A systematic review of influenza A virus prevalence and transmission dynamics in backyard swine populations globally

Abstract

Background Backyard swine farming is critical to generating subsistence and food security in rural and peri-urban households in several developing countries. The objective of this systematic review was to analyze the molecular and serological prevalence of influenza A virus (IAV) in backyard swine populations globally. Results We identified 34 full-text research articles in NCBI-PubMed and Google Scholar databases that have reported IAV sero- and/or virological prevalence in backyard swine up to 11 July 2021. The highest number of studies were reported from Asia (n = 11) followed by North America (n = 10), South America (n = 6), Africa (n = 6), and Europe (n = 1). While the maximum number of studies (44.12%) reported human-to-swine transmission of IAV, swine-to-human (5.88%), poultry-to-swine (5.88%), and wild birds-to-swine (2.94%) transmissions were also reported. An overall higher IAV seroprevalence (18.28%) in backyard swine was detected compared to the virological prevalence (1.32%). The human-origin pandemic A(H1N1)pdm09 virus clade 1A.3.3.2 was the more frequently detected IAV subtype in virological studies (27.27%) than serological studies (18.92%). In addition, the avian-origin highly pathogenic H5N1 and H5N8 viruses were also detected, which further substantiated the evidence of avian–swine interactions in the backyards. Conclusion Human–swine and avian–swine interactions in backyards may transmit IAV between species. Monitoring the circulation and evolution of IAV in backyard swine would help stakeholders make informed decisions to ensure sustainable backyard swine farming and public safety.

Overview of Diagnostic Methods, Disease Prevalence and Transmission of Mpox (Formerly Monkeypox) in Humans and Animal Reservoirs

“…Most cases of Mpox in animals were detected in nonhuman primates and rodents; only one study each reported Mpox DNA in a pet dog ( Canis lupus familiaris ) [ 154 ] and antibodies in a domestic pig ( Sus scrofa domesticus ) [ 113 ]. While domestic pigs are reported to harbor several virus pathogens, including RNA [ 186 , 187 , 188 , 189 , 190 , 191 , 192 ] and DNA [ 193 , 194 ] viruses, the occurrence of Mpox antibodies in a domestic pig indicates the possibility of natural infection of domestic pigs with Mpox and warrants the surveillance of Mpox in domestic pig populations to investigate their status and significance.…”

Risk factors influencing swine influenza A virus infection in South Korea: A systematic review and meta-analysis of prevalence and seroprevalence

“…In the case of sampling on farms, additional information on farms was also reviewed (herd size, pig density, and accommodation types) ( 9 ). If the variables were not found in the literature, they were marked as “not reported.” An adequate sample size to estimate the pooled prevalence and seroprevalence was calculated to achieve the desired precision of 95% confidence intervals (CIs) using previously reported data and methodology (at least 600 and 750 samples were required for prevalence and seroprevalence, respectively) ( 18 – 20 ). Attempts were made to contact the authors for further information related to their study if necessary.…”

Flavonoids as Potential Antiviral Agents for Porcine Viruses

“…The influenza virus belongs to the Orthomyxoviridae family and includes four genera, Alphainfluenzavirus, Betainfluenzavirus, Gammainfluenzavirus, and Deltainfluenzavirus, corresponding to influenza virus A (IAV), B (IBV), C (ICV), and D (IDV), respectively [71]. IAV has a broad host spectrum and is one of the most critical causative pathogens of viral respiratory diseases in avians, humans, and pigs [72][73][74]. In addition, it can spill over from avians to humans and pigs, causing rapid spread and evolution of the virus between and within species [74][75][76].…”

“…IAV has a broad host spectrum and is one of the most critical causative pathogens of viral respiratory diseases in avians, humans, and pigs [72][73][74]. In addition, it can spill over from avians to humans and pigs, causing rapid spread and evolution of the virus between and within species [74][75][76]. The surface antigen haemagglutinin (HA) is subdivided into 18 HA subtypes (H1-H18) [73].…”