A cross-sectional #study of avian #influenza virus in #poultry #markets of #Guangdong #China, 2025

 

Abstract

Background: 

Guangdong, China is a critical epicenter for avian influenza virus (AIV) emergence, where H5N1 and highly pathogenic H7N9 were first identified. Monitoring AIV genotype distribution and genetic diversity in this region is essential for providing early warnings and mitigating the risk of human infections.

Methods: 

In May 2025, a cross-sectional study was conducted across 4 representative cities in Guangdong. We collected 500 environmental swabs and 45 wastewater samples from 23 live poultry markets (LPMs). Samples were screened for influenza A virus (IAV) and subtyped for H5, H7, and H9. Next generation sequencing (NGS) and phylogenetic analyses were employed to characterize viral diversity and zoonotic potential.

Results: 

AIV was detected in 49.2% (246/500) of environmental samples. H9 was the dominant subtype (38.2%), followed by H5 (3.2%) and H7 (0.8%); 2.4% of positive samples showed multi-subtype co-occurrence. “Non-restricted zone” markets (80.0%) and “waste storage areas” (68.4%) were identified as primary contamination hotspots. Phylogenetic analysis revealed that H5 and H9 viruses are accumulating mutations linked to enhanced human-type receptor affinity. Notably, H5 and H6 sequences exhibited long internal branches and clustered with isolates from other Asian countries rather than domestic strains, highlighting a significant gap in current domestic molecular surveillance and a lack of continuous evolutionary data for these genotypes.

Conclusions: 

Widespread AIV contamination persists in Guangdong LPMs, dominated by H9 with low-level circulation of highly pathogenic subtypes. The identified surveillance gaps for H5/H6 and the presence of multi-subtype environments underscore the urgent need for strengthened, integrated molecular monitoring and stricter market regulation to mitigate public health risks.

Source: 

Link: https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2026.1914072/full

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#Bundibugyo virus #glycoprotein seroreactivity following recombinant VSV–Zaire #Ebola virus glycoprotein #vaccination in outbreak-affected populations of #DRC: a longitudinal cohort study

 

Summary

Background

There are currently no licensed vaccines for disease caused by Bundibugyo virus (BDBV). The recombinant vesicular stomatitis virus–Zaire Ebola virus glycoprotein (rVSVΔG-ZEBOV-GP) vaccine has been widely deployed during Ebola virus disease outbreaks caused by Ebola virus (EBOV). Human studies have shown cross-reactive BDBV antibody responses following licensed Ebola virus disease vaccine administration, but the durability and longitudinal kinetics of these responses in populations vaccinated during outbreaks remain unknown. We aimed to evaluate BDBV glycoprotein seroreactivity following rVSVΔG-ZEBOV-GP vaccination in two longitudinal cohorts from regions of the Democratic Republic of the Congo affected by Ebola virus disease outbreaks.

Methods

This longitudinal cohort study was done in Mbandaka, Equateur Province, and Beni, North Kivu Province. Individuals aged 1 year and older who received the rVSVΔG-ZEBOV-GP vaccine under the WHO ring-vaccination protocol were eligible for enrolment. These populations were defined as: people with confirmed Ebola virus disease, contacts of people with Ebola virus disease or contacts-of-contacts, and health-care or front-line workers in areas affected by Ebola virus disease. Participants were enrolled from June 2 to July 3, 2018, in Mbandaka and from Aug 15 to 29, 2018, in Beni. Serum samples were collected from vaccine recipients and antibody reactivity was assessed using a multiplex pan-filovirus immunoassay. Both cohorts were followed up over 5 years, with seven data collection periods in each province. We evaluated longitudinal trends in EBOV and BDBV glycoprotein seroreactivity using a pan-filovirus multiplex immunoassay across follow-up visits.

Findings

We analysed 5849 serum samples from 1081 participants. 715 (66%) of 1081 participants were male and 366 (34%) were female. BDBV glycoprotein seroreactivity differed substantially between study sites. At baseline, 16 (3%) of 482 participants in Mbandaka and 62 (10%) of 599 in Beni were seroreactive to BDBV glycoprotein. In Mbandaka, BDBV glycoprotein antibody reactivity remained stable through to 6 months after initial vaccination before increasing from a mean median fluorescent intensity (MFI) of 1238 (SD 1599) at 2·5 years, with 16 (5%) of 355 seroreactive, to 4845 (5881) at 3·5 years and 116 (35%) of 329 seroreactive (p<0·0001), followed by waning at later visits. In Beni, BDBV glycoprotein antibody reactivity increased rapidly after the initial vaccination, with seroreactivity peaking at 21 days to a mean MFI of 6678 (SD 6997) with 283 (52%) of 541 participants seroreactive and at 6 months to an MFI of 6852 (6560) with 270 (54%) of 501 seroreactive. Although antibody levels decreased after 6 months, EBOV glycoprotein and BDBV glycoprotein antibody reactivity remained above baseline through to 5 years after vaccination.

Interpretation

The differing patterns of BDBV glycoprotein seroreactivity observed between Beni and Mbandaka warrant further investigation into the epidemiological and immunological factors associated with this seroreactivity, including the epidemiological significance of baseline seroreactivity observed before vaccination. To our knowledge, these findings provide the first longitudinal human data describing BDBV glycoprotein seroreactivity following licensed Ebola virus disease vaccination in populations living in regions now affected by the current outbreak of disease caused by BDBV. They add to the growing body of human evidence describing cross-reactive antibody responses following licensed Ebola virus disease vaccination and support rigorous clinical evaluation of rVSVΔG-ZEBOV-GP during the ongoing outbreak while BDBV-specific vaccines continue to be developed.

Funding

The US Food and Drug Administration, the Gates Foundation, and the US Defense Advanced Research Projects Agency.

Source: 

Link: https://www.sciencedirect.com/science/article/pii/S0140673626016089?dgcid=rss_sd_all

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Highly persistent #antibody levels but limited population #immunity in #gannets after #HPAI #outbreak

 

Abstract

The recent large-scale circulation of High Pathogenicity Avian Influenza (HP AI) viruses H5Nx of clade 2.3.4.4b has been responsible for massive die-offs in wild species, notably in long-lived seabirds, with unknown implications for the immunity of surviving individuals. In the North Atlantic, northern gannet colonies were heavily affected in 2022, with more than 40% mortality observed among breeding adults and some surviving individuals developing dark irises. Using samples collected in 2023 and 2024 on Rouzic colony (France), we report persistent individual anti-AI antibody levels and seroneutralisation titres, with most of the immune individuals showing dark irises. A modelling approach further stressed the importance of long-lasting immunity in such species by showing that the proportion of individuals which kept their immunity between years strongly limited decreases in population size in case of repeated outbreaks. Overall, our results highlight the existence and importance of long-lasting immunity in long-lived species for population persistence.

Competing Interest Statement

The authors have declared no competing interest.

Funder Information Declared

CNRS Ecology Evolution SEE-Life program for long term monitoring

Ceva Wildlife Research Fund, CWR1

Agence Nationale de la Recherche, https://ror.org/00rbzpz17, ECOPATHS (ANR-21-CE35-0016), WILDFLU (ANR-25-CE35-0691)

Ailes Marines

Observatoire de Recherche Montpelliérain de l'Environnement OREME, https://ror.org/00cesps27, SO ECOPOP

Source: 

Link: https://www.biorxiv.org/content/10.64898/2026.08.25.745523v1

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Person died from a #WNV #infection acquired in the #Netherlands (RIVM, August 26 '26)

 

    In the province of Utrecht, someone has died from West Nile fever. 

    The person contracted the West Nile virus in the Netherlands and died in a hospital. Due to privacy and out of respect for the relatives, RIVM will not make any further statements about this person. 

    So far in 2026, there have been three cases of West Nile virus infections reported that were probably contracted in the Netherlands. 

    It is still very unlikely for people to contract West Nile fever in the Netherlands.

West Nile fever

    The West Nile virus occurs in birds. The common house mosquito can contract the virus when feeding on the blood of an infected bird. An infected mosquito can then pass the virus on to other birds, to mammals such as horses, and to humans. Humans and horses can fall ill with the West Nile virus, but they cannot pass the virus on to others. The disease caused by the West Nile virus is called West Nile fever.

    About 80% of people who contract the West Nile virus do not show any symptoms. Around 19% experience flu-like symptoms, and 1 per cent may develop neurological symptoms. People over 50 and people with weakened immune systems due to illness or medication have a higher risk of becoming very ill from West Nile fever. A small proportion of people who have a severe form of West Nile fever may die.

Alert on West Nile virus

    Experts from various organisations are closely keeping an eye on how often West Nile virus occurs in the Netherlands among humans, horses, birds, and mosquitoes. 

    So far this year, West Nile virus has been found in the provinces of Utrecht, North Brabant, and South Holland. It is possible that the virus is also present in other parts of the Netherlands. That is why RIVM has asked doctors across the country to be alert if they see people with symptoms that match West Nile fever.

What can you do to prevent West Nile fever?

    The West Nile virus is spread by common house mosquitoes that feed on the blood of an infected bird. Mosquitoes are mostly active at dusk. 

    To avoid mosquito bites as much as possible, you can, for example:

        ° wear clothing that covers the skin (long sleeves, long trousers)

        ° keep mosquitoes out (insect screens for windows/doors)

        ° use mosquito repellents on exposed skin

        ° sleep under a mosquito net

Source: 

Link: https://www.rivm.nl/en/news/person-died-from-west-nile-virus-infection-acquired-in-netherlands

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Evaluating the #impact of #antiviral post-exposure #prophylaxis for health-care workers during #orthoebolavirus outbreaks: a modelling study

 

Summary

Background

Orthoebolavirus outbreaks place health-care workers (HCWs) at substantial risk, and HCW illness or death can weaken response capacity. The 2026 Bundibugyo virus outbreak in DR Congo highlights the need for deployable countermeasures when species-specific vaccines are unavailable. With candidate antivirals under evaluation, we aimed to estimate the impact of HCW-targeted antiviral post-exposure prophylaxis (PEP) across different readiness, disruption, and allocation scenarios.

Methods

We adapted a previously published stochastic branching-process model of orthoebolavirus transmission, representing health care, community, and funeral transmission; time-varying non-pharmaceutical interventions; and HCW-targeted PEP. The model was calibrated to two historical outbreaks using sequential approximate Bayesian computation: the 2013–16 west Africa epidemic, to define a high-burden, reasonable worst-case scenario archetype (west Africa-like archetype); and the 2018–20 North Kivu and Ituri outbreak in eastern DR Congo, to define an archetype with longer transmission under conflict-related response disruption (DR Congo-like archetype). The primary outcome was HCW deaths averted. For both archetypes, we simulated three antiviral deployment readiness scenarios (scenario 1: 100% coverage on day 0; scenario 2: scaled up to 80% coverage over 180 days; and scenario 3: scaled up to 50% coverage over 1 year) and compared their impact on HCW deaths with a scenario of no antiviral. For the DR Congo-like archetype only, we simulated four disruption scenarios: no antiviral PEP, ideal delivery (100% coverage and no dosing delay), delayed dosing with coverage preserved, and delayed dosing with delayed coverage. As a secondary outcome, we assessed number of PEP doses required per HCW death averted under different allocation scenarios.

Findings

At baseline (no antiviral PEP), cumulative HCW deaths reached a median of 553 (IQR 208–983) in the west Africa-like archetype by week 60, compared with 61 (19–125) in the DR Congo-like archetype by week 80. Assuming 80% efficacy and 80% coverage with antiviral PEP in the same timeframe in a central analysis, cumulative HCW deaths fell to 200 (68–349; equivalent reduction of 64% [63–66] relative to baseline) in the west Africa-like archetype and 22 (10–44; equivalent reduction of 64% [60–68]) in the DR Congo-like archetype. Under different scenarios of deployment readiness at 80% antiviral efficacy, the median reduction in HCW deaths compared with no PEP was 80% (95% CrI 79–81) in the west Africa-like archetype and 80% (76–84) in the DR Congo-like archetype for scenario 1; 60% (57–62) and 52% (41–58), respectively, for scenario 2; and 19% (16–22) and 22% (7–29), respectively, for scenario 3. In the DR Congo-like operational disruption analyses, an ideal scenario (PEP delivered at 100% coverage without a delay after exposure) averted 83% (79–87) of HCW deaths compared with no antiviral; maintaining 100% coverage but introducing delayed dosing (1–5 days post-exposure) reduced this finding to 50% (40–55) compared with no antiviral. Delayed coverage and dosing resulted in only 35% (25–47) of the ideal scenario impact. At 80% antiviral efficacy with same-day dosing, targeted allocation of recognised high-risk exposures (such as personal protective equipment breaches or direct body-fluid contact) required 44 doses (95% Crl 43–44) per HCW death averted versus 109 doses (85–161) with broad allocation.

Interpretation

HCW-targeted antiviral PEP could substantially reduce HCW deaths during orthoebolavirus outbreaks if efficacious antivirals can be delivered rapidly and high operational coverage is maintained. Comparisons of antiviral use cases and alternative response investments are needed to determine how resources can best support outbreak response.

Funding

Gilead Sciences, UK National Institute for Health and Care Research, Oxford Martin School, Miller Institute, EU Global Health EDCTP3, and Coalition for Epidemic Preparedness Innovations.

Translations

For the French and Swahili translations of the abstract see Supplementary Materials section.

Source: 

Link: https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(26)00437-8/fulltext?rss=yes

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Predicting the #Risk of Avian #Influenza #Zoonosis using Viral #Genome Sequencing Data

 

Abstract

Avian Influenza viruses (AIVs) infect a broad host range despite having a natural reservoir in wild aquatic birds. Whilst most strains stay within their host species, some break the species barrier through genetic adaptations. We are most concerned about zoonotic cases, where a human becomes infected. Despite these events being rare, they are associated with high mortality and introduce the risk of onward human-to-human transmission of AIV. As a novel pathogen within the human population, this could have pandemic potential. Using genetic composition features for 8 AIV proteins drawn from viral sequence data, we employ machine-learning algorithms to classify AIV cases as zoonotic or not. These genetic features encode host 'signatures' which can indicate zoonosis and include frequency measures such as dipeptide composition and amino acid physiochemical properties. We consistently find XGBoost to outperform all other algorithms. We optimise parameters for ten classification models: one for each of the 8 proteins and two combined models. Following this, we show that a multi-model approach gives the best performing prediction for AIV zoonosis. We have identified all 8 proteins as having a role in predicting zoonotic transmission. Of particular importance is the PB2 and HA proteins, with specific amino acid physiochemical properties such as charge, secondary structure and hydrophobicity amongst the most indicative features in our combined models. Our alignment-free computational study can identify AIV cases still within avian hosts which are genetically closest to zoonotic AIV cases, thereby identifying the cases most likely to cross the species barrier. In a resource limited environment, our model could be used to quickly identify high priority cases for further investigation.

Competing Interest Statement

The authors have declared no competing interest.

Source: 

Link: https://www.biorxiv.org/content/10.64898/2026.08.21.746166v1

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#Bundibugyo Virus Disease #Outbreak, #DRC - Situation #Report No. 15, Data as of 23 August '26 (WHO, summary): 5,584 cases & 2,680 deaths in DRC

 

{Summary}

{Click on Image to Enlarge}

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Event description

Democratic Republic of the Congo

    More than three months into the response, the Bundibugyo virus disease  (BVD) outbreak in the Democratic Republic of the Congo remains characterized by  sustained transmission, high mortality and continued geographic expansion. 

    The epidemiological picture is increasingly heterogeneous, with  persistent transmission in established hotspots in Ituri, intensifying transmission  in parts of Nord-Kivu and Haut-Uélé, and continued geographic expansion  through the emergence of cases in previously unaffected health zones. 

    Since External Situation Report #14, a total of 563 new confirmed cases and 302 confirmed deaths have been reported, bringing the cumulative total to  5 584 confirmed cases, including 2 680 deaths. 

    The number of affected health zones has increased from 55 to 57 across  six provinces, with Viadana in Bas-Uélé and Mutwanga in Nord-Kivu being  the most recently affected health zones.

Figure 1. Daily growth trend in confirmed Bundibugyo virus disease cases in the  Democratic Republic of the Congo, by date of report, data as of 23 August 2026

{Click on Image to Enlarge}

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(...)

    During the most recent 21 days (3 – 23 August 2026), 1 782 confirmed  cases were reported nationally. Compared with the preceding 21-day period (13  July – 2 August 2026), reported cases declined slightly by 57 (−3.1%). Given  the small magnitude of this decline and the potential influence of reporting  delays and retrospective data reconciliation, this should be interpreted cautiously  because it does not yet provide clear evidence of declining transmission. 

    The national trend also masks a continued redistribution of reported incidence, with cases declining by 13.4% in Ituri but increasing by 32.5% in  Nord-Kivu and 122.2% in Haut-Uélé. Consequently, Ituri’s contribution to newly  reported cases declined from 84.0% to 75.1%, while the contribution of Nord-Kivu  increased from 12.9% to 17.6% and that of Haut-Uélé more than doubled  from 2.9% to 6.7%.

    During the same period, 973 confirmed deaths were reported nationally, a  slight decrease of 16 deaths (−1.6%) compared with the preceding 21 days. A  marked geographic redistribution of mortality was nevertheless observed. While  deaths declined by 8.8% in Ituri, they increased by 15.1% in Nord-Kivu and  85.2% in Haut-Uélé. Consequently, Ituri’s contribution to newly reported deaths  declined from approximately 78.3% to 72.6%, while Nord-Kivu’s contribution  increased from 18.7% to 21.9% and Haut-Uélé’s nearly doubled from 2.7% to  5.1%. Transmission therefore remains dominated by Ituri but is increasingly  distributed across other active foci, indicating that the outbreak is becoming progressively less concentrated in its original epicentre.

(...)

    At health-zone level, the changing geographic pattern is more pronounced, with substantial variation in reported incidence across established  and emerging transmission foci. In Ituri, reported cases declined markedly in  Mongbwalu from 223 to 50 (−173; −77.6%), Lita from 96 to 56 (−40; −41.7%),  and Nizi from 292 to 210 (−82; −28.1%), while Bunia declined slightly from 411  to 384 (−27; −6.6%) and Rwampara from 271 to 258 (−13; −4.8%). In contrast,  cases increased in Bambu from 33 to 63 (+30; +90.9%), Mangala from  55 to 92 (+37; +67.3%), and Nia-Nia from 69 to 89 (+20; +29.0%).

    Outside Ituri, reported cases increased substantially in Katwa from 115  to 162 (+47; +40.9%) and Beni from 34 to 53 (+19; +55.9%) in Nord-Kivu, and  in Isiro from 19 to 49 (+30; +157.9%) and Wamba from 9 to 47 (+38; +422.2%)  in HautUélé. These patterns indicate that the declining contribution of  Ituri is being driven primarily by substantial reductions in several established  hotspots, particularly Mongbwalu and Nizi, rather than by a uniform decline across  the province.

    At the same time, increasing incidence in selected health zones within  Ituri and the continued growth of foci in NordKivu and Haut-Uélé indicate an  increasingly heterogeneous and geographically dispersed transmission pattern. 

    Reported deaths at health-zone level show a broadly similar geographic redistribution  but also highlight important discordance with trends  in reported cases. In Nord-Kivu, deaths in Katwa increased from 71 to 112 (+41;  +57.7%), alongside the increase in reported cases, while deaths in Beni increased  from 29 to 35 (+6; +20.7%). In Haut-Uélé, deaths increased in Isiro  from 11 to 18 (+7; +63.6%) and Wamba from two to 17 (+15; +750.0%),  consistent with increasing reported incidence in both health zones. In Ituri, deaths  declined substantially alongside cases in several established hotspots,  including Mongbwalu from 82 to 20 (−62; −75.6%), Nizi from 146 to 58 (−88;  −60.3%), Lita from 62 to 25 (−37; −59.7%), and Rwampara from 173 to 72  (−101; −58.4%).

    However, the pattern was not consistent across all health zones. Most  notably, Bunia recorded a 29.8% increase in deaths, from 104 to 135 (+31),  despite a 6.6% decline in reported cases. Deaths also increased in Bambu from 5  to 13 (+8; +160.0%), alongside the increase in cases, while Mangala showed  little change in deaths, from 37 to 40 (+3; +8.1%), despite a 67.3% increase in  reported cases. These discordant trends warrant cautious interpretation of  apparent declines in reported incidence. Where fatal infections are more  consistently ascertained than non-fatal cases, a reduction in reported cases  without a corresponding reduction in deaths may reflect differences in case  ascertainment,  reporting delays, or the lag between case detection and death  rather than a true decline in transmission. Interpretation of recent health-zone  mortality patterns in Ituri is further limited by 250 cumulative deaths that had not  yet been assigned to a health zone as of 23 August 2026.

    Ten previously affected health zones reported no confirmed cases  during the most recent 21 days (3 – 23 August 2026): Adja, Boga,  Kambala and Mahagi in Ituri; Goma and Lubero in Nord-Kivu; Rungu in Haut-Uélé;  Lubunga and WanieRukula in Tshopo; and Miti-Murhesa in Sud-Kivu. During  the same period, six health zones were reported as affected for the first  time: Mutwanga in Nord-Kivu; Gombari in Haut-Uélé; Bafwasende and Tshopo in  Tshopo; and Buta and Viadana in Bas-Uélé.

(...)

    Mortality remains high, with 302 confirmed deaths reported during the last seven days, including 171 (56.6%) in the community and 131 (43.4%) in  BVD treatment facilities. The persistently high proportion of community deaths  (defined as both deaths at home and at non-BVD health facilities) highlights  continued challenges with early detection, referral and timely access to treatment,  while mortality in BVD treatment facilities may reflect late  presentation, quality of care and patient vulnerabilities, including age, malnutrition  and comorbidities; further analysis to understand the risk factors 

is underway.

    Among 4807 confirmed cases and 1820 deaths with available age and  sex information, adults aged 20 – 59 years continue to account for the majority of confirmed cases, representing about two-thirds of cases overall and  58% in the most recent epidemiological week. However, mortality remains disproportionately concentrated among young children.

    In week 34, children aged <5 years accounted for 17% of reported cases but 29% of deaths, continuing the increased contribution of this age group to  mortality observed in recent weeks. Overall, the sex distribution of cases is  relatively balanced, although females account for slightly more cases, while  deaths are broadly similar between males and females. These findings continue to  indicate a high burden of transmission among working-age adults alongside  

disproportionate mortality among young children.

(...)

    The current BVD outbreak continues to follow a markedly different  trajectory from previous major Ebola disease outbreaks. 

    

    During the first 102 days of reporting, the 7-day moving average of  daily cases remained substantially higher than levels observed during  comparable periods of the 2014 – 2016 West Africa and 2018 – 2020 Democratic  Republic of the Congo outbreaks, reaching more than 90 confirmed cases per day  at its recent peak. With 5514 confirmed cases, including 2642 deaths, reported as  of 22 August 2026, this is the largest BVD outbreak ever recorded and the  secondlargest Ebola disease outbreak on record. Notably, the number of deaths  has already surpassed the 2287 deaths reported during the entire 2018–2020  outbreak in eastern Democratic Republic of the Congo.

Figure 7. Comparison of three major Ebola disease outbreak trajectories during  the first 102 days of reporting using seven-day moving averages of the daily number of confirmed cases reported.

{Click on Image to Enlarge}

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    The security situation in eastern Democratic Republic of the Congo  remains volatile and continues to present operational challenges for the  outbreak response. Recent insecurity has included armed clashes, attacks  affecting civilians and health services, population displacement and constraints on  humanitarian access in parts of the affected area. In addition, the AFC/M23 group  recently announced restrictions on movement to and from Ebola-affected government-controlled areas as a measure to reduce the risk of disease  importation into areas under their control.

    While the operational implications of these measures are still being assessed, continued insecurity, displacement and  restrictions on population  movement underscore the complexity of maintaining coordinated outbreak  response activities across areas with different security and administrative  contexts.

Uganda and France

    Uganda has now recorded 38 consecutive days without a new confirmed BVD case  since the last patient was discharged on 16 July 2026. All  identified contacts completed follow-up, with no further cases detected. The  continued high level of transmission in neighbouring eastern Democratic Republic  of the Congo, however, means that the risk of cross-border reintroduction  remains. France has reported no new confirmed BVD cases for 50 consecutive  days since the imported case was discharged on 4 July 2026. The outbreak is thus  considered over by WHO’s norm of 42 days without any cases. 

Risk Assessment

    According to WHO’s latest Rapid Risk Assessment as of 20 August 2026, the risk of further spread remains very high within the Democratic  Republic of the Congo and high for neighbouring countries sharing land  borders with the country. 

    The assessment reflects sustained transmission, continued geographic expansion, high mortality, population mobility, insecurity and persistent  response challenges. The risk is considered low elsewhere in Africa and globally.  The second IHR Emergency Committee, convened on 18 August 2026, also  reviewed the evolving situation and emphasized that the outbreak remains far  from controlled, and continues to constitute a Public Health Emergency of  International Concern.

(...)

Situation interpretation

    The BVD outbreak continues to evolve into a more complex and geographically dispersed phase , in which modest reductions in some  established hotspots are being offset by intensification and emergence of  transmission elsewhere. 

    The simultaneous persistence of high mortality, community deaths, health-worker infections, uneven contact followup, localized treatment  constraints and community resistance indicates that expansion of response  capacity alone is not yet translating consistently into transmission control. The  priority must remain faster, locally differentiated and community-centred  operations, concentrating resources on active and emerging transmission foci,  closing critical surveillance, IPC and treatment gaps, and ensuring rapid access to  affected communities. At the same time, sustained regional preparedness and  cross-border coordination are essential to contain further geographic spread.

Source: 

Link: https://www.afro.who.int/health-topics/ebola-disease

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Impaired #Neuraminidase and Polymerase Activities Correspond With Limited Aerosol Infectivity of #B3.13 and #D1.1 #H5N1 Lineages in #Human Respiratory Cultures

 

Abstract

The ongoing panzootic of clade 2.3.4.4b highly pathogenic avian influenza (HPAI) H5N1 viruses has reached a critical point, marked by unprecedented mammalian spillover and sustained outbreaks in U.S. dairy cattle. While these viruses remain highly lethal in traditional ferret models, human infections-primarily linked to the B3.13 and D1.1 lineages-have been notably mild, typically presenting as conjunctivitis with minimal respiratory involvement. In this study, we address this disconnect by evaluating the infectivity of recent H5N1 isolates using a physiologically relevant air-liquid interface (ALI) culture system that incorporates an aerosol settling chamber. We demonstrate that while direct liquid inoculation leads to efficient replication, aerosolized H5N1 strains exhibit a significant defect in their ability to infect human respiratory epithelium. In contrast, a prototypic H5N1 virus remains highly pathogenic and lethal in ferrets regardless of the inoculation route, showing systemic dissemination to the brain and other organs. Our findings identify two primary viral determinants driving this respiratory restriction: reduced neuraminidase (NA) enzymatic activity and impaired polymerase activity. Collectively, these results suggest that commonly used mammalian models may overstate current human pandemic risk. This work highlights the critical need for alternative risk-assessment platforms to identify the specific genetic shifts required for these viruses to overcome existing barriers to human adaptation.

Source: 

Link: https://www.biorxiv.org/content/10.64898/2026.08.18.745466v1

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2nd meeting of #IHR EC on the #epidemic of #Ebola Bundibugyo virus disease in #DRC – Temporary #recommendations (WHO, August 25 '26)

 

On 18 August 2026, the Emergency Committee regarding the epidemic of Ebola Bundibugyo virus disease in the Democratic Republic of the Congo met for the second time to reassess the situation, in line with International Health Regulations (2005).

    The Director-General, considering the advice of the Committee, issued the following updated temporary recommendations for States Parties. The recommendations for the Democratic Republic of the Congo provide more detailed guidance on surveillance, case detection and investigation, infection prevention and control, clinical care, risk communication and community engagement than those previously issued, and include a new section on social measures, mass gatherings and domestic mobility.

Temporary recommendations

    These temporary recommendations are issued by the Director-General of WHO for subsets of States Parties according to the public health risk associated with the Bundibugyo virus disease (BVD) epidemic they face.

    All current WHO interim technical guidance can be accessed on this page of the WHO website. WHO evidence-based guidance has been and will continue to be updated in line with the evolving situation, updated scientific evidence, and WHO risk assessment.

    The implementation of these temporary recommendations by States Parties shall be with full respect for the dignity, human rights and fundamental freedoms of persons, in accordance with the principles set out in Article 3 of the IHR.

    Note: The text in backets next to each temporary recommendation indicates the status with respect to the set of temporary recommendations issued on 22 May 2026.

For States Parties with community transmission of Bundibugyo virus (Democratic Republic of the Congo) [Modified]

    As of 14 August 2026, the WHO Secretariat assessed the risk for these States Parties as “Very high”. 

    At the time these temporary recommendations are issued, only the Democratic Republic of the Congo falls in this group. [Modified]

    The epidemic is caused by BDBV, a virus belonging to the Orthoebolavirus genus. Unlike Ebola virus causing Ebola virus disease, although clinical trials are ongoing, there are no currently approved therapeutics or vaccines against BDBV. Should effective BVD-specific vaccines and therapeutics become available, based on experience from the 2013–2016 Ebola virus disease epidemic in West Africa, they are likely to have a complimentary effect on transmission and mortality, but they will not be a substitute for effective, core public health interventions. [Modified]

Coordination and high-level engagement

    ° Declare, or maintain, the BDBV epidemic a health emergency, at national or sub-national level, in accordance with domestic laws, and as appropriate. [Extended with rephrasing]

    ° Scale-up national disaster or health emergency management mechanisms, including an activated emergency operation centre, under the authority of the Head of State or relevant government authority, to coordinate response and preparedness activities across Government sectors, administrative levels, and partners. [Modified]

    ° Establish, and maintain up to date, a single national plan (e.g., action plan, response plan) to guide response efforts, across Government sectors and partners, reflecting the role and responsibilities of Government entities and all partners involved in the response, to ensure efficient and effective implementation and monitoring of comprehensive BVD control measures. 

    ° These measures must include: [New, resulting from splitting of temporary recommendation previously under “Coordination and high-level engagement]

        § community protection, including risk communication and community engagement;

        § enhanced surveillance and case identification;

        § contact tracing;

        § laboratory diagnostic testing;

        § infection prevention and control (IPC);

        § case management;

        § safe and dignified burials;

        § continuity of essential health services;

        § logistics; and

        § health workforce management and protection, including timely payment of salaries and, as appropriate, hazard pay.

[Modified]

    ° Negotiate, as applicable, and establish security corridors, including cross-border, to allow responders to safely reach affected communities, including in IDP camps and other humanitarian settings, as well as to allow communities to seek appropriate health care. [Extended]

    ° Establish immigration procedures to allow timely and fluid influx and outflux of international responders both, to cater for identified response needs and to allow for their rotation. [New]

    ° Establish customs clearance procedures, as well as other administrative and regulatory ones, to expedite the importation of supplies needed to sustain the response [New]

    § Notify WHO, through the relevant WHO IHR Contact Point in the WHO Regional Office, of the detection of suspected, probable and confirmed BVD cases on a daily basis, as per WHO case definitions available here. [Extended]

Risk communication and community engagement

    ° Integrate, at the lowest level designated to coordinate response activities, the implementation of risk communication and community engagement interventions (community networks, workforce capacity, community intelligence and feedback systems, and accountability processes). [New]

    ° Scale up trust-building and community engagement through trusted communication channels and local actors, including local leaders, religious leaders, traditional healers and survivors, to support community participation in fostering the acceptance of public health measures, including early detection, case referral, contact tracing, safe and dignified burial practices, and adoption of protective behaviours. [Extended with rephrasing, including merging of one temporary recommendation previously under “Risk communication and community engagement”]

    ° Strengthen community awareness, engagement and participation, to establish and strengthen trust, by identifying and addressing cultural norms and beliefs that may serve as barriers to their full participation in the response; and by integrating interventions and community feedback, within the wider response, to address the needs of the population, particularly in contexts of the protracted humanitarian crisis in the Eastern provinces of the Democratic Republic of Congo. [Extended]

    ° Activate and train local networks, including community health workers, Red Cross volunteers, and other trusted community actors to promote protective behaviours; facilitate early detection and referral of suspected BVD cases; support contact tracing activities; and collect and relay community feedback to enhance the acceptance of public health measures. [Extended with rephrasing]

    ° Enable adherence to movement restrictions, associated with the application of control measures, by providing food, water, communication, financial and psychosocial support. [Extended]

Surveillance and laboratory

    ° Establish and maintain up to date a register of signals consistent with BVD (“alerts”, e.g., including for clusters of unexplained illness or deaths), including status of their investigation. [Extended with rephrasing, previously under “Coordination and high-level engagement”]

    ° Establish and maintain an up to date a line list of suspected cases, probable cases, and confirmed BVD cases, including a consolidated one at the national level, while building chains of transmission. [Extended, previously under “Coordination and high-level engagement”]

    ° Establish and maintain up to date the list of contacts of all confirmed and probable BVD cases, monitor, on a daily basis, each contact for 21 days after the date of last known exposure, and record their status. Both the evolution of the epidemic and resources available may require reiterative risk-based prioritization of contacts requiring identification and monitoring. [Extended with rephrasing, including merging of two temporary recommendations previously under “Coordination and high-level engagement” and “Surveillance and laboratory”]

    ° Establish a mechanism to monitor the evolution of indicators related to the performance of contact tracing activities. [Extended]

    ° Strengthen surveillance and laboratory capacity, decentralized across sub-national administrative levels (e.g., provinces and districts/health zones) with community BDV transmission, as well as in their neighbouring sub-national administrative levels, through: [Extended with rephrasing]

    ° dedicated surveillance and response teams within each health zone and in neighbouring health zones determined to be at high-risk for the introduction of BVD; [Extended]

    ° active case finding and enhanced community surveillance; [Modified]

    ° the investigation of “alerts” within 24 hours from detection; and [Extended]

    ° scale-up and strengthen decentralized RT-PCR laboratory capacities for quality, safe and timely testing for BDBV, including sample collection, rapid referral and transportation of samples and timely dissemination of laboratory test results; and train laboratory personnel accordingly. [Modified]

Safe and dignified burials

    ° Implement protocols, including for their recording and monitoring, in all areas with community BVD transmission, as well as neighbouring areas, ensuring funerals and burials are conducted by well-capacitated, -trained and appropriately PPE-equipped personnel, including safe handling and disinfection of the burial sites with provision made for the presence of the family and cultural practices, and in accordance with relevant national laws and regulations. [Extended with rephrasing]

    ° Investigate each death, occurring outside BVD isolation and treatment centers, to identify or link to BVD chains of transmission and to better understand the reasons underpinning the community’s reluctance to accept safe and dignified burials. [New]

Patient referral pathway and access to safe and optimized intensive care

    ° Establish dedicated BVD isolation and treatment centers or units for suspected,    probable, and confirmed BVD cases, located within, or close to, areas with community BVD transmission, with sufficient staff who are specifically trained and equipped to implement optimized intensive supportive care. [Extended]

    ° Establish protocols for early identification and transferring suspected BVD patients safely to dedicated health care facilities for their isolation, assessment and treatment in a humane and patient-centred approach. This includes trained ambulance teams, mechanisms to notify the receiving health care facility, the application of appropriate IPC precautions during transfer, and decontamination protocols for vehicles and equipment. [Extended with rephrasing]

    ° Establish protocols for the handling and disposal of medical waste, including segregation at point of generation, safe collection and storage, and decontamination by autoclaving or incineration prior to final disposal, in accordance with international guidance. [Modified]

    ° Establish survivor follow-up programmes, including counselling, psychosocial support and stigma-reduction programmes, clinical care, as well as sexual health advice, semen testing, and condoms as appropriate. [Extended]

    ° Maintain the provision of essential health services package – through implementing infection, prevention and control measures to protect healthcare workers –, and monitor any disruption thereof. This package of essential health services includes, at minimum, malaria diagnosis and treatment, and maternal and child health services. [Extended with rephrasing]

Infection prevention and control in health facilities and communities [Modified]

    ° Strengthen measures to prevent health-care associated infections (HAIs), including systematic mapping and assessment of public and private health facilities – that are not BVD isolation and treatment centers –, the establishment, dissemination and implementation of protocols for standards and transmission-based precautions, including screening, triage, isolation, targeted IPC interventions and sustained monitoring and supervision [Modified]

    ° Provide regularly scheduled IPC training to, and assessments of health workers supervision in their proper use of personal protective equipment (PPE) supported by designated IPC focal points at facility-level, and standardized supportive-supervision checklists (e.g. WHO IPC scorecard). [Modified]

    ° Provide health facilities with sufficient and uninterrupted supplies, including PPE, safe injection equipment, with monitoring of stock out rates. [Modified, including moving part of previous temporary recommendation under “Coordination and high-level engagement”]

    ° Establish channels for health workers to report and be assessed following exposures, and have access to psychosocial support and, when possible post-exposure prophylaxis under compassionate use or clinical trial. All BVD cases occurring among health workers must be investigated promptly to implement timely corrective actions within health facilities and mitigation measures as appropriate at the community level. [Extended with rephrasing]

    ° Build community IPC capacity by training community leaders and emphasizing that hand hygiene not only contributes to bringing the BVD epidemic under control but also reduces the risk of transmission of other communicable diseases present in the same areas. Hand hygiene shall be facilitated at critical spots, such as schools, churches, bars, markets, local gatherings sites, points of entry, etc. [Extended with rephrasing]

Social measures, mass-gathering events, and domestic mobility [New]

    ° Postpone mass gatherings in areas with ongoing community BDV transmission. For mass gathering events planned in other areas, the decision to hold them shall be based on event-specific risk assessment. [Modified, previously under “Border health, international travel and mass-gathering events”]

    ° Enact and implement measures reducing crowding in food and drink establishments and nightclubs. [New]

    ° Enact and implement measures limiting to one the number of passengers motorbikes. [New]

    ° Enact and implement measures for the safe opening of schools. [New]

    ° Establish 24/7 health check points along the roads connecting areas with community BVD transmission and areas determined to be at high-risk for the introduction of BVD, as informed by the analysis of population mobility patterns. [New]

    ° Establish BVD surveillance on vessels navigating inland waterways, connecting areas with community BVD transmission with major urban centers, including the Capital Kinshasa. [New]

International travel and border health [Modified]

    ° Establish arrangements with States Parties adjacent to areas experiencing community BVD transmission and characterised by substantial cross border movement and trade activities, to enhance surveillance at ground crossings and along bordering areas. This includes establishing coordination mechanisms for sharing of information regarding contacts who have, or may have, crossed the border, thus enabling continuity of follow-up; as well as the identification and follow up of contacts following the detection of a BVD case in the. [Extended with rephrasing]

    ° Implement measures, in accordance with national laws and regulations, to prevent suspected, probable, and confirmed BVD cases, as well as their contacts, based on the assessment of exposure, from undertaking international travel, unless the travel is part of an appropriate medical evacuation. [Extended]

    ° Prevent the cross-border movement of the human remains of deceased suspected, probable or confirmed BVD cases, unless authorized through bilateral arrangements. [Extended]

    ° Implement exit screening at all points of entry – airports, ports and ground crossings – consisting of, at a minimum, a questionnaire encompassing history of potential exposure to BVD, a temperature measurement and, in case of fever, an in-depth assessment of the risk of BVD, by personnel trained and adequately equipped with PPE. [Extended with rephrasing]

    ° Report to WHO, through the relevant WHO IHR Contact Point in the WHO Regional Office, the implementation of any international traffic related measure adopted. [Extended]

Operations, supplies and logistics

    ° Report to WHO, through the relevant WHO IHR Contact Point in the WHO Regional Office, the implementation of any international traffic related measure adopted. [Extended]

    ° Establish and maintain a timely, robust and monitored end-to-end emergency supply chain to ensure needs-based forecasting, procurement, importation, storage, transportation and distribution of all relevant commodities and countermeasures, including PPE, diagnostics, therapeutics, IPC materials, medical supplies and essential non-medical equipment, while ensuring visibility of stocks, pipelines, consumption and potential gaps. [New, replacing terminated temporary recommendation previously under “Operations, supplies and logistics”]

    ° Establish and coordinate the capacity to rapidly construct, rehabilitate, equip and maintain isolation and treatment facilities and other health infrastructure, ensuring their safe and functional operation in accordance with the standards and technical IPC and case management international guidance. [New, replacing terminated temporary recommendation previously under “Operations, supplies and logistics”]

    ° Establish, operationalize and steer a national health logistics partners coordination cell that provides shared visibility of needs, stocks and partner pipelines of relevant health products; identifies gaps, bottlenecks and duplications; and facilitates the prioritization and mobilization of logistics resources in line with national response priorities. [New, replacing terminated temporary recommendation previously under “Operations, supplies and logistics”]

Research and development of medical countermeasures

    ° Engage, when feasible, with research partners and international institutions to: [Extended]

        § define a robust laboratory strategy, urgently implement head-to-head comparison studies of PCR diagnostics to validate or invalidate the PCR platforms currently used in the field and other upcoming products. [Extended]

        § conduct in-depth investigations to identify and characterize BDBV transmission dynamics associated with specific settings, including related modes of BDBV transmission (e.g. caretaking at home, hospital, or at traditional healers, re-use of needles), as well as exposure to animal populations. [New]

        § implement ethically approved, scientifically robust clinical trials to advance the development and use of candidate therapeutics for treatment and post-exposure prophylaxis, as well as for candidate vaccines. [Extended]

        § establish, with a view to support research, expedited and efficient national regulatory and ethics reviews, community engagement, pharmacovigilance (where applicable), data sharing and equitable access arrangements. [Extended]

Reporting on the implementation of temporary recommendations

    ° Report to WHO, on a monthly basis, on the status of, and challenges related to, the implementation of these temporary recommendations, using a standardized tool and channels that will be made available by WHO, also allowing for the monitoring of progress and the identification of gaps in the national response. [Modified]

For States Parties with land borders adjoining States Parties with community BVD transmission [Modified]

    ° As of 14 August 2026, the WHO Secretariat assessed the regional risk “High”. 

    At the time these temporary recommendations are issued, these States Parties include Angola, Burundi, Central African Republic, Republic of Congo, Rwanda, South Sudan, Tanzania, Uganda and Zambia: [Modified]

        § Establish, or maintain, a national coordination mechanism articulated with subnational levels. [Extended with rephrasing]

        § Enhance and maintain operational readiness respond to BVD cases, focusing on gaps identified through BVD-specific readiness assessments, and including, but not limited to:

        § identifying areas at highest risk of importation of BVD cases;

        § raising community awareness regarding BVD;

        § raising awareness among health workers regarding BVD;

        § enhancing community-based surveillance for and investigations of clusters of unexplained deaths;

        § establishing weekly zero reporting of suspected BVD cases across health facilities;

        § establishing timely access to laboratories, at national and, if needed, at subnational levels, qualified to perform test for BDBV and relevant differential testing. Considerations may be given to shipment to an international reference laboratory for inter-laboratory comparison as part of external quality assurance implementation;

        § establishing rapid response teams for the investigation and management of BVD patients and their contacts;

        § establishing a mechanism for the identification and monitoring of contacts;

        § training health workers in infection, prevention and control (IPC) measures and interventions, including standards and transmission-based precautions for the isolation and treatment of BVD cases;

        § identifying and training workforce should a rapid scale-up of response operations be necessary, including the identification of resources for hazard pay; and

        § conducting simulation exercises.

[Modified, including merging of two temporary recommendations previously under this Section]

        § Provide the general public with accurate and up to date information regarding the BVD epidemic, as well as measures to reduce the risk of exposure; and, where the risk of importation is assessed as highest, engage community leaders, community health workers, and trusted community actors to promote protective behaviours, conduct surveillance, facilitate referral of suspected BVD cases, collect and respond to community feedback [Modified]

        § Establish, with a view to support research, expedited and efficient national regulatory and ethics reviews, community engagement, pharmacovigilance (where applicable), data sharing and equitable access arrangements. [Extended]

Border health and international travel

    ° Provide travellers with accurate and up to date information regarding the BVD epidemic and measures to reduce the risk of exposure, including discouraging travel to areas with community BVD transmission. [Modified with rephrasing]

    ° Establish arrangements with States Parties with adjacent areas experiencing community BDV transmission and characterised by substantial cross border movement and trade activities, to enhance surveillance at ground crossings and along bordering areas. This includes establishing coordination mechanisms for the detection and assessment of travellers with unexplained febrile illness; and the timely sharing of information regarding contacts who have, or may have, crossed the border, thus enabling continuity of follow-up. [Extended with rephrasing]

    ° Pre-position PPE, other IPC materials, sample collection kits, case investigation forms, and safe burial supplies in border areas and points of entry, prioritizing those where the risk of importation is assessed as highest. [Extended with rephrasing]

    ° Activate health contingency plans at airport, ports, and ground crossings, involving conveyance operators, to detect, assess, and manage travellers from States Parties with community BDV transmission, presenting with symptoms compatible with BVD, and the identification of their contacts, according to established protocols. This entails the availability of trained personnel, referral mechanisms, and the application of IPC measures. [Extended with rephrasing]

    ° Coordinate with conveyance operators to facilitate timely communication, prior to arrival, of any suspected BVD cases on board conveyances, and to identify contacts associated with conveyances on an international voyage. Conduct international contact tracing operations as necessary, including by obtaining relevant information from the operators; identifying contacts associated with conveyances on an international voyage; and communicating with States Parties known as transit or final destination of those contacts. [Modified, including merging of one temporary recommendation previously under this Section]

    ° Neither the suspension of flights or waterways routes with States Parties with community BDV transmission, nor denial of entry to travellers and conveyances arriving from those States Parties, are recommended. [Extended with rephrasing]

    ° Report to WHO, through the relevant WHO IHR Contact Point, the implementation of any international traffic related measure adopted. [Extended]

    ° Treat as a health emergency, including, when warranted or necessary, through a formal declaration according to domestic laws, the detection of a suspected or confirmed BVD case, of a contact thereof, or of a cluster of unexplained deaths. This includes investigating any of those events within 24 hours and, by instituting case isolation and management; establishing a definitive diagnosis; and undertaking the identification and monitoring of contacts. [Extended with rephrasing]

    ° Notify to WHO immediately, through the relevant WHO IHR Contact Point in the WHO Regional Offices, any suspected, probable or confirmed BVD case, as per WHO case definitions available here. [Extended]

    ° Report to WHO, on a quarterly basis, on the status of, and challenges related to, the implementation of these temporary recommendations, using a standardized tool and channels that will be made available by WHO, also allowing for the monitoring of progress and the identification of gaps in the national response. [Modified]

    ° In the presence of a probable or confirmed BVD case, take actions based on the temporary recommendations for States Parties with community BDV transmission. [Modified]

For all other States Parties

    ° As of 14 August 2026, the WHO Secretariat assessed the risk for these States Parties as “Low”.

    ° Make arrangements to detect, assess, report and manage travellers with unexplained febrile illness arriving from areas with community BDV transmission. These include, but are not limited to, disseminating accurate and up to date information regarding the BVD epidemic and the definition of BVD cases to public and private health care facilities, including travel clinics, general practitioners, and authorities at points of entry; identifying laboratories to conduct testing for BDBV; identifying isolation facilities allowing for safe assessment and clinical care. [Extended with rephrasing, incorporating a temporary recommendation previously under this Section]

    ° Provide non-governmental organizations and other entities deploying personnel internationally to respond to the BVD epidemic with information on risk, measures to minimize the risk of exposure, and advice for managing a potential exposure. [Extended]

    ° Prepare to facilitate the evacuation and repatriation of nationals (e.g., health workers) who have been exposed to BVD cases. [Extended]

    ° Provide the general public with accurate and up to date information regarding the BVD epidemic and measures to reduce the risk of exposure, including discouraging travel to areas with community BDV transmission. [Extended with rephrasing]

    ° Provide, at points of entry, incoming travellers from areas with community BDV transmission, with information about measures to take should they develop symptoms compatible with BVD within 21 days after arrival. [Extended with rephrasing]

    ° Coordinate with conveyance operators to facilitate timely communication, prior to arrival, of any suspected BVD cases on board conveyances, and to identify contacts associated with conveyances on an international voyage. Conduct international contact tracing operations as necessary, including by obtaining relevant information from the operators; identifying contacts associated with conveyances on an international voyage; and communicating with States Parties known as transit or final destination of those contacts. [Modified]

    ° At the time these temporary recommendations are issued, neither the suspension of flights from States Parties with community BDV transmission, nor denial of entry to travellers and conveyances arriving from those States Parties, are recommended. [Extended]

    ° Report to WHO, through the relevant WHO IHR Contact Point, the implementation of any international traffic related measure adopted. [Extended]

    ° Notify to WHO immediately, through the relevant WHO IHR Contact Point in the WHO Regional Offices, any suspected, probable or confirmed BVD case, as per WHO case definitions available here.

    ° In the presence of a probable or confirmed BVD case, take actions based on the temporary recommendations for States Parties with community BDV transmission. [Modified]

Source: 

Link: https://www.who.int/news/item/24-08-2026-second-meeting-of-the-ihr-emergency-committee-on-the-epidemic-of-ebola-bundibugyo-virus-disease-in-the-democratic-republic-of-the-congo-temporary-recommendations

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