Demographic and ecological risk factors for human influenza A virus infections in rural Indonesia

Abstract

BackgroundIndonesia has the world's highest reported mortality for human infections with highly pathogenic avian influenza (HPAI) A(H5N1) virus. Indonesia is an agriculturally driven country where human‐animal mixing is common and provides a unique environment for zoonotic influenza A virus transmission.ObjectivesTo identify potential demographic and ecological risk factors for human infection with seasonal influenza A viruses in rural Indonesia, a population‐based study was conducted in Cileunyi and Soreang subdistricts near Bandung in western Java from 2008 to 2011.MethodsPassive influenza surveillance with RT‐PCR confirmation of influenza A viral RNA in respiratory specimens was utilized for case ascertainment. A population census and mapping were utilized for population data collection. The presence of influenza A(H3N2) and A(H1N1)pdm09 virus infections in a household was modeled using Generalized Estimating Equations.ResultsEach additional child aged <5 years in a household increased the odds of H3N2 approximately 5 times (OR=4.59, 95%CI: 3.30‐6.24) and H1N1pdm09 by 3.5 times (OR=3.53, 95%CI: 2.51‐4.96). In addition, the presence of 16‐30 birds in the house was associated with an increased odds of H3N2 (OR=5.08, 95%CI: 2.00‐12.92) and H1N1pdm09 (OR=12.51 95%CI: 6.23‐25.13).ConclusionOur findings suggest an increase in influenza A virus infections in rural Indonesian households with young children and poultry.

Risk Factors for Respiratory Syncytial Virus Lower Respiratory Tract Infections: Evidence from an Indonesian Cohort

“…The ownership of rabbits, however, was found to be low (1.2% of households). A previous study of ours—also from rural West Java, Indonesia—also found poultry to be a risk factor for development of H3N2 influenza [ 29 ]. Household ownership of livestock such as rabbits and chickens likely leads to exposure to organic dust early in life due to the population’s proximal living with their animals.…”

Human Susceptibility to Influenza Infection and Severe Disease

“…Health-care personnel are at increased risk of exposure to IAV as was shown during the 2009 A/H1N1 pandemic (Lietz et al 2016). Individuals who work in close contact with animals, such as birds and swine, may also have an increased risk of zoonotic transmission (Harris et al 2017;Root et al 2017). Although rare, the zoonotic emergence of novel IAV strains has resulted in some of the most widespread influenza virus outbreaks in history (Webster and Laver 1972;Taubenberger and Kash 2010).…”

“…Children younger than 5 are at increased risk of infection, likely because of immature immune development, discussed in detail below. As a result, healthy adults that work with children, such as day-care providers or early educators, or those who have young children at home are >1.5 times more likely to come into contact with influenza viruses (Root et al 2017;Huang et al 2019). A final consideration for increased susceptibility to IAV infection is population density.…”

Cost-Effectiveness Analysis for Influenza Vaccination Coverage and Timing in Tropical and Subtropical Climate Settings: A Modeling Study

“…Wang et al 7 studied vaccination campaigns in Taiwan and concluded that 3 times the cost of vaccination is generated in savings. The potential for cost savings within tropical areas in which influenza infections occur year-round, such as Singapore 8 and Indonesia, 9 needs to be studied to assess whether vaccination is cost-effective in the absence of clear influenza seasons.…”