Enteric fever and its impact on returning travellers.

Enteric fever, a systemic illness, is caused by Salmonella enterica serovar Typhi or S. enterica serovar Paratyphi A, B or C. The organism is transmitted to humans by the faecal oral route and is endemic in countries with poor sanitation and lacking clean drinking water. There are around 27 million individuals infected with S. Typhi worldwide annually. Enteric fever is a particular problem in travellers to endemic areas, especially those visiting friends and relatives. Currently, the two main vaccines recommended for travellers are the Vi polysaccharide vaccine and the oral Ty21a vaccine. These internationally licensed vaccines are safe and effective against S. Typhi. However, there is currently no commercially available vaccine against S. Paratyphi, which is increasingly reported as a cause of enteric fever. Vaccine uptake and taking appropriate precautions are poor in travellers visiting friends and relatives abroad; this problem requires addressing. Ciprofloxacin is no longer recommended for empirical treatment of infection because of increasing reports of resistance, especially from South Asia. Ceftriaxone and azithromycin are currently the most commonly used antimicrobials for empirical treatment of enteric fever but resistance to both these agents is emerging.