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Sequencing and Characterization of Five Extensively Drug-Resistant Salmonella enterica Serotype Typhi Isolates Implicated in Human Infections from Punjab, Pakistan.

ABSTRACT: A large outbreak of extensively drug-resistant (XDR) Salmonella enterica serotype Typhi infections is ongoing in Pakistan, predominantly in Sindh Province. Here, we report the sequencing and characterization of five XDR Salmonella Typhi isolates from the Punjab province of Pakistan that are closely related to the outbreak strain and carry the same IncY plasmid.

SUBMITTER: Tagg KA

PROVIDER: S-EPMC7098906 | biostudies-literature | 2020 Mar

REPOSITORIES: biostudies-literature

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Sequencing and Characterization of Five Extensively Drug-Resistant Salmonella enterica Serotype Typhi Isolates Implicated in Human Infections from Punjab, Pakistan.

Tagg Kaitlin A KA Amir Afreenish A Ikram Aamer A Chen Jessica C JC Kim Justin Y JY Meservey Elizabeth E Joung Yoo J YJ Halpin Jessica L JL Batra Dhwani D Leeper Molly M MM Katz Lee S LS Saeed Asim A Freeman Molly M Watkins Louise Francois LF Salman Muhammad M Folster Jason P JP

Microbiology resource announcements 20200326 13

A large outbreak of extensively drug-resistant (XDR) <i>Salmonella enterica</i> serotype Typhi infections is ongoing in Pakistan, predominantly in Sindh Province. Here, we report the sequencing and characterization of five XDR <i>Salmonella</i> Typhi isolates from the Punjab province of Pakistan that are closely related to the outbreak strain and carry the same IncY plasmid. ...[more]

PMID: 32217683

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Project description:BackgroundSalmonella enterica serotype Typhi (S Typhi) is a major public health problem in low-income and middle-income countries. We aimed to investigate the effectiveness and impact of the typhoid conjugate vaccine Typbar-TCV against S Typhi among children in an outbreak setting of extensively drug-resistant (XDR) S Typhi in Pakistan.MethodsThis cohort study was done from Feb 21, 2018, to Dec 31, 2019. A census survey of all households located in the Qasimabad and Latifabad subdistricts of Hyderabad, Pakistan, was done at baseline, and 174 005 households were registered in the census. The Typbar-TCV immunisation campaign was initiated at temporary vaccination centres and 207 000 children aged 6 months to 10 years were vaccinated from Feb 21, 2018, to Dec 31, 2018. Social mobilisers informed parents about the vaccination process. Vaccination records were maintained electronically and linked with the household census surveys. Active surveillance for suspected and blood-culture-confirmed S Typhi was established in hospitals, clinics, and laboratories to assess the following outcomes: cases of suspected typhoid fever, culture-confirmed S Typhi, and antimicrobial resistance. An age-stratified cohort of 1100 vaccinated children was randomly selected from the vaccination registry, tested for Vi-IgG antibodies (data not reported), and followed up fortnightly (via telephone calls or household visits) until Dec 31, 2019, for ascertainment of outcomes during the study period. 20 847 vaccinated and unvaccinated children were randomly selected from the census registry as a quality control cohort and followed up from Oct 1 to Dec 31, 2019, for ascertainment of outcomes. Vaccine effectiveness against suspected, culture-confirmed, and XDR S Typhi was calculated.Findings23 407 children from the census registry and surveillance system were included in the vaccine effectiveness analysis. 13 436 (57·4%) children were vaccinated, 12 214 (52·2%) were male, and 10 168 (43·4%) were aged 6-59 months. 5378 (23·0%) of 23 407 children had suspected S Typhi, among whom 775 (14·4%) had culture-confirmed S Typhi and 361 (68·6%) of 526 had XDR S Typhi. Vaccine effectiveness was 55% (95% CI 52-57) against suspected S Typhi (regardless of culture confirmation), 95% (93-96) against culture-confirmed S Typhi, and 97% (95-98) against XDR S Typhi.InterpretationTypbar-TCV is effective in protecting children against S Typhi infection in an outbreak setting, and was able, with moderate deployment, to curtail a major XDR S Typhi outbreak in a densely populated setting. The vaccine shows efficacy against S Typhi irrespective of antimicrobial resistance.FundingBill & Melinda Gates Foundation.

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Dataset Information

Sequencing and Characterization of Five Extensively Drug-Resistant Salmonella enterica Serotype Typhi Isolates Implicated in Human Infections from Punjab, Pakistan.

Publications

Sequencing and Characterization of Five Extensively Drug-Resistant Salmonella enterica Serotype Typhi Isolates Implicated in Human Infections from Punjab, Pakistan.

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