Prospective Study to Assess the Response to Therapy and Its Predictors in Children with Scrub Typhus

Doxycycline is the drug of choice for pediatric scrub typhus (ST) while azithromycin is considered as an equally effective alternative. This study was undertaken to assess the response to therapy and its predictors in pediatric ST cases treated with doxycycline and azithromycin. Children ≤12 year with fever ≥7 days were screened for ST by IgM ELISA (positive if optical density >0.5). All positive cases were divided into two groups based on whether treated with doxycycline or azithromycin. Fever clearance time (FCT), duration of hospitalization and other clinical characteristics of cases in both groups were compared. Out of 2710 children admitted with fever for more than 7 days, 660 cases (24.35%) tested positive for ST by IgM ELISA. Cases treated with azithromycin and doxycycline were 316 (47.87%) and 344 (52.12%), respectively. In our study, the FCT (p = 0.004), mean duration of hospital stay (p = 0.011), persistence of fever for >48 h after starting antibiotic therapy (p = 0.001) and severe ST requiring ICU admission (p = 0.046) were significantly lower in children who received doxycycline. The logistic regression analysis revealed that the presence of splenomegaly (Adjusted Odds Ratio (AOR) 2.60; 95% Confidence interval (CI) = 1.49-4.53; p = 0.001) and lung crepts (AOR 2.02; 95% CI = 1.06-3.85; p = 0.032) in azithromycin-treated group and presence of meningeal signs (AOR 16.11; 95% CI = 5.47-47.45; p < 0.001), anemia (AOR 2.28; 95% CI = 1.02-5.08; p = 0.044), lung crepts (AOR 2.66; 95% CI = 1.16-6.05; p = 0.020) and absence of eschar (AOR 3.48; 95% CI = 1.70-7.13; p = 0.001) in the doxycycline group was significantly associated with prolonged FCT (>48 h). Doxycycline is superior to azithromycin in defervescing fever, reducing hospital stay and preventing severity in pediatric ST.