Abstract
BACKGROUND: Tropical coinfections (CI) are the simultaneous occurrence of two or more vector-borne diseases in a single host. The prevalence of such illnesses is not uncommon among tropical and subtropical regions such as India; however, these CIs have not been systematically studied prospectively. Mixed infections can prove potentially detrimental if underdiagnosed or undertreated. We undertook this study to estimate the prevalence and compare the clinical profile, laboratory characteristics, and various outcomes among the patients with tropical CI who presented with acute undifferentiated febrile illness (AUFI).
MATERIALS AND METHODS: A prospective, observational study was conducted on adult patients hospitalized with tropical CIs. As per the clinical suspicion, a panel of tests for dengue fever (D), malaria (M), scrub typhus (S), leptospirosis (L), chikungunya (C), and brucella (B) was carried out. Statistical analysis was done using standard methods.
RESULTS: The mean age of the population was 39.4 ± 17.3 years. Among 986 patients presenting with AUFI, 8.1% of the patients had CIs. Of these CIs, 95% had dual infections, and 5% had CIs with three tropical pathogens. We observed 17 diverse tropical CI combinations; four predominant being D + L, D + S, D + C, and S + L with a prevalence of 26.2, 25, 15, and 13.8%, respectively. 16.25% of the patients with tropical CIs died, mostly those suffering from D + S and D + L. Coinfection with D + S had predominant acute kidney injury (AKI), whereas acute transaminitis was highest in the D + L category. Acute respiratory distress syndrome (ARDS) was clinically significant in S + L, and multiorgan dysfunction was highest in the D + S combination. Using logistic regression, AKI, hepatitis, ARDS, shock, gastrointestinal bleeding, and myocarditis were independent risk factors for mortality.
CONCLUSION: Our study identified 17 different combinations of CIs. Four groups, i.e., D + L, D + S, D + C, and S + L-accounted for 80% of CIs. Despite significant organ involvement in certain CI combinations, we conclude that a clinical bedside differentiation of tropical CIs from monomicrobial infections is often difficult. Hence, optimal treatment for a possible CI may well be commenced empirically and early, bearing in mind an 8% probability of a concurrent tropical coinfection.