Typhoid fever is a systemic infection caused by the gram-negative Salmonella enterica, subspecies enterica, serotype Typhi. Transmission is primarily via the oral route following ingestion of food or water contaminated by faeces and occasionally the urine of acutely ill persons or those who are chronic carriers. Direct faecal–oral transmission can also occur.

Following an incubation period of 10-20 days, clinical presentation range from mild fever, diarrhoea, myalgia and headache to severe disseminated disease with multi-organ involvement in 10-15% of cases. The case–fatality rate (CFR) is <1% with prompt antibiotic therapy, but may be as high as 20% in untreated or inappropriately treated cases.

Typhoid is also regarded as a travel-related disease with a considerably higher risk following travel to many developing areas of the WHO African, Eastern Mediterranean, South-east Asia and Western Pacific regions. In 2021, an estimated 9.3 million cases of enteric fever and 107,500 related deaths were reported worldwide, with South Asia bearing the highest burden.

Typhoid fever is endemic in Malaysia, with the incidence rate of typhoid and paratyphoid fever ranging from 0.20 to 0.55 per 100,000 population annually in recent years (2020–2024). The mortality rate during the same period was reported to be between 0.00-0.02 per 100,000 population. A recent outbreak of typhoid fever occurred in Kelantan in 2024.