Molecular Surveillance Identifies Multiple Transmissions of Typhoid in West Africa.
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Authors
International Typhoid Consortium,
Wong, Vanessa
Okoro, Chinyere
Baker, Stephen
Pickard, Derek J
Page, Andrew J
Olanipekun, Grace
Munir, Huda
Alter, Roxanne
Fey, Paul D
Hart, Peter J
Kariuki, Samuel
Breiman, Robert F
Jacobs, Jan
Lunguya, Octavie
Msefula, Chisomo
MacLennan, Calman A
Smith, Anthony M
Onsare, Robert S
De Pinna, Elizabeth
Obaro, Stephen
Publication Date
2016-09-22Journal Title
PLoS neglected tropical diseases
ISSN
1935-2727
Volume
10
Issue
9
Pages
e0004781
Language
eng
Type
Article
This Version
VoR
Physical Medium
Electronic-eCollection
Metadata
Show full item recordCitation
International Typhoid Consortium,, Wong, V., Holt, K. E., Okoro, C., Baker, S., Pickard, D. J., Marks, F., et al. (2016). Molecular Surveillance Identifies Multiple Transmissions of Typhoid in West Africa.. PLoS neglected tropical diseases, 10 (9), e0004781. https://doi.org/10.1371/journal.pntd.0004781
Abstract
BACKGROUND: The burden of typhoid in sub-Saharan African (SSA) countries has been difficult to estimate, in part, due to suboptimal laboratory diagnostics. However, surveillance blood cultures at two sites in Nigeria have identified typhoid associated with Salmonella enterica serovar Typhi (S. Typhi) as an important cause of bacteremia in children. METHODS: A total of 128 S. Typhi isolates from these studies in Nigeria were whole-genome sequenced, and the resulting data was used to place these Nigerian isolates into a worldwide context based on their phylogeny and carriage of molecular determinants of antibiotic resistance. RESULTS: Several distinct S. Typhi genotypes were identified in Nigeria that were related to other clusters of S. Typhi isolates from north, west and central regions of Africa. The rapidly expanding S. Typhi clade 4.3.1 (H58) previously associated with multiple antimicrobial resistances in Asia and in east, central and southern Africa, was not detected in this study. However, antimicrobial resistance was common amongst the Nigerian isolates and was associated with several plasmids, including the IncHI1 plasmid commonly associated with S. Typhi. CONCLUSIONS: These data indicate that typhoid in Nigeria was established through multiple independent introductions into the country, with evidence of regional spread. MDR typhoid appears to be evolving independently of the haplotype H58 found in other typhoid endemic countries. This study highlights an urgent need for routine surveillance to monitor the epidemiology of typhoid and evolution of antimicrobial resistance within the bacterial population as a means to facilitate public health interventions to reduce the substantial morbidity and mortality of typhoid.
Keywords
International Typhoid Consortium
Identifiers
External DOI: https://doi.org/10.1371/journal.pntd.0004781
This record's URL: https://www.repository.cam.ac.uk/handle/1810/289690
Rights
CC0 No rights reserved