Typhoid

Typhoid fever is a serious illness caused by a bacterium called Salmonella Typhi. It can be life-threatening and is usually spread through contaminated food or water. Typhoid is more common in places with poor sanitation and unsafe drinking water, both in cities and rural areas.

The increasing number of people living in certain areas, combined with climate change in areas where sanitation and water supply are contaminated, might make typhoid more common worldwide. Antimicrobial resistance, where antibiotics don’t work as well against some bacteria, makes typhoid more difficult to treat, leading to a higher number of people suffering severe disease, or death. It can also make outbreaks more difficult to contain. Roughly 9 million people become sick from typhoid every year, and 110,000 people die from it worldwide (2019 figures).

Travellers can also get typhoid, especially in places like Asia and sub-Saharan Africa. Even if you're vaccinated, you can still get sick if exposed to contaminated food or water. So, it's important for travellers to be careful about what they eat and drink.

Similarly, paratyphoid, caused by Salmonella Paratyphi A, B and C can spread the same way, causing symptoms that are indistinguishable to typhoid fever. S. Paratyphi is mainly restricted to Asia/Oceania and there is no vaccine available for it yet. 13 million cases of typhoid and paratyphoid fever occurred in 2019.

When someone contracts typhoid fever, the bacteria first enter the intestinal tract before spreading to the bloodstream. This typically leads to symptoms that may closely resemble other febrile (fever-related) illnesses, such as:

• Sustained high fever
• Fatigue
• Headaches
• Nausea
• Abdominal discomfort
• Constipation or diarrhoea
• Rash (which may occur in some cases)

In severe cases, typhoid fever can result in significant complications, such as internal bleeding in the digestive system or splitting/perforation of the digestive system or bowel, allowing the infection to spread to nearby tissues. In the most extreme situations, typhoid fever can cause death.

The Salmonella Typhi bacteria are present in the faeces (poo) of infected individuals. If proper handwashing isn't done afterwards, the bacteria can be spread to others, for example, through preparing food that someone else might eat. Salmonella enterica serovar Typhi can also be found in the urine, and other bodily fluids like vomit, of infected individuals.

In areas with inadequate sanitation, human waste containing these bacteria can pollute the water supply. Consuming water or food washed in contaminated water can result in typhoid fever.

Other ways typhoid fever can be transmitted include:

• Using a toilet contaminated with bacteria and then touching your mouth before washing your hands.
• Consuming seafood from water sources contaminated by infected faeces or urine.
• Eating raw fruit or vegetables that have been washed in contaminated water.
• Consuming unpasteurised milk products contaminated with the bacteria.
• Ice made from contaminated water
• Engaging in oral or anal sexual activity with someone who carries the Salmonella typhi bacteria.

There are three recommended types of typhoid vaccines available internationally. Some countries have these included within their childhood immunisation programme. Travellers visiting certain countries are also recommended to receive a typhoid vaccine.  See our typhoid vaccine page for more information.

Despite being vaccinated, it’s still important to take precautions against typhoid.  These include:

• Only drink sealed bottled water, or water that has been boiled, and avoid drinking water or eating food that has been contaminated.
• Avoiding unpasteurized milk or ice cream
• Avoiding shellfish or seafood that could come from contaminated water
• Practice good hand hygiene by washing your hands thoroughly with soap and water – this is especially important for food handlers.                                              

Typhoid can be treated with antibiotics, but extremely drug-resistant (XDR) typhoid strains have emerged. Only one type of oral antibiotic remains effective against XDR typhoid, but resistance is also starting to emerge against this antibiotic in some places.

This highlights the urgent need for widespread vaccination using the Typhoid Conjugate Vaccine (TCV) in high-risk areas which would reduce the occurrence of the disease and slow down the spread of drug-resistant typhoid. Rolling out the TCV vaccine effectively could prevent two-thirds of cases and deaths.

Roughly 9 million people become sick from typhoid every year, and 110,000 people die from it worldwide (2019 figures). Although the number of deaths from typhoid fever has been decreasing worldwide, it remains a significant health concern, particularly for children under 14 years old.

The graph below outlines the estimated annual deaths from typhoid and paratyphoid fever by age.

Source: Our World in Data