Typhoid fever, which is caused by Salmonella enterica serovar Typhi (also known as Salmonella Typhi), is a serious infection that can be life-threatening. The disease is commonly transmitted through the consumption of contaminated food or water.

Typhoid fever is most prevalent in areas with poor sanitation and inadequate clean water, both in rural and urban settings. Urbanization and climate change have the potential to worsen the global incidence of typhoid, as well as increasing antibiotic resistance, which makes it easier for the disease to spread and more difficult to treat.

Approximately 9 million people become ill with typhoid fever each year, and 110,000 people die from the disease worldwide (as of 2019). The disease is particularly prevalent in children and populations that lack access to safe drinking water and proper sanitation.

Travellers are at risk of contracting typhoid fever in many countries where the disease is endemic, especially in Asia and sub-Saharan Africa. Even travellers who have been vaccinated should be cautious about consuming potentially contaminated food and water, as vaccination does not provide complete protection. Travellers are at risk of contracting the disease when exposed to poor personal hygiene, food hygiene, and water quality standards.

Symptoms and treatment

Salmonella Typhi lives only in humans. In persons with typhoid fever the bacteria enter through the intestinal tract and eventually invade the bloodstream. The resulting illness is often clinically non-distinguishable from other febrile illnesses. Symptoms include:

  • prolonged high fever
  • fatigue
  • headache
  • nausea
  • abdominal pain
  • constipation or diarrhoea
  • rash, in some cases.

Severe cases may lead to serious complications or even death.

Typhoid fever can be treated with antibiotics. However, increased resistance to antibiotics, including fluoroquinolones and newer antibiotics such as cephalosporins and azithromycin, as well as the emergence of extensively drug resistant strains of Salmonella Typhi leads to more complicated and expensive treatment options in the most affected regions.

Even after symptoms pass, approximately 2–5% of cases become chronic carriers and inadvertently spread typhoid through ongoing faecal shedding of the bacteria and contamination. It is important for people being treated for typhoid fever to do the following:

  • take prescribed antibiotics for the full prescribed course;
  • wash their hands with soap and water after using the bathroom, and avoid preparing or serving food to other people, whilst the infection persists; and
  • have their doctor test (after the antibiotic course) to ensure that no Salmonella Typhi bacteria remain in their body.

Prevention and control

Preventing and controlling typhoid can be achieved through various effective measures such as ensuring access to safe water and sanitation, providing health education, promoting appropriate hygiene practices among food handlers, and administering typhoid vaccines.

There are three types of typhoid vaccines recommended for use. The first one is the typhoid conjugate vaccine, which is given via injection and is suitable for children aged six months and above, as well as adults up to 65 years old. The second one is the unconjugated Vi polysaccharide vaccine, which is also given via injection and is recommended for individuals over the age of two. Lastly, the live attenuated oral vaccine is appropriate for those over six years of age.

Since October 2017, the typhoid conjugate vaccine has been recommended as a single dose for routine childhood immunization programs. The other two vaccines have been used for many years in older children and adults at risk of typhoid, such as travelers, but require multiple doses for continued protection as they do not provide long-lasting immunity.

In December 2017, two typhoid conjugate vaccines were prequalified by WHO and are recommended for use in countries with high levels of typhoid burden or antimicrobial resistance. It is expected that the widespread use of the conjugate vaccine in these priority countries will help to reduce the use of antibiotics for typhoid treatment and slow the increase in antibiotic resistance in Salmonella Typhi.