Invasive Salmonella infections among children in Bintulu, Sarawak, Malaysian Borneo: a 6-year retrospective review

Anand Mohan,Yuwana Podin,Rohaidah Hashim,Chandran Munusamy,Mong-How Ooi,Yee-Chin Tan,Peter Sie-Teck Lau,Sobana Muthuvelu,Su-Lin Chien,Nurul Aiman Khairuddin,David Chun-Ern Ng,Ming-Kui Wong

doi:10.1186/s12879-019-3963-x

Abstract

BackgroundInvasive Salmonella infections result in significant morbidity and mortality in developing countries. In Asia, typhoid and paratyphoid fever are reported to be the major invasive Salmonella infections, while invasive non-typhoidal Salmonella (iNTS) infections are believed to be uncommon. Data from Sarawak, in Malaysian Borneo, are limited.MethodsA retrospective study identifying all children aged < 15 years with invasive Salmonella infections from 2011 to 2016 was conducted in Bintulu Hospital in Sarawak. Population incidences, clinical and bacterial characteristics were examined.ResultsForty-four patients were identified during the 6-year study period: 43 had iNTS infection and 1 had typhoid fever. The average annual iNTS incidence was 32.4 per 100,000 children aged < 5 years. None of the children had malaria or HIV infection, and only 7% were severely malnourished. Salmonella Enteritidis and Salmonella Java were the commonest NTS serovars identified. Pneumonia was the most common manifestation of iNTS disease, present in 20 (47%) children. Other manifestations included gastroenteritis, fever without a source, septic arthritis and meningitis. Salmonella Enteritidis was identified in 76% of those with pneumonia, significantly more frequently than in children with other manifestations. Over 25% of children with iNTS developed severe disease and nearly 10% suffered long term morbidity or mortality. While 78% of Salmonella Java isolates were multi-drug resistant, nearly all other isolates were susceptible to most antimicrobials, including ampicillin.ConclusionsBintulu Division in Sarawak observed a very high incidence of childhood iNTS infections. Enteric fever was uncommon. The epidemiology of invasive Salmonella infections in Malaysian Borneo differs considerably from that of neighbouring countries in Asia.

Highlights

Invasive Salmonella infections result in significant morbidity and mortality in developing countries
Study site The study was conducted at Bintulu Hospital, a 294 bed district hospital which provides medical, surgical and intensive care services to adults and children living in Bintulu Division and Belaga district of Kapit Division in Sarawak, Malaysian Borneo
Case definitions An invasive Salmonella infection case was defined as a child < 15 years with a positive culture of Salmonella enterica species from any normally sterile site sample obtained within 48 h of admission

Summary

Introduction

Invasive Salmonella infections result in significant morbidity and mortality in developing countries. In Asia, typhoid and paratyphoid fever are reported to be the major invasive Salmonella infections, while invasive nontyphoidal Salmonella (iNTS) infections are believed to be uncommon. Invasive Salmonella infections, caused by the various serovars of Salmonella enterica subspecies enterica, result in significant morbidity and mortality in developing countries [1, 2]. A large multicentre prospective study involving 5 Asian countries reported only 5 paediatric iNTS cases in its 12 month surveillance period [7]. The same study confirmed that typhoid and paratyphoid fever remain the predominant invasive Salmonella infections in Asian children, with annual incidences in Indonesia, India and Pakistan ranging from 149 to 573 per 100,000 children aged 2–5 years [8]. Unlike in Africa, little is known regarding the characteristics of these iNTS infections

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