ETIDIOH - NEW

  Situation at a glance On 1 September 2025, WHO received an alert from the Ministry of Health of the Democratic Republic of the Congo (DRC) regarding suspected cases of Ebola virus disease (EVD) in the Bulape Health Zone, Kasai Province, DRC .  The first known index case was a pregnant woman who presented at Bulape General Reference Hospital on 20 August 2025 with symptoms of high fever, bloody diarrhoea, haemorrhage and extreme weakness . She died on 25 August from multiple organ failure .  On 4 September 2025 , following confirmatory laboratory testing, the Ministry of Health declared an outbreak of EVD .  Ebola virus disease is a serious , often fatal illness in humans. The virus is transmitted to humans through close contact with the blood or secretions of infected wildlife and then spreads through human-to-human transmission .  As of 4 September 2025, 28 suspected cases, including 15 deaths (case fatality ratio (CFR): 54%), have been reported from three ar...

  ABSTRACT Bourbon virus (BRBV) is an emerging tick-borne virus that can cause severe and fatal disease in humans . BRBV is vectored via the Amblyomma americanum tick , which is widely distributed throughout the central, eastern, and southern United States . Serosurveillance studies in Missouri and North Carolina identified BRBV-neutralizing antibodies in approximately 0.6% of tested individuals . To date, no specific antiviral therapy exists. As part of an initial screen, several nucleoside analogs were tested for their ability to inhibit BRBV replication in cell culture. Among the compounds assessed, molnupiravir , an antiviral drug with oral availability and broad spectrum antiviral activity against RNA viruses, showed antiviral activity against BRBV production in vitro. In vivo, pre-exposure administration of molnupiravir protected susceptible type I interferon receptor knockout (Ifnar1-/-) mice against lethal BRBV infection. The protection by molnupiravir was associated with l...

{Summary} Time Period: August 24, 2025 - August 30, 2025 -- H5 Detection :  3 sites ( 0.7% ) -- No Detection :  428 sites ( 99.3% ) -- No samples in last week :  31 sites (...) Source: US Centers for Disease Control and Prevention,  https://www.cdc.gov/nwss/rv/wwd-h5.html ____

  Summary Background Influenza vaccination is widely recommended to prevent death and serious illness in vulnerable people , including those with heart failure . However, the randomised evidence to support this practice is limited and few people are vaccinated in many parts of the world. We aimed to determine whether influenza vaccination can improve the outcome of patients after an episode of acute heart failure requiring admission to hospital in China . Methods We undertook a pragmatic, multiregional, parallel-group, cluster (hospital)-randomised, controlled, superiority trial over three winter seasons in China. Participating hospitals were located in the counties of 12 provinces with the capability of establishing a point-of-care service to provide free influenza vaccination to a sufficient number of patients before their discharge, if allocated to the intervention group. No such service was used in hospitals allocated to usual care (control) but patients were informed of fee-fo...

  Abstract H5N1 highly pathogenic avian influenza viruses have spread globally and pose a risk for a human pandemic . Prior studies suggest that early life exposures to group 1 influenza viruses (H1N1 and H2N2) prime antibodies that cross-react to the hemagglutinin of H5N1 , which is also a group 1 virus. Less is known about how immune history affects antibody responses against the neuraminidase (NA) of H5N1 viruses. Here, we measured NA inhibition antibodies against multiple H5N1 viruses using sera from 155 individuals born between 1927 and 2016 . We found that individuals primed in childhood with H1N1 viruses were more likely to possess higher levels of antibodies that cross-react with the NA of H5N1 viruses compared to individuals primed in childhood with H2N2 or H3N2 viruses. While young children rarely possessed cross-reactive NA antibodies, we found that childhood infections with contemporary H1N1 , but not H3N2, viruses can elicit them. These data suggest that immune history...

  Summary -- What is already known about this topic? - As of January 1, 2025, 37 human cases of highly pathogenic avian influenza (HPAI) A( H5N1 ) had been detected in California , none of which occurred in San Francisco. -- What is added by this report? - On January 9, 2025, a case of HPAI A(H5N1) infection was identified in a school-aged child in San Francisco through enhanced surveillance (influenza A virus subtyping of a sample of specimens weekly). No source of exposure was identified, and investigations found no laboratory evidence of human-to-human transmission among close contacts. -- What are the implications for public health practice? - Enhanced surveillance and timely subtyping of a subset of influenza A–positive specimens, including specimens from persons without known A(H5N1) exposure, are important to detect avian influenza A virus infections. Public health investigations are critical to monitoring for human-to-human transmission. Abstract In response to a highly pat...

  Kinshasa – Health authorities in the Democratic Republic of the Congo have declared an outbreak of Ebola virus disease in Kasai Province where 28 suspected cases and 15 deaths , including four health workers, have been reported as of 4 September 2025. The outbreak has affected Bulape and Mweka health zones in Kasai Province where health officials have been carrying out investigations after the cases and the deaths reported presented with symptoms including fever, vomiting, diarrhoea and haemorrhage . Samples tested on 3 September at the country’s National Institute of Biomedical Research in the capital Kinshasa confirmed the cause of the outbreak as Ebola Zaire caused by Ebola virus disease.    A national Rapid Response Team joined by World Health Organization (WHO) experts in epidemiology, infection prevention and control, laboratory and case management has been deployed to Kasai Province to rapidly strengthen disease surveillance, treatment and infection prevention an...

{Summary} -- During current surveillance week (28 August - 3 September 2025):  - 72 new confirmed human cases of West Nile Virus infection have been confirmed;  -- The total number of cases since the beginning of epidemic season has risen to 502 (they were 430 in the last bulletin); of these:  - 226 were West Nile Neuroinvasive Disease (WNND):  11 in Piedmont, 16 in Lombardy, 17 Veneto, 1 Friuli-Venezia Giulia, 1 Liguria, 15 Emilia-Romagna, 3 Tuscany, 71 Latium, 2 Molise, 72 Campania, 1 Apulia, 2 Basilicata, 5 Calabria, 1 Sicily, 8 Sardinia,  - 40 were asymptomatic cases detected in blood donors ,  - 226 were West Nile Fever cases (one of them imported from Kenya ), - 5 asymptomatic cases,  - 5 unspecified.  -- So far there have been 33 fatal cases : 3 in Piedmont, 1 Lombardy, 1 Emilia-Romagna, 14 Latium, 12 Campania, 2 Calabria.  - The Case-Fatality rate among WNND cases is thus far at 14.6% (in 2018 it was 20%, in 2024 14%).  -- During...

  Abstract Avian influenza A(H9N2) has been circulating in poultry across Asia, the Middle East, and Africa, posing human health risks . In Ghana , it has co-circulated among poultry with influenza A ( H5N1 ). This report describes Ghana’s first confirmed human case of avian influenza A(H9N2) virus infection in a two-year-old boy from Upper East Region , identified through active respiratory surveillance . Molecular and genomic analyses confirmed the virus was of the G1 lineage , closely related to other West African strains , with mammalian adaptive mutations known to increase human infection potential. The child experienced mild symptoms , received outpatient care, and recovered. Health authorities conducted epidemiological investigations . No source was identified for the child’s infection; no additional human infections were detected. This case highlights the importance of robust avian influenza surveillance in animals and humans, particularly in regions with human-animal inter...

  Neurological-respiratory disease in backyard domestic birds raised in a farm with partial laboratory results of H5 avian influenza virus . Zoning was implemented for the control of the outbreak with stamping out measures for all affected and contact birds on the farm, and surveillance will be carried out in the perifocal and protection areas. A body of water representing a possible place of contact between domestic and wild birds is located on the premises. Source: WOAH,  https://wahis.woah.org/#/in-review/6755 ____

  A poultry farm in Santarém Region. Source: WOAH,  https://wahis.woah.org/#/in-review/6759 ____

  A poultry farm in Schleswig-Holstein State. Source: WOAH,  https://wahis.woah.org/#/in-review/6760 ____

  Abstract Mosquito-borne diseases are deeply embedded within ecological communities, with environmental changes—particularly climate change—shaping their dynamics . Increasingly intense droughts across the globe have profound implications for the transmission of these diseases , as drought conditions can alter mosquito breeding habitats , host-seeking behaviours and mosquito–host contact rates . To quantify the effect of drought on disease transmission, we use West Nile virus as a model system and leverage a robust mosquito and virus dataset consisting of over 500 000 trap nights collected from 2010 to 2023, spanning a historic drought period followed by atmospheric rivers. We pair this surveillance dataset with a novel modelling approach that incorporates monthly changes in bird host community competence , along with drought conditions , to estimate the effect of drought severity on West Nile virus risk using panel regression models. Our results show that while drought decreases ...

  Key Points -- Question:  Is regular application of azelastine nasal spray associated with reduced risk of SARS-CoV-2 infections? - Findings:  In this randomized placebo-controlled clinical trial that included 450 participants , the incidence of laboratory-confirmed SARS-CoV-2 infections was significantly lower with application of azelastine nasal spray compared with placebo treatment. -- Meaning:  The use of azelastine nasal spray may help to reduce the risk of SARS-CoV-2 infections. Abstract Importance    Limited pharmaceutical options exist for preexposure prophylaxis of COVID-19 beyond vaccination. Azelastine, an antihistamine nasal spray used for decades to treat allergic rhinitis, has in vitro antiviral activity against respiratory viruses, including SARS-CoV-2. Objective    To determine the efficacy and safety of azelastine nasal spray for prevention of SARS-CoV-2 infections in healthy adults. Design, Setting, and Participants   ...

  {A Great White Pelican, one of the affected species in the outbreak.} By Charles J. Sharp - Own work, from Sharp Photography, sharpphotography.co.uk, CC BY-SA 4.0,  https://commons.wikimedia.org/w/index.php?curid=66151818 Wild birds of different species in Western Cape Region. Source: WOAH,  https://wahis.woah.org/#/in-review/6732 ____

  Abstract Objectives There have been few studies in pregnant women of medications that are used to reduce severe complications from COVID-19 infection. Currently, nirmatrelvir/ritonavir (Paxlovid) is recommended by the National Institutes for Health to treat non-hospitalized pregnant patients with mild-to-moderate COVID-19 illness. The aim of this study was to determine the transplacental passage of molnupiravir, nirmatrelvir/ritonavir and favipiravir utilizing an ex vivo placental perfusion model. Methods Human placental cotyledons were continuously perfused in a double open circuit. The study molecules and antipyrine, a marker of placental viability, were dissolved in the maternal solution. The experiment was conducted over 90 minutes, and every 5 minutes, samples of the maternal solution and fetal exchange solutions were collected for analysis. We calculated the concentrations of study molecules, fetal transfer ratios and the clearance indexes to determine placental transfer. R...

  Abstract The incursion of high pathogenicity avian influenza A virus (IAV) into US dairy cows is unprecedented in the era of molecular diagnosis and pathogen sequencing. This raises questions over the likelihood of further outbreaks and whether dairy cattle could be a mixing vessel for novel strains of IAV. Using a panel of BSL2-safe reassortant viruses representing clade 2.3.4.4b H5 epizootic lineages circulating since 2020, we found that a cow B3.13 isolate displayed enhanced replication in cow mammary gland cells , along with increased viral polymerase activity and stronger interferon antagonism in cow cells compared to an earlier EA-2020-C genotype virus. However, multiple avian and mammalian IAV strains , including other clade 2.3.4.4b high pathogenicity genotypes, were replication competent in bovine cells, particularly those of the mammary gland , suggesting that there is a diverse circulating IAV pool with the potential to infect cows. Moreover, we show that cow mammary c...

  Public Domain. Source: WikiArt,  https://www.wikiart.org/en/camille-corot/the-augustan-bridge-at-narni-1826 ____

  Abstract Climate change is increasingly recognized as a major driver of emerging infectious diseases, particularly vector-borne diseases (VBDs), which are expanding in range and intensity worldwide. Europe , traditionally considered low-risk for many arboviral infections , is now experiencing autochthonous transmission of pathogens such as dengue, chikungunya, Zika virus, West Nile virus, malaria, and leishmaniasis . Rising temperatures , altered precipitation patterns , and milder winters have facilitated the establishment and spread of competent vectors , including Aedes, Anopheles, Phlebotomus, and Culex species , in previously non-endemic areas. These climatic shifts not only impact vector survival and distribution but also influence vector competence and pathogen development , ultimately increasing transmission potential. This narrative review explores the complex relationship between climate change and VBDs, with a particular focus on pediatric populations . It highlights h...

  ABSTRACT Influenza viruses utilize host proteases to activate the viral fusion protein, hemagglutinin (HA), into its fusion-competent form. Although proteolytic activation of HA is essential for virus replication, the cell-type dependence of HA activation within the airway epithelium and the subcellular location(s) in which it occurs are not well established. To address these questions, we investigated the proteolytic activation of HA in differentiated human airway epithelial cells using contemporary and historical H1N1 and H3N2 strains . We find that activation is efficient across viral strains and subtypes but depends on cellular tropism , with ciliated cells activating HA more effectively than non-ciliated cells. Similar to prior observations in immortalized cell lines, we find that HA activation occurs intracellularly, constraining the antiviral activity of host-directed protease inhibitors . These results establish that HA activation within the airway epithelium depends on c...