ETEC_Household_transmission. ETEC_Household_transmission

Enterotoxigenic E. coli (ETEC) is the most common cause of bacterial diarrhea in children in Low Middle Income Countries (LMICs), closely followed by V. cholerae and rotavirus infection. Previous large-scale sequencing studies have found seven major ETEC lineages currently in circulation worldwide. With a focus on diarrhea in travelers there is still very little known about its true diversity or pathways for transmission in truly endemic regions. We will conduct a longitudinal cluster-based cohort study in Mathbaria Bangladesh in which we will enroll index ETEC diarrhea cases from the health complex along with age, time and sex matched ETEC negative controls from the same community as the index case. We will prospectively follow the members of the case and control households for incident ETEC infections and identify sources and modes of transmission to guide intervention strategies. This is a pilot study that will provide the reference data set with which to more accurately track ETEC transmission. We will investigate whether the relative risks of ETEC infection in the family members of the index ETEC-associated diarrhea cases is higher compared to the risk in the index control (without ETEC) households. These infections will be through within household transmission and there is also a likelihood of infection due to exposure to external sources. We will also investigate if anti-ETEC antibodies may contribute to the susceptibility to ETEC infections among the household members exposed to ETEC. This collaborative project between WSI, Johns Hopkins University, and icddr,b, Bangladesh. We will use PacBio long-read sequencing combined with Illumina sequencing to create high-quality complete reference genomes. These reference genomes allow for fast and accurate comparison between different ETEC strains, and these data will form the foundation of ETEC genomics research for us and a Fellowship application by Subhra Chakraborty (Johns Hopkins University) for large scale follow up work in Bangladesh.