Microbiological and Clinical Aspects of Diphtheria-Confirmed Cases from Capital City of Indonesia, Jakarta, and Surrounding Areas in 2017

Background: The World Health Organization reported Indonesia as one of the countries with the most prevalent cases of diphtheria worldwide. The microbiological aspects of diphtheria-inducing bacteria are of great significance in tracing disease transmission and case management. However, clinical aspects are critical for updating clinical features and case management in the field, which may sometimes differ from theoretical foundations. Objectives: This study aimed to identify the microbiological and clinical aspects, including molecular typing and case fatality rates, in diphtheria-confirmed cases from the capital city of Indonesia, Jakarta, and surrounding areas in 2017. Methods: The microbiological aspect of 40 diphtheria-confirmed cases were obtained by re-identify diphtheria-inducing bacteria isolated from the samples, while the clinical aspects of the cases were obtained from the medical records and epidemiological data. The chi-square test was used to examine the correlation between fatal cases and myocarditis and diphtheria antitoxin administra-tion delay. In this study, P ≤ 0.05 was set as the significance level. Results: All 40 diphtheria confirmed cases were induced by toxigenic Corynebacterium diphtheriae with two biotypes, namely inter-medius (60.0%) and mitis (40.0%). There are six sequence types of bacteria with two main sequence types, ie, ST534 (46.4%) and ST377 (35.7%). The proportions of cases that had a fever and sore throat were 72.5% and 77.5%, respectively; however, the prevalence rates of the cases with pseudomembrane and bull neck were 100% and 47%, respectively. Most cases were administered a combination of penicillin or erythromycin with other antibiotics (40%), and 22.5% of the cases only received penicillin. Myocarditis was noticed in three fatal cases, and their relationship was statistically significant (P = 0.000). All five fatal cases (12.5% of cases) received diphtheria antitoxin (DAT) lately or had not received it yet. Conclusions: Toxigenic C. diphtheriae with two biotypes (namely mitis and intermedius) and two main sequence types (ie, ST534 and ST377) was the causative agent of diphtheria-confirmed cases from Jakarta and surrounding areas in 2017. It was also concluded that those fatal cases were correlated with myocarditis complications.