Enteric fever: a travel medicine oriented view

Abstract

Enteric fever continues to be an important infection among populations in endemic countries and among travelers to these areas. This review aims to describe recent epidemiological trends and developments in diagnosis, treatment and prevention. Data indicate that the burden of enteric fever is declining in many middle-income countries, whereas the bulk of cases occur in the Indian subcontinent and in south-east Asia. In these regions, Salmonella Paratyphi A is increasingly seen and sometimes surpasses Salmonella Typhi as the main pathogen. Enteric fever caused by S. Paratyphi A is indistinguishable from that caused by S. Typhi. In addition, drug resistance, including nalidixic acid/quinolone resistance now occurs in the majority of clinical isolates of S. Typhi and S. Paratyphi A in Asia. Currently, third generation cephalosporins and azythromycin are the only reasonable therapeutic options for most cases of travel-related enteric fever. The ongoing emergence of S. Paratyphi A results in partial benefit from current typhoid vaccines in the prevention of enteric fever in travelers. Increasing antimicrobial resistance complicates therapy for travel-related enteric fever. New vaccines, offering protection against both agents of enteric fever, are urgently needed; however, none of the current vaccine candidates is likely to be available for several years.