114 research outputs found

    Incidence and neutralizing antibody seroprevalence of influenza B virus in Egypt: Results of a community-based cohort study

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    Since 2000, two lineages of influenza B viruses, Victoria and Yamagata, have been circulating at similar frequencies worldwide. Little is known about the circulation of those viruses in Egypt. This study aims to describe the epidemiology of influenza B virus infections in Egypt, 2017-2019. This was performed through a household prospective cohort study on influenza infections among 2400 individuals from five villages. When a study participant had influenza like symptoms, a nasal swab and an oropharyngeal swab were obtained and tested by RT-PCR for influenza B infections. A serum sample was obtained from all participants annually to detect neutralizing antibodies using microneutralization assay. 9.1% of subjects were positive for influenza B viruses during season 2017-2018 mostly among preschoolers and 7.6% were positive during the season 2018-2019 with higher risk in females, potentially due to mothers being infected after contact with their children. The overall seroprevalence among the participants was 53.2% and 52.2% against the Victoria and Yamagata lineages respectively, the majority of seropositive participants were students. Multivariate analysis showed that age and having chronic diseases were the strongest predictors of infection. Our results show that both influenza B lineages circulated between 2017 and 2020 in Egypt almost in equal proportion. Encouraging the uptake of seasonal influenza vaccines is recommended

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance.

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    Investment in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing in Africa over the past year has led to a major increase in the number of sequences that have been generated and used to track the pandemic on the continent, a number that now exceeds 100,000 genomes. Our results show an increase in the number of African countries that are able to sequence domestically and highlight that local sequencing enables faster turnaround times and more-regular routine surveillance. Despite limitations of low testing proportions, findings from this genomic surveillance study underscore the heterogeneous nature of the pandemic and illuminate the distinct dispersal dynamics of variants of concern-particularly Alpha, Beta, Delta, and Omicron-on the continent. Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve while the continent faces many emerging and reemerging infectious disease threats. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

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    INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

    Global Distribution and Molecular Evolution of Bat Coronaviruses

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    Bat coronaviruses cause a wide range of illnesses in humans and animals. Bats are known to harbor a wide diversity of Alphacoronaviruses and Betacoronaviruses. Betacoronaviruses have been linked to Severe Acute Respiratory Syndrome (SARS), Middle East Respiratory Syndrome (MERS), and other diseases such as gastroenteritis, bronchiolitis, and pneumonia. In the last 20 years, three betacoronaviruses emerged and caused widespread outbreaks in humans, including two deadly betacoronavirus epidemics, SARS-CoV, with mortality rate of 10%, and MERS-CoV, with mortality rate of 34.7%, and SARS-CoV-2, which caused the COVID-19 pandemic, with mortality rate of 3.4%. Studies have shown that bats are the main natural reservoirs for these viruses or their ancestral viruses. Observed variations in bat coronavirus genomes indicate that these viruses may have a potential to transmit to other hosts in close contact with humans and subsequently transmit to humans. As of today, there are no reported cases of direct coronavirus transmission from bats to humans. One reason for this might be that intermediate hosts are required for the transmission of bat coronaviruses to humans. Further studies are needed to map the amino acids and genomic regions responsible for the interactions between the spike of coronavirus and its receptors

    Middle East Respiratory Syndrome Coronavirus (MERS-CoV): State of the Science

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    Coronaviruses belong to a large family of viruses that can cause disease outbreaks ranging from the common cold to acute respiratory syndrome. Since 2003, three zoonotic members of this family evolved to cross species barriers infecting humans and resulting in relatively high case fatality rates (CFR). Compared to Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV, CFR = 10%) and pandemic Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2, CFR = 6%), the Middle East Respiratory Syndrome Coronavirus (MERS-CoV) has scored the highest CFR (approximately 35%). In this review, we systematically summarize the current state of scientific knowledge about MERS-CoV, including virology and origin, epidemiology, zoonotic mode of transmission, and potential therapeutic or prophylactic intervention modalities.</jats:p

    Middle East Respiratory Syndrome Coronavirus (MERS-CoV): State of the Science

    No full text
    Coronaviruses belong to a large family of viruses that can cause disease outbreaks ranging from the common cold to acute respiratory syndrome. Since 2003, three zoonotic members of this family evolved to cross species barriers infecting humans and resulting in relatively high case fatality rates (CFR). Compared to Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV, CFR = 10%) and pandemic Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2, CFR = 6%), the Middle East Respiratory Syndrome Coronavirus (MERS-CoV) has scored the highest CFR (approximately 35%). In this review, we systematically summarize the current state of scientific knowledge about MERS-CoV, including virology and origin, epidemiology, zoonotic mode of transmission, and potential therapeutic or prophylactic intervention modalities

    Antigenic diversity and cross-reactivity of avian influenza H5N1 viruses in Egypt between 2006 and 2011

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    Influenza epidemics are a major health concern worldwide. Highly pathogenic avian influenza (HPAI) H5N1 viruses in Egypt have been subject to rapid genetic and antigenic changes since the first outbreak in February 2006 and have been endemic in poultry in Egypt since 2008. In this study, 33 H5N1 viruses isolated from avian hosts were antigenically analysed by using a panel of eight mAbs raised against the A/Viet Nam/1203/04 (H5N1; clade 1) and A/bar-headed goose/Qinghai-lake/1A/05 (H5N1; clade 2.2) influenza viruses. Rats were immunized with inactivated whole-virus vaccine produced by reverse genetics with the haemagglutinin and neuraminidase genes of eight antigenically different HPAI H5N1 virus isolates and six internal genes from A/Puerto Rico/8/1934 (PR8) to produce polyclonal antibodies. Cross-reactivity between the obtained polyclonal antibodies and the isolated viruses was assayed. Antigenic cartography of the isolated viruses showed that three antigenic clusters were defined based on haemagglutination inhibition (HI) analysis using mAbs and the majority of viruses isolated in 2010 and 2011 fell into two of these clusters. An antigenic map based on polyclonal rat antisera showed that all virus isolates fell within one extended cluster. Accordingly, continuous surveillance and antigenic characterization will help us determine which virus isolate(s) should be used in poultry vaccine preparation.</jats:p
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