Typhoid Fever (Human)

Primary reference(s)

WHO, 2018. Typhoid. World Health Organization (WHO). Accessed 11 October 2020.

Additional scientific description

Typhoid fever is a life-threatening infection caused by the bacterium Salmonella Typhi. Once Salmonella Typhi bacteria have been ingested, they multiply and spread into the bloodstream. Urbanisation and climate change have the potential to increase the global burden of typhoid. In addition, increasing resistance to antibiotic treatment is making it easier for typhoid to spread through overcrowded populations in cities and inadequate and/or flooded water and sanitation systems (WHO, 2018a).

Improved living conditions and the introduction of antibiotics resulted in a drastic reduction of typhoid fever morbidity and mortality in industrialised countries. In developing areas of Africa, the Americas, South-East Asia and the Western Pacific regions, however, the disease continues to be a public health problem.

The global typhoid fever disease burden is estimated to be 11–20 million cases annually, resulting in about 128,000 to 161,000 deaths per year (WHO, 2018a).

Salmonella Typhi only affects humans. Persons with typhoid fever carry the bacteria in their bloodstream and intestinal tract. Symptoms include prolonged high fever, fatigue, headache, nausea, abdominal pain, and constipation or diarrhoea. Some patients may have a rash. Severe cases may lead to serious complications or even death. Typhoid fever can be confirmed through blood testing (WHO, 2018a).

Typhoid risk is higher in populations that lack access to safe water and adequate sanitation. Poor communities and vulnerable groups including children are at highest risk (WHO, 2018a).

The World Health Organization (WHO) has published guidance on case classification and surveillance standards (WHO, 2018b).

Metrics and numeric limits

Not found.

Examples of drivers, outcomes and risk management

Typhoid fever is common in places with poor sanitation and a lack of safe drinking water. Access to safe water and adequate sanitation, hygiene among food handlers and typhoid vaccination are all effective in preventing typhoid fever (WHO, 2018a).

Two vaccines have been used for many years to protect people from typhoid fever: an injectable vaccine based on the purified antigen for people aged over 2 years; and a live attenuated oral vaccine in capsule formulation for people aged over 5 years (WHO, no date).

All travellers to endemic areas are at potential risk of typhoid fever, although the risk is generally low in tourist and business centres where standards of accommodation, sanitation and food hygiene are high. Typhoid fever vaccination should be offered to travellers to destinations where the risk of typhoid fever is high (WHO, 2018a).

The following recommendations will help ensure safety while travelling: ensure food is properly cooked and still hot when served; avoid raw milk and products made from raw milk – drink only pasteurised or boiled milk; avoid ice unless it is made from safe water; when the safety of drinking water is questionable, boil it or if this is not possible, disinfect it with a reliable, slow-release disinfectant agent (usually available at pharmacies); wash hands thoroughly and frequently using soap, especially after contact with pets or farm animals, or after having been to the toilet; and wash fruit and vegetables carefully, particularly if they are eaten raw. If possible, vegetables and fruits should be peeled (WHO, 2018a).

WHO response for typhoid. In December 2017, the World Health Organization (WHO) pre-qualified the first conjugate vaccine for typhoid. This new vaccine has longer-lasting immunity than older vaccines, requires fewer doses and can be given to children from the age of 6 months. This vaccine will be prioritised for countries with the highest burden of typhoid disease. This will help reduce the frequent use of antibiotics for typhoid treatment, which will slow the rise in antibiotic resistance in Salmonella Typhi. In October 2017, the Strategic Advisory Group of Experts (SAGE) on immunisation, which advises the WHO, recommended typhoid conjugate vaccines for routine use in children over 6 months of age in typhoid endemic countries. SAGE also called for the introduction of typhoid conjugate vaccines to be prioritised for countries with the highest burden of typhoid disease or of antibiotic resistance to Salmonella Typhi. Shortly after SAGE’s recommendation, the Gavi Board approved USD 85 million in funding for typhoid conjugate vaccines starting in 2019 (WHO, 2018a).