Nationwide Increase in Reported #Human #Rabies #Exposures: Rabies #PEP Administration (US CDC, HAN, Sept. 10 '26, Summary)

 

Summary

    The Centers for Disease Control and Prevention (CDC) is issuing this Health Alert Network (HAN) Health Advisory in response to recent reports of increases in human exposures to rabid or possibly rabid animals and rabies post-exposure prophylaxis (PEP) administration errors. 

    Since July 2026, multiple United States jurisdictions have reported local increases in human rabies exposures involving known rabies vectors or animals in which rabies is less commonly reported. 

    Several high-profile rabies outbreaks and mass rabies exposure events have highlighted the importance of performing careful rabies risk assessments and following evidence-based recommendations for administering PEP. 

    Health departments can help clinicians who provide rabies vaccination in their jurisdictions stay aware of the importance of rabies risk assessments before administering PEP. 

    Clinicians and healthcare facilities can work to make sure that PEP is administered only when appropriate and that human rabies immune globulin (HRIG) and rabies vaccines are administered according to Advisory Committee on Immunization Practices (ACIP) recommendations.

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Source: 

Link: https://www.cdc.gov/han/php/notices/han00533.html

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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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Toward #medical #countermeasures against #hantaviruses

 

Abstract

Hantaviruses are zoonotic threats that can cause hemorrhagic fever with renal syndrome and severe cardiopulmonary syndrome. Despite disease severity, there are no approved vaccines or therapeutics available for the prevention or management of hantavirus infections. Here, we discuss advances in the development of vaccines, neutralizing antibodies, and small-molecule antiviral therapeutics.

Source: 

Link: https://doi.org/10.1016/j.chom.2026.08.002

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#Ebola disease caused by #Bundibugyo virus - #DRC (WHO, September 10 '26): 6,757 cases and 3,267 deaths so far

 

Situation at a glance

    Since the last Disease Outbreak News was published on 28 August 2026, the Bundibugyo virus outbreak in the Democratic Republic of the Congo has expanded to one additional health zone, Kayna, in North Kivu. 

    This increase brings the total number of affected health zones to 61 across six out of 26 provinces of the country: Bas-Uélé, Haut-Uélé, Ituri, North Kivu, South Kivu, and Tshopo. 

    As of 7 September 2026, the Democratic Republic of the Congo has reported 6757 confirmed cases, including 3267 deaths, resulting in a crude case fatality ratio (CFR) of 48.3%. 

    The transmission dynamics remain variable across affected locations, with evidence of ongoing geographical expansion and sustained increase in cases in some health zones. 

    The continuously high CFR highlights the seriousness of the disease and persistent challenges in timely case detection, access to early and adequate patient care, and effective interruption of transmission. 

    Delayed detection of cases continues to increase the risk of further spread within households, communities, and healthcare settings.

Description of the situation

    Since the publication of the previous Disease Outbreak News on 28 August 2026, additional confirmed cases and deaths of Bundibugyo virus disease (BVD) have been reported only in the Democratic Republic of the Congo.

    As of 7 September 2026, a cumulative total of 6778 confirmed cases has been reported: 6757 in the Democratic Republic of the Congo (including two cases diagnosed in the Democratic Republic of the Congo and subsequently treated in Germany), 20 cases in Uganda and one case in France. 

    Overall, 3269 deaths have been reported, including two in Uganda. 

    As of 7 September, at least 1611 patients have recovered, including 1590 in the Democratic Republic of the Congo, 18 in Uganda, two in Germany and one in France.

    The sustained level of transmission in the Democratic Republic of the Congo continues to pose a risk of cross-border spread. Health screening and surveillance activities remain operational at airports, ports, and official land border crossings; however, travel through informal crossing routes persists and may facilitate virus exportation, importation, and subsequent transmission. In this context, strengthened cross-border coordination, together with ongoing surveillance and preparedness efforts, remains critical to limiting further regional spread and supporting an effective public health response.

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Democratic Republic of the Congo

    Since the previous Disease Outbreak News was published on 28 August 2026, an additional 963 confirmed cases, including 481 confirmed deaths, have been reported in the Democratic Republic of the Congo. 

    While part of this increase may be attributable to strengthened surveillance activities, enhanced laboratory testing, improved diagnostic capacity, and reconciliation of previously unreported data, the continued growth in both cases and deaths also reflects sustained community transmission and significant geographic expansion of the outbreak. 

    As of 7 September, the Democratic Republic of the Congo has reported a total of 6757 confirmed cases, including 3267 deaths (CFR 48.3%). 

    A total of 1590 patients have recovered to date.

    Confirmed cases have been reported from 61 health zones (HZ) across six provinces, with 51 HZ from five provinces reporting at least one case in the last 21 days. 

    Ituri remains the most affected province, with 28 of its 36 health zones reporting cases, followed by North Kivu (16/34), Tshopo (7/23), Haut-Uélé (6/13), Bas-Uélé (3/11), and South Kivu (1/34). 

    No new cases have been reported from South Kivu province since 29 May 2026. 

    Kayna HZ in North Kivu province is the most recently affected area. 

    As of 7 September, 71 new confirmed cases had been reported in the preceding 24 hours from 17 health zones located in Ituri, North Kivu, and Haut-Uélé provinces.

    Ituri continues to be the epicentre of the outbreak, accounting for 5406 confirmed cases since the start of the outbreak, including 1114 new confirmed cases reported in the previous 21 days, as of 7 September. 

    North Kivu is the second most affected province, with a cumulative number of 1066 confirmed cases, including 453 reported in the last 21 days, as of 7 September. 

    One of the highest CFR (65.4%) observed in this outbreak has been reported from North Kivu province; and investigations are ongoing to better understand the factors contributing to this elevated mortality rate.

    The number of individuals requiring follow-up as contact has also risen considerably with the expansion of the outbreak. 

    As of 7 September, 85.3% of identified contacts were successfully monitored during the previous 24 hours with 21 359 contacts seen out of 24 719 requiring follow up. 

    The large volume of contacts under surveillance highlights the extent of potential exposure within affected communities and the substantial demands placed on response operations.

    The outbreak continues to unfold within a complex humanitarian setting characterized by insecurity, armed conflict, and widespread population displacement. 

    More than 26 million people are experiencing acute food insecurity, while approximately one million internally displaced persons reside in Ituri Province alone. 

    Ongoing insecurity and displacement limit access to healthcare and essential services, constrain the ability of response teams to reach affected areas, and impede surveillance, case investigation and contact tracing activities. 

    Overcrowding, limited water, sanitation and hygiene services, and restricted access to healthcare in mining communities, informal settlements and sites for internally displaced persons further undermine early case detection, infection prevention and control measures, and the provision of timely care. These conditions also reduce the effectiveness of response interventions and outreach efforts.

Figure 2: Number of confirmed Bundibugyo virus disease cases in the Democratic Republic of the Congo, by date of notification, as of 7 September 2026

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Figure 3: Number of deaths among confirmed Bundibugyo virus disease cases in the Democratic Republic of the Congo by date of notification, as of 7 September 2026. 

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WHO advice

    Based on the currently available information, WHO advises against any restriction of travel to, or trade with, affected countries. 

    WHO continues to closely monitor and, where necessary, verify travel and trade measures in relation to this event.

    The updated Temporary Recommendations issued to States Parties on 24 August 2026 underscore the importance of coordinated outbreak control, strengthened cross‑border collaboration, and sustained surveillance and preparedness to prevent further regional spread and ensure an effective public health response. 

    Rapid recognition of cases, testing and optimized supportive care can reduce mortality, and improve community perceptions and acceptance of health care within the response.

    On 7 August, the WHO Technical Advisory Group on candidate vaccine prioritization released a report regarding possible candidate vaccines for Bundibugyo virus disease. 

    The members recommended that Ervebo, the only licensed Ebola vaccine (previously known as ebolavirus Zaire), be prioritized for inclusion in a randomized clinical trial in the context of the ongoing outbreak in the Democratic Republic of the Congo. 

    Following a review of additional evidence on 19 August 2026, the WHO Strategic Advisory Group of Experts on Immunization (SAGE) concluded that available evidence remains insufficient to support the programmatic use of Ervebo for the prevention of BVD, and that its efficacy against BVD in humans remains unknown. 

    WHO therefore recommends that Ervebo be used for BVD only within the context of a research protocol.  

    Ervebo vaccination of healthcare and frontline workers is now underway. As of 6 September 2026, a total of 2007 people had been vaccinated across six health zones in three provinces: Tshopo, Bas-Uélé and Ituri.

    On 2 July, a clinical trial to find effective treatments against BVD began patient enrollment on 2 July. The trial, known as the PARTNERS trial, is now open in five different clinical management facilities in Ituri province, and has enrolled over 300 people who are confirmed cases.  

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Source: 

Link: https://www/who.int/emergencies/disease-outbreak.news.item/2026-DON617

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Emergence and spread of NA-I223V and NA-S247N double-mutant #H1N1pdm09 #influenza viruses with reduced #oseltamivir susceptibility in the #Netherlands and beyond, 2023 to 2026

 

Abstract

In 2023/24, A(H1N1)pdm09 influenza viruses with neuraminidase (NA)-S247N emerged in NA-clade C.5.3.3 carrying NA-I223V, spread internationally, then faded. Such double mutants reappeared sporadically in 2024/25. They expanded again in 2025/26 in NA-clade D.3 viruses carrying NA-S247N after acquiring NA-I223V in Europe – notably Spain, the Netherlands, Finland and France, and beyond. Dutch double mutants from both seasons showed median 12- and 13-fold reduced inhibition by oseltamivir. These findings underscore the need for ongoing genomic and phenotypic monitoring of antiviral susceptibility.

© Creative Commons License. This work is licensed under a Creative Commons Attribution 4.0 International License.

Source: 

Link: https://doi.org/10.2807/1560-7917.ES.2026.31.36.2600733

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Autochthonous #chikungunya virus (CHIKV) #outbreak in province of #Modena, Emilia-Romagna region, #Italy, August to October 2025: #epidemiology, clinical features and virological findings

 

Abstract

Between 10 August and 31 October 2025, 343 cases (306 confirmed and 37 probable) of symptomatic autochthonous chikungunya virus (CHIKV) infection were notified in eight municipalities in the province of Modena, Emilia-Romagna region, northern Italy. The infection was diagnosed by detection of CHIKV RNA in blood and urine samples, and by detection of IgM antibodies against CHIKV. Most common symptoms were arthralgia (n = 326) and fever (n = 317). No fatalities were reported. Chikungunya virus RNA was detected in 39 (14.8%) of 263 pools of Aedes albopictus mosquitoes, thereby confirming local vector-borne transmission. Sequences from 11 case samples and two mosquito pools were whole genome sequenced. The viral strain belonged to the East/Central/South African (ECSA) lineage 2 and was closely related to the strains circulating in Reunion Island in 2024–25. The public health response included rapid vector control measures, reinforced epidemiological surveillance and multidisciplinary coordination between public health authorities and clinicians, laboratories and entomologists. This was one of the largest autochthonous CHIKV outbreaks ever recorded in a temperate European region. It highlights the critical importance of integrated, multidisciplinary preparedness and response for arboviral threats in non-endemic areas.

© Creative Commons License. This work is licensed under a Creative Commons Attribution 4.0 International License.

Source: 

Link: https://doi.org/10.2807/1560-7917.ES.2026.31.36.2500962

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#Genomic characterization of Lao #Mobatvirus strains reveals host-associated clustering in Southeast Asian #bats

 

ABSTRACT

While members of the genus Orthohantavirus are well-established human pathogens, the zoonotic potential of bat-associated hantavirids, particularly those within the genus Mobatvirus, remains largely unresolved. To investigate the genetic diversity of these lineages in Southeast Asia, we conducted an expanded surveillance programme in Lao PDR from May 2023 to October 2025 in bat populations and wild animals from local wet markets. Using molecular screening and deep sequencing to characterize hantavirids from bat populations and wild animals from local wet markets, we identified 20 positive samples across four bat species, recovering coding-complete genomes for multiple novel variants. Phylogenetic analysis confirmed that these viruses clustered within Mobatvirus, resolving into two major subclades. The first subclade clustered with Quezon and Robina viruses found in fruit-eating bats. The second subclade further split into two lineages corresponding to Ðakrông and Xuân Sơn viruses, which are associated with trident and leaf-nosed bats, respectively. Despite the strong host association observed, the detection of these viruses in a wet market highlights this setting as a potential human exposure interface. These findings significantly expand the known diversity of mobatviruses in Laos and highlight the urgent need for serological surveillance in at-risk human populations to assess the potential for spillover.

Source: 

Link: https://www.microbiologyresearch.org/content/journal/jgv/10.1099/jgv.0.002333

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#Italy, #WNV & #Usutu Virus Seasonal #Surveillance #Report No. 7, September 10 '26 (ISS, summary): 594 human cases & 41 deaths

 

{Excerpt}

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{Highlights}

    ° Since the beginning of 2026 season in Italy, 594 confirmed human cases of infection with West Nile Virus have been recorded (they were 521 in the last week report). Of these: 

        § 306 were WNND (West Nile Neuroinvasive Disease) (5 imported: 1 from Maldives, 1 France, 1 Belgium, 1 Greece and 1 the Netherlands), 

        § 81 were asymptomatic cases among blood donors, 

        § 202 were West Nile Fever (1 imported case from Burkina Faso), 

        § 4 were cases of unspecified nature, 

        § 1 was an asymptomatic case.

    ° The number of affected provinces has risen to 79 in 19 Regions.

    ° Among confirmed cases, 41 fatalities have been recorded. The case-fatality rate (CFR) among WNND cases is now at 13.3% (last year it was at 15.0%).

    ° So far this season 12 confirmed human cases of infection with Usutu virus have been reported (of which 7 in Lombardy, 1 Emilia-Romagna, 1 Marche, 1 Latium, 1 Piedmont, 1 Veneto).

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Source: 

Link: https://www.epicentro.iss.it/westnile/bollettino/Bollettino_WND_2026_7.pdf

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Updated #H1N1pdm09 #influenza virus #ferret infection #model permits refined #antiviral #assessment using aerosol inhalation challenge

 

Abstract

Seasonal influenza viruses continue to pose a significant threat to human health. As influenza viruses exhibit sustained genetic drift, it is imperative that animal studies utilize challenge strains that reflect contemporary, currently circulating viruses when evaluating pathogenicity, viral tropism, transmissibility, and antiviral sensitivity to better inform public health responses. Ferrets are considered the gold-standard small animal model for assessing currently circulating influenza viruses. Seasonal influenza A(H1N1)pdm09 viruses replicate well in both the upper and lower respiratory tract of ferrets, providing an important model for developing improved vaccination and therapeutic strategies; however, many of these studies have relied on a 2009 virus isolate. Utilising representative influenza A(H1N1)pdm09 virus strains from 2009 to 2022, we explored virus replication kinetics and lung pathogenesis in ferrets following intranasal inoculation with these contemporary strains. Our results revealed strain specific differences, with greater lung viral loads and pathogenesis following inoculation with A/Sydney/5/2021 compared to other strains. Efficient transmissibility of A/Sydney/5/2021 virus to naïve recipients was also observed following both contact and airborne exposure to infected donor ferrets. To refine this updated model, we performed side-by-side evaluation of oseltamivir antiviral efficacy following traditional intranasal or aerosol inhalation influenza challenges. Pre-treatment with oseltamivir demonstrated greater reductions in viral shedding from the upper respiratory tract than post-infection treatment of ferrets infected by aerosol inhalation, while the intranasal route showed reduced oseltamivir efficacy independent of the timing of antiviral treatment. These findings provide the basis for using an updated A(H1N1)pdm09 challenge virus for ferret studies as an alternative to the commonly used, but now less relevant 2009 early pandemic viruses. It also highlights how different methods of virus inoculation can influence outcomes of ferret antiviral studies, with an aerosol challenge model able to demonstrate differences between therapeutic and prophylactic treatments, which were not apparent with an intranasal challenge model.

Source: 

Link: https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1014604

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#Risk factors for #hospital admission and #mortality in patients with #influenza virus #infection: a systematic review and meta-analysis

 

Summary

Background

Identifying risk factors associated with hospital admission and mortality in patients with influenza is crucial for guiding clinical management and public health strategies. To support an update of WHO influenza clinical guidelines, this systematic review and meta-analysis assessed risk factors for hospital admission and all-cause mortality in patients with seasonal influenza.

Methods

We systematically searched Medline, Embase, Cochrane Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature, and Global Health for observational studies published from Jan 1, 2000, until Oct 30, 2025, that enrolled patients of any age with laboratory-confirmed seasonal influenza and reported an adjusted effect estimate for the association between at least one risk factor and hospital admission or all-cause mortality, or both. We conducted inverse-variance random-effects model meta-analyses to summarise the evidence and assessed the certainty of evidence using the GRADE approach. We registered the protocol with PROSPERO, CRD42024535669.

Findings

We identified 35 808 records, of which 63 studies enrolling 2 150 518 participants (mean age 3·6–87·9 years) were eligible. In patients with non-severe influenza, evidence with moderate or high certainty showed that older age (odds ratio 1·72 per 10-year increase for adults [95% CI 1·02–2·89]); cardiovascular disease (2·72 [1·24–5·94]); HIV, immunodeficiency, or immunosuppression (2·70 [1·55–4·70]); chronic respiratory disease (2·24 [1·90–2·64]); and any neurological disease (2·31 [1·65–3·24]) were major risk factors for hospital admission—pregnancy (1·88 [1·73–2·05]), diabetes (1·84 [1·26–2·67]), and malignancy (1·75 [1·12–2·75]) were additional risk factors for hospital admission. In patients with severe influenza, evidence with moderate or high certainty showed that secondary bacterial infection (4·13 [1·53–11·14]), malnutrition (3·29 [1·57–6·89]), sepsis (3·19 [2·08–4·89]), acute kidney injury (2·92 [1·11–7·73]), age 65 years or older (2·47 [2·21–2·75]), chronic cardiovascular disease (2·43 [1·16–5·09]), malignancy (2·21 [1·31–3·72]), and chronic neurological disease (2·08 [1·13–3·83]) were major risk factors for all-cause mortality—any liver disease (1·86 [1·35–2·58]); HIV, immunodeficiency, or immunosuppression (1·79 [1·51–2·13]), and chronic obstructive pulmonary disease (1·74 [1·37–2·20]) were additional risk factors for all-cause mortality.

Interpretation

Age 65 years or older, immunocompromised status, cardiovascular disease, neurological disease, and chronic respiratory disease are major risk factors for hospital admission in patients with non-severe seasonal influenza. Secondary bacterial infection, malnutrition, sepsis, acute kidney injury, age 65 years or older, chronic cardiovascular disease, malignancy, and chronic neurological disease are major risk factors for all-cause mortality in patients with severe seasonal influenza. Our findings support risk stratification and targeted prevention and treatment strategies for seasonal influenza.

Funding

WHO.

Source: 

Link: https://www.thelancet.com/journals/lanres/article/PIIS2213-2600(26)00195-5/abstract?rss=yes

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Increased #receptor #binding and #spike #glycosylation, remodeled immune escape of surging #SARS-CoV-2 subvariant BA.3.2.2/RE.2.2/Cicada

 

Significance

SARS-CoV-2 evolved into distinct phylogenetic clades, generating a series of mutant strains. Notably, variants such as BA.1, BA.2.86, and BA.3.2 deserve special attention as they emerged abruptly at high detection frequencies during specific periods and harbored extensive mutations in the spike protein relative to contemporaneously prevalent strains, often accompanied by unique phenotypic characteristics. In this study, we primarily evaluated the structural and functional features of the BA.3.2.2 S protein, revealing its distinct traits in receptor binding, immune evasion, cross-species transmission, and glycosylation evolution. We observed constrained viral immune escape, as certain antibodies that were nonneutralizing against previously dominant subvariants exhibited neutralizing activity against recently emerged BA.3.2.2. These findings provide mechanistic insights for viral surveillance, vaccines, and therapeutics development.

Abstract

SARS-CoV-2 continues to evolve. The subvariant BA.3.2 (Cicada), a derivative of the Omicron BA.3 subtype first detected in late 2024, harbors multiple spike protein mutations, ORF7 and ORF8 deletions, and has recently evolved sublineages (BA.3.2.1 and BA.3.2.2), rendering it a critical target for epidemiological surveillance. The BA.3.2.2 sublineage, represented by RE.2.2, shows a marked upward trend in late 2025. Using surface plasmon resonance, we found that RE.2.2’s spike (S) protein receptor-binding domain (RBD) exhibits relatively high affinity for human receptor angiotensin-converting enzyme 2, with structural analysis identifying the R493Q reverse mutation as the key determinant. Pseudovirus infection and antibody neutralization assays demonstrated that RE.2.2 exhibited a distinct neutralization profile compared to contemporaneous dominant subvariants. Notably, several antibodies that previously lacked neutralizing activity (e.g., S2K146 and L4.65) to other subvariants regained neutralizing potency against RE.2.2, which was associated with key mutations including G446D. Profiling of RE.2.2 RBD binding to ACE2 orthologs across species showed no significant difference in species tropism from the representative Omicron BA.1. Importantly, RE.2.2 exhibits the newly emerged N-linked glycosylation at spike protein N529 (absent in all other subvariants), a modification potentially associated with immune evasion or spike protein conformational dynamics. In addition, we corroborated the “O-follow-N” glycosylation observation as previously reported, where O-linked glycans preferentially localize near N-glycosylation sites, implying coordinated glycan organization as an extra layer of spike regulation. These findings illuminate the evolutionary characteristics, functional changes, and the constrained virus immune escape of BA.3.2.2 (RE.2.2), providing critical insights into antibody development and variant surveillance.

Source: 

Link: https://www.pnas.org/doi/10.1073/pnas.2614163123

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Increasing spatial scale of #analysis weakens and can mask the #dilution effect for #hantaviruses

 

Abstract

Despite its major implications for biodiversity conservation and public health, the generality of a protective effect of biodiversity on zoonotic pathogen transmission (i.e., the dilution effect) remains strongly debated. This controversy may partly arise from the diversity of analytical approaches used, but also from the spatial scales at which studies are conducted. Here, we explicitly test whether increasing the spatial scale of analysis affects the detection of the relationship between hantavirus infection prevalence and rodent species richness, using a global dataset spanning multiple regions. Although the association between species richness and infection prevalence remains negative across all spatial scales, we show that the magnitude of the dilution effect progressively weakens as spatial aggregation increases and can become statistically non-significant at coarse spatial resolutions. These results, which are consistent across world regions, indicate that the dilution effect is likely a general feature of hantavirus–rodent systems, but that its empirical detection is highly sensitive to the spatial scale of analysis. Our findings highlight how large-scale spatial aggregation can mask underlying ecological processes and emphasize the need to carefully match spatial scale to the biological mechanisms under investigation when testing biodiversity–disease relationships. Finally, we discuss the ecological and methodological mechanisms that may obscure dilution effects and outline why scale-explicit approaches are essential for robust inference in biodiversity-disease research.

Source: 

Link: https://journals.plos.org/globalpublichealth/article?id=10.1371/journal.pgph.0007045

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Divergent avian #strains drive an off-season #influenza A peak in municipal #wastewater

 

ABSTRACT

Wastewater sequencing is an increasingly valuable tool in tracking the spread of infectious disease agents across space and time in areas of dense human settlement. Among pathogens that can be readily detected by this approach is influenza A, which follows predictable patterns of prevalence through the winter months in North America. Here, we leverage routine surveillance of a municipal wastewater treatment plant in Northern California to describe an atypical, off-season spike in influenza A concentrations that rivals that of the winter respiratory virus season. Drawing upon metagenomic data generated through hybrid-capture sequencing, we assemble and subsequently characterize fragments of divergent influenza genomes that appear to derive predominantly from the avian H16 clade. These strains exhibit close evolutionary relationships to influenza isolated from migratory shorebirds, hinting at potential host species and mechanisms of geographic spread. Analysis of read abundances suggests that these avian strains dominate the pool of influenza circulating during the summer months, when typical human-infecting strains are essentially absent. Together, our results expand the value of wastewater sequencing to encompass sensitive tracking of outbreaks within animals in interface regions where human settlement abuts wildlands, increasing overall pandemic preparedness.

IMPORTANCE

Researchers now commonly search municipal wastewater for viral genetic material, which can indicate trends in the diversity and abundance of strains circulating in communities. Here, we show that under certain conditions, municipal wastewater can also capture the signatures of viruses circulating among animal populations, such as birds. Specifically, we draw on a targeted form of nucleic acid sequencing to discover a strain of influenza that is fairly genetically distinct from known relatives and may be circulating among shorebirds in Northern California. These findings both broaden the possible use cases of wastewater sequencing and provide new insights into avian viruses, some of which can jump host species to make other animals or people sick.

Source: 

Link: https://journals.asm.org/doi/10.1128/spectrum.02027-26

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Identification of Serum #Antibodies Cross-Reactive with Pathogenic #Betacoronavirus Amongst Rural Communities Within the Forested Region of the Republic of #Guinea

 

Abstract

Objectives: 

The SARS-CoV-2 pandemic caused major morbidity, mortality, and economic disruption, highlighting the need to better understand zoonotic spillover risks posed by coronaviruses. We investigated whether archived human sera from forested Guinea contained evidence of prior exposure to coronaviruses antigenically related to known pathogenic human coronaviruses. 

Methods: 

Archived sera collected in 2017–2018 from wildlife hunter communities in Guinea were analysed using serological assays against spike glycoproteins from SARS-CoV, SARS-CoV-2, MERS-CoV, and seasonal human coronaviruses. Binding responses to receptor binding domains were also assessed, together with spatial and subgroup analyses. 

Results: 

Pre-pandemic sera showed IgG cross-reactivity to SARS-CoV, SARS-CoV-2, and MERS-CoV spike antigens. A distinct subgroup demonstrated strong binding to both SARS-CoV and MERS-CoV receptor binding domains. 

Conclusions: 

These findings highlight the utility of sero-epidemiology in identifying potential zoonotic spillover. However, further investigation is needed to identify these viruses and determine their homology to known pathogenic coronaviruses.

Source: 

Link: https://www.mdpi.com/1999-4915/18/9/989

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#Taiwan, Seasonal #Influenza and #COVID19 Epidemics Weekly #Update (CDC, September 8 '26): H1N1pdm09 flu virus & SARS-CoV-2 PQ.16.1.1 variant are predominant

 

{Excerpts}

(...)

    The CDC pointed out that in week 35 (August 30th - September 5th), there were 115,136 outpatient and emergency room visits for influenza-like illnesses, an increase of 11.0% from the previous week, showing a recent upward trend. 

    The percentage of emergency room visits reached 11.2%, exceeding the epidemic threshold (11.0%), indicating the start of the epidemic period. 

    Additionally, last week (September 1st - September 7th), there were 105 new cases of severe influenza complications (97 H1N1, 4 H3N2, 4 untyped A cases) and 19 deaths (18 H1N1, 1 untyped A case). 

    Laboratory monitoring data shows that the influenza virus currently circulating in the community is mainly type A, with type A H1N1 accounting for 79.4% of the cases. 

    This flu season (2023-2024) has seen a cumulative total of 1,329 severe cases (717 H1N1, 498 H3N2, 24 untyped type A, and 90 type B) and 253 deaths (131 H1N1, 102 H3N2, 8 untyped type A, and 12 type B). 

    The majority of severe cases are among those aged 65 and above (65.1%) and those with a history of chronic diseases (82.8%). 68.6% of those affected have not received the flu vaccine this season.

    According to data from the Taiwan Centers for Disease Control (CDC), the COVID-19 epidemic in Taiwan is declining, but it is still in its epidemic period. 

    In week 35 (August 30 - September 5), there were 20,199 outpatient and emergency room visits related to COVID-19, a 9.7% decrease compared to the previous week (August 23 - August 29). 

    Last week (September 1 - September 7), there were 73 new severe cases and 15 deaths. 

    Since October 2025, there have been a cumulative total of 622 locally transmitted cases of COVID-19 complicated by severe illness, of which 106 have died. 

    The majority of severe cases are among those aged 65 and above (72.7%) and those with a history of chronic diseases (83.0%). 84.9% of these cases have not received the COVID-19 vaccine this season. 

    In the past four weeks, the predominant variant strain in locally transmitted cases has been PQ.16.1.1.

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Source: 

Link: https://www.cdc.gov.tw/Bulletin/Detail/5gJTj70wu9L3psY5kQLUuA?typeid=9

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#Bundibugyo Virus Disease #Outbreak in #DRC - Situation #Report No. 17, Data as of 06 September 2026 (WHO, summary): 6,686 cases & 3,226 deaths in DRC

 

{Summary}

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Event description

Democratic Republic of the Congo

    The epidemiological pattern of the Bundibugyo virus disease (BVD) outbreak in the Democratic Republic of the Congo is becoming increasingly heterogeneous, with divergent transmission trends across affected provinces  and health zones.

    Ituri remains the principal focus, while substantial transmission continues  in Nord-Kivu and Haut-Uélé and new areas continue to be affected. 

    Since External Situation Report #16, a further 586 confirmed cases and  276 confirmed deaths have been reported, bringing the cumulative total to 6686 confirmed cases, including 3226 deaths [case fatality ratio (CFR)  48.3%], as of 6 September 2026. 

    Ituri accounts for 80.2% of cumulative confirmed cases, down from  82.2% in the previous update, while Nord-Kivu has now surpassed 1000  cumulative cases. 

    The number of affected health zones increased from 60 to 61 across six  provinces, with Kayna Health Zone in Nord-Kivu being the latest affected.

    At the national level, daily incidence remains high but fluctuating, with  the seven-day moving average declining from its mid-August peak before  rising again in early September. This overall pattern masks increasingly divergent  provincial trajectories. 

    Ituri, while still the main driver of the outbreak, has declined substantially from its mid-August peak but remains at a high level with recent  fluctuations. 

    In contrast, Nord-Kivu is experiencing a marked and sustained increase, reaching its highest incidence since the start of the outbreak, while  transmission remains sustained in Haut-Uélé. Tshopo and Bas-Uélé continue to  report low but intermittent transmission, while no recent transmission is evident in  Sud-Kivu.

    Overall, the trends reinforce an increasingly heterogeneous epidemic,  with declining transmission in some areas occurring alongside intensification and  continued geographic spread elsewhere.

    During the most recent 21 days (17 August – 6 September 2026), 1665 confirmed cases were reported nationally.

    Compared with 1759 cases during the preceding 21-day period (27 July  – 16 August 2026), this represents a decrease of 94 cases (−5.3%). 

    Reported cases declined by 18.3% in Ituri, from 1356 to 1108, but  increased by 47.4% in Nord-Kivu, from 293 to 432, and by 14.0% in Haut-Uélé,  from 100 to 114. Consequently, Ituri’s contribution to newly reported cases fell  from 77.1% to 66.5%, while Nord-Kivu’s contribution increased from 16.7% to  25.9% and Haut-Uélé’s from 5.7% to 6.8%. The latest period also included eight  cases in Tshopo and three in Bas-Uélé. Overall, the modest national decline masks  a continued redistribution of transmission away from Ituri, particularly towards Nord-Kivu, where incidence continues to increase.

Figure 1. Daily national trend in confirmed Bundibugyo virus disease cases, with  seven-day moving average, by date of report, Democratic Republic of the Congo, as of 06 September 2026

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    During the same period, 848 confirmed deaths were reported nationally,  compared with 941 deaths during the preceding 21 days, representing a decrease  of 93 deaths (−9.9%). The national decline was driven by Ituri,  where reported deaths decreased from 671 to 548 (−18.3%). In contrast, deaths  increased from 224 to 253 (+12.9%) in NordKivu and from 42 to 43 (+2.4%) in  Haut-Uélé. Consequently, Ituri’s contribution to newly reported deaths declined  from 71.3% to 64.6%, while Nord-Kivu’s increased from 23.8% to 29.8% and  Haut-Uélé’s from 4.5% to 5.1%. Tshopo and BasUélé reported two deaths  respectively during the latest period, with no net increase in cases and deaths.  

    Overall, the modest national reduction in both cases (−5.3%) and deaths (−9.9%) masks divergent provincial trajectories and should be interpreted  cautiously given reporting delays and retrospective data  reconciliation. The continued increase in both cases and deaths in Nord-Kivu,  alongside sustained transmission in Haut-Uélé, indicates that the outbreak is  increasingly geographically heterogeneous rather than showing a uniform decline.

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    Additionally, during the most recent 21 days, 52 of the 61 affected health zones (85.2%) reported at least one new confirmed case, while nine  (14.8%) reported no new cases: Adja, Kambala and Mahagi in Ituri; Goma in  Nord-Kivu; Lubunga, Tshopo and Wanie-Rukula in Tshopo; Miti-Murhesa in Sud- Kivu; and Buta in Bas-Uélé. Importantly, provincial trends should not be  interpreted as uniform across their constituent health zones. In Ituri, for example,  the overall 18.3% decline in cases occurred alongside renewed or  increasing transmission in several health zones, including Bunia, Nizi, Mangala,  Bambu, Komanda, Lita and Mandima, while previously prominent hotspots such as  Mongbwalu showed declining activity. Similarly, the overall increase in Nord- Kivu reflects both strong resurgence in established hotspots, particularly Katwa,  Beni and Butembo, and recent or renewed activity in additional health zones.  

    These divergent subprovincial trajectories indicate that transmission is shifting geographically rather than declining uniformly, underscoring the need to  monitor and target response interventions at the health-zone level rather than  relying on provincial or national trends alone.

(...)

    Weekly confirmed deaths peaked at 364 during 10 – 16 August, followed  by declines to 302 and 270 over the subsequent two weeks. However,  this downward trend did not continue in the most recent week, with deaths  increasing slightly to 276 during 31 August – 6 September (+2.2%). More  importantly, the latest increase was driven entirely by community deaths, which  rose sharply from 171 to 207 (+21.1%), while deaths occurring in treatment  facilities continued to decline from 99 to 69 (−30.3%). Consequently, the  proportion of confirmed deaths occurring in the community increased from 56.6%  during 17 – 23 August to 63.3% during 24 – 30 August and 75.0% during 31  August – 6 September, the highest weekly proportion observed during the  reporting period. This divergence is concerning, as the increase in community deaths alongside the continued decline in treatment facilities deaths  indicates that the earlier reduction in overall mortality has not been sustained.

    The persistence of high community mortality may reflect multiple barriers along the pathway to care, including delayed detection and notification,  delayed referral or transfer to treatment facilities, limited recognition of illness or  perceived severity, geographic and transport barriers, care-seeking outside formal  health facilities, and community acceptance or trust. These factors may result in  patients reaching treatment facilities late or dying before referral can be  completed.

    The increasing proportion of community deaths, despite expanding  treatment capacity, therefore suggests that increasing bed capacity alone may be  insufficient and reinforces the need to strengthen early case detection, rapid referral and community-level pathways to timely care.

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Risk Assessment

    The risk of further spread remains very high within the Democratic Republic of the Congo and high for neighbouring countries sharing land borders  with the country. This assessment reflects sustained transmission, continued  geographic expansion, high mortality, population mobility, insecurity and  persistent response challenges. 

    The risk is considered low  elsewhere in Africa and globally. 

    The second IHR Emergency Committee, convened on 18 August 2026, also  reviewed the evolving situation and emphasized that the outbreak remains far  from controlled, and continues to constitute a Public Health Emergency of International Concern.

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Situation interpretation

    The outbreak remains uncontrolled and increasingly heterogeneous,  with improving trends in some areas occurring  alongside continued  transmission, geographic redistribution and the emergence of new hotspots. The  widening geographic footprint is creating an increasingly complex operational  environment, requiring response capacity to be sustained across widely dispersed  and sometimes difficult-to-access areas. 

    The six affected provinces collectively  cover an area of approximately 630 000 km², although transmission remains concentrated within specific health  zones and health areas. This geographic dispersion increases demands on  surveillance, contact tracing, referral and case management capacity, laboratory  networks, logistics and field coordination, and increases the risk that emerging transmission may not be detected or contained rapidly. Further gains  will therefore depend on translating the substantial expansion in response capacity  into rapid, locally delivered action in active and emerging hotspots. 

    Priorities should include early detection and referral, enhanced contact  tracing, IPC interventions around cases, addressing the drivers of community  deaths, and maintaining operational readiness in areas at risk of further spread. 

Source: 

Link: https://www.afro.who.int/countries/democratic-republic-of-congo/publication/ebola-bundibugyo-virus-disease-outbreak-0

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Avian Influenza Report: August 30 – September 5 '26 (Wk 36) (CHP, HK SAR, September 8, '26): 1 New Human Case of Infection with #H9N2 virus in #China

 

{Excerpt}

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Avian influenza A(H9N2):

    ° Beijing:

        § A six-year-old girl with onset on August 15, 2026.

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Source: 

Link: https://www.chp.gov.hk/files/pdf/2026_avian_influenza_report_vol22_wk36.pdf

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Pan - #Ebolavirus nanoparticle #vaccine provides protection in rodents from lethal #infection by #Zaire and #Sudan viruses

 

Abstract

Both Zaire ebolavirus (EBOV) and Sudan ebolavirus (SUDV) are members of the genus Ebolavirus and cause outbreaks marked by high fatality rates and repeated spillover from animal reservoirs. Filoviral glycoproteins (GPs) are the primary targets of neutralizing antibodies and form the basis of current vaccines. Here we describe the design, structural characterization, and evaluation of two-component self-assembling icosahedral I53-50 nanoparticles displaying prefusion EBOV or SUDV GP antigens, either individually or in cocktail and mosaic multivalent formats. EBOV-GP-I53-50 and SUDV-GP-I53-50 nanoparticles elicited strong homologous protection in mice and guinea pigs. In the mouse-adapted EBOV model (maEBOV), mosaic and cocktail formulations produced weak survival below that of the matched EBOV-GP-I53-50 GP immunogen. In contrast, in the gpaSUDV guinea pig model (gpSUDV), cocktail and mosaic nanoparticles elicited robust protection against gpSUDV, and detectable antibody responses to both SUDV and EBOV GPs. These findings demonstrate that multivalent GP-I53-50 nanoparticle immunogens can protect rodents from death, severe clinical signs of disease, and weight loss in relevant models. Together with the established clinical safety of the I53-50 platform, these results support continued efforts toward the development of a pan-ebolavirus vaccine.

Source: 

Link: https://www.nature.com/articles/s41467-026-76114-1

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