Influenza A and D Viruses in Non-Human Mammalian Hosts in Africa: A Systematic Review and Meta-Analysis

Abstract

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.

Influenza A Virus in Pigs in Senegal and Risk Assessment of Avian Influenza Virus (AIV) Emergence and Transmission to Human

“…It is caused by viruses belonging to the Orthomyxoviridae family, which consists of segmented, single-stranded, negative-sense RNA viruses [ 2 ]. This family contains four influenza virus genera: Alphainfluenzavirus (influenza A virus, IAV), Betainfluenzavirus (influenza B virus, IBV), Gammainfluenzavirus (influenza C virus, ICV) and Deltainfluenzavirus (influenza D virus, IDV), which are classified according to antigenic variations of their nucleoprotein (NP) and matrix 1 (M1) proteins [ 3 , 4 , 5 ]. Infections with human IAV and IBV are responsible for annual seasonal epidemics leading to about half a million deaths worldwide [ 6 ].…”

Seroprevalence of Influenza A Virus in Dromedaries in North-Western Nigeria

“…Influenza A viruses (IAVs) belong to the family Orthomyxoviridae, and contain singlestranded RNA genomes of eight gene segments [1,2]. IAVs are further classified into subtypes based on variations of their envelope glycoproteins: hemagglutinin antigen (HA) and neuraminidase antigen (NA) [3].…”

“…Studies have detected IAVs in wild and domestic animals throughout Africa [1,5,6]. IAV subtypes H1N1, H3N8, and H5N1 have been detected in dogs and cats from Nigeria, Kenya, and Egypt [1].…”

“…Studies have detected IAVs in wild and domestic animals throughout Africa [1,5,6]. IAV subtypes H1N1, H3N8, and H5N1 have been detected in dogs and cats from Nigeria, Kenya, and Egypt [1]. Highly pathogenic avian influenza (HPAI) A/H5N1 outbreaks have been reported in numerous African countries, including Nigeria, where an estimated 1.6 million poultry deaths have been reported since 2015, specifically in live bird markets near Lagos [6,7].…”