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

Unveiling the burden of scrub typhus in acute febrile illness cases across India: A systematic review & meta-analysis

Background & objectives Scrub typhus is an emerging mite-borne zoonotic infection that has been overlooked, despite being one of the most widespread severe vector-borne diseases. With an estimated one billion people at risk worldwide and one million annual cases, it poses a significant public health concern. While various studies have investigated the prevalence of scrub typhus in different regions of India, a comprehensive regional systematic review and meta-analysis on the seropositivity of scrub typhus among acute febrile cases has been lacking. To address this gap, we conducted a systematic review and meta-analysis to compile information on the current seroprevalence of scrub typhus in acute febrile illness cases in India. Methods A literature search of multiple databases on prevalence of scrub typhus in acute febrile illness in India, 60 eligible studies out of 573 studies. The prevalence of individual studies was double arcsine transformed, and the pooled prevalence was calculated using inverse variance method. Results In total, these studies encompassed 34,492 febrile cases. The overall seroprevalence of scrub typhus among acute febrile illness cases in India was found to be 26.41 per cent [95% confidence interval (CI): 22.03-31.03]. Additionally, the pooled case fatality rate (based on data from six studies) among scrub typhus-positive cases yielded a case fatality rate of 7.69 per cent (95% CI: 4.37-11.72). Interpretation & conclusions This meta-analysis shows that scrub typhus is a significant health threat in India. Preventive measures to control scrub typhus need to be given priority.

Doxycycline vs azithromycin in patients with scrub typhus: a systematic review of literature and meta-analysis

INTRODUCTION

Scrub typhus is a bacterial mite-borne disease associated with poor clinical outcomes if not treated adequately. The study aimed to compare the time to defervescence, clinical failure, mortality and treatment-related adverse effects of two common drugs (doxycycline and azithromycin) used for its treatment.

METHODOLOGY

This was a systematic review and meta-analysis. All studies up to 20.03.2023 were screened for eligibility in Pubmed and Embase using a search string containing terms related to scrub typhus, doxycycline and azithromycin. After two phases of screening, all comparative studies where doxycycline and azithromycin were used to treat scrub typhus were included. The studies were critically appraised using standardised tools, and a meta-analysis was performed for time to defervescence (primary outcome), clinical failure, mortality and treatment-related adverse effects.

RESULTS

Of 744 articles from two databases, ten were included in the meta-analysis. All but two studies had a high risk of bias. The meta-analysis for time to defervescence had a high heterogeneity and did not show any significant difference between doxycycline and azithromycin arms [Mean difference of -3.37 hours (95%CI: -10.31 to 3.57), p=0.34]. When the analysis was restricted to studies that included only severe scrub typhus, doxycycline was found to have a shorter time to defervescence [mean difference of -10.15 (95%CI: -19.83 to -0.46) hours, p=0.04]. Additionally, there was no difference between the two arms concerning clinical failure, mortality and treatment-related adverse effects.

CONCLUSION

The current data from studies with a high risk of bias did not find statistically significant differences in clinical outcomes between doxycycline and azithromycin for scrub typhus.

Clinical profile and predictors of therapeutic outcome with azithromycin in pediatric scrub typhus: A study from Eastern India

In this prospective study, children from 1-month to 12-years, admitted with positive IgM ELISA testing for scrub typhus, were enrolled over 1-year and administered an empirical single dose of azithromycin (10 mg/kg). All 189 (median age 4.84-years) children had fever with median duration of 8 days at admission. Shortness of breath, altered sensorium, headache, lymphadenopathy, hepatosplenomegaly, pallor, oedema and hypotension were the most prominent symptoms/signs. About 46% of children developed complications, among them hepatic, neurological and cardiovascular were most common. Our study showed a remarkable response to azithromycin, with mean defervescence of 32 h and no mortality. The presence of shortness of breath, headache, altered sensorium, hepatosplenomegaly, meningeal signs, severe anemia, leucocytosis, hyponatremia along with/without any of above mentioned three systemic complications were independent predictors for delayed treatment response by multivariate logistic regression analysis. Hepatic, neurological and cardiovascular complications are an emerging trend. Empiric azithromycin based on clinical suspicion of scrub typhus can be lifesaving.