Old tools, new applications: Use of environmental bacteriophages for typhoid surveillance and evaluating vaccine impact

by Yogesh Hooda, Shuborno Islam, Rathin Kabiraj, Hafizur Rahman, Himadree Sarkar, Kesia E. da Silva, Rajan Saha Raju, Stephen P. Luby, Jason R. Andrews, Samir K. Saha, Senjuti Saha Typhoid-conjugate vaccines (TCVs) provide an opportunity to reduce the burden of typhoid fever, caused bySalmonella Typhi, in endemic areas. As policymakers design vaccination strategies, accurate and high-resolution data on disease burden is crucial. However, traditional blood culture-based surveillance is resource-extensive, prohibiting its large-scale and sustainable implementation.Salmonella Typhi is a water-borne pathogen, and here, we tested the potential of Typhi-specific bacteriophage surveillance in surface water bodies as a low-cost tool to identify whereSalmonella Typhi circulates in the environment. In 2021, water samples were collected and tested for the presence ofSalmonella Typhi bacteriophages at two sites in Bangladesh: urban capital city, Dhaka, and a rural district, Mirzapur.Salmonella Typhi-specific bacteriophages were detected in 66 of 211 (31%) environmental samples in Dhaka, in comparison to 3 of 92 (3%) environmental samples from Mirzapur. In the same year, 4,620 blood cultures at the two largest pediatric hospitals of Dhaka yielded 215 (5%) culture-confirmed typhoid cases, and 3,788 blood cultures in the largest hospital of Mirzapur yielded 2 (0.05%) cases. 75% (52/69) of positive phage samples were collected from sewage. All isolated phages were tested against a panel of ...
Source: PLoS Neglected Tropical Diseases - Category: Tropical Medicine Authors: Source Type: research