Typhoid fever is a life-threatening illness caused by the bacteria Salmonella typhi. Typhoid fever is spread by eating or drinking contaminated food or water or through close contact with someone who is infected. Travelers visiting developing countries are at greatest risk for getting typhoid fever. Symptoms include constant fever up to 104°F, diarrhea, constipation, stomach pain, slow heart rate, and exhaustion. Typhoid fever is treated with antibiotics. A person will usually recover in 2-3 days with prompt antibiotic treatment.