Typhoid fever is a serious bloodstream infection caused by Salmonella enterica serotype Typhi, transmitted through contaminated food and water in regions with limited sanitation. WHO estimates 9 million typhoid cases and 110,000 deaths globally each year, with the heaviest burden in South Asia, sub-Saharan Africa, and parts of Southeast Asia. Most US cases are in returned travelers, with roughly 80% of CDC-reported cases linked to travel to South Asia.

In the pre-antibiotic era and in settings with no access to treatment, untreated typhoid killed about 10 to 20% of the people who got it. With prompt antibiotic treatment, mortality drops below 1%. The catch is rising antibiotic resistance: extensively drug-resistant (XDR) typhoid strains have spread out of Pakistan since 2016 and now appear in returning travelers from multiple South Asian countries. The vaccine, food-and-water precautions, and getting medical attention fast all matter more than they did a decade ago. Our outbreak-aware travel guide covers typhoid alongside the other endemic diseases that shape pre-departure planning for South Asia.

Key Takeaways

What is typhoid fever and where is the risk highest?

Typhoid fever is a bloodstream infection caused by Salmonella Typhi, spread through contaminated food and water in regions with limited safe-water and sanitation infrastructure. CDC reports roughly 80% of US typhoid cases are linked to travel to South Asia (India, Pakistan, Bangladesh, Nepal). Sub-Saharan Africa, parts of Southeast Asia, and Central and South America carry the next-highest endemicity.

The infection has a long human history: typhus and typhoid were leading killers in industrializing cities until water and sewage infrastructure separated drinking water from sewage. The same separation hasn't happened in much of the global south, which is why typhoid persists at high rates in regions where private bottled water has become the workaround for unreliable municipal supply.

CDC's traveler health pages categorize typhoid risk by destination, ranging from "vaccinate all travelers" for South Asia to "vaccinate selectively" for short urban-only stays in lower-incidence regions. The destination-specific risk lookup at the disease risks by region page covers how to read the country-level guidance.

How does typhoid spread?

Typhoid spreads through contaminated water, food prepared with contaminated water, and food handled by an asymptomatic chronic carrier (Salmonella Typhi can persist in the gallbladder of recovered people for years). Travelers most often acquire it from drinking water, ice, raw or lightly cooked vegetables, salads, dairy from unreliable cold chains, or food sold by street vendors using untreated water.

Typhoid Mary is the historical archetype. Mary Mallon, a household cook in early-1900s New York, infected at least 51 people across multiple jobs while never having symptoms herself. The chronic-carrier state explains why typhoid keeps recurring in places where any segment of the food-handling workforce isn't reliably screened or treated. Modern outbreaks still trace to chronic carriers periodically.

Cooking inactivates Salmonella Typhi at standard temperatures (above 70°C for several minutes). Refrigeration and freezing do not. Bottled and boiled water, peeled-by-you fruit, and food served visibly hot all-the-way-through cover most exposures. The travelers' diarrhea post lays out the same precautions in operational detail.

Oral vs injectable typhoid vaccine: which should you choose?

Oral Ty21a (Vivotif) is a live-attenuated vaccine in 4 capsules taken every other day over 1 week, requiring refrigeration and good stomach-acid status. Injectable Typhim Vi is a single inactivated polysaccharide shot 2 weeks before travel. Both give roughly 50 to 80% protection lasting 2 to 5 years per CDC. The choice usually comes down to convenience, age (oral approved for 6+, shot for 2+), and immune status.

Oral Vivotif is contraindicated in immunocompromised people, pregnant people, and anyone taking antibiotics within 72 hours before or 3 days after the dosing schedule. The capsules need consistent refrigeration during the week of dosing. Adherence matters: missing capsules drops effectiveness sharply, which is one reason the injectable version is often preferred for travelers with complex schedules.

Typhim Vi is a single shot, no refrigeration after injection, no contraindications beyond standard ones, but provides shorter protection (about 2 years vs 5 years for oral). Boosters are required for repeat travel. People going to high-endemicity regions every year often prefer the oral series for the longer durability. The travel vaccinations timing guide covers when each vaccine fits into the broader pre-departure plan.

What are the symptoms and when do they appear?

Symptoms develop gradually 6 to 30 days after exposure (typically 1 to 3 weeks), starting with fatigue, headache, and a fever that climbs day by day from 38°C into the 39 to 40°C range over the first week. Abdominal pain, constipation in adults or diarrhea in children, dry cough, and sometimes a faint rose-colored rash on the trunk follow. Untreated illness lasts 3 to 4 weeks with a 10 to 20% mortality rate.

The fever pattern is distinctive enough that experienced clinicians recognize it. Stepwise rising fever each evening, then a plateau in the second week with relative bradycardia (heart rate slower than expected for the fever level), and abdominal tenderness in the right lower quadrant. The rose spots are seen in only 10 to 20% of cases and fade within hours, so most patients don't show them at examination.

Severe complications appear in the third week if untreated: intestinal perforation (a surgical emergency), gastrointestinal bleeding, encephalopathy, and septic shock. Returned travelers with unexplained fever lasting more than 3 days after travel to an endemic region need a typhoid workup, including blood cultures (the highest yield in the first week of illness) and sometimes bone marrow culture later in the course.

How do you reduce risk on the ground?

Pair vaccination with food-and-water precautions: only sealed bottled water or water boiled for 1 minute (3 minutes above 2,000 m), no ice unless you saw it made from safe water, no raw vegetables or salads, fruit only if you peel it yourself, no street food unless you watched it cooked through, and no dairy unless from a reliable cold chain. CDC's traveler page calls these the "boil it, cook it, peel it, or forget it" rules.

Restaurant choice matters even within a destination. International hotel chains in major cities generally have water-treatment systems and trained food handlers. Small establishments rely on municipal water and personal hand hygiene. The risk gradient is real, but no setting in a high-endemicity region is zero risk, which is why vaccination is the durable protection.

Hand hygiene before every meal and after every bathroom visit is the highest-impact behavior. Soap and water for 20 seconds beats hand sanitizer for bacterial pathogens. Carry your own soap if necessary. Carry alcohol sanitizer as a backup, but don't substitute it for soap-and-water washing when soap is available. Our hand hygiene technique guide goes through the technique in operational detail.

FAQ

How long is typhoid contagious?

Untreated patients shed Salmonella Typhi in stool from the first week of illness through several months. With antibiotic treatment, most patients clear the bacteria within 2 to 4 weeks. Roughly 2 to 5% of treated patients become chronic carriers, continuing to shed bacteria for a year or longer. CDC requires repeat negative stool cultures before food handlers can return to work after typhoid.

What antibiotic treats typhoid?

For susceptible strains, fluoroquinolones (ciprofloxacin) and third-generation cephalosporins (ceftriaxone) are first-line. For multidrug-resistant strains common in South Asia, azithromycin or ceftriaxone is used. For XDR typhoid (resistant to ceftriaxone too), carbapenems and azithromycin are the remaining options. Treatment duration is typically 7 to 14 days, longer for severe cases.

Can you get typhoid from someone in your household?

Yes, though it's uncommon if hand hygiene is maintained. Typhoid spreads fecal-orally, so household transmission usually requires either a chronic carrier handling food or shared bathroom surfaces with poor hand hygiene during acute illness. Confirmed cases trigger contact-tracing and stool-culture screening of household members and food handlers in many jurisdictions.

How is typhoid different from food poisoning Salmonella?

Typhoid is caused by Salmonella enterica serotype Typhi, a host-restricted human pathogen that invades the bloodstream and causes systemic illness over 3 to 4 weeks. Common food-poisoning Salmonella (non-typhoidal serotypes like Enteritidis or Typhimurium) cause acute gastroenteritis with diarrhea over 4 to 7 days and rarely invade the bloodstream in healthy adults. Different organisms, different illnesses, different vaccines.

Is typhoid the same as typhus?

No. Typhus is a separate disease caused by Rickettsia bacteria spread by lice, fleas, or mites, with a different presentation and treatment. The names are confusingly similar because both produce high fever and historical chroniclers often conflated them. Modern medicine separates them by causative organism, vector, and clinical features.