An increasing trend of rural infections of human influenza A (H7N9) from 2013 to 2017: A retrospective analysis of patient exposure histories in Zhejiang province, China

Abstract

BackgroundAlthough investigations have shown that closing live poultry markets (LPMs) is highly effective in controlling human influenza A (H7N9) infections, many of the urban LPMs were shut down, but rural LPMs remained open. This study aimed to compare the proportional changes between urban and rural infections in the Zhejiang province from 2013 to 2017 by analyzing the exposure histories of human cases.MethodsAll laboratory-confirmed cases of H7N9 from 2013 (the first wave) to 2017 (the fifth wave) in the Zhejiang province of China were analyzed. Urban and rural infections were defined based on the locations of poultry exposure (direct and indirect) in urban areas (central towns) and rural areas (towns and villages on the outskirts of cities). A Chi-square trend test was used to compare the proportional trend between urban and rural infections over time and logistic regression was used to obtain the odds ratio by years.ResultsFrom 2013 to 2017, a statistically significant trend in rural infections was observed (p <0.01). The incremental odds ratio by years of rural infections was 1.59 with 95% confidence intervals of 1.34 to 1.86. Each year, significant increases in the proportion of live poultry transactions in LPMS and poultry processing plants were detected in conjunction with an increased proportion of urban and rural infections.ConclusionThe empirical evidence indicated a need for heightened infection control measures in rural areas, such as serving rural farms and backyards as active surveillance points for the H7N9 virus. Other potential interventions such as the vaccination of poultry and extending the closure of LPMs to the provincial level require further careful investigations.

Virus-induced pathogenesis, vaccine development, and diagnosis of novel H7N9 avian influenza A virus in humans: a systemic literature review

“…153 However, some reports indicate that differences in immunity between men and women remain a consideration. 155 Recently, Chen et al 156 reported that an increasing trend of H7N9 human infections in rural areas of Zhejiang Province in China during 2013-2017 was the result of rural live poultry markets that remained open despite the epidemic; this suggests that closing live poultry markets is an effective way to control H7N9 human infections.…”

“…Early detection of neutralizing antibodies and rapid availability of the vaccine are required to prevent H7N9 pandemics. In the development of H7N9 vaccines, the peptides of HA7 and NA9 molecules 3,9 with median age 62 years 9 Ages with higher risk of further complications <5 years and >65 years 3,9 Susceptibility by sex and area 67% of confirmed cases are males 9,153,154 Increasing trend in rural areas 156…”

Mapping the Urban and Rural Planning Response Paths to the Pandemics of Infectious Diseases

“…The increase in the scale of agricultural production and grazing lead to an increase in the contact rate between humans and livestock and wild animals, increasing the possibility of infection, such as avian in uenza, swine in uenza, and Middle East respiratory syndrome(Rohr and Barrett et al, 2019). Poultry farming was one of the main sources of H7N9 infection in urban and rural areas of Zhejiang Province from 2013 to 2017 (Chen and Wang et al, 2018). According to a United Nations study, "approximately 60% of human infectious diseases originate in animals" (UNESCAP CSAM, 2020).…”

Research progress on human infection with avian influenza H7N9

“…Currently, people infected with H7N9 avian influenza are mainly middle-aged and elderly [47]. The infection rate in rural areas is higher than that in urban areas [48].…”