Purpose
- This page provides information healthcare providers can use to identify, diagnose, and treat typhoid fever and paratyphoid fever.
- It also provides information that can be useful for counseling patients who travel to places where these diseases are common.
Evaluation
Clinical features
Typhoid fever and paratyphoid fever are systemic illnesses caused by Salmonella Typhi and Salmonella Paratyphi, respectively. Both diseases have an insidious onset characterized by some or all of the following symptoms:
- Fever
- Headache
- Constipation or diarrhea
- Malaise
- Chills
- Myalgias
- Emesis
A transient, maculopapular rash of rose spots may be present on the trunk.
Severe cases may have encephalopathy, gastrointestinal bleeding, or intestinal perforation, which typically occur after 2–3 weeks of illness.
Few clinical features reliably distinguish these illnesses from a variety of other infectious diseases.
Diagnosis
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.
Usually, multiple cultures are needed to identify the pathogen. Serologic tests, such as the Widal test, are not recommended because of the high rate of false positives.
CDC offers testing for Salmonella Typhi and Salmonella Paratyphi. CDC accepts specimens for analysis only from state public health laboratories and other federal agencies. Private healthcare providers and institutions must submit specimens to their state public health laboratory for processing.
Prevention
The Advisory Committee on Immunization Practices (ACIP) recommends vaccination for people 2 years and older traveling to areas where the diseases are endemic or an outbreak is occurring.
Two typhoid fever vaccines are available in the United States.
| Vaccine | Administration method | Recommended dosage | How long to complete immunization before travel | Minimum age for vaccination | Booster needed |
|---|---|---|---|---|---|
| Ty21a (Vivotif, Emergent BioSolutions) | Oral capsules | 4 capsules, 1 taken every other day | 1 week | 6 years | Every 5 years |
| ViCPS (Typhim Vi, Sanofi Pasteur) | Intramuscular injection | Single injection of 0.5 mL | 2 weeks | 2 years | Every 2 years |
Additional resources
Typhoid vaccines are not 100% effective. All travelers should follow recommended food and water precautions to prevent infections during travel.
Safe eating and drinking habits also help protect travelers from other illnesses, including travelers' diarrhea, cholera, dysentery (severe diarrhea), and hepatitis A.
- Travelers should wash hands thoroughly with soap and water, especially after using the bathroom and before preparing food or eating.
- Use hand sanitizer with at least 60% alcohol if soap and water are not available.
Treatment
Antibiotic use helps patients recover faster and lowers the risk of complications and death.
High rates of antimicrobial resistance can limit treatment options. Antimicrobial susceptibility testing can help guide treatment decisions.
While waiting for culture results, obtain a thorough travel history to inform empiric treatment.
- Ceftriaxone resistance is now common among travelers returning from Iraq and Pakistan. It has been observed less frequently in travelers returning from neighboring countries, including India and Afghanistan. For patients who traveled to Iraq or Pakistan and patients who did not travel internationally:
- Uncomplicated illness may be treated empirically with azithromycin.
- Complicated illness may be treated empirically with a carbapenem.
- Uncomplicated illness may be treated empirically with azithromycin.
- Ceftriaxone and azithromycin remain appropriate empiric treatment options for patients returning from most countries other than Iraq and Pakistan.
- Most typhoid fever and paratyphoid fever infections diagnosed in the United States are caused by strains that are not susceptible to fluoroquinolones. Do not use fluoroquinolones for empiric treatment.
Complications
Without treatment, typhoid fever and paratyphoid fever can last for about a month. Before widespread antibiotic use, the case fatality rate for typhoid fever was higher than 10%. With appropriate treatment, the fatality rate of typhoid fever is lower than 1%. Paratyphoid fever is usually less severe and has a lower case fatality rate than typhoid fever.
About 10% of inadequately treated patients experience relapse, with an illness that is often milder than the initial one. Relapse can happen 1–3 weeks after recovery from the initial illness.
About 1%–4% of people with typhoid fever become chronic carriers and remain positive for Salmonella Typhi for more than one year.