BACKGROUND: Viral hepatitis B (HBV) infection is a significant public health issue in the United States with approximately 2.2 million HBV-infected persons. An understanding of HBV epidemiology is necessary for targeted public health efforts. This study aimed to determine Delaware HBV incidence trends, identify its distribution and factors associated with HBV infection during the period from 2005-2015.
METHODS: We performed a retrospective study on persons suspected of having HBV reported to the Delaware Division of Public Health through Delaware Electronic Reporting and Surveillance System (DERSS) from 01/01/2005- 12/31/2015. The charts of 4,981 persons were reviewed and included in the analysis.
RESULTS: Of 4,981 persons, 2,119 [1,988 (39.9%) confirmed, 131 (2.6%) probable] were identified as either acute or chronic HBV infection. Between 2005 and 2015, acute HBV incidence declined 80.9%, from 4.2 cases to 0.8 per 100,000 population; chronic HBV declined 60%, from 36.0 to 14.4 per 100,000 population, for an overall reduction of 62.2%, from 40.2 to 15.2 per 100,000 population. During the period of 2005-2015, males had a higher yearly incidence rate than females. Rates declined 63.5% and 60.1% among males and females, respectively. Interestingly, there was an increase of 13.4% in the incidence in females during 2010-2015. A decline was seen in all racial groups during 2005-2015. Asian had higher HBV incidence than white and black with rates 25.1-fold and 5.9-fold higher in 2005, respectively, and 31.5-fold and 6.4-fold higher in 2015, respectively. Asian had an increase of 40.0% in the HBV incidence during 2010-2015. A decline in HBV infection was seen in all age groups from 2005-2015. However, during 2010-2015, an increase of 12.2% was seen amongst those 15-39 years. 66% of infected patients were identified in five cities: Wilmington, Newark, New Castle, Dover, and Bear. In a multivariable logistic model, significant predictors for HBV infection included being male [adjusted odds ratio (aOR): 1.6, 95%CI:1.4-1.8], age 15-39 years (aOR: 2.3, 95%CI: 1.4-3.7). Compared with white, Asian, black, and others had greater risk, with aOR of 5.3 (95%CI: 4.4-6.4), 1.6 (95%CI: 1.4-1.8), and 1.4 (95%CI: 1.1-1.9), respectively. Having received ≥1 dose of HBV vaccination had some protective effect, aOR: 0.4, 95%CI:0.2-0.5.
CONCLUSIONS: HBV infection is significant in Delaware and concentrated mainly in a few big cities. Despite overall decline, increases were seen in females, age group of 15-39 years, and Asian population during 2010-2015. Further studies should be conducted to identify factors contributing to these increases