Viral hepatitis is caused by infection with any of at least five distinct viruses: hepatitis A virus (HAV), hepatitis B virus (HBV), hepatitis C virus (HCV), hepatitis D virus (HDV), and hepatitis E virus (HEV). Most viral hepatitis infections in the United States are attributable to HAV, HBV, and HCV. All three of these unrelated viruses can produce an acute illness characterized by nausea, malaise, abdominal pain, and jaundice, although many of these acute infections are asymptomatic or cause only mild disease. This presentation of data emphasizes the reporting of new hepatitis infections as of December 31, 2010. The reported number of new hepatitis infections is based on data from the 50 states, and the District of Columbia. Data made available to the Atlas only includes counts (not rates) of confirmed acute cases of viral hepatitis A, B, and C.
Surveillance of Viral Hepatitis Infection
As part of Centers for Disease Control and Prevention‚ National Notifiable Disease Surveillance System (NNDSS), viral hepatitis case-reports are received electronically from state health departments via the CDC National Electronic Disease Surveillance System (NEDSS) a computerized public health surveillance system that provides CDC with data regarding cases of nationally notifiable diseases on a weekly basis. The Atlas includes viral hepatitis data submitted to the CDC NEDSS by state and local health departments. National surveillance for viral hepatitis (including hepatitis A, acute hepatitis B, and acute hepatitis C) is based on case definitions developed and approved by the Council of State and Territorial Epidemiologists (CSTE) and CDC. In 2010, reported cases of acute viral hepatitis were required to meet CSTE-defined clinical and laboratory criteria Limitations NNDSS is a passive surveillance system and is subject to several limitations regarding acute and chronic viral hepatitis reporting. First, NNDSS was designed for reporting of acute infectious disease for which a single laboratory test (e.g., culture positivity) can confirm a diagnosis. This limitation is especially problematic for HBV and HCV; for example, an average of four documents or reports must be reviewed to confirm each case of acute hepatitis C virus infection. Further, follow-up of patients is difficult. With the exception of selected, specially funded sites, states and localities do not receive federal funding to support viral hepatitis surveillance Cell suppression. A data suppression rule is applied to all data where the reported number of cases within a state is less than or equal to 5.