Environmental Surveillance for Salmonella Typhi and its Association With Typhoid Fever Incidence in India and Malawi

© The Author(s) 2023. Published by Oxford University Press on behalf of Infectious Diseases Society of America..

BACKGROUND: Environmental surveillance (ES) for Salmonella Typhi potentially offers a low-cost tool to identify communities with a high burden of typhoid fever.

METHODS: We developed standardized protocols for typhoid ES, including sampling site selection, validation, characterization; grab or trap sample collection, concentration; and quantitative PCR targeting Salmonella genes (ttr, staG, and tviB) and a marker of human fecal contamination (HF183). ES was implemented over 12 months in a historically high typhoid fever incidence setting (Vellore, India) and a lower incidence setting (Blantyre, Malawi) during 2021-2022.

RESULTS: S. Typhi prevalence in ES samples was higher in Vellore compared with Blantyre; 39/520 (7.5%; 95% confidence interval [CI], 4.4%-12.4%) vs 11/533 (2.1%; 95% CI, 1.1%-4.0%) in grab and 79/517 (15.3%; 95% CI, 9.8%-23.0%) vs 23/594 (3.9%; 95% CI, 1.9%-7.9%) in trap samples. Detection was clustered by ES site and correlated with site catchment population in Vellore but not Blantyre. Incidence of culture-confirmed typhoid in local hospitals was low during the study and zero some months in Vellore despite S. Typhi detection in ES.

CONCLUSIONS: ES describes the prevalence and distribution of S. Typhi even in the absence of typhoid cases and could inform vaccine introduction. Expanded implementation and comparison with clinical and serological surveillance will further establish its public health utility.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:229

Enthalten in:

The Journal of infectious diseases - 229(2024), 4 vom: 12. Apr., Seite 979-987

Sprache:

Englisch

Beteiligte Personen:

Uzzell, Christopher B [VerfasserIn]
Abraham, Dilip [VerfasserIn]
Rigby, Jonathan [VerfasserIn]
Troman, Catherine M [VerfasserIn]
Nair, Satheesh [VerfasserIn]
Elviss, Nicola [VerfasserIn]
Kathiresan, Lalithambigai [VerfasserIn]
Srinivasan, Rajan [VerfasserIn]
Balaji, Veeraraghavan [VerfasserIn]
Zhou, Nicolette A [VerfasserIn]
Meschke, John Scott [VerfasserIn]
John, Jacob [VerfasserIn]
Kang, Gagandeep [VerfasserIn]
Feasey, Nicholas [VerfasserIn]
Mohan, Venkata Raghava [VerfasserIn]
Grassly, Nicholas C [VerfasserIn]

Links:

Volltext

Themen:

India
Journal Article
Malawi
Salmonella Typhi
Typhoid fever
Typhoid-Paratyphoid Vaccines
Typhoid-paratyphoid vaccines
Wastewater surveillance

Anmerkungen:

Date Completed 15.04.2024

Date Revised 25.04.2024

published: Print

Citation Status MEDLINE

doi:

10.1093/infdis/jiad427

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM362711925