EPIDEMIOLOGICAL INVESTIGATION OF ACUTE VIRAL HEPATITIS OUTBREAK: SUBSTANTIATION OF A SINGLE SOURCE

Abstract

Objective: An outbreak of AVH was investigated with the objective of describing its epidemiological features. Material and Methods: This descriptive outbreak investigation of AVH was done from August to December 2022, in the catchment area of the southern region of Karachi. An active surveillance of the affected region was conducted. WHO’s standard case definition for AVH was used to identify cases. Suspected cases were tested for hepatitis A virus (HAV) and E virus (HEV) using immunochromatographic testing (ICT). Drinking water samples were tested for faecal contamination. Control measures were implemented to contain the outbreak. Descriptive analysis was done as per time, person, and place. Results: A total of 109 individuals were included in this study from 10th August 2021 to 31st October 2021. Out of these, 59 cases were confirmed serologically for Hepatitis A and E. Out of confirmed cases of AVH, 85.1% were positive for HEV, 12.8% for HAV, and 2.1% for both HAV and HEV. Males were affected more than females (P < 0.05). One of the areas reported leakage in the drinking water pipeline and had the highest attack rate. Drinking water samples were found negative for contamination Conclusion: This study described the detailed methodology for the epidemiological investigation of an outbreak and described the epidemiological features of acute viral hepatitis and various measures taken to curb an outbreak. Key Words: Acute viral hepatitis, Hepatitis A, Hepatitis E, Outbreak investigation, Jaundice