#Ebola #Bundibugyo Virus Disease #Outbreak, #DRC, #Uganda - Situation #Report No. 14, Data as of 16 August '26 (WHO, edited): 5,021 cases & 2,378 deaths in DRC

 

{Click on Image to Enlarge}

___

Event description

Democratic Republic of the Congo

    The Bundibugyo virus disease (BVD) outbreak in the Democratic Republic of the Congo has expanded to a sixth province, with the detection of a confirmed  case in Bas-Uélé province in the north-east, indicating further geographic  spread beyond the main transmission areas in the eastern part of the country. 

    Since External Situation Report #13, an additional 640 confirmed cases and 367 confirmed deaths have been reported, reflecting continued sustained  transmission and high mortality. 

    The crude case fatality ratio (CFR) has increased from 45.9% to 47.4%,  continuing the upward trend observed over several weeks.

    As of 16 August 2026, a total of 5 021 confirmed cases, including 2 378 confirmed deaths have been reported across 55 health zones in six provinces. 

    Buta health zone in Bas-Uélé province and Tshopo health zone in Tshopo  province are the latest affected health zones. 

    Ituri remains the epicentre, accounting for 84.8% of cumulative confirmed  cases and 79.0% of cumulative confirmed deaths.

Figure 1. Daily growth trend in confirmed Bundibugyo virus disease cases in the Democratic Republic of the Congo, by date of report, as of 16 August 2026

{Click on Image to Enlarge}

___

    During the most recent 21 days (27 July – 16 August 2026), a total of 1 759 confirmed cases and 941 confirmed deaths were reported nationally. 

    Transmission remained concentrated in Ituri, which accounted for 1 356  cases (77.1%) and 671 deaths (71.3%), followed by Nord-Kivu with 293 cases  (16.7%) and 224 deaths (23.8%), and Haut-Uélé with 101 cases (5.7%) and 42  deaths (4.5%). 

    Compared with the preceding 21-day period (6 – 26 July 2026), the  number of newly reported cases increased by 121 (+7.4%), and deaths by 25  (+2.7%). However, trends varied substantially between provinces. In Ituri, newly  reported cases and deaths declined by 68 (−4.8%) and 97 (−12.6%)  respectively. 

    In contrast Nord-Kivu reported an increase of 123 newly reported cases  (+72.4%) and 101 deaths (+82.1%). Haut-Uélé recorded the largest relative  increase, with 61 additional newly reported cases (+156.4%) and 21 additional  newly reported deaths (+100.0%). Tshopo remained a smaller transmission focus,  while the detection of a case and death in Bas-Uélé indicates further  geographic expansion.

    At the health-zone level, transmission remained geographically widespread. Of the 55 health zones affected since the start of the outbreak, 47  (85.5%) reported at least one confirmed case during the most recent 21 days.  

    Eight health zones reported no new confirmed cases during this period: Adja, Ariwara, Boga and Kambala in Ituri; Goma in NordKivu; Rungu in Haut-Uélé; Lubunga in Tshopo; and Miti-Murhesa in Sud-Kivu. 

    Seven health zones reported confirmed cases for the first time since the  beginning of the outbreak: Gombari in Haut-Uélé, Lubero in Nord-Kivu, Bafwasende, Kabondo, Tshopo and Wanie-Rukula in Tshopo, and Buta in Bas-Uélé.  This indicates continued geographic expansion, including into previously  unaffected health zones.

    Despite this expansion, transmission remains highly concentrated in a limited number of health zones. Bunia, Rwampara, Nizi, Katwa, Mongbwalu and  Nia-Nia together reported 1 186 cases during the most recent 21 days, accounting  for 67.4% of all cases reported nationally during this period. 

    The distribution of transmission is also changing. Cases increased  substantially in Bunia (+80; +24.9%), Rwampara (+69; +31.5%) and Katwa  (+63; +71.6%), while substantial relative increases were observed in Wamba  (+31; +281.8%), Beni (+34; +226.7%), Fataki (+37; +246.7%) and Isiro (+18;  +150.0%). Conversely, cases declined in established transmission foci such as Mongbwalu (−134; −61.5%) and Nizi (−97; −34.8%). Overall, the data indicate a redistribution of transmission, with declining activity in some established hotspots occurring alongside intensification in others and continued geographic expansion into new health zones.

(...)

    Mortality remains high and varies substantial across affected areas. Ituri continues to account for the largest absolute burden, with 1 878 cumulative confirmed deaths, representing 79.0% of all deaths nationally.  However, the CFR is considerably higher in Nord-Kivu (70.5%), than in Ituri  (44.1%) and Haut-Uélé (45.3%). This disparity was also evident during the most  recent 21 days, when Nord-Kivu accounted for only 16.7% of reported cases but  24.0% of reported deaths nationally.

    At health-zone level, the largest numbers of deaths were reported from  major transmission foci in Ituri, particularly Bunia, Rwampara and Mongbwalu.  However, CFRs were substantially higher in several health zones in Nord-Kivu, including, Butembo (85.6%), Beni (75.8%) and Katwa (68.1%), compared  with Bunia (29.8%), Rwampara (38.9%), and Mongbwalu (49.9%). These marked  geographic variation indicate that mortality is not explained by  transmission intensity alone and warrants further assessment of differences in case detection, timeliness of presentation and referral, community  deaths, access to care and clinical management. 

    Mortality remains high both in the community and among patients in treatment facilities. During the past six weeks, an average of approximately 162  community deaths and 98 treatment facility deaths were reported each week. 

    Community deaths accounted for approximately 60% of all confirmed  deaths during this period. The high proportion of community deaths highlights  persistent challenges in early case detection, referral and access to designated  treatment facilities. 

    Mortality among patients reaching treatment facilities may reflect late  presentation and severe disease at admission, while further assessment is needed  to determine the contribution of clinical management capacity, quality of  care and patient vulnerabilities, including age, malnutrition and comorbidities. For  the purposes of this report, community death refers to death occurring outside a  designated Ebola treatment facility, including at home, in the community, or in  another (non-Ebola) health facility.

(...)

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

    

    During the first 95 days of reporting, the 7-day moving average increased  progressively, reaching more than 90 confirmed cases per day, substantially  higher than the levels observed during comparable period of the 2014 – 2016 

West Africa and 2018 – 2020 Democratic Republic of the Congo outbreaks. 

    With 5 021 confirmed cases reported as of 16 August 2026, this has  become the largest BVD outbreak ever recorded and the second-largest Ebola  disease outbreak on record. 

    The sustained high incidence and continued geographic expansion indicates  that transmission remains intense and that the outbreak has not yet entered a  clear declining phase.

Figure 5. Comparison of three major Ebola disease outbreak trajectories during the first 95 days of reporting using seven-day moving averages of the daily number of confirmed cases reported.

{Click on Image to Enlarge}

___

Uganda and France

    Uganda has now recorded 31 consecutive days without a new confirmed  BVD case since the last patient was discharged on 16 July 2026. All identified  contacts have 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 crossborder reintroduction remains.

    France has reported no new confirmed BVD cases for 43 consecutive days  since the imported case was discharged on 4 July 2026. This period is more  than twice the maximum 21-day incubation period for BVD. No secondary  transmission has been detected, and all five identified flight contacts completed  follow-up without developing symptoms.

Risk Assessment

    The risk of further geographic spread within the Democratic Republic of the Congo remains very high, while the risk of cross-border spread remains  elevated. 

    The detection of a case in Buta, Bas-Uélé and additional affected health  zones in Tshopo, together with sustained transmission in highly mobile areas of  Ituri, Nord-Kivu and Haut-Uélé, increases the potential for onward spread along major transport corridors. Tshopo, particularly the Kisangani transport hub, is of 

particular concern because of its connectivity with other parts of the country and  the potential for longer-distance dissemination towards Kinshasa. 

    Continued transmission in eastern and north-eastern Democratic  Republic of the Congo also increases the likelihood of cross-border movements of  infected persons. 

    Uganda, South Sudan and the Central African Republic remain at  particularly high risk of importation, given their geographic proximity to affected 

areas of the Democratic Republic of the Congo, established cross-border population movements and connectivity along major mobility corridors. 

    Enhanced surveillance, information sharing, preparedness and cross- border coordination should therefore be maintained along priority mobility corridors and at points of entry.

(...)

Situation interpretation

    The BVD outbreak is evolving into a more geographically dispersed emergency, with persistent transmission in established hotspots occurring  alongside intensification in other areas and continued seeding of new locations. 

    The combination of very high mortality, substantial deaths outside  designated treatment facilities, increasing surveillance workload and  uneven response capacity suggests that current interventions are not yet  achieving sufficient speed, coverage or intensity to interrupt transmission. 

    The response should therefore be increasingly risk-informed and geographically differentiated, with the intensity and combination of  interventions adapted to local transmission patterns and operational gaps, while  simultaneously establishing sufficient response capacity ahead of transmission in 

newly affected and high-risk areas. 

    Given increasing connectivity between affected areas and major  populationmovement corridors, stronger interprovincial and cross-border  surveillance and preparedness are also critical to prevent further geographic spread.

Source: 

Link: https://www.afro.who.int/countries/democratic-republic-of-congo/publication/ebola-bundibugyo-virus-disease-outbreak-5

____

Enhanced #Pathogenicity and Contact #Transmissibility of #Human-origin Avian #Influenza #H5N1 Clade 2.3.4.4b Genotype B3.13 Compared to D1.1 in #Ferrets

 

Abstract

Since its emergence in 2020, multiple genotypes of the H5N1 clade 2.3.4.4b have been identified, with B3.13 and D1.1 emerging in the USA as two major and concerning genotypes. However, their relative pathogenicity and transmissibility in mammals have not been fully elucidated. We compared the pathogenicity and transmissibility of the first two human H5N1 clade 2.3.4.4b cases caused by B3.13 in Texas (A/Texas/37/2024; HPhTX B3.13) and D1.1 in Louisiana (A/Louisiana/12/2024; HPhLA D1.1) in a ferret model of infection and transmission. HPhTX B3.13 infection resulted in more severe clinical disease and enhanced viral shedding, with evidence of increased transmission relative to HPhLA D1.1. Histopathological analysis revealed more extensive lung pathology in animals infected with HPhTX B3.13, consistent with increased viral loads and inflammatory responses. Importantly, both genotypes showed no significant differences in reactivity to ferret sera raised against candidate vaccine virus (CVV) strains, receptor binding properties, or neuraminidase (NA) activity and thermostability. Whole-genome sequencing revealed no adaptive mutations in HPhTX B3.13 following infection or transmission. In contrast, HPhLA D1.1 showed rapid acquisition of the mammalian-adaptive mutation E627K in infected ferrets and both E627K and Q194K in the only fatal contact animal. Both mutations were associated with enhanced polymerase activity and computational analyses suggested that they enhance interactions with the mammalian host factors ANP32A and B. Our findings indicate that B3.13 is already well adapted for mammalian infection and transmission whereas D1.1 retains evolutionary potential through the rapid acquisition of adaptive mutations, highlighting important genotype-specific differences relevant to zoonotic risk assessment and pandemic preparedness.

Competing Interest Statement

The A.G.-S. laboratory has received research support from Avimex, Dynavax, Pharmamar, and Accurius, outside of the reported work within the last three years. A.G.-S. has consulting agreements for the following companies involving cash and/or stock within the last three years: Castlevax, Amovir, Vivaldi Biosciences, Contrafect, Avimex, Pagoda, Accurius, Applied Biological Laboratories, Pharmamar, CureLab Oncology, CureLab Veterinary, Virofend, Prosetta and A.A.C.T., outside of the reported work. A.G.-S. has been an invited speaker in meeting events within the last three years organized by Seqirus, Novavax and Hipra. A.G.-S. is inventor on patents and patent applications on the use of antivirals and vaccines for the treatment and prevention of virus infections and cancer, owned by the Icahn School of Medicine at Mount Sinai, New York, outside of the reported work. The Icahn School of Medicine at Mount Sinai has licensed some of these inventions to Medimmune, Avimex, Leinco Technologies, Castlevax, Virofend, Kerafast, Cell Signaling, EMD Millipore, Genentech, Paratus and Nura Bio, and as a result receives financial compensation. Subject to Mount Sinai receiving such financial consideration, AG-S will receive a portion of that consideration pursuant to the terms of the Mount Sinai Intellectual Property Policy. All other authors declare no commercial or financial conflict of interest.

Funder Information Declared

NIH/NIAID, 75N93021C00014

Horizon Europe Program, KAPPA-FLU no. 101084171

Source: 

Link: https://www.biorxiv.org/content/10.64898/2026.08.10.744032v1

____

#Ebola disease caused by #Bundibugyo virus - #DRC (WHO D.O.N., August 15 '26): 4,665 cases and 2,184 deaths so far

 

Situation at a glance

    The Bundibugyo virus disease (BVD) outbreak in the Democratic Republic of the Congo is in a phase of intense transmission. 

    It is the largest Ebola outbreak ever reported in the country and expanding faster than any previous Ebola outbreak. 

    The epidemic is increasingly characterized by sustained transmission within interconnected geographic clusters. 

    Initially confined to the Mongbwalu health zone in Ituri Province, the outbreak has now expanded to 54 health zones across six provinces (Ituri, North Kivu, South Kivu, Haut-Uélé, Tshopo, and Bas-Uélé). 

    The most recently affected Bas-Uélé province recorded one confirmed case in Buta health zone with travel history to Haut-Uélé and onset of symptoms on 4 August. 

    As of 12 August 2026, a total of 4665 confirmed cases, including 2184 deaths, have been reported, corresponding to a crude case fatality ratio (CFR) of 46.8%. 

    The ongoing rise in cases, broader geographic spread, and continued high mortality demonstrate the rapidly changing scope of this public health emergency of international concern. 

    During the most recent reporting week (epidemiological week 32, 3 to 9 August 2026), the highest weekly number of reported cases (579) and deaths (304) were recorded, highlighting the exceptional pace of transmission. 

    The ongoing humanitarian crisis, compounded by insecurity, population displacement and mobility, and cross-border movements, continues to pose significant challenges to response efforts and increase the risk of further geographical spread. 

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

    However, a substantial scaling up of response activities is underway to get ahead of the outbreak. 

    Following their missions to the Democratic Republic of the Congo, WHO’s Director-General and Regional Director for Africa, and the Director General of Africa CDC, highlighted surveillance activities and closer work with communities as priority areas. 

    Expanding the number of treatment centers, across more areas, is underway, along with training for the health and care workers to staff them. 

    France has reported no secondary transmission following an imported case detected on 24 June 2026. 

    As of 14 August, 41 days had passed since the patient’s discharge on 4 July, with no additional confirmed cases reported. 

    In Uganda the most recent imported case was discharged from a treatment centre on 16 July, and the 42-day enhanced monitoring period will cease on 27 August. 

    Uganda remains at risk of BVD re-introduction due to ongoing transmission in neighbouring Democratic Republic of the Congo and is undertaking heightened surveillance activities given continued population movement and the risk of cross-border transmission. 

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

Description of the situation

    Since the previous Disease Outbreak News was published on 1 August 2026, additional confirmed cases and deaths of BVD have been only reported in the Democratic Republic of the Congo.  

    Cumulatively as of 12 August 2026, 4686 confirmed cases have been reported: 4665 in the Democratic Republic of the Congo (including two cases diagnosed in the Democratic Republic of the Congo and subsequently treated in Germany), 20 in Uganda and one in France. 

    A total of 2186 deaths have been reported, including two in Uganda. 

    As of 12 August, at least 986 patients have recovered including 965 in the Democratic Republic of the Congo, 18 from Uganda have recovered, two in Germany and one from France.  

    As reported in the Disease Outbreak News published on 1 August 2026, with more confirmed cases than the 2018-2020 outbreak, which reported 3,317 cases, this outbreak now represents the largest Ebola disease outbreak ever documented in the country. 

(...)

Democratic Republic of the Congo  

    Since 1 August 2026 when the last Disease Outbreak News was published, an additional 1060 confirmed cases, including 597 confirmed deaths, have been reported in the Democratic Republic of the Congo. 

    The increase is in part due to strengthened surveillance activities, enhanced laboratory testing, and diagnostic capacity. However, most of the increase reflects the expansion of the outbreak.  

    As of 12 August 2026, a total of 4665 confirmed cases, including 2184 deaths (CFR 46.8%), have been reported in the Democratic Republic of the Congo. To date, 965 patients have recovered. 

    Cases have been reported from 54 health zones (HZ) across six provinces: Ituri (28/36 HZ), North Kivu (12/34 HZ), South Kivu (1/34 HZ), Haut-Uélé (6/13 HZ), Tshopo (6/23 HZ), and Bas- Uélé (1/11 HZ). The most recently affected province, Bas-Uélé, reported one confirmed case in Buta Health Zone. The case had a travel history to Haut-Uélé, with symptom onset on 4 August. 

    As of 12 August, of the 54 affected health zones, 100 new confirmed cases were reported in the last 24 hours from 22 health zones in all affected provinces except for Sud-Kivu. 

    The highest number of new cases in the last 24 hours (67) was reported from Ituri province followed by Nord-Kivu (25). Ituri remains the most affected province, accounting for 85% (3979/4665) of all confirmed cases and 79% (1726/2184) of reported deaths nationwide.  

    As of 12 August, the proportion of contacts followed up in the last 24 hours is at 84.2% (17 460 seen out of 20 740 to follow up). 

    As of 9 August, infections among health workers continue, with at least 155 confirmed cases, including 45 deaths (CFR: 29%) and 68 recoveries since beginning of the outbreak. These infections highlight ongoing occupational exposure risks, persistent challenges in implementing infection prevention and control (IPC) in health-care facilities—especially outside of the designated Ebola treatment centres which have more established protocols and access to supplies--and continued exposure risk in the community. 

    The outbreak is taking place amid a severe humanitarian crisis and ongoing insecurity, characterized by large-scale population displacement, significant population mobility, and constrained access to critical services, including health care, safe water, food, shelter, and protection. 

    Response efforts in the affected provinces have been hindered by insecurity and attacks on health facilities, which have curtailed access for response teams, discouraging potential patients from seeking care, disrupting surveillance and response activities and increasing the risk of undetected transmission. 

    Since the declaration of the Ebola public health emergency of international concern (PHEIC) on 17 May 2026, 12 attacks on health care have been recorded, with additional reports under verification. These challenges underscore the importance of community-centred response efforts led by local authorities and trusted community leaders.  

Figure 2: Number of confirmed cases (n = 4665), in the Democratic Republic of the Congo, by date of reporting and as of 12 August 2026 

{Click on Image to Enlarge}

___

Figure 3: Number of deaths among confirmed cases (n = 2184), in the Democratic Republic of the Congo, by date of reporting, as of 12 August 2026

{Click on Image to Enlarge}

___

{*} Note that the large number of reported deaths on 22 July represents the completion of a data reconciliation exercise, including deaths that occurred earlier in the outbreak, rather than newly recorded deaths. 

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 individuals. 

    The incubation period for BVD ranges from two 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

    For detailed information about the ongoing 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: Ongoing outbreak in the Democratic Republic of the Congo | WHO | Regional Office for Africa | WHO| Regional Office for Africa  

    Health authorities in the Democratic Republic of the Congo, in collaboration with WHO and partners, are continuing to implementing extensive public health measures, including: 

    ° the continental preparedness and response plan, 

    ° a strategic six-month framework plan designed to guide coordinated efforts to strengthen outbreak response measures, including 

    ° emergency coordination, 

    ° disease surveillance, 

    ° laboratory testing, 

    ° infection prevention and control, 

    ° clinical care, 

    ° community engagement, 

    ° research, 

    ° logistics and support for essential health services, 

    ° engaging donors and mobilizing additional resources to address critical funding gaps and 

    ° sustain response operations across affected and at-risk areas. 

    A substantial scale-up is ongoing across all response pillars to get ahead of the outbreak.

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, was separated from the risk for other countries in the African Region. 

    The risk in the Democratic Republic of the Congo was 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 was 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 was 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 was 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. 

    An updated Rapid Risk Assessment is being developed in advance of the upcoming IHR Emergency Committee meeting regarding the epidemic of Ebola Bundibugyo virus disease in the Democratic Republic of the Congo scheduled for 18 August. This is the second meeting of the committee, following their initial meeting after the Director-General characterized the situation as a Public Health Emergency of International Concern on 17 May 2026.  

(...)

Source: 

Link: https://www.who.int/emergencies/disease-outbreak-news/item/2026-DON615

____

#Risk #assessment of avian #influenza #H5N5 virus from the first #human case using the #ferret model

 

ABSTRACT

The incursion of Eurasian-origin genotype A6 A(H5N5) virus into North America expanded the genetic diversity among North American highly pathogenic avian influenza viruses and heightened concern about zoonotic risk. Following a fatal human infection with the A(H5N5) virus A/Washington/2148/2025, viral replication was assessed in polarized human bronchial epithelial cells, and pathogenicity, transmissibility in direct contact and respiratory droplet models, and airborne virus shedding were evaluated in ferrets to inform pandemic risk assessment. A(H5N5) displayed robust replication in Calu-3 cells at 33°C and 37°C, showing kinetics and peak titers comparable to those of contemporary genotype B3.13 and D1.1 A(H5N1) viruses. In ferrets, A(H5N5) replicated efficiently in the respiratory tract, disseminated to extrapulmonary tissues, and caused fatal disease in all inoculated animals. Airborne transmission was not observed, and infrequent, low-level detection of virus in air samples paralleled that of A(H5) viruses that are not transmissible via air in ferrets. In a direct contact model, limited transmission was detected within 4 days of exposure, with evidence of lower respiratory tract replication in contact animals. These findings indicate that the A(H5N5) virus has the capacity for robust replication in an airway epithelial cell line and can cause severe systemic infection and mortality in ferrets but has not acquired adaptations for airborne spread in mammals. Collectively, these results underscore heterogeneity among clade 2.3.4.4b A(H5Nx) viruses in North America and the need for genotype-by-genotype evaluation of newly emerged viruses to understand public health risk.

IMPORTANCE

The emergence of Eurasian-origin genotype A6 highly pathogenic avian influenza A(H5N5) virus in North America has increased viral diversity and raised concerns about zoonotic and pandemic risk. In this study, we evaluated the replication kinetics, pathogenesis, and transmission of A/Washington/2148/2025 A(H5N5) virus, which was isolated from the first reported human infection with this influenza virus subtype, using polarized human bronchial epithelial cells and the ferret model. The A(H5N5) virus replicated efficiently in vitro at temperatures representative of the upper and lower respiratory tracts and caused fatal systemic disease in inoculated ferrets. Limited transmission was observed during 4 days of direct contact. Airborne virus detection was infrequent and did not result in airborne transmission. These findings show that A(H5N5) virus can replicate robustly in mammalian cells and cause severe disease but lacks adaptations supporting efficient airborne spread, informing assessment of the pandemic risk posed by genotype A6 influenza viruses.

Source: 

Link: https://journals.asm.org/doi/10.1128/jvi.00856-26

____

Bundibugyo Virus Disease Outbreak in the #DRC, #Uganda & #France - Situation Report 13, Data as of 09 August 2026 (WHO, summary): 4,381 cases & 2,011 deaths in DRC

 

{Click on Image to Enlarge}

___

Event description

Democratic Republic of the Congo

    The Bundibugyo virus disease (BVD) outbreak in the Democratic Republic of the Congo remains in a phase of intense and expanding transmission, with cumulative deaths crossing the grim milestone of 2,000 only 86 days after the outbreak was officially declared on 15 May 2026. 

    Since External Situation Report #12, an additional 579 confirmed cases and 304 confirmed deaths have been reported, bringing the cumulative total to 4,381 confirmed cases and 2,011 confirmed deaths as of 9 August 2026, corresponding to a case fatality ratio of 45.9%. 

    Ituri remains the epicentre, accounting for 85.8% of cumulative cases and 80.6% of cumulative deaths.

{Click on Image to Enlarge}

___

    The epidemic is increasingly characterized by sustained transmission within interconnected geographic clusters alongside continued geographic expansion. 

    

    The Bunia–Rwampara–Mongbwalu–Nizi corridor remains the principal transmission focus, while persistent transmission in North Kivu and  increasing activity in Haut-Uélé indicate spread beyond the original Ituri epicentre. 

    The number of affected health zones increased from 51 in External Situation Report #12 to 53 as of 9 August 2026, with Gombari in Haut-Uélé and  Bafwasende in Tshopo being the most recently affected health zones. 

    Overall, the outbreak now affects 53 of 140 health zones across five provinces.

(...)

    Persistently high mortality continues to highlight gaps in early detection  and timely access to care. 

    

    Community deaths remain frequent, with 34 of 51 reported deaths (66.7%)  occurring outside treatment centres on 9 August 2026.

    Surveillance performance improved, with all 242 validated suspected cases  being investigated on 9 August 2026. 

    Contact follow-up also increased to 86.7%, exceeding 85% for the first  time, although performance remained substantially lower in Haut-Uélé at 57.9%,  partly due to incomplete reporting. 

    Despite these improvements, gaps in alert reporting, contact identification  and follow-up around confirmed cases persist. 

    Treatment capacity also remains under pressure, with several treatment  and transit centres in Ituri saturated, while North Kivu continues to face constraints in referral capacity and Haut-Uélé still lacks a standard Ebola  treatment centre in its six affected health zones.

    Intense transmission is also occurring against a backdrop of increasing  operational and workforce pressures. 

    Challenges related to the timely remuneration of response personnel have  been reported in some affected areas, with potential implications for  workforce motivation and the continuity of response activities, including  community-based interventions and operations at points of entry and points of  control. 

    Community resistance, insecurity and operational incidents continued to  pose challenges to the timely implementation of response activities, including safe  and dignified burials. 

    These pressures are particularly concerning as epidemiological analyses  indicate that transmission is occurring faster than cases are being detected and  isolated, while contact-tracing capacity is increasingly stretched. 

    Despite the absence of further international transmission, the continued high incidence in eastern Democratic Republic  of the Congo poses a substantial risk of cross-border spread, particularly to Uganda and South Sudan through  major population movement corridors. 

    Surveillance at points of entry (PoEs) and points of control (PoCs) continued  along key mobility corridors, although operational constraints persist at  some sites. 

    Continued strengthening of cross-border surveillance, information sharing  and coordination with neighbouring countries remains essential for the early  detection and management of potential cross-border transmission.

Uganda and France

    No new BVD cases have been reported in Uganda. The last confirmed  patient was discharged on 16 July 2026, and all identified contacts subsequently  completed follow-up. As of 9 August 2026, 24 days had elapsed since the last  patient's discharge without a new confirmed case. However, continued high  transmission in neighbouring eastern Democratic Republic of the Congo poses a risk of reintroduction.

    France has reported no secondary transmission following the imported  case detected on 24 June 2026. The patient recovered and was discharged on 4  July 2026 after two consecutive negative polymerase chain (PCR) test results, and all five identified flight contacts completed 21 days of follow-up without  developing symptoms. As of 9 August 2026, 36 days had elapsed since the  patient's discharge without an additional confirmed case being reported in France.

(...)

Situation interpretation

    The BVD outbreak remains uncontrolled, with transmission continuing to  outpace response capacity. Persistent community deaths, geographic expansion  and gaps in contact follow-up indicate continued undetected community transmission, while pressure on treatment facilities, uneven infection  prevention and control capacity, workforce constraints and community resistance continue to challenge response effectiveness. 

    The response should now shift to targeted interruption of transmission in  the main clusters and emerging hotspots, while deepening community leadership  and ownership of the response. This requires empowering trusted local leaders  and community networks to drive active case finding, contact tracing, early care- seeking, and safe and dignified burials, alongside faster case investigation and  isolation and rapid infection prevention and control interventions. Workforce and  payment constraints require urgent resolution, while neighbouring countries  should maintain heightened preparedness given the continued risk of cross-border spread.

Source: 

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

____

#Risk #assessment of introduction, spread, and zoonotic #spillover of #MERS-CoV Clade B in #camel populations of the Nile Basin and Across #Africa (WHO, summary)

 

INTRODUCTION  

    The Global Early Warning System for Health Threats and Emerging Risks at the Human-Animal Ecosystems Interface (GLEWS+) is a joint initiative of the Food and Agriculture Organization of the UN (FAO), the World Health Organization (WHO), and the World Organisation for Animal Health (WOAH). 

    Within this framework, the GLEWS+ Risk Assessment (RA) mechanism enables the three organizations to jointly assess emerging health threats at the human–animal–ecosystem interface and provide evidence-based risk estimates. 

    These assessments support Members and State Parties in strengthening the prevention, detection, response and control measures.  

Event Description and Scope of the Assessment 

    Middle East respiratory syndrome coronavirus (MERS-CoV) is a zoonotic virus for which dromedary camels (Camelus dromedarius) are recognized as the primary animal reservoir. 

    Viral circulation within camel populations poses a risk of transmission to humans, particularly in settings characterized by frequent and close human–camel interactions. 

    Historically, MERS-CoV strains detected in dromedary camels in Africa have belonged to clade C, whereas clade B viruses have been associated with the majority of reported human MERS cases and have predominantly circulated in dromedary camel populations in the Middle East. 

    The recent detection of MERS-CoV clade B genome fragments in camels from the Nile Basin region represents a notable epidemiological development, suggesting the possibility of inter-regional viral movement and genetic mixing. 

    This finding may have implications for virus circulation and transmission dynamics, including potential changes in the risk of zoonotic spillover to humans and/or alterations in viral transmissibility and pathogenicity. 

    This assessment evaluates the risk of spread of MERS-CoV clade B within camel populations at both sub-regional (Nile Basin) and regional (Africa) levels. 

    It also assesses the risk of spillover from infected camels to humans in Nile Basin countries. 

    The assessment considers available virological, epidemiological, ecological, and socio-economic factors that influence virus circulation, including camel husbandry practices, pastoralist mobility patterns, cross-border animal movements, live-animal trade networks, and the extent of human-camel contact in the region.  

    Information used in this assessment was compiled from eight countries in Africa reporting camel populations exceeding 10,000 in 2024. 

    The countries included in the assessment are:     

        ° Chad, 

        ° Egypt*, 

        ° Eritrea*, 

        ° Ethiopia*, 

        ° Kenya*, 

        ° Libya, 

        ° South Sudan* and 

        ° Sudan*. 

    The six countries belonging to the Nile Basin sub-region are indicated by an asterisk (*). 

    This risk assessment reflects information available to 27 July 2026. FAO, WHO and WOAH will review and update the assessment as new information becomes available.  

SUMMARY 

    Middle East respiratory syndrome coronavirus (MERS-CoV) is an enveloped, positive-sense RNA virus belonging to the genus Betacoronavirus. 

    It causes Middle East respiratory syndrome (MERS), a zoonotic respiratory disease first recognized in 2012, following the detection of human cases in Saudi Arabia and Jordan. 

    As of 11 June 2026, a total of 2,637 laboratory-confirmed human cases have been reported to WHO globally, the majority from countries in the Arabian Peninsula, with an estimated crude case fatality ratio (CFR) of approximately 37%. (WHO, 2025c) 

    Dromedary camels (Camelus dromedarius) are the primary animal reservoir of MERS-CoV and the main source of zoonotic transmission to humans. 

    Human infections are thought to occur through direct or indirect contact with infected camels. 

    Consumption of raw camel products is considered a plausible route of exposure, although it has not been definitively confirmed as a primary transmission pathway. 

    Human-to-human transmission can occur, particularly in healthcare settings and among those in close-contact. 

    MERS-CoV antibodies have been found in other camelid species, including Bactrian camels, hybrid camels, llamas and alpacas, indicating susceptibility to infection (Islam, 2003). 

    However, these species are not considered to play a significant role in the current epidemiology of MERS.  

    MERS-CoV has evolved into three genetic clades (A, B, and C) with distinct geographic patterns. 

    Clade B predominates in the Arabian Peninsula and has been associated with all recent human infections. 

    Clade A has not been detected since 2015 and is considered extinct. 

    Clade C circulates among dromedary camels across Africa and despite frequent camel imports from Nile Basin countries into the Arabian Peninsula, has not become established in local camel populations. 

    Experimental and phenotypic studies indicate that clade B viruses exhibit higher replication efficiency in human respiratory tissues and experimentally infected camelids, more efficient cellular entry, and prolonged viral shedding compared with clade C viruses. (Rodon, 2023) 

    These characteristics suggest a greater zoonotic potential and an increased likelihood of transmission to humans. (Zhou, 2021) 

    The global camel population is estimated at over 42 million heads as of 2023, with more than 80% of the population in Africa (FAO, 2025a). 

    Camel trade within Africa is predominantly regional and fragmented, with significant informal cross-border movement. (WHO, 2025d, FAO, 2026) In the Nile Basin and the Horn of Africa {1}. 

    Camel trade and movement are largely driven by informal cross-border pastoralist systems, with frequent but poorly documented movements between neighboring countries such as Sudan, Ethiopia, Kenya, and South Sudan. 

    Sudan plays a central role as a major camel exporter, with substantial formal and informal movements to neighboring countries and toward North Africa, while Egypt functions primarily as a terminal hub where camels from multiple origins converge for trade and slaughter. 

    In contrast, long-distance east-to-west transcontinental movement appears limited, with little evidence of sustained camel movement from the Nile Basin into North or West Africa. (Younan et al., 2016) 

    Recent genomic surveillance studies have suggested the introduction of MERS-CoV clade B strains into camel populations in the Nile Basin, outside its historically recognized circulation in the Arabian Peninsula. 

    In Egypt, phylogenetic analyses of a camel-derived sample identified genome fragments clustering with clade B viruses from the Arabian Peninsula, circulating alongside endemic African clade C viruses (Gomaa, Edwards, Wang, Taweel, et al., 2025). 

    Recombination analyses in these studies were interpreted by the authors as suggesting potential genomic mixing between introduced clade B and endemic clade C lineages, highlighting a potential for inter-regional viral exchange and the emergence of novel variants. 

    However, as the publicly available sequences are incomplete, these findings require confirmation through full genome sequencing.  

    In a separate study (Hassan et al., 2025), metagenomic sequencing of nasal swabs from camels imported from Sudan also detected MERS-CoV genome fragments clustering with clade B human and camel strains. 

    Whole genome sequencing would be necessary to confirm these findings and better characterize their evolutionary relationships. 

    Overall, while these observations suggest the possible introduction of clade B viruses into camel population in the Nile Basin sub-region, additional research is required to determine whether there is sustained circulation, establishment, or recombination of clade B viruses in continental African camel populations. 

    Using a qualitative evidence-based approach and considering the assessed likelihood and consequences in the countries assessed, the overall risk at sub-regional level (Nile Basin) of further introduction and spread of MERS-CoV clade B within camel populations is minor. 

    The risk of introduction and spread from camel populations in the Nile Basin to camel populations in neighbouring countries is also assessed as minor. 

    However, if MERS-CoV clade B is introduced and established in camel populations in the Nile Basin countries, the public health risk of spillover from camels to humans exposed to infected camels or their products is assessed as high.  

    The level of confidence in the risk estimates is considered low for the first two questions, reflecting limitations in the quality and completeness of available genomic data, the presence of plausible but unconfirmed transmission pathways, very limited surveillance in camels and humans, and evolving camel trade dynamics that may facilitate virus spread within and beyond the Nile Basin. 

    The level of confidence is considered moderate for the third question. 

    While the clinical presentation and potential consequences of MERS-CoV infection in humans are well documented and observed in previous outbreaks, important uncertainties remain regarding the social, behavioral, and contextual factors that influence the likelihood of camel- to- human spillover in the Nile Basin.  

(...)

{1} Countries in the Horn of Africa are: Djibouti, Eritrea, Ethiopia, and Somalia

Source: 

Link: https://www.who.int/publications/m/item/risk-assessment-of-the-introduction--spread--and-zoonotic-spillover-of-mers-cov-clade-b-in-camel-populations-of-the-nile-basin-and-across-africa

____

 

#COVID19, Global #Risk #Assessment - Version 10 (WHO, August 6 '26, summary)

{Summary} 

Overall risk statement

    As of 30 July 2026, the global public health risk from COVID-19 remains moderate following an assessment of data and information reported between 1 January and 30 July 2026. 

    While the direct public health impact of COVID-19 has declined compared with the early phases of the pandemic (the COVID-19 Public Health Emergency of International Concern - PHEIC, was lifted on 5 May 2023), the SARS-CoV-2 virus continues to circulate globally, maintaining its capacity to cause severe disease and fatalities, particularly among high-risk populations, including older and immunocompromised adults and people living with comorbidities. 

    As of 28 June 2026, over 779 million confirmed cases and over seven million confirmed deaths have been reported globally to WHO since the event was confirmed to WHO in 2020, while seroprevalence estimates suggest that there are orders of magnitude more infections and reinfections that remain unreported. 

    Uncertainties persist regarding the long-term consequences for the health of individuals suffering repeated infections and/or affected by post-COVID-19 condition (PCC). 

    Global estimates indicate that 6% of people with symptomatic COVID-19 infection develop PCC, with reduced risk in vaccinated individuals. 

    Of these, approximately 15% have persistent symptoms even at 12 months.

    Continued global circulation and ongoing virus evolution and diversification, including in established animal reservoirs, warrant constant monitoring and vigilance. 

    While available vaccines remain effective against severe disease and death despite continued COVID-19 variants evolution, the global vaccine uptake was very low in 2025, even by those at high risk of developing severe disease. 

    This further enables virus circulation and genetic evolution and increases health risks for vulnerable individuals. 

    Decreased reporting, reduced genomic sequencing (and sharing of sequence information) have led to gaps in surveillance, especially from low- and middle-income countries, which affects the representativeness and completeness of available data. 

    Consequently, the ability to accurately assess the public health risk from COVID-19 remains constrained, resulting in a low level of confidence in the current assessment.

    As indicated by sentinel surveillance through WHO’s Global Influenza Surveillance and Response System (GISRS) and wastewater surveillance, SARS-CoV-2 circulation continues at a low level globally, with test positivity remaining below 5% since December 2025. 

    The virus is co-circulating with seasonal influenza and Respiratory Syncytial Virus (RSV). 

    The previously observed decline in deaths and hospitalizations continued throughout this assessment period and can be explained by high population immunity, improved clinical management, and unchanged virulence of circulating variants. 

    Most currently circulating SARS-CoV-2 variants belong to the JN.1 Omicron sublineages, which show immune escape but do not result in increased disease severity compared to other Omicron sublineages, reflected by the stability of severity indicators.

    In December 2025, WHO published the Strategic Plan for Coronavirus Disease Threat Management (2025–2030) which recommends continued integration of COVID-19 into broader respiratory disease surveillance systems. 

    In March 2026, WHO provided updated recommendations for routine COVID-19 vaccination with a continued focus on targeting populations at high risk of severe disease. WHO also regularly updates recommendations for vaccine composition, with the latest published in May 2026.

(...)

Source: 

Link: https://www.who.int/publications/m/item/covid-19-global-risk-assessment--version-10

____