Enteric fever

What you need to know • In endemic areas and in returning travellers, consider enteric fever in the differential diagnosis in patients with acute fever, particularly if they have abdominal symptoms • Routine blood tests and blood culture can aid the diagnosis; serological tests, including the Widal test, are not recommended • Antimicrobial resistance is common, so refer to national guidelines or formularies for choice of antibiotic • In endemic areas, rule out other causes of acute fever such as malaria and dengue with tests and consider adding empirical treatment with doxycycline (or azithromycin) for scrub typhus and leptospirosis • The Vi polysaccharide vaccine and Ty21a vaccine are available for use in travellers.The typhoid Vi conjugate vaccine is now recommended by the WHO in endemic areasEnteric fever, also known as typhoid fever, is a common infectious disease in low and middle income countries.1 It is the commonest bacterial cause of fever in returning travellers and migrants from these areas. 2 3 About 14 million people are affected annually with 136 000 deaths, mainly in low and middle income countries, according to estimates from the Global Burden of Disease Study in 2017. 1 Diagnosis is complicated as symptoms overlap with other causes of fever and early investigations are inconclusive.Antimicrobial resistance is a growing concern.General practitioners have an important role in early diagnosis and management, prompt referral of patients with severe disease, and prevention including vaccination. How is it caused?Enteric fever encompasses typhoid fever, caused by infection with bacteria Salmonella Typhi (S Typhi), and paratyphoid fever, caused by Salmonella Paratyphi A and B. S Typhi is estimated to cause 76% of enteric fever globally.1 Paratyphoid fever is mostly seen in parts of South Asia and China. 1 4 Ingestion of food or water contaminated by infected human faeces causes infection.5Who gets enteric fever?Poor access to clean drinking water and inadequate sanitation and hygiene increase the risk of transmission.5 6 Enteric fever is most common in South Asia (incidence >500 per 100 000 population); South-East Asia, sub-Saharan Africa, and Oceania (>100 per 100 000 population); and Latin America and Caribbean (1-10 per 100 000 population). 1 7 Children and young adults are more commonly affected.8 -10 Among travellers, enteric fever is more common in adults after a visit to endemic areas. 2 3Use of proton pump inhibitors increases susceptibility to enteric fever by reducing gastric acidity, as per a systematic review.11 The role of HIV infection as a risk factor is unclear, but it may contribute to disease severity.12 A case series reported neonatal sepsis due to S Typhi and Paratyphi in babies born to infected mothers.