Estimated #Transmissibility and #CFR of #Bundibugyo Virus, #Uganda, 2007

 

Abstract

Because the epidemiology of Bundibugyo virus remains unclear, we reanalyzed the first recognized outbreak (Uganda, 2007). Adjusting for case under-ascertainment and the effect of control measures, we estimated the effective reproduction number (1.55, falling to <1 after intervention) and case-fatality rate (31%, declining to 25%). The underascertainment rate was 15%.

Source: 

Link: https://doi.org/10.3201/eid3210.261175

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The First 100 Days of Five #Ebola #Outbreaks — #DRC, #Uganda, and West #Africa, 2007–2026 (MMWR, Sept. 15 '26)

 

Summary

    ° What is already known about this topic?

        § The Democratic Republic of the Congo (DRC) is experiencing its largest and deadliest Ebola disease outbreak, which is also the largest Ebola outbreak caused by Bundibugyo virus and the second largest Ebola outbreak worldwide.

    ° What is added by this report?

        § The 2026 Ebola outbreak resulted in 5,458 confirmed cases and 2,606 deaths in DRC in the first 100 days after initial detection, indicating rapid growth. No previous Ebola outbreak caused >800 cases during the first 100 days.

    ° What are the implications for public health practice?

        § This Ebola outbreak appears to be expanding faster than any previously documented Ebola outbreak, with seven times as many cases 100 days after initial detection than the 2014 Ebola outbreak in West Africa, the largest outbreak worldwide. Urgent implementation of public health interventions to identify cases, trace contacts, and limit transmission are needed to bring the outbreak under control.

Abstract

The first 100 days after identification of an outbreak are important to understanding transmission dynamics, impact of early public health interventions, and trajectory of potential future cases and deaths. A large Ebola disease outbreak in the Democratic Republic of the Congo (DRC), which has become the country’s largest and deadliest, is ongoing. To better understand the current outbreak, this report compared metrics from the first 100 days of this outbreak with those of four past Ebola outbreaks. The historic outbreaks of Ebola disease selected for this comparison include the two largest (the 2014 outbreak in West Africa and a 2018 outbreak in DRC), and the only two previous outbreaks caused by Bundibugyo virus (the 2007 outbreak in Uganda and the 2012 outbreak in DRC). This activity was reviewed by CDC, deemed not research, and conducted consistent with applicable federal law and CDC policy.*

Source: 

Link: http://dx.doi.org/10.15585/mmwr.mm7537e1

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Notes from the Field: #Clinical Characteristics of Patients with #Ebola Disease Caused by #Bundibugyo Virus — #Uganda, 2026

 

Summary

    ° What is already known about this topic?

        § Clinical and epidemiologic descriptions of Bundibugyo virus disease (BVD) are rare; case-fatality rates in previous outbreaks have ranged from 32% to 55%. Effective treatments have not been described.

    ° What is added by this report?

        § Among the first 21 cases (20 confirmed; one probable) in the 2026 Uganda BVD outbreak, 18 were admitted to the Mulago National Referral Hospital Ebola Treatment Unit (ETU). Among these 18, all had elevated liver enzymes, hypoalbuminemia, and hyponatremia on ETU admission. All 18 received treatment with remdesivir through an off-label, compassionate-use protocol. Among 20 confirmed cases, 18 (90%) patients survived; two deaths occurred among patients with confirmed cases whose infections were recognized late. Seeking care promptly might have reduced the number of deaths.

    ° What are the implications for public health practice?

        § Communicating with the public about the benefits of seeking health care promptly when BVD is suspected might improve patient outcomes. Clinical trials of remdesivir for patients with BVD might be warranted.

Abstract

    Ebola disease is a viral hemorrhagic fever caused by viruses of the genus Orthoebolavirus. Bundibugyo virus (Orthoebolavirus bundibugyoense), first identified in 2007 in Bundibugyo District, Uganda, is one of four orthoebolaviruses known to cause Ebola disease in humans; only two previous Bundibugyo virus disease (BVD) outbreaks have been documented. Transmission occurs through direct contact with infectious blood or other body fluids. Common signs and symptoms include fever, abdominal pain, diarrhea, vomiting, weakness, and bleeding from orifices and injection sites. Case-fatality rates (CFRs) among confirmed cases in the two previous outbreaks ranged from 32% to 55% (1,4). No licensed vaccine or specific treatment is available for BVD; clinical management is primarily supportive. On May 15, 2026, the Uganda Ministry of Health confirmed an outbreak of BVD imported from the neighboring Democratic Republic of the Congo (DRC). On August 26, 2026, the outbreak was declared over in Uganda with 20 confirmed BVD cases and one probable case reported, although the outbreak in DRC is ongoing. This report describes the clinical and epidemiologic characteristics of all 21 cases. This activity was reviewed by CDC, deemed not research, and conducted consistent with applicable federal law and CDC policy.*

Source: 

Link: http://dx.doi.org/10.15585/mmwr.mm7535a2

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Early Action #Review of #Detection, Notification, and #Response Timeliness during Cross-Border #Bundibugyo Virus Disease #Outbreak, #Uganda, 2026

 

Abstract

Bundibugyo virus disease (BVD), an Ebola virus species with no licensed vaccine or therapeutic, reemerged in May 2026 as a cross-border outbreak in Uganda and the Democratic Republic of the Congo. During a 2-day workshop, July 8–9, 2026, we conducted an early action review of the outbreak response using the 7-1-7 framework (7 days to detect, 1 day to notify, 7 days to complete early response actions) to assess timeliness and identify bottlenecks and enablers across 9 response pillars. Uganda declared its outbreak on May 15, 2026; by July 8, the country had recorded 20 confirmed cases (15 imported, 5 locally transmitted) and a case-fatality rate of 15%. Uganda met all 3 targets: detection in 6 days, notification in <1 day, and response completion in 2 days. Low clinical suspicion, cross-border data-sharing gaps, fragmented digital systems, and delayed community engagement were common bottlenecks; strong leadership and coordination structures were most cited enablers.

Source: 

Link: https://wwwnc.cdc.gov/eid/article/32/10/26-1411_article

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#Bundibugyo at the #Border: The 2026 #Ebola #Outbreak and the Case for Pre-emptive #Countermeasure #Equity

 

Abstract

The 2026 Ebola outbreak caused by Bundibugyo ebolavirus in the Democratic Republic of the Congo and Uganda exposes a persistent structural flaw in global health security: preparedness remains overwhelmingly reactive and pathogen-specific. Despite the $518 million Africa CDC-WHO joint continental plan, no licensed BDBV vaccine or therapeutic is available; a 21-day (three-week) detection delay and cross-border transmission expose inadequate inter-epidemic investment in non-Zaire ebolavirus countermeasures. We argue for sustained, ring-fenced financing, institutionalised cross-border coordination, species-inclusive diagnostics, and real-time genomic data sharing to move African Ebola preparedness from reactive to pre-emptive.

Source: 

Link: https://www.sciencedirect.com/science/article/pii/S1477893926000682?via%3Dihub

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Operational #epidemiology of the early phase of the 2026 #Bundibugyo virus disease #outbreak in the #DRC and #Uganda

 

Abstract

The 2026 Bundibugyo virus disease outbreak in the Democratic Republic of the Congo (DRC) and Uganda occurred in a fragile cross-border setting marked by delayed recognition, diagnostic uncertainty, insecurity, population mobility, community mistrust, and healthcare-worker exposure. We conducted a retrospective operational epidemiology study using official situation reports, public health declarations, ministry statements, WHO and Africa CDC updates, cross-border communiqués, and selected partner statements. This analysis reflects publicly available data from the early outbreak period, with the primary DRC data lock on 27 May 2026 and Uganda and regional triangulation through 29 May 2026. We reconstructed the early timeline, described epidemiological and geographic progression, quantified response indicators, and applied a transparent health-zone prioritization framework. The earliest documented symptom onset was 24 April 2026. The Institut National de Recherche Biomédicale (INRB) detected non-Zaire ebolavirus in eight of 13 samples on 14 May, giving a 20-day symptom-onset-to-first-laboratory-detection interval; species-level Bundibugyo virus confirmation and official declaration followed on 15 May. By the DRC data lock on 27 May, 125 confirmed cases and 17 confirmed deaths had been reported, giving a confirmed case fatality ratio of 13.6%. DRC also reported 906 suspected cases and 223 suspected deaths, giving a suspected fatality proportion of 24.6%. Confirmed cases expanded from three to 13 health zones across three provinces within 12 days. Ituri province accounted for 110 confirmed cases (88.0%); Bunia, Rwampara, and Mongbwalu health zones together contributed 90 cases (72.0%). Uganda reported nine confirmed cases and one death by 29 May. Operational pressure included 2,635 listed contacts in DRC, 436 contacts under follow-up in Uganda, and 126 of 774 collected samples (16.3%) pending testing in DRC. Healthcare workers represented 16 of 125 DRC confirmed cases (12.8%) and at least three of nine Uganda cases (33.3%). Applying the health-zone prioritization framework, Rwampara, Mongbwalu, and Bunia were classified as higher priority health zones. Excluding confirmed burden did not change any health-zone tier; data classification confidence was high for 10 zones and moderate for three. Within this early operational snapshot, outbreak visibility reflected both transmission and operational factors, particularly detection delay, laboratory backlog, cross-border movement, healthcare-linked exposure, and community trust or security incidents. The framework provides a transparent basis for rapid decision support during an outbreak’s early phase by directing surveillance, laboratory, case-management, infection prevention and control, contact-tracing, and community-engagement resources toward health zones where multiple operational risks converge.

Source: 

Link:https://journals.plos.org/globalpublichealth/article?id=10.1371/journal.pgph.0006680

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#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

 

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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

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    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.

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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

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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

 

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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.

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    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

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#Ebola Bundibugyo Virus Disease Outbreak, #DRC & #Uganda - Situation #Report 12, Data as of 02 August 2026 (WHO, edited): 3802 cases & 1707 deaths in DRC

 

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Event description  

    The Bundibugyo virus disease (BVD) outbreak in the Democratic Republic of the Congo continues to expand rapidly, with sustained transmission, persistently high mortality, and ongoing geographic spread. 

    It is now the largest BVD outbreak ever recorded and the second largest Ebola disease outbreak in history after the 2013 – 2016 West Africa epidemic. 

    Since its detection only a few months ago, the epidemic has grown at an exceptional rate, highlighting its intensity and the challenges facing response efforts. 

    Although no new international spread has been detected, continued transmission indicates that the outbreak remains in an expansion phase and continues to pose a high risk of regional and international spread. 

Democratic Republic of the Congo 

    Since the last update of 26 July 2026 (Weekly External Situation Report #11), the Democratic Republic of the Congo has reported an additional 540 confirmed cases and 270 confirmed deaths, representing increases of 16.6% and 18.8%, respectively, in cumulative confirmed cases and deaths. 

    Although the absolute numbers of newly reported cases and deaths remain substantial, the proportional increases are markedly lower than those reported during the previous reporting period, reflecting the absence of the large retrospective data reconciliation that contributed to last week's increase. 

    Nevertheless, the reporting of more than 500 additional confirmed cases and more than 250 confirmed deaths within a single week indicates that transmission remains intense and that the outbreak continues to expand. 

    The crude case fatality ratio (CFR) increased from 44.1% to 44.9%, reflecting persistently high mortality despite ongoing response efforts. 

    During the reporting period, the cumulative number of affected health zones increased from 48 to 51, with Kabondo and Wanie-Rukula in Tshopo Province and Lubero in North Kivu Province becoming the latest affected health zones, further demonstrating the continued geographic expansion of the outbreak. 

Figure 1.  Weekly trend of confirmed cases of Bundibugyo virus disease in the Democratic Republic of the Congo by epidemiological week of notification, epidemiological weeks 18 – 31, 2026 

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    During the last 21 days, transmission remained highly concentrated geographically, with an additional 1,867 confirmed cases and 953 confirmed deaths reported nationally. 

    Approximately 87.9% (n=1,641) of recently reported confirmed cases and 84.8% (n=808) of deaths occurred in Ituri Province, with the Bunia–Rwampara–MongbwaluNizi corridor continuing to represent the principal transmission focus. 

    North Kivu, Haut-Uélé, and Tshopo together accounted for 223 cases (11.9%) and 144 deaths (15.1%), while South Kivu reported no new confirmed cases. 

    However, an imported confirmed death from Tshopo Province generated new contacts requiring follow-up in South Kivu. 

    Of the 51 affected health zones, 42 reported at least one confirmed case during the preceding 21 days, whereas nine health zones (Gety, Kambala, Lubunga, Mangobo, Mabalako, Makiso-Kisangani, Miti-Murhesa, Rungu, and Vuhovi) have not reported a confirmed case for more than three weeks, suggesting that transmission may have been interrupted in these areas, provided surveillance remains sufficiently sensitive to detect any ongoing transmission. 

    The largest increases in confirmed cases over the previous 21 days were recorded in Bunia (312 cases), Nizi (285), Rwampara (216), Mongbwalu (207), Katwa (104), Lita (84), Nia-Nia (66), Mangala (63), Fataki (31), and Butembo (29). 

    Together, these ten health zones accounted for approximately 84% of all additional confirmed cases reported nationally during the period. 

    Bunia, Nizi, Mongbwalu, and Rwampara remained the principal transmission corridor, accounting for nearly 55% of all newly reported confirmed cases. 

    Continued increases in Lita, Nia-Nia, Mangala, and Fataki indicate sustained transmission within the Ituri epicentre, while ongoing transmission in Katwa and Butembo confirms persistent transmission in North Kivu. 

    Continued increases in Isiro and Wamba further indicate that the outbreak is becoming increasingly established in Haut-Uélé Province.  

    Mortality remained concentrated within the same transmission corridor driving the epidemic. 

    More than half (55.4%) of all confirmed deaths continue to occur outside designated treatment facilities, indicating that many patients are still being detected only late in illness or after death. 

    Delayed case detection and delayed access to specialised treatment therefore remain major contributors to mortality. 

    Recent analyses indicate a median interval of eight days from symptom onset to death, with almost half of deaths occurring within the first week of illness, emphasizing the narrow window available for life-saving clinical intervention.  

(...)

    Children younger than five years continue to experience disproportionately high mortality. 

    Although they account for fewer than one in ten confirmed cases nationally, they represent approximately 17% of all confirmed deaths, experience the highest case fatality ratios of any age group, and have the shortest interval between symptom onset and death. 

    Conversely, adults aged 20 – 59 years continue to account for most transmission, representing nearly two-thirds of confirmed cases. These findings suggest that outbreak control should continue to prioritise interrupting transmission among working-age adults while simultaneously strengthening rapid identification and referral of young children to reduce mortality. 

(...)

    Surveillance performance remains suboptimal. As of 2 August 2026, 18,276 contacts were under follow-up nationally, of whom 14,466 (79.2%) were successfully seen during the previous 24 hours, remaining well below the operational target of 95%. 

    Contact tracing capacity continues to lag behind the growing number of contacts to follow, particularly in Ituri and North Kivu, while persistently low follow-up rates and intermittent reporting in Haut-Uélé and Tshopo limit interpretation of recent trends.  

(...)

    Since the beginning of the outbreak, the Democratic Republic of the Congo has reported 3,802 confirmed cases, including 1,707 confirmed deaths, corresponding to a crude CFR of 44.9%. 

    The outbreak now affects 51 health zones across five provinces. Ituri Province remains the epicentre, accounting for 3,317 confirmed cases (87.2%) and 1,382 confirmed deaths (81.0%) nationwide. 

    The most affected health zones remain Bunia (914 cases, 270 deaths), Rwampara (655 cases, 263 deaths), Mongbwalu (552 cases, 263 deaths), Nizi (402 cases, 194 deaths), Lita (141 cases, 84 deaths), and Nyankunde (115 cases, 34 deaths) in Ituri Province, together with Katwa (186 cases, 122 deaths) and Butembo (87 cases, 69 deaths) in North Kivu Province. Collectively, these health zones account for the overwhelming majority of confirmed cases and deaths reported nationwide. 

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Uganda and France  

    No new cases have been reported in Uganda or France since the previous update. 

    In Uganda, the last confirmed patient was discharged on 16 July 2026, and 17 days have passed without a new confirmed case. 

    All identified contacts have completed the required 21-day follow-up, and no contacts remain under active monitoring. 

    In France, the imported confirmed BVD case reported on 24 June 2026 recovered and was discharged on 4 July 2026 after two consecutive negative PCR test results. 

    No secondary transmission was identified, and all five flight contacts completed their 21-day follow-up without developing symptoms. 

    As of 2 August 2026, 29 days have passed since the patient's discharge without any additional confirmed BVD cases being reported from France. 

    Despite the absence of new cases, Uganda remains at high risk of reintroduction because of the ongoing outbreak in the neighbouring Democratic Republic of the Congo. 

Risk Assessment 

    The overall public health risk in the Democratic Republic of the Congo remains very high. The outbreak continues to expand, with sustained transmission, persistently high mortality, and continued spread to newly affected health zones. 

    Transmission remains concentrated within the Bunia–Rwampara–Mongbwalu–Nizi corridor, while ongoing spread in Haut-Uélé and Tshopo indicates progressive geographic expansion beyond the original epicentre. 

    The risk of further national and international spread remains high because transmission continues along major internal and cross-border mobility corridors linking the outbreak to Uganda, South Sudan, and other neighbouring countries. 

    Although Uganda and France have reported no additional cases since their previous imported events, sustained transmission in eastern Democratic Republic of the Congo continues to pose a significant risk of crossborder spread. Continued cross-border surveillance, rapid information sharing, and preparedness remain essential to ensure early detection and rapid containment of any imported cases. 

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Situation interpretation 

    The BVD outbreak in the Democratic Republic of the Congo remains in an expansion phase despite an increasingly robust response. 

    Persistently high mortality, frequent community deaths, delayed case detection, and suboptimal contact tracing continue to sustain transmission, while weak infection prevention and control in health facilities contributes to ongoing healthcare-associated transmission. 

    Although response capacity has expanded substantially, including laboratory services, case management, logistics, and regional preparedness, further progress will depend on rapidly improving early case detection, achieving high-quality contact tracing, strengthening infection prevention and control, reducing community deaths through earlier access to treatment, and maintaining coordinated crossborder preparedness to prevent regional and international spread. 

Source: 

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

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A #review of #Bundibugyo virus and the 2026 #outbreak: lessons for #epidemic #preparedness

 

Summary

The ongoing 2026 outbreak of Ebola virus disease caused by Bundibugyo virus (BDBV) in the Democratic Republic of the Congo and Uganda has renewed attention to one of the least studied human-pathogenic orthoebolaviruses. Since its discovery in western Uganda in 2007, only two recognised outbreaks of BDBV had been reported, limiting opportunities to define the epidemiology, pathogenesis, diagnosis, clinical spectrum, and optimal management of BDBV or to develop species-specific countermeasures. The current outbreak, declared a Public Health Emergency of International Concern by WHO on May 17, 2026, has also exposed the gap between scientific innovation and operational readiness. Although pan-filovirus diagnostics, investigational vaccines, therapeutics, and adaptive clinical trial platforms are now available, their deployment has been constrained by delayed diagnosis, limited access to species-inclusive diagnostics, insecurity due to conflict, population displacement, and fragile health systems. In this Review, we synthesise evidence on BDBV from its discovery to the current 2026 outbreak, highlighting advances in epidemiology, clinical management, diagnostics, vaccines, therapeutics, and preparedness. More broadly, the outbreak shows that scientific innovation alone is insufficient; its public health impact depends on integrated, species-inclusive systems capable of rapidly detecting, evaluating, and responding to outbreaks caused by any human-pathogenic Orthoebolavirus spp.

Source: 

Link: https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(26)00414-7/fulltext

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#BUNDIBUGYO VIRUS DISEASE #OUTBREAK, #DRC, #Uganda, #France - Situation #Report 11, as of 26 July 2026 (WHO, summary): 3262 cases & 1437 deaths in DRC

 

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Event description  

    ° The Bundibugyo virus disease (BVD) outbreak in the Democratic Republic of the Congo continued to intensify during the reporting period, with sustained transmission, increasing mortality, and ongoing geographic expansion within the country. 

    ° The cumulative number of reported cases has exceeded the two previously documented Bundibugyo virus disease outbreaks, making this the largest outbreak caused by the Bundibugyo virus to date. 

    ° Although no new cases have been reported outside the Democratic Republic of the Congo, persistent transmission in areas connected by major national and cross-border mobility corridors continues to sustain a high risk of regional spread. 

    ° These epidemiological trends underscore the need for strengthened surveillance, cross-border collaboration, and preparedness to rapidly detect and contain any international spread. 

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Situation interpretation 

    ° The BVD outbreak in the Democratic Republic of the Congo continues to intensify despite the ongoing scale-up of response operations. 

    ° The sustained increase in transmission and mortality indicates that the outbreak remains uncontrolled. 

    ° Although transmission remains concentrated within a number of interconnected health zones, its continued expansion into adjacent areas suggests that current interventions have not yet been sufficient to reduce transmission intensity or halt the geographic spread of the outbreak. 

    ° The persistently high proportion of community deaths, suboptimal contact follow-up, and critically weak IPC capacity indicate that many transmission chains continue to be detected too late to prevent onward spread. 

    ° Although no international spread has been reported during the current reporting period, sustained transmission along major domestic and cross-border mobility corridors continues to pose a substantial risk of regional spread. 

    ° Strengthening early case detection, community engagement, IPC, and coordinated cross-border preparedness remains critical to interrupt transmission and reduce the risk of further national and international spread. 

Source: 

Link: https://www.afro.who.int/countries/democratic-republic-of-congo/publication/ebola-bundibugyo-virus-disease-outbreak-3

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#BUNDIBUGYO VIRUS DISEASE #OUTBREAK: #DRC, #Uganda, #France - Situation Report No. 10, as of 19 July '26 (WHO, edited): 2423 cases & 967 deaths in DRC

 

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Event description  

    ° Transmission of Bundibugyo virus disease (BVD) remained intense in the Democratic Republic of the Congo during the reporting week, with continued detection of new confirmed cases and deaths across multiple affected areas, alongside further expansion of the outbreak's geographic footprint. 

    ° The epidemiological situation outside the Democratic Republic of the Congo remained stable, with no new cases or evidence of secondary transmission reported in Uganda or France. 

    ° However, the persistence and geographic expansion of transmission within the Democratic Republic of the Congo continue to increase the risk of cross-border spread, highlighting the need for sustained regional surveillance, preparedness, and response efforts. 

Democratic Republic of the Congo 

    ° Since the last update of 12 July 2026 (Situation Report #9), the epidemiological situation in the Democratic Republic of the Congo has continued to deteriorate, with sustained transmission and ongoing geographic expansion. 

    ° An additional 460 confirmed cases and 248 confirmed deaths have been reported, representing increases of 23.4% and 34.5% in cumulative confirmed cases and confirmed deaths, respectively. 

    ° The crude case fatality ratio (CFR) among confirmed cases increased from 36.6% to 39.9%, likely reflecting delayed case detection, late presentation for care, and the persistently high proportion of deaths occurring outside designated treatment facilities, rather than increased disease severity. 

    ° During the reporting period, the outbreak expanded to five additional health zones across Haut-Uélé and Ituri provinces, increasing the total number of affected health zones from 42 to 47. 

    ° The newly affected health zones were Pawa, Boma Mangbetu, and Isiro in Haut-Uélé Province, and Mahagi and Adja in Ituri Province. 

Figure 1.  Weekly trend of confirmed cases of Bundibugyo virus disease in the Democratic Republic of the Congo by epidemiological week of report, epidemiological weeks 18 – 29, 2026 

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    ° Despite this continued geographic expansion, recent transmission remains concentrated in a subset of affected areas. 

    ° Of the 47 affected health zones, 40 have reported at least one confirmed case during the past 21 days. 

    ° During this period, 1,090 confirmed cases and 568 confirmed deaths were reported. 

    ° Ituri Province continues to bear the overwhelming burden of the outbreak, accounting for 946 cases (86.8%) and 476 deaths (83.8%), while the remaining four affected provinces together accounted for 144 cases (13.2%) and 92 deaths (16.2%). 

    ° In contrast, seven affected health zones have now gone more than 21 consecutive days without reporting a confirmed case, suggesting an absence of recent transmission, provided that surveillance remains sufficiently sensitive to detect ongoing transmission. 

    ° These health zones include Miti-Murhesa (60 days) in South Kivu Province; Aungba (30 days) and Gety (59 days) in Ituri Province; and Goma (55 days), Kalunguta (56 days), Mabalako (36 days), and Vuhovi (38 days) in North Kivu Province. 

    ° Recent transmission remained highly concentrated in a limited number of health zones. 

    ° The largest increases over the 21-day period were recorded in Bunia (281 cases), Nizi (173), Rwampara (155), Mongbwalu (105), Katwa (59), Lita (49), Nia-Nia (40), Mangala (37), and Bambu and Butembo (24 each). Together, these ten health zones accounted for approximately 86.9% of all additional confirmed cases reported during the period. 

    ° Bunia, Rwampara, Mongbwalu, and Nizi remained the principal transmission corridor. 

    ° The rapid increase in cases in Nizi, a health zone hosting several internally displaced persons (IDP) camps, together with the emergence of cases in Adja Health Zone, indicates continued westward and northward expansion of transmission within Ituri Province. 

    ° Mortality was similarly concentrated. The largest increases in confirmed deaths over the same 21-day period were reported in Bunia (129 deaths), Nizi (84), Mongbwalu (80), Rwampara (73), Katwa (45), Mangala (26), Lita (18), Butembo (16), Nyankunde (13), and Beni (11). 

    ° Collectively, these ten health zones accounted for approximately 87.0% of all additional confirmed deaths reported during the period. 

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    ° Overall, the distribution of confirmed deaths remained heavily skewed towards deaths occurring outside designated treatment centres, highlighting persistent delays in case detection, referral, and access to treatment. 

    ° Between 24 June and 19 July 2026, 673 confirmed deaths were reported, of which 400 (59.4%) occurred outside designated treatment centres and 273 (40.6%) occurred within designated treatment centres. 

    ° During the most recent reporting week (13 – 19 July 2026), mortality remained high, with community deaths (defined as deaths occurring outside designated treatment centres) accounting for 65.4% of all reported deaths, compared with 34.6% occurring within designated treatment centres. 

    ° This persistent predominance of community deaths suggests that delays in case detection, referral, and timely access to treatment continue to contribute substantially to mortality and underscore the need to strengthen community surveillance, rapid referral, and early access to care. 

    ° Since the beginning of the outbreak, the Democratic Republic of the Congo has reported 2,423 confirmed cases, including 967 confirmed deaths, corresponding to a crude case fatality ratio (CFR) of 39.9%. 

    ° Ituri Province remains the epicentre, accounting for 2,160 confirmed cases (89.1%) and 811 confirmed deaths (83.9%) reported nationally. 

    ° The most affected health zones continue to be Bunia (639 cases, 211 deaths), Rwampara (450 cases, 133 deaths), Mongbwalu (363 cases, 203 deaths), Nizi (214 cases, 93 deaths), Nyankunde (99 cases, 28 deaths), Lita (78 cases, 27 deaths), and Mangala (61 cases, 38 deaths) in Ituri Province, together with Katwa (104 cases, 72 deaths), Butembo (58 cases, 30 deaths), and Beni (37 cases, 25 deaths) in North Kivu Province. 

    ° Collectively, these ten health zones account for approximately 86.8% of all confirmed cases (2,103 of 2,423) and 88.9% of all confirmed deaths (860 of 967) reported nationally, demonstrating that, despite continued geographic expansion, the burden of the outbreak remains highly concentrated. 

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    ° As of 19 July 2026, a total of 10,519 contacts were under follow-up in the Democratic Republic of the Congo, of whom 8,531 (81.1%) were successfully seen within the previous 24 hours. 

    ° Ituri Province accounted for the majority of contacts under follow-up, with 7,537 contacts, including 6,123 (81.3%) successfully seen during the reporting period. 

    ° In North Kivu Province, 1,801 of 2,149 contacts (83.8%) were successfully followed up, while Haut-Uélé Province, one of the newly affected provinces, reported 607 contacts, of whom only 317 (52.3%) were seen within the previous 24 hours. 

    ° South Kivu Province had no contacts under active follow-up, reflecting the absence of recent transmission requiring contact monitoring, whereas contact follow-up data for Tshopo Province were not reported.  

    ° The overall contact follow-up rate remains below the operational target for effective contact tracing. Although follow-up performance in Ituri Province improved slightly compared with previous weeks, more than 1,400 contacts were not reached during the reporting period. The markedly low follow-up rate in Haut-Uélé Province is of particular concern given the recent geographic expansion of the outbreak. These gaps increase the risk of undetected infections, missed chains of transmission, and sustained community transmission in both established and newly affected areas. 

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Uganda  

    ° No new confirmed cases have been reported in Uganda since the previous update. 

    ° The most recent confirmed case, reported on 21 June 2026, was identified in a truck driver travelling along the Democratic Republic of the Congo Uganda international route. 

    ° Since then, no additional imported or locally acquired cases have been detected, and there is no evidence of ongoing transmission.  

    ° As of 19 July 2026, the outbreak remains limited to 21 cases (20 confirmed and one probable), including three deaths (two confirmed and one probable). 

    ° All 18 recovered patients have now been discharged from care, with the last confirmed patient discharged on 16 July 2026. 

    ° Since the beginning of the outbreak, 836 contacts have been identified, all of whom successfully completed the required 21-day follow-up period, during which six secondary cases were detected. 

    ° No contacts are currently under follow-up, reflecting the absence of active transmission chains.  

    ° Following the discharge of the last confirmed patient on 16 July 2026, Uganda entered the 42-day countdown required to declare the end of the outbreak. As of 19 July 2026, the country was on Day 5 of the countdown. 

    ° Nevertheless, Uganda remains at high risk of reintroduction due to the ongoing outbreak in the neighbouring Democratic Republic of the Congo. 

    ° Continued population movement across the shared border underscores the importance of maintaining cross-border coordination, surveillance, rapid case detection, and response readiness until transmission has been interrupted in both countries. 

Figure 5.  Weekly trends of confirmed cases of Bundibugyo virus disease in Uganda by epidemiological week of report, epidemiological weeks 18 – 29, 2026 

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France 

    ° No additional Bundibugyo virus disease (BVD) cases have been reported in France since the previous update. 

    ° No secondary transmission has been identified among the five flight contacts who were placed under precautionary quarantine following exposure to the imported case reported on 24 June 2026. 

    ° All five flight contacts successfully completed the 21-day monitoring period. 

Risk Assessment 

    ° The overall public health risk in the Democratic Republic of the Congo remains very high, driven by sustained transmission, increasing mortality, and continued geographic expansion from three to five affected provinces. 

    ° Although transmission remains concentrated in Ituri Province, the emergence of newly affected health zones in HautUélé and Tshopo provinces highlights the continued potential for spread into previously unaffected areas. 

    ° The rising CFR and the high proportion of community deaths continue to indicate delays in case detection, isolation, referral, and access to clinical care. 

    ° Contact tracing performance remains below the operational target, particularly in Ituri Province, where follow-up coverage is substantially lower than in North Kivu despite Ituri accounting for the majority of ongoing transmission. 

    ° Uganda remains at high risk of reintroduction because of the ongoing outbreak in neighbouring Democratic Republic of the Congo, despite reporting no new cases during the reporting period. 

    ° The absence of secondary transmission following the imported case in France demonstrates the effectiveness of rapid public health measures, but also underscores the continued risk of international spread through travel.  

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Situation interpretation 

    ° The BVD outbreak in the Democratic Republic of the Congo continues to intensify despite the ongoing scale-up of response operations. 

    ° Although transmission remains highly concentrated in a limited number of health zones in Ituri Province, continued geographic expansion into Haut-Uélé and Tshopo provinces indicates that new transmission foci continue to emerge. 

    ° Persistently high mortality, driven by the large proportion of deaths occurring outside designated treatment centres, together with a rising CFR, indicates that many patients are still being detected and referred too late to benefit from optimal clinical care. 

    ° While surveillance, laboratory, case management, and operational capacities continue to expand, important gaps remain in contact tracing, infection prevention and control, and community engagement, particularly in newly affected areas. 

    ° Strengthening early case detection, improving contact follow-up, expanding timely access to clinical care, reinforcing infection prevention and control measures in healthcare settings, and sustaining community trust and cross-border preparedness will be critical to interrupt transmission and reduce mortality 

Source: 

Link: https://www.afro.who.int/countries/uganda/publication/ebola-bundibugyo-virus-disease-outbreak-democratic-republic-congo-4

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