Lab Medicine Significance 7/10

Enteric Fever: Blood Culture Remains the Diagnostic Standard Despite Performance Limitations

This Lancet review on typhoid and paratyphoid fever emphasizes that blood or bone marrow culture remains the reference standard for diagnosis despite limited sensitivity, particularly after prior antibiotic exposure. Drug resistance is a growing concern, with ciprofloxacin and ceftriaxone resistance now common in Pakistan, making local susceptibility data essential for treatment decisions. The authors highlight that typhoid Vi-conjugate vaccines offer improved prevention, but laboratory capacity for culture-based diagnosis and antimicrobial susceptibility testing remains critical in endemic regions.

The original study

Enteric (typhoid and paratyphoid) fever.

Authors
Kuehn R, Rahden P, Hussain HS, Karkey A, Qamar FN, Rupali P, et al.
Journal
Lancet (London, England)
Type
Journal Article, Review
PMID
40914181
Read the original study →

Original abstract

Enteric fever, caused by the human-restricted bacteria Salmonella enterica serovar Typhi (typhoid) and Salmonella enterica serovar Paratyphi A, B, and C (paratyphoid), affects persons residing in, or travelling from, areas lacking safe water, sanitation, and hygiene infrastructure. Transmission is by the faecal-oral route. A gradual fever onset over 3-7 days with malaise, headache, and myalgia is typical. Symptoms can be altered by previous antimicrobial use. Life-threatening complications can arise in the second week of untreated illness. Differentiation from other febrile illnesses is challenging. Blood or bone marrow culture remain reference standard diagnostic methods, despite the low sensitivity of blood culture. Azithromycin, ciprofloxacin (excepting cases originating in south Asia due to drug resistance), or ceftriaxone are recommended treatment options for both typhoid and paratyphoid; however, choice should be guided by local resistance patterns. Ciprofloxacin-resistant and ceftriaxone-resistant typhoid is common in Pakistan. Three vaccine types are available for prevention of typhoid disease, including the newer, more effective typhoid Vi-conjugate vaccines. Vaccination as well as water, sanitation, and hygiene measures are cornerstones of prevention.