Epidemiology of Shiga toxin-producing Escherichia coli O157:H7 in Africa in review

Athumani M Lupindu

doi:10.4102/sajid.v33i1.31

Abstract

Shiga toxin-producing Escherichia coli (STEC) O157:H7 is responsible for intestinal and extra-intestinal disease syndromes in human. Isolation of the pathogen from animals, food, clinical samples and environment has been reported from all continents. A review of STEC O157:H7 in Africa from a structured literature search of the PubMed electronic database is presented. It describes the epidemiological status of the pathogen on the aspects of source, transmission, pathogenesis, disease syndromes, diagnosis, disease burden and the challenges in treatment and control strategies. About a quarter of African countries have reported isolation of STEC O157:H7 either from humans, animals, food or the environment. Different methods have been used in detection of the pathogen. Most reported human infections do not show temporal relationships with reports of isolation of the pathogen from other sources such as animals, water or food. Lack of a direct link between isolates from humans and other sources makes it difficult to point out incident specific determinants and direction of transmission. The aim of this review is to give an insight into the features of STEC O157:H7 infection in Africa and draw the attention of various stakeholders to the public health threat of the pathogen for possible interdisciplinary and multi-sectoral joint efforts in the control strategies.

Highlights

Escherichia coli strains that cause diarrhea in humans are either enterotoxigenic E. coli (ETEC), enteroaggregative E. coli (EAEC), enteropathogenic E. coli (EPEC), enteroinvasive E. coli (EIEC), diffusely adherent E. coli (DAEC) or verocytotoxigenic E. coli (VTEC).[1]
One of the VTEC stains associated with diarrhea, bloody diarrhea, haemorrhagic colitis and haemolytic uremic syndrome (HUS) is the Shiga toxin-producing Escherichia coli (STEC) O157:H7.2 Once described as a rare serotype causing human infection,[3] STEC O157:H7 is widespread in food products[4,5,6] and the environment.[7,8]
A STEC O157:H7 prevalence of more than 7% was reported in patients with diarrhoea in Morogoro, Tanzania in 2006.17 In 2012, the pathogen was isolated from cattle in the same area with a prevalence of 0.9%

Summary

Introduction

Escherichia coli strains that cause diarrhea in humans are either enterotoxigenic E. coli (ETEC), enteroaggregative E. coli (EAEC), enteropathogenic E. coli (EPEC), enteroinvasive E. coli (EIEC), diffusely adherent E. coli (DAEC) or verocytotoxigenic E. coli (VTEC).[1]. The aim is draw the attention of public health stakeholder to this health problem in Africa so that multidisciplinary joint efforts can be applied in the control strategies

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Conclusion