Typhoid fever is a life-threatening illness caused by the bacterium Salmonella Typhi. Typhoid fever is not common in the United States, Canada, Western Europe, Australia, or Japan, but it is common in many other countries. It affects an estimated 22 million people worldwide each year. These cases do not include people who do not seek medical care, who are not tested for either disease, or whose disease is not reported to CDC.
Paratyphoid fever is a life-threatening illness caused by the bacterium Salmonella Paratyphi. Paratyphoid fever is not common in the United States, Canada, Western Europe, Australia, or Japan, but it is common in many other countries. These cases also do not include people who do not seek medical care, who are not tested for either disease, or whose disease is not reported to CDC.
People who are actively ill with typhoid fever or paratyphoid fever and people who are carriers of Salmonella Typhi or Salmonella Paratyphi bacteria can both spread the bacteria to other people. Carriers are people who have recovered from typhoid fever or paratyphoid fever but continue to carry the bacteria. About 1 in 20 people remain carriers after they've recovered. Both groups of people shed (excrete) Salmonella Typhi or Salmonella Paratyphi in their feces (poop).
Yes. Typhoid fever and paratyphoid fever can be prevented. Get vaccinated against typhoid fever (there is no vaccine against paratyphoid fever). Find out how to avoid getting sick from food and drinks.
No. Salmonella Typhi and Salmonella Paratyphi live only in humans.
Carefully selecting what you eat and drink when you travel is important. This is because the typhoid fever vaccines do not work 100% of the time, and there is no paratyphoid fever vaccine. Avoiding risky foods will also help protect you from other illnesses, including travelers’ diarrhea, cholera, dysentery, and hepatitis A.
When you travel to areas of risk, remember to “Boil it, cook it, peel it, or forget it.”
If you have a high fever and feel very ill, see a doctor immediately.
Resistance to antibiotics is increasing in the bacteria that cause typhoid fever and paratyphoid fever. When bacteria are resistant to antibiotics, the bacteria are not killed and their growth is not stopped. To help guide treatment, your doctor may order special tests to see if your type of Salmonella is antibiotic-resistant.
People who do not get treatment can continue to have fever for weeks or months, and can develop complications. As many as 30% of people who do not get treatment die from complications of the infection.
Even if your symptoms seem to go away, you may still be carrying Salmonella Typhi or Salmonella Paratyphi. If so, the illness could return, or you could pass the bacteria to other people.
In fact, if you are a health care worker or work at a job where you handle food or care for small children, you might be barred (prevented) legally from going back to work until a doctor has determined you no longer carry the bacteria.
If you are traveling to a country where typhoid fever is common, consider being vaccinated against typhoid fever. Visit a doctor or travel clinic to discuss options. Remember that you should complete the vaccinations at least 1-2 weeks (depending on vaccine type) before you travel so that the vaccine has time to take effect.
Typhoid vaccines lose effectiveness after several years. If you were vaccinated in the past, ask your doctor to if it is time for a booster vaccination. Taking antibiotics will not prevent typhoid fever; they only help treat it.
|Number of doses recommended
|Time between doses
|How long to complete immunization before travel
|Minimum age for vaccination
|Ty21a (Vivotif, Swiss PaxVax)
|1 capsule by mouth
|Every 5 years
|ViCPS (Typhim Vi, Sanofi Pasteur)
|Every 2 years
Typhoid fever and paratyphoid fever are bacteremic illnesses that have an insidious onset characterized by fever, headache, constipation or diarrhea, malaise, chills, and myalgias, with few clinical features that reliably distinguish them from a variety of other infectious diseases. Diarrhea may occur, and vomiting is not usually severe.
A transient, maculopapular rash of rose-colored spots may be present on the trunk. Confusion, delirium, and intestinal perforation may occur in severe cases, typically after 2-3 weeks of illness. The incubation period for typhoid fever is typically 6-30 days and for paratyphoid fever, 1-10 days.
Blood culture is the mainstay of diagnosis. Bone marrow cultures have sensitivity of 80% in some studies and can remain positive despite antibiotic therapy. Stool and urine cultures are positive less frequently. Multiple cultures are usually needed to identify the pathogen. Serologic tests, such as the Widal test, are not recommended because of the high rate of false positives.
Without therapy, the illness can last for 3-4 weeks and death rates range between 12% and 30%. Relapse occurs in up to 10% of untreated patients approximately 1-3 weeks after recovering from the initial illness and is often more mild than the initial illness. A chronic carrier state, in which stool or urine cultures for Salmonella_Typhi remain positive for more than 1 year, occurs in up to approximately 5% of infected persons.
Typhoid fever and paratyphoid fever are transmitted commonly through the consumption of drinking water or food contaminated with the feces of people who have typhoid fever cases or are chronic carriers.
Reduced susceptibility to fluoroquinolones (e.g., ciprofloxacin) and the emergence of multidrug resistance has complicated treatment of infections. There have also been sporadic reports and at least one documented outbreak of ceftriaxone-resistant Salmonella Typhi infections.
The role of new vaccines to control epidemics or to eliminate the disease has not been explored yet. These new vaccines include two typhoid fever protein conjugated vaccines licensed for use in India.