Typhoid or Enteric fever is a serious and common infection (in many countries) caused by the gram-negative bacilli Salmonella typhi. It is characterized by sustained fever, abdominal pain, and a rash.

This bacterial infection primarily affects the intestinal tract and can lead to a range of symptoms, ranging from mild to severe. Enteric fever is a significant public health concern, particularly in areas with poor sanitation and limited access to clean water.

Contamination of food products and water supplies with infected faecal matter causes widespread infections. Flies can spread the infection directly from stool to food. Typhoid is a water and food-borne disease. Poor as well as developing countries such as Asian countries (India, Pakistan, Shri Lanka, Bangladesh), African countries have Enteric fever as a major health menace.

The primary causative agent of enteric fever is Salmonella enterica serotype Typhi, although another strain, Paratyphi, can also cause a similar illness known as paratyphoid fever. These bacteria are highly adapted to the human host and are typically transmitted through the ingestion of contaminated food or water. Poor sanitation and hygiene practices contribute to the spread of the disease, making it more prevalent in areas with inadequate sanitation infrastructure.

The incubation period for enteric fever is typically 6 to 30 days, depending on the dose of ingested bacteria and other factors.

The symptoms of typhoid fever start 7-14 days after consuming food or drinks contaminated with the Salmonella typhi bacteria. Untreated typhoid runs a course having four classical stages each lasting for about a week.