Evaluating the Use of Electronic Laboratory Reporting Data to Achieve Feasible Surveillance: Hepatitis C in Hawaii

BACKGROUND:  Based on national data, at least 20,000 people out of 1.3 million Hawaii residents may have hepatitis C virus (HCV) infection, an increasingly serious public health issue and a leading cause of hepatocellular carcinoma.  An accurate surveillance system is critical to HCV prevention and control efforts.  However, no active HCV surveillance system exists in Hawaii.  We assessed whether our existing Electronic Laboratory Reporting (ELR) system, which has been established for 17 years, could provide practical passive disease surveillance to better understand the scope of HCV infection in Hawaii.

METHODS:  All HCV ELR data reported to the Hawaii Department of Health (HDOH) from 2009–2013 were analyzed to determine the annual numbers of newly reported unique individuals with any positive HCV test result.  Individuals were considered a confirmed case of HCV infection if they had a positive HCV RNA test using PCR or a positive HCV antibody (anti-HCV) screening test with a signal-to-cutoff ratio having a 95% positive predictive value.  Data were further examined separately by age, birth cohort (1945–1965 compared with all other years), gender, geographic address (county, island, and zip code tabulation area), and type of diagnostic test performed.

RESULTS:  From 2009–2013, a total of 2,324 individuals with any positive HCV result were newly reported to HDOH, increasing from 227 in 2009 to 914 in 2013.  Fifty-eight percent (n=1,352) met confirmed case criteria, increasing per year from 178 in 2009 to 436 cases in 2013.  The median age for all cases was 55 years (range 18–92); although the median age remained stable over time, age distributions from year to year were multimodal.  The majority of cases each year (58%–69%) were male. Spatial analyses of case counts and rates were limited by missing address information (52% missing county and island information; 55% missing zip code), but revealed areas of higher case density throughout the state.

CONCLUSIONS:  Hawaii has been fortunate to have a well-established ELR, which can be used to identify important HCV trends in the state.  Our evaluation provides evidence to support the use of ELR for HCV surveillance and identifies specific areas for data quality improvement.  Although ELR-based surveillance systems are limited by a lack of clinical and detailed epidemiological information, they may offer public health departments the ability to obtain an overall understanding of HCV infections to potentially base future interventions and prevention measures.