Common-Source Outbreak of Hepatitis A in an Indian Himalayan Mountain Camp

Abstract

Background: Hepatitis A is an emerging public health problem worldwide, with alerts issued in developed countries, although it remains under-reported, under-diagnosed, and under-investigated in the developing world. Prolonged epidemics can occur due to person-to-person transmission. The ongoing outbreak of hepatitis A reported in the United States is one of its largest-ever outbreaks of the disease. A public health emergency for hepatitis A was declared in Florida, with over 2000 cases across several regions of The United States, in the year 2019. Methods: The outbreak investigation was carried out on 30 travelers in an Indian Himalayan mountain camp. Clinical features were correlated with laboratory parameters for establishing diagnosis by standard case definition. Line listing and epidemic curve were plotted to corroborate outbreak variables. Clinicodemographic, clinical, laboratory, and outbreak variables were descriptively analyzed. Results: Most of the 30 patients with hepatitis A were young male patients within the age range of 20 - 30 years. The most common clinical features among the case-patients were anorexia and vomiting. The epidemic curve revealed a peak of 15 case-patients from June 22 to July 5, 2019. Liver function tests showed mild derangement in all the case-patients. All the patients required hospitalization, with a mean duration of hospital stay reported as 11.86 ± 2.53 days. All the patients fully recovered with no fatalities. Conclusions: Hepatitis A outbreaks can occur through the consumption of untreated mountain stream/river water due to upstream contamination with human/animal excrements. Strengthening surveillance systems, traveler education, vaccination, and intersectoral coordination for safe water supply remains a necessary public health measure.