High prevalence of typhoidal Salmonella enterica serovars excreting food handlers in Karachi-Pakistan: a probable factor for regional typhoid endemicity.

Taranum Ruba Siddiqui,Sobiya Mohiuddin Ayaz,Adnan Khan,Safia Bibi,Muhammad Ayaz Mustufa

doi:10.1186/s41043-015-0037-6

Abstract

BackgroundTyphoid fever is the persistent cause of morbidity worldwide. Salmonella enterica serovar’s carriers among food handlers have the potential to disseminate this infection on large scale in the community. The purpose of this study was to determine the prevalence of typhoidal S. enterica serovars among food handlers of Karachi.MethodsThis cross-sectional study was conducted in Karachi metropolis. A total of 220 food handlers were recruited on the basis of inclusion criteria from famous food streets of randomly selected five towns of Karachi. Three consecutive stool samples were collected from each food handler in Carry Blair transport media. Culture, biochemical identification, serotyping, and antimicrobial susceptibility tests for S. enterica serovars were done.ResultsOut of 220 food handlers, 209 consented to participate, and among them, 19 (9.1 %) were positive for S. enterica serovars. Serotyping of these isolates showed that 9 (4.3 %) were typhoidal S. serovars while 10 (4.7 %) were non-typhoidal S. serovars. Of the typhoidal S. serovars, 7 were S. enterica serovar Typhi and 1 each of S. enterica serovar Paratyphi A and B. The resistance pattern of these isolates showed that 77.7 % were resistant to ampicillin and 11.1 % to cotrimoxazole. All typhoidal S. enterica serovar isolates were sensitive to chloramphenicol, ceftriaxone, cefixime, nalidixic acid, and ofloxacin.ConclusionsCarrier rate of typhoidal S. enterica serovars in food handlers working in different food streets of Karachi is very high. These food handlers might be contributing to the high endemicity of typhoid fever in Karachi, Pakistan.

Highlights

Typhoid fever is the persistent cause of morbidity worldwide
The aim of this paper is to describe the estimate of Salmonella carrier state in food handlers working in different regions of Karachi
Present study showed that 4.3 % healthy food handlers were carriers of typhoidal S. enterica serovars which is much higher than the study reported from Iran, i.e., 1.88 % [12]

Summary

Introduction

Typhoid fever is the persistent cause of morbidity worldwide. Salmonella enterica serovar’s carriers among food handlers have the potential to disseminate this infection on large scale in the community. Typhoid fever remains a public health problem worldwide It is caused by Salmonella enterica serovar Typhi and S. enterica serovar Paratyphi A, Paratyphi B, and Paratyphi C. Siddiqui et al Journal of Health, Population and Nutrition (2015) 33:27 through fecal oral route, these carriers serve as a main source for the transmission of infection as they continue to harbor and excrete the organism in their feces. Carriers of these pathogens among food handlers may be another reason for endemicity in these areas as they transmit the infection on a large scale in the community. At least five consecutive negative sets of cultures should be done to ensure safe food handling [6]

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