Influenza B viruses in pigs, Taiwan

Abstract

Influenza B viruse infections from humans to pigs remained sporadic and accidental currently in Taiwan but might have paved potential avenues for newly emerging zoonotic influenza in the future.

A Systematic Review Analyzing the Prevalence and Circulation of Influenza Viruses in Swine Population Worldwide

“…The results were further confirmed with virus isolation which retrieved 13 IAV isolates [170]. More recently, IBV of Victoria/B lineage was detected in swine nasal swab samples collected from apparently healthy swine at three swine farms in 2014 [171].…”

“…The molecular detection approaches followed by sequencing are largely used for the research focusing on the influenza virus epidemiology [73,78,82,87,94,128,146,150]. [5,37,43,45,46,61,74,88,137,157,171,176,188,191,199,207,215,[219][220][221]241,243,248,250,263,289,290,301,306,307,326,334] IAV, IDV, H1N1, H1N2, H3N2, A(H1N1)pdm09 [45,192,227,282,285,287,302,322] 8. Blood/ serum IDEXX Ab test, ELISA, HI assay, NI assay, VN assay, MN assay, western blot, virus isolation (MDCK cells) H1N1, H1N2, H3N2, A(H1...…”

“…A large number of investigations have reported sub-clinical influenza virus infections in asymptomatic (apparently healthy) swine [78,103,150,161,171,278,300], indicating that influenza infections can go undetected while the swine may be shedding virus and hence may infect other swine and farm workers in contact [183]. Intriguingly, most of the swine samples processed in Australia, Europe, and North America were obtained from the symptomatic swine whi Egypt is recognized as a "hot spot" for the influenza virus reassortment due to its geographical location [345].…”

“…While an overwhelming majority of investigations reported IAV in the swine across the world ( Figure 7A), there were only a few reports which documented either active infections or past exposures of the swine to the influenza virus types IBV [37,171,186,277] (Figure 7B), ICV [38,117,186] ( Figure 7C) or IDV [5,[43][44][45][46]217] (Figure 7D). A low prevalence of IBV was observed in swine given that only one study reported the IBV antibodies in swine samples in England during 1991-1992 [186] with no evidence of further spill over to other European countries.…”

“…The active infection of IBV was later reported in US swine when two IBV isolates were obtained in 2009. A recent study from Taiwan reported three strains of the Victoria/B lineage of IBV in naturally infected swine in 2014 [171], again Various studies have spotted wild birds visiting the swine farms or in the vicinity which suggested that wild birds may have served as the carriers for the introduction of the different avian-origin IAV subtypes to the swine populations [59,80,100,246,332]. The highest number of avian-origin IAV strains were reported in Chinese swine which shows frequent avian-swine interaction in China, a country that has historically been an epicenter for influenza virus disease [69].…”