Title : Atypical presentation and comorbidities of scrub typhus in Western Nepal: High prevalence of afebrile cases, severe pyuria, and exceptional response to doxycycline
Abstract:
Background: Scrub typhus, caused by Orientia tsutsugamushi, typically presents with acute fever and a pathognomonic black eschar. However, emerging atypical clinical profiles pose diagnostic dilemmas. This study outlines an unusual clinical spectrum of scrub typhus characterized by the absence of classic signs, high respiratory and urinary co-presentations, and their therapeutic outcomes in a clinic-based setting in Western Nepal.
Methods: A retrospective descriptive study was conducted over an 8-month period at a medical facility in Palpa, Western Nepal. A total of 590 patients presenting with non-specific constitutional symptoms who tested positive for Scrub Typhus via Rapid Diagnostic Test (RDT) IgM/IgG were included. Clinical features, microscopic urinalysis, and treatment outcomes with Doxycycline were
systematically analyzed.
Results: Among the 590 confirmed cases, classic diagnostic markers were entirely absent: not a single patient (0%) presented with an eschar. Crucially, 65% of the patients were completely afebrile at presentation, with a cough being the predominant respiratory symptom. Concurrently, a striking 65% of the patients exhibited severe urinary tract involvement (Heavy UTI), characterized by significant pyuria with 30–40 pus cells/HPF on urinalysis, mimicking primary bacterial UTI despite the lack of systemic fever. Empiric or targeted therapy with Doxycycline demonstrated a 100% clinical recovery rate, successfully resolving both the respiratory symptoms and the severe pyuria without requiring secondary antibiotics.
Conclusion: Scrub typhus in Western Nepal frequently presents atypically without fever or eschars, often masquerading as respiratory tract infections or heavy urinary tract infections (severe pyuria). Clinicians in endemic zones must maintain a high index of suspicion for scrub typhus in patients presenting with unexplained cough or sterile pyuria. Furthermore, the 100% efficacy of Doxycycline highlights its role as an indispensable first-line definitive therapy for both typical and atypical manifestations.
