and preparedness measures.

(...)

Source: 

Link: https://www.afro.who.int/countries/democratic-republic-of-congo/publication/ebola-bundibugyo-virus-disease-outbreak-1

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# Influenza at #human - #animal #interface - Summary and #risk #assessment, from 13 June to 7 July 2026 (WHO): 1 new case of #H5 virus, 2 of #H9N2 and one of #H3N2v

 

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:

1. What is the current global public health risk of additional human cases of infection with avian influenza A(H5) viruses?    
• Most human infections so far have been reported in people exposed to A(H5) viruses, for example, through contact with infected poultry or contaminated environments, including live poultry markets, and occasionally infected mammals and contaminated environments. 
• As long as the viruses continue to be detected in animals and related environments humans are exposed to, further human cases associated with such exposures are expected but remain unusual. 
• The impact for public health if additional sporadic cases are detected is minimal. 
• The current overall global public health risk is low.  
2. What is the likelihood of sustained human-to-human transmission of avian influenza A(H5) viruses related to the events above?    
• No sustained human-to-human transmission  has  been identified associated with the recent reported human infections with avian influenza A(H5) viruses.
•  There has been no reported human-to-human transmission of A(H5N1) viruses since 2007, although there may be gaps in investigations.
•  In 2007 and the years prior, small clusters of A(H5) virus infections in humans were reported, including some involving health care workers, where limited human-to-human transmission could not be excluded; however, sustained human-to-human transmission was not reported.
•  Current evidence suggests that influenza A(H5) viruses related to these events did not acquire the ability to efficiently transmit between people.    
3. What is the likelihood of international spread of avian influenza A(H5) viruses by travellers?    
• Should infected individuals from affected areas travel internationally, their infection may be detected in another country during travel or after arrival. 
• If this were to occur, further communitylevel spread is considered unlikely as current evidence suggests these viruses have not acquired the ability to transmit easily among humans.    

A(H9N2), China  

    ° 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. 

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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):  

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(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:    

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.
•  The impact to public health if additional sporadic cases are detected is minimal. 
• The overall risk of additional sporadic 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.   
3. What is the likelihood of international spread of swine influenza 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 that these viruses have not acquired the ability to transmit easily among humans.   

Overall risk management recommendations: 

    ° Surveillance and investigations 

        • Due to the constantly evolving nature of influenza viruses, WHO continues to stress the importance of global strategic surveillance in animals and humans to detect virologic, epidemiologic and clinical changes associated with circulating influenza viruses that may affect human (or animal) health. 

            Continued vigilance is needed within affected and neighbouring areas to detect infections in animals and humans. 

            Close collaboration with the animal health and environment sectors is essential to understand the extent of the risk of human exposure and to prevent and control the spread of animal influenza. 

            WHO has published guidance on surveillance for human infections with avian influenza A(H5) viruses. 

        • As the extent of influenza virus circulation in animals is not clear, epidemiologic and virologic surveillance and the follow-up of suspected human cases should continue systematically. 

            Guidance on investigation of non-seasonal influenza and other emerging acute respiratory diseases has been published on the WHO website. 

        • Countries should: 

            - increase avian influenza surveillance in domestic and wild birds, 

            - enhance surveillance for early detection in cattle populations in countries where HPAI is known to be circulating, include HPAI as a differential diagnosis in non-avian species, including cattle and other livestock populations, with high risk of exposure to HPAI viruses; 

            - monitor and investigate cases in non-avian species, including livestock, 

            - report cases of HPAI in all animal species, including unusual hosts, to WOAH and other international organizations, 

            - share genetic sequences of avian influenza viruses in publicly available databases, 

            - implement preventive and early response measures to break the HPAI transmission cycle among animals through movement restrictions of infected livestock holdings and strict biosecurity measures in all holdings, 

            - employ good production and hygiene practices when handing animal products, and protect persons in contact with suspected/infected animals.{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: 

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

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