Active hepatitis B surveillance in Houston: Identifying misclassified hepatitis B cases from an “unknown hepatitis B” database

Hepatitis B (Hep B) infection is a contagious liver disease that results from contact with the Hepatitis B virus (HBV). It can be acute or chronic ranging in severity from mild to a serious lifelong illness. When not detected and treated, it can adversely affect some vital organs of infected persons. Currently, an estimated 1.4 million people are living with chronic Hep B infection in the U.S. From 2009 to 2010, a total of 6,489 Hep B cases were reported to Houston's Disease Surveillance System (MAVEN) through passive surveillance. A review of Houston's 2009-2010 Hep B database revealed that 90.8% of the cases were wrongly categorized as “unknown” which led to under-reporting.

An active surveillance project was initiated in order to accurately classify cases as chronic or acute. Using a Clinical Information Management System (EPIC Web), Hep B clinical and lab data were matched against the unknown cases. Case status was determined using CDC's result algorithm for HBV serologic testing and the Texas Epidemiology Case Criteria Guide (2010 & 2011). Of the 605 cases found and reviewed in EPIC Web, 53 (8.8%) acute and 360 (59.5%) chronic Hep B cases were identified. There were 88 misclassified cases of hepatitis C and 105 cases that did not meet criteria.

These results show the importance of enhanced Hep B surveillance in understanding and describing the burden of Hep B infection in a large metropolitan city. This will assist in the implementation of targeted prevention efforts to appropriately address this health problem.