What Is Typhoid Fever?
Typhoid fever is a serious and potentially life-threatening bacterial infection caused by Salmonella typhi. The bacteria spread through contaminated food and water or through close contact with an infected person. Typhoid is most prevalent in parts of the world with poor sanitation and limited access to clean drinking water. The World Health Organization estimates that 11 to 20 million people contract typhoid fever each year, with 128,000 to 161,000 deaths globally. A closely related but generally milder illness, paratyphoid fever, is caused by Salmonella paratyphi.
How Typhoid Spreads
Typhoid bacteria are shed in the stool and urine of infected individuals. Contamination occurs when sewage comes into contact with water used for drinking or washing food. Travelers most commonly contract typhoid by consuming contaminated water, ice made from contaminated water, raw fruits and vegetables washed in unsafe water, or food prepared by someone carrying the bacteria. Flies can also transfer the bacteria from waste to food. Notably, some people become chronic carriers of Salmonella typhi, shedding bacteria for years without showing symptoms themselves.
Symptoms to Watch For
Symptoms typically develop 1 to 3 weeks after exposure and tend to worsen gradually over several days. Unlike many other infections, typhoid often presents with a sustained high fever that increases in a stepwise pattern over the first week of illness.
- Sustained high fever, often reaching 39-40 degrees Celsius (103-104 degrees Fahrenheit)
- Headache, body aches, and general weakness
- Stomach pain, bloating, and loss of appetite
- Constipation in the early stages, followed by diarrhea as the illness progresses
- A flat, rose-colored rash on the chest and abdomen in some patients
- Enlarged spleen and liver in more advanced cases
- Confusion or delirium in severe, untreated infections
Vaccination Options
Two typhoid vaccines are currently available, and travelers to high-risk areas should receive one at least 1 to 2 weeks before departure. Neither vaccine provides 100% protection, with effectiveness ranging from 50% to 80%, so vaccination should be combined with safe food and water practices.
- Injectable vaccine (Vi polysaccharide): A single shot given at least 2 weeks before travel, providing protection for approximately 2 years; suitable for adults and children aged 2 and older
- Oral vaccine (Ty21a): A series of 4 capsules taken every other day, completed at least 1 week before travel, providing protection for approximately 5 years; suitable for adults and children aged 6 and older; must be stored refrigerated
Safe Food and Water Practices
Because vaccines are only partially effective, practicing strict food and water safety is essential when traveling to regions where typhoid is common. Following the traveler's rule of 'boil it, cook it, peel it, or forget it' can significantly reduce your risk.
- Drink only bottled, boiled, or chemically treated water, and use it for brushing teeth as well
- Avoid ice in beverages unless you are certain it was made from safe water
- Eat only foods that have been thoroughly cooked and are served steaming hot
- Avoid raw fruits and vegetables unless you can peel them yourself with clean hands
- Skip street food vendors unless the food is prepared fresh in front of you and served hot
- Wash hands thoroughly with soap and water before eating and after using the restroom
- Carry alcohol-based hand sanitizer for situations where soap and water are unavailable
Treatment and Recovery
Typhoid fever is treated with antibiotics, and most people begin to feel better within 2 to 3 days of starting treatment. Commonly prescribed antibiotics include ciprofloxacin, azithromycin, and ceftriaxone. However, antibiotic resistance is a growing concern, particularly in South Asia and Southeast Asia, where extensively drug-resistant (XDR) typhoid strains have emerged. These XDR strains are resistant to all first-line oral antibiotics, requiring treatment with intravenous drugs that may only be available in hospital settings.
If you suspect typhoid, seek medical attention promptly, as untreated typhoid can lead to serious complications including intestinal perforation, internal bleeding, and sepsis. Full recovery typically takes several weeks, and patients should rest, stay hydrated, and complete the entire course of antibiotics even after symptoms improve. Stopping antibiotics early, even if you feel better, can lead to relapse and may contribute to the development of antibiotic resistance. Follow-up stool cultures may be recommended to confirm that the bacteria have been completely eliminated from your system.
High-Risk Destinations for Travelers
Typhoid risk is highest in regions with inadequate water treatment and sanitation infrastructure. Travelers to the following regions should take special precautions and strongly consider vaccination before departure. The risk is not limited to rural areas; even major cities in high-prevalence countries can pose a risk, particularly if you eat street food, drink tap water, or stay in budget accommodations with limited hygiene standards.
- South Asia: India, Pakistan, and Bangladesh account for the majority of global typhoid cases, with some regions reporting XDR strains resistant to all oral antibiotics
- Southeast Asia: Parts of Vietnam, Cambodia, Myanmar, and Indonesia have significant typhoid transmission, particularly in areas with limited clean water access
- Sub-Saharan Africa: Kenya, Nigeria, and the Democratic Republic of Congo report notable case numbers, often complicated by limited diagnostic and treatment facilities
- Central and South America: Haiti, Peru, and parts of Mexico have active transmission zones, especially in rural areas and urban slums
- The Middle East: Parts of Iraq, Yemen, and Afghanistan experience periodic typhoid outbreaks linked to conflict-related infrastructure damage
Chronic Carriers and Reinfection
After recovering from typhoid fever, approximately 1% to 5% of patients become chronic carriers of Salmonella typhi. These individuals harbor the bacteria in their gallbladder and continue to shed them in their stool for months or even years, potentially infecting others without showing any symptoms themselves. The most famous historical example is Mary Mallon, known as Typhoid Mary, who worked as a cook in New York City in the early 1900s and is believed to have infected over 50 people. Today, chronic carriers can be treated with prolonged antibiotic courses, and in rare cases, surgical removal of the gallbladder may be recommended to eliminate the reservoir of bacteria. If you have recovered from typhoid, follow-up testing is important to ensure you have not become a carrier.