Microbiota and Health Study: a prospective cohort of respiratory and diarrheal infections and associated risk factors in Bangladeshi infants under two years

Abstract

Background: Early childhood respiratory and diarrheal infections are major causes of morbidity and mortality worldwide. There is a need to further assess the epidemiology through prospective and community-based studies to gain key insights that could inform preventative measures to reduce the risk of infectious disease in this vulnerable population. We aimed to analyze the burden and determinants of acute respiratory infection (ARI) and diarrhea episodes affecting infants during their first 2 years of life with state-of-the-art molecular technologies. Methods: The ARI and diarrhea episodes were prospectively collected in a community-based, longitudinal cohort of infants (n=267) from birth to 2 years of life in Bangladesh. Women were recruited during the third trimester of pregnancy. Demographic, socioeconomic, and environmental information on the households was recorded. Nasopharyngeal and fecal samples were collected during regular scheduled visits from mother-infant pairs, and also from the infants during unscheduled visits for reported illnesses. New generation sequencing methods will be utilized to determine microbiota composition and function, supplemented by the state-of-the-art multiplex molecular detection technology for a wide range of bacterial and viral pathogens. Discussion: This study sought to assess the epidemiology of both respiratory and gastrointestinal illnesses during the first 2 years of life in children from a peri-urban community of Dhaka, Bangladesh. Characteristics of the mothers, as well as birth characteristics of infants enrolled in the Microbiota and Health Study are presented here. We will determine any potential association between microbiota composition and the abovementioned illnesses, and also examine the influence of known and hypothesized risk factors on the occurrence of infections. Such putative factors include environmental, socioeconomic, maternal, clinical, and selected genetic factors, namely the variation of the fucosyltransferase genes (FUT2 and FUT3) of mothers and infants. This study will add to current knowledge about these early childhood infectious diseases, and will provide data to generate hypotheses for the development of nutritional approaches to be used as prevention strategies. Trial registration: The study was retrospectively registered at clinicaltrials.gov as NCT02361164 (February 11, 2015).

Changing Epidemiology of Acute Respiratory Infections in Under-Two Children in Dhaka, Bangladesh

“…The Microbiota and Health Study ( clinicaltrials.gov : NCT02361164) was a longitudinal, community-based cohort study conducted between April 2013 and October 2016 on 267 newborn infants born in Nandipara, a peri-urban community of Dhaka, Bangladesh, as previously described ( 16 ). Healthy pregnant women were enrolled in the third trimester of pregnancy.…”

“…Demographic, maternal health, socioeconomic, and household characteristics collected at baseline, infants' characteristics at birth ( 16 ), as well as breastfeeding status and occurrence of ARIs in the first 2 months of life were considered as variables suspected to be associated with ARI burden. Selected categorical variables were recoded to obtain more balanced group sizes and to increase the power in the statistical analysis ( Supplementary Table 1 ).…”

“…This study was approved by the Institutional Review Board (IRB) of icddr,b comprising Research Review Committee (RRC) and Ethical Review Committee (ERC). Study design, data collection, and baseline characteristics are provided elsewhere ( 16 ).…”

“…The Microbiota and Health Study (clinicaltrials.gov: NCT02361164) was a longitudinal, community-based cohort study conducted between April 2013 and October 2016 on 267 newborn infants born in Nandipara, a peri-urban community of Dhaka, Bangladesh, as previously described Abbreviations: ARI, Acute respiratory infection; EBF, Exclusively breastfed; IRR, Incidence rate ratio; IY, Infant-year; LRTI, Lower respiratory tract infection; NBF, Not breastfed; PBF, Partially breastfed; WASH, Water, sanitation, and hygiene. (16). Healthy pregnant women were enrolled in the third trimester of pregnancy.…”

“…We conducted a longitudinal, community-based study of ARIs in children followed from birth to 2 years living in Nandipara, a peri-urban community of Dhaka, Bangladesh ( 16 ). The goal of the present analysis is to examine a wide range of potential risk factors, including socioeconomic, environmental, WASH, and maternal and perinatal variables, employing an analytical hierarchical approach to identify the most likely causal links to ARI incidence.…”