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Influenza D virus has been identified in America, Europe, and Asia. We detected influenza D virus antibodies in cattle and small ruminants from North (Morocco) and West (Togo and Benin) Africa. Dromedary camels in Kenya harbored influenza C or D virus antibodies, indicating a potential new host for these viruses. [ABSTRACT FROM AUTHOR]

Influenza D virus (IDV) was first isolated in 2011 in the USA and has since been shown to circulate in cattle, pigs, sheep, wild boar, and camels. In Africa, there is limited data on the epidemiology of IDV and, so, we investigated the presence of IDV among domestic ruminants and wild animals in Namibia by screening nasal swabs using an IDV-specific molecular assay. IDV RNA was detected in bovines (n=2), giraffes (n=2) and wildebeest (n=1). The hemagglutinin-esterase-fusion (HEF) gene from one of the bovine and the wildebeest samples was successfully sequenced as well as the full genome for the second bovine sample. Phylogenetic analysis of the HEF gene positioned the African virus variants within the D/OK lineage but with a long branch. The African variant had an amino acid diversity of 2.41% and most likely represents a distinct genotype within the lineage. Notably, the polymerase acidic protein gene (PA) was more closely related to a different lineage (D/660), indicative of potential reassortment. This is the first genetic characterization of IDV in Africa and it adds important data to our understanding of the global IDV distribution. [ABSTRACT FROM AUTHOR]

We conducted a systematic review and meta-analysis to investigate the prevalence and current knowledge of influenza A virus (IAV) and influenza D virus (IDV) in non-human mammalian hosts in Africa. PubMed, Google Scholar, Wiley Online Library and World Organisation for Animal Health (OIE-WAHIS) were searched for studies on IAV and IDV from 2000 to 2020. Pooled prevalence and seroprevalences were estimated using the quality effects meta-analysis model. The estimated pooled prevalence and seroprevalence of IAV in pigs in Africa was 1.6% (95% CI: 0–5%) and 14.9% (95% CI: 5–28%), respectively. The seroprevalence of IDV was 87.2% (95% CI: 24–100%) in camels, 9.3% (95% CI: 0–24%) in cattle, 2.2% (95% CI: 0–4%) in small ruminants and 0.0% (95% CI: 0–2%) in pigs. In pigs, H1N1 and H1N1pdm09 IAVs were commonly detected. Notably, the highly pathogenic H5N1 virus was also detected in pigs. Other subtypes detected serologically and/or virologically included H3N8 and H7N7 in equids, H1N1, and H3N8 and H5N1 in dogs and cats. Furthermore, various wildlife animals were exposed to different IAV subtypes. For prudent mitigation of influenza epizootics and possible human infections, influenza surveillance efforts in Africa should not neglect non-human mammalian hosts. The impact of IAV and IDV in non-human mammalian hosts in Africa deserves further investigation. [ABSTRACT FROM AUTHOR]

Influenza D virus (IDV) was first isolated in 2011 in Oklahoma, USA from pigs presenting with influenza-like symptoms. IDV is known to mainly circulate in ruminants, especially cattle. In Africa, there is limited information on the epidemiology of IDV, although the virus has likely circulated in the region since 2012. In the present study, we investigated the seropositivity of IDV among domestic ruminants and swine in West and East Africa from 2017 to 2020. Serum samples were analyzed using the hemagglutination inhibition (HI) assay. Our study demonstrated that IDV is still circulating in Africa, with variations in seropositivity among countries and species. The highest seropositivity was detected in cattle (3.9 to 20.9%). Our data highlights a need for extensive surveillance of IDV in Africa in order to better understand the epidemiology of the virus in the region. [ABSTRACT FROM AUTHOR]