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Gastrointestinal infection
INTRODUCTION
Salmonella enterica serotype Typhi (S. Typhi), the organism that causes typhoid fever is common in areas with compromised sanitary and water conditions. Typhoid fever was estimated to have caused about 22 million cases and 216 000 deaths in 2000 [1]. Most studies that were used for burden-of-disease estimation are from the South and South East Asian region. Only one study representing Africa was included. Therefore these estimates are considered conservative for the global burden of typhoid fever. Population-based incidence estimates for typhoid fever are not available globally, but typhoid fever complications are frequently reported in the literature from almost all regions of the world [2, 3].
Typhoid fever is mainly spread by the faecal-oral route; therefore transmission is high in areas where the risk of food and especially water contamination is high. Factors that influence contamination of drinking water are the non-availability of piped water, and improper drainage of sewage [4]. Individual risky behaviours such as not washing hands after defecation and before meals are another contributing factor for typhoid spread. In South East Asia, the incidence of typhoid fever in children is high in urban low socioeconomic squatter settlements where population density is high and living conditions are compromised [5].
Humans are the exclusive host for S. Typhi. The most common source of infection is the ingestion of food contaminated with S. Typhi [6]. Occasionally contaminated eggs and frozen oysters have been found to be associated with typhoid infection [7]. The documented risk factors based on studies in high-risk areas such as Pakistan are consumption of ice cream and flavoured iced drinks from street vendors, raw fruit and vegetables, and a history of contact with a typhoid patient before illness [8]. Hand washing and past evidence of infection with Helicobacter pylori are among other risk factors [9]. Individual host factors such as HLA-linked genes may also increase susceptibility to infection; however, the underlying mechanism of action is not yet completely understood [10].
Typhoid fever remains a major health problem in the rapidly growing urban settlements of Asia and Africa. Migrating populations frequently have to settle on untitled land which usually has no electricity, water supply, or sanitation infrastructure. The identification of...