Diphtheria Remains a Threat to the Health System Even in the Era of Vaccination: A Cross-sectional Observational Study from Karnataka, India

Abstract

Introduction: Diphtheria is an infectious disease caused by a gram-positive facultatively anaerobic bacilli, Corynebacterium (C.) diphtheriae. The present health statistics and data from the few studies that have been carried out suggest that our war with this disease is still going on and is far from being over in spite of the vaccine that’s freely available. Aim: To study clinical profile, complications, and outcome of diphtheria in karnataka population and to correlate with immunisation status. Materials and Methods: This was a hospital-based prospective cross-sectional observational study done in the Department of Paediatrics, Karnataka Institute of Medical Sciences, Hubballi, Karnataka, India, from January 2018 to November 2018. Patients admitted with history suggestive of diphtheria were enrolled and categorised into probable and confirmed cases. The age, sex, area of residence, religion, immunisation status, mean time of presentation to hospital from onset of illness, use of inotropes and mechanical ventilation were recorded in a predesigned proforma. Throat swab smear for C.diphtheria and culture, complete blood count, Renal Function Tests (RFT) with serum electrolytes, chest radiograph, Electrocardiogram (ECG) and 2-Dimensional (2D) Echocardiogram (ECHO) were also recorded. Results: Out of total 28 cases, 18 fulfilled the inclusion criteria. Male to female ratio was 2:1 and the mean age of presentation was 9.7 years. Highest incidence (n=14, 77.8%) was seen in the age group of 09-11 years. Most common clinical presentation was fever and sore-throat present in all 18 (100%), neck swelling in 13 (72.2%), dysphagia in 05 (27.7%). Examination revealed tonsillar hypertrophy and pseudomembrane in 17 (94.4%) patients, whereas one patient had laryngeal diphtheria, which was diagnosed when swab was sent while intubating in view of membranous laryngitis. Mean time of presentation to hospital after the onset of symptoms was 5.65 days. All children received appropriate antibiotics and Antidiphtheritic Serum (ADS). Total of seven patients were ventilated, of which 5 (27.7%) succumbed, and two were extubated. Four (22.2%) patients developed myocarditis in the second week, and all succumbed to resistant arrhythmias. One patient developed sepsis with ventilator dependency, and succumbed to inotrope resistant septic shock. On follow-up, 5 (27.7%) developed palatal palsy among which three had associated polyneuropathy; all these children recovered with only supportive care. Conclusion: Diphtheria is down but not out, the present study unmasks the fact that the disease is equally prevalent in immunised and older children with the changing epidemiology of diphtheria in the era of vaccines.