Serological report of influenza a (H7N9) infections among pigs in Southern China

Abstract

BackgroundIn 2013, a novel H7N9 avian influenza virus (AIV) was isolated from ill humans in Shanghai and Anhui Province, China. Since then, the virus has spread quickly throughout China. Previous isolation of H7N2 virus from swine suggests that additional H7 subtype AIVs may be transmitted through pigs. However, prior to the recent zoonosis of H7N9, there were very few studies on the seroprevalence of the H7 subtypes in this species. Thus, there is a need to perform serological surveys for novel H7N9 as well as other H7 subtype AIVs in swine. This surveillance may help us understand risk factors for outbreaks of influenza A (H7N9) virus.ResultsOnly 2.0% (26/1310) of the pig sera had antibodies with an HI titer ≥1:20, and none had an MN titer ≥1:80, against the H7 antigen. Thus, no samples were found to be positive against H7N9. However, 13.6% (178/1310) of the pig sera had antibodies with HI titer ≥1:20 and 8.5% (112/1310) by MN titer ≥1:80 against H9 antigen. Thirty-seven percent (484/1310) of the pig sera had antibodies with HI titer ≥1:20 and 18.2% (238/1310) had MN titer ≥1:80 against pandemic 2009.ConclusionsPigs in southern China have been shown to be infected with multiple avian influenza viruses. As the prevalence of novel influenza A viruses (e.g., H7N9 avian influenza virus) may be increasing among poultry in China, similar seroepidemiological studies of pigs should be conducted in the future.

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

“…The first report of H10N5 avian-origin influenza virus in a domestic swine in Hubei province further extended the diversity of swine influenza viruses and provided another evidence of interspecies transmission of avian influenza virus to the swine under natural conditions [95]. Several other avian-origin H3N2, H4N8, H6N6, H7N9, H5N1, and H9N2 virus antibodies were detected in swine in China during April 2010-June 2014 [86,[96][97][98].…”

“…[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(H1N1)pdm09, H5N1, H5N2, H5N3, H9N2, H7N9, H3N1, H4N8, H6N6, H6N2, H7N2, IBV, ICV, IDV [37,38,46,52,59,70,79,96,…”

Validation of a serum neutralization test for detection of antibodies specific to cyprinid herpesvirus 3 in infected common and koi carp (Cyprinus carpio)

“…; Zhou et al . ), especially for long‐term control of viral diseases. As significant progress has been made in recent years in understanding immunity in fish (Salinas, Zhang & Sunyer ; Fischer, Koppang & Nakanishi ; Somamoto, Koppang & Fischer ), routine detection of specific antibodies produced in response to infection could also represent an interesting alternative or supplement to current PCR procedures (Anonymous ; OIE ).…”

“…This strategy of latency, based on restriction in gene expression in non-permissive temperatures, ensures the maintenance of viral genome for an extended period in the absence of productive and symptomatic infection (Bretzinger et al 1999;Dishon et al 2007;Eide et al 2011a;Sunarto et al 2014 Sunarto et al 2014) and rapid spread to cohabitating na€ ıve fish. Serological investigations based on adaptive humoral immune response are common and useful in mammals (Loeffen et al 2012;Fan et al 2015;Pfahl et al 2016) and poultry (Gilbert et al 2014;Zhou et al 2014), especially for long-term control of viral diseases. As significant progress has been made in recent years in understanding immunity in fish (Salinas, Zhang & Sunyer 2011;Fischer, Koppang & Nakanishi 2013;Somamoto, Koppang & Fischer 2014), routine detection of specific antibodies produced in response to infection could also represent an interesting alternative or supplement to current PCR procedures (Anonymous 2015a;OIE 2015).…”

Establish and Apply a Safe and Convenient Pseudovirus-Based Assay to Detect Neutralizing Antibodies against Influenza A (H7N9) Virus

“…After the virus shedding period, serologic assays are performed to detect virus specific antibodies [10,11].…”