Typhoid

FAQs for Health Care Providers

Typhoid Risk, Diagnosis, and Treatment in Afghan Evacuees

Have there been confirmed cases in the Afghan evacuees? No, but at risk.

Epidemiology

Salmonella Typhi causes an estimated 5,700 infections and 620 hospitalizations each year in the United States. Typhoid fever is most common in travelers who visit South Asia, especially Pakistan, India, and Bangladesh. Worldwide, an estimated 11 to 21 million infections occur each year.

In 2015 the adjusted monthly case count for typhoid fever in Afghanistan was 6,445.¹ Typhoid also was noted to have seasonal variance, with the greatest incidence in the summer months (time of departure for the evacuees), which parallels findings that typhoid, in general, increases with times of increase in temperature and rainfall.¹ Of note, a widespread vaccination program does not exist in Afghanistan for typhoid. Lack of safe water and poor sanitation is the major risk factor (unimproved sanitation facility is about 46.8% of the Afghanistan population in 2017).² Typhoid fever prevalence peaks between ages 5-12 in Afghanistan or other endemic areas.³

When should I consider typhoid?

Clinical Presentation

Consider typhoid fever when patients present with sustained fever. Fevers tend to be high (103-104 ⁰F (39-40 ⁰C)) and last for more than 3 days. They are frequently accompanied by gastrointestinal symptoms (abdominal pain, emesis, diarrhea, or constipation). Although diarrhea may occur, especially early, constipation is more common. Other common symptoms include: chills, weakness, malaise, myalgias, headache, cough, and loss of appetite. A transient maculopapular rash of “rose-colored spots” may be observed, they are non-blanching, subtle and may be difficult to visualize on darker skin (Figure 1 and 2). The incubation period is typically 6-30 days from exposure.

Complications may include bacteremia with sepsis or shock, gastrointestinal complications (e.g., intestinal perforation, peritonitis, intestinal hemorrhage, hepatitis), and neurologic complications. Intestinal perforation, encephalopathy, and delirium may occur in severe cases, typically after 2 to 3 weeks of illness. Intestinal perforation usually occurs in the ileum during the 3^rd week of febrile illness and is due to necrosis of the Peyer’s patches in the antimesenteric bowel wall.

Is typhoid contagious? Yes, via contaminated water and food, and person-to-person contact.

Between 1-6% of Salmonella Typhi infected patients become asymptomatic chronic typhoid carriers, who can transmit Salmonella Typhi with stool or urine cultures commonly remaining positive over a year. People may not have had a history of typhoid disease but still may be asymptomatically infected (“carriers”). Carriers of the infection can spread it to others.

The bacterial infection is transferred enterically, especially in places with poor sanitation and lack of safe drinking water. Transfer of typhoid occurs through the following mechanisms: person eats food or drinks a beverage that has been touched by a person who is actively shedding Salmonella Typhi in their feces and who has not washed their hands thoroughly after using the bathroom, drinks sewage-contaminated water with Salmonella Typhi, eats raw food that has been rinsed with sewage-contaminated water with Salmonella Typhi.

Are there special infectious disease precautions for someone with typhoid?

Common contact precautions are recommended in the healthcare setting.

Infected patients should be advised to keep taking antibiotics until suggested end date by physician (even if the patient has no symptoms), wash hands carefully with soap and water after using the bathroom, use contact precautions (gloves), do not prepare or serve food for other people.

How do I diagnose typhoid?

The gold standard for diagnosis of typhoid is blood cultures (which may detect both typhoid and paratyphoid); however, multiple cultures are usually needed to identify the pathogen. Blood cultures are positive in 50-70% of patients with typhoid, more commonly early in infection, and stool cultures are positive in up to 30-40% of cases, generally later in infection.

In difficult cases bone marrow cultures need to be performed and have sensitivity of 80% (and may remain positive for some time even during antibiotic treatment). Serologic tests such (e.g. Widal test) should not be used due to lack of sensitivity and specificity.

What is the treatment for typhoid?

Without treatment, the illness can last for 3 to 4 weeks and death rates range between 12-30%. Relapse occurs in up to 10% of untreated patients approximately 1 to 3 weeks after recovering from the initial illness and is often milder than the initial illness.

Empiric therapy

Uncomplicated disease: Patients with no evidence of systemic toxicity and can tolerate oral therapy.

• Azithromycin (for fluoroquinolone resistance): 1g PO daily for 5-7 days

• Cefixime 200 mg PO BID for 10-14 days (if Azithromycin is not available)

Alternatives

• Ciprofloxacin 500 mg PO BID for 7-10 days or 400 mg BID IV for 7-10 days

• Ofloxacin 400 mg PO or IV BID for 7-10 days

NOTE: Fluoroquinolone resistance rates are high; Azithromycin resistance occurs, but at lower rates.

For severe or complicated disease (e.g., systemic toxicity, depressed consciousness, prolonged fever, organ system dysfunction, or other features that prompt hospitalization)

Infection acquired outside Pakistan or Iraq

• Ceftriaxone 2g IV q12-24h for 10-14 days

• Cefotaxime 1-2g IV q6-8h for 10-14 days

Infection acquired in Pakistan or Iraq

• Meropenem: 1-2g IVq8h (carbapenem use is recommended due to the presence of multidrug resistance in these areas).

Note: Adjunctive corticosteroid for severe infection: For patients with suspected or known enteric typhoid fever and severe systemic illness (delirium, obtundation, stupor, coma, or shock), adjunctive dexamethasone 3 mg/kg followed by 1mg/kg q6h for total of 48hrs may be helpful.

Directed therapy

Definitive antimicrobial therapy for enteric fever should be based on results of susceptibility testing.

Resources

• CDC Typhoid Fever. Symptoms.

• CDC. Drug-resistant Salmonella serotype typhi.

• Epidemiology, microbiology, clinical manifestations, and diagnosis of enteric (typhoid and paratyphoid) fever - UpToDate

• Treatment and prevention of enteric (typhoid and paratyphoid) fever - UpToDate

References

1. Wagner AL, Mubarak MH, Johnson LE, et al. Trends of vaccine-preventable diseases in Afghanistan from the disease early warning system, 200-2015. PloS One 2017, 12€:e0178677.

2. CIA.gov. World Fact Book.

3. World Health Organization. Communicable disease profile. Afghanistan and neighboring countries.

Contributors

Christina Lee, MD

Hannah Lee, MD

William Stauffer, MD