typhoid

Typhoid fever is a systemic infection caused by Salmonella enterica serovar Typhi (S. Typhi). It is transmitted predominantly through ingestion of contaminated food or water, or via a chronic carrier. Incubation is typically 6–30 days.

Symptoms include sustained fever, malaise, headache, abdominal pain, and loss of appetite. Constipation or diarrhea may occur; rose spots—pink, blanching macules on the trunk—can appear. Without treatment, complications such as intestinal perforation or hemorrhage, meningitis, or sepsis may develop.

Diagnosis relies on culture of blood, bone marrow, stool, or urine; blood culture is most useful early. The Widal test has limited accuracy and is rarely used in high-income settings; PCR can aid in some cases.

Treatment requires antibiotics guided by local susceptibility. Options include ceftriaxone, azithromycin, or fluoroquinolones in areas with susceptible strains. Severe disease requires intravenous therapy; duration is typically 7–14 days. Drug resistance, including multidrug-resistant strains, complicates management.

Prevention focuses on safe water and sanitation, food hygiene, and vaccination. Vaccines include oral Ty21a and injectable Vi polysaccharide vaccines, with newer protein-conjugate vaccines also used. Vaccination is advised for travelers to high-risk areas and during outbreaks.

Typhoid is endemic in parts of South Asia, sub-Saharan Africa, and Latin America; travelers can acquire disease elsewhere. Public health measures such as surveillance, carrier management, vaccination campaigns, and improvements in water and sanitation reduce incidence. Typhoid is distinct from paratyphoid fever caused by Salmonella Paratyphi A, B, and C.