Clinical profile and predictors of severity in paediatric scrub typhus with pulmonary involvement

Clinical profile and outcomes of pediatric scrub typhus associated with elevated hepatic transaminases

BACKGROUND

Hepatic transaminase (HT) elevation is frequently seen in children with scrub typhus (ST), but the clinical implication of this common finding is not known.

OBJECTIVE

To describe the clinical profile and outcome of pediatric ST with elevated hepatic transaminase.

METHODS

In this prospective cohort study, all children < 12 years of age presenting with fever for ≥ 5 days and positive immunoglobulin M (IgM) serology for ST were included. Clinical findings, laboratory features and outcomes of children with elevated HT were compared with those who had normal HT.

RESULTS

Of 560 ST positive children included, 257 (45.8%) had associated HT elevation. The common age group affected was 5 to 12 years of age (54.9%). Most of the children came during the second week of fever (68.5%) with mean duration of fever of 9.1 days. The common initial presenting symptoms were cough (77.8%), vomiting (65%) and myalgia (59.1%) and signs were hepatomegaly (64.2%), splenomegaly (57.6%) and generalized lymphadenopathy (54.1%). Eschar was seen in 49.8% of children. Thrombocytopenia (58%) and anemia (49%) were the frequently seen laboratory abnormalities. Severe forms of ST were seen in 45.5% children, of which pneumonia was most common. The fever clearance time (48 ± 19.2 h) and mean duration of hospital stay (6.7 ± 3.3 days) were prolonged in these children. On logistic regression analysis, generalized lymphadenopathy (p = 0.002), ascites (p = 0.037), thrombocytopenia (p < 0.001) and hypoalbuminemia (p = 0.023) were found to be associated with HT elevation in these children.

CONCLUSIONS

Hepatic transaminase (HT) levels increase with the duration of untreated fever and is found to be associated with severe forms of scrub typhus. Children with elevated HT have delay in fever defervescence and their duration of hospital stay was prolonged.

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.