# Shigella Infections in Household Contacts of Pediatric Shigellosis Patients in Rural Bangladesh

## TL;DR

Household members of children with Shigella infections are highly likely to also get infected, suggesting easy transmission within homes in rural Bangladesh.

## Contribution

This study quantifies the high risk of Shigella transmission among household contacts and identifies environmental risk factors.

## Key findings

- Household contacts were 44 times more likely to develop Shigella infections compared to controls.
- Most household infections matched the species and serotype of the index patient’s infection.
- Environmental factors like latrine fly counts and contaminated water were linked to Shigella presence.

## Abstract

To examine rates of Shigella infections in household contacts of pediatric shigellosis patients, we followed contacts and controls prospectively for 1 week after the index patient obtained care. Household contacts of patients were 44 times more likely to develop a Shigella infection than were control contacts (odds ratio 44.7, 95% CI 5.5–361.6); 29 (94%) household contacts of shigellosis patients were infected with the same species and serotype as the index patient’s. Pulsed-field gel electrophoresis showed that 14 (88%) of 16 with infected contacts had strains that were indistinguishable from or closely related to the index patient’s strain. Latrine area fly counts were higher in patient households compared with control households, and 2 patient household water samples were positive for Shigella. We show high susceptibility of household contacts of shigellosis patients to Shigella infections and found environmental risk factors to be targeted in future interventions.