Typhoid Fever: Symptoms, Transmission, Diagnosis, Treatment, and Prevention

Typhoid fever (enteric fever) is a systemic infection caused by Salmonella enterica serovar Typhi. It remains a major public health challenge in regions with inadequate sanitation and water treatment infrastructure.

Transmission

• Fecal-oral route: contaminated water, food, or hands.
• Chronic carriers (1–4% of recovered patients) shed bacteria in stool for over a year (the classic "Typhoid Mary" scenario).
• No animal reservoir exists; humans are the only host.

Clinical Presentation (Incubation: 1–3 Weeks)

Phase	Features
Week 1	Step-ladder fever (rising daily), headache, malaise, relative bradycardia (Faget sign), cough, abdominal discomfort
Week 2	High sustained fever, "rose spots" (faint salmon-colored macules on trunk), hepatosplenomegaly, delirium ("typhoid state"), constipation or "pea soup" diarrhea
Weeks 3–4	Complications or resolution; significant weight loss, debility

Complications (10–15% of Untreated Cases)

• Intestinal perforation (typically terminal ileum) → peritonitis
• GI hemorrhage (from Peyer's patch erosion)
• Encephalopathy, myocarditis, cholecystitis, osteomyelitis
• Mortality 10–30% untreated; <1% with appropriate antibiotics

Diagnosis

• Blood culture: Gold standard (positive 40–80% in week 1; yield declines after antibiotics).
• Bone marrow culture: Higher yield (~90%), remains positive despite antibiotic therapy.
• Stool/urine culture: Useful in later weeks and for carrier detection.
• Widal test: Low specificity; not recommended as a standalone diagnostic.
• Typhidot / Tubex: Rapid serology; variable accuracy.

Treatment

• Uncomplicated: Ceftriaxone IV/IM × 7–10 days OR Azithromycin PO × 7 days (lower relapse rate). Fluoroquinolones (e.g., ciprofloxacin) where susceptibility is confirmed.
• Severe/complicated: Ceftriaxone IV + consider dexamethasone for encephalopathy.
• Chronic carrier state: 4–6 weeks of antibiotics + cholecystectomy if gallstones are present.

Prevention

• Safe water, sanitation, and hygiene (WASH) infrastructure.
• Vaccines: Ty21a (oral, live attenuated, 3–4 doses), Vi polysaccharide (IM, single dose), TCV — typhoid conjugate vaccine (longer duration, can be given under age 2).
• Food safety mantra: "Boil it, cook it, peel it, or forget it."