Enteric (typhoid and paratyphoid) fever

Enteric fever, caused by the human-restricted bacteria Salmonella enterica serovar Typhi (typhoid) and Salmonella enterica serovar Paratyphi A, B, and C (paratyphoid), affects persons residing in, or travelling from, areas lacking safe water, sanitation, and hygiene infrastructure. Transmission is by the faecal–oral route. A gradual fever onset over 3–7 days with malaise, headache, and myalgia is typical. Symptoms can be altered by previous antimicrobial use. Life-threatening complications can arise in the second week of untreated illness. Differentiation from other febrile illnesses is challenging. Blood or bone marrow culture remain reference standard diagnostic methods, despite the low sensitivity of blood culture. Azithromycin, ciprofloxacin (excepting cases originating in south Asia due to drug resistance), or ceftriaxone are recommended treatment options for both typhoid and paratyphoid; however, choice should be guided by local resistance patterns. Ciprofloxacin-resistant and ceftriaxone-resistant typhoid is common in Pakistan. Three vaccine types are available for prevention of typhoid disease, including the newer, more effective typhoid Vi-conjugate vaccines. Vaccination as well as water, sanitation, and hygiene measures are cornerstones of prevention.