Washoe County Health District Enhanced Hepatitis C Surveillance, 2002 - 2012

Between May 2002 and December 2012 the Washoe County Health District conducted enhanced surveillance for hepatitis C virus (HCV) infections.  Data elements gathered during this enhanced surveillance period included demographics, reasons for testing, other hepatitis markers, genotypes, pregnancy status, cirrhosis, cancer, outcome, past and current risk factors, and insurance status. Enhanced surveillance for HCV was discontinued beginning in 2013 because the epidemiological profile from 2002 through 2012 had not demonstrated any significant changes and personnel resources were restricted.

Results presented in this report identify reported reasons for HCV testing, clinical conditions among reported cases, and behavioral risk factors. For 4,299 (65%) of the 6,633 lab results on Washoe County residents reported between May 2002 and December 2012, the patient’s health care provider submitted a completed case report during the same period. Of the 4,299 case reports received, 293 (6.8%) could not be classified based on CDC’s case definition and 181 (4.2%) did not meet the case definition. Therefore, the following statistics reflect only the 4,118 cases with complete information.

Reported Reasons for HCV Testing

Forty-one (41%) of the cases were identified through follow-up testing on a previous marker of hepatitis or evaluation of elevated liver enzymes. Nearly twenty-two percent (22%) of cases were identified through passive screening, including asymptomatic persons with or without risk factors, blood or organ donors, and pregnant women.

Table 1. Reported Hepatitis C Cases by Reasons for Testing, Washoe County, May 2002 – December 2012.

* Excludes those cases who did not meet case definition (4,299-181=4,118)

Clinical Conditions among Reported Cases

Eight percent (8.5%) of cases were found to have cirrhosis and liver cancer. A significant proportion of cases had unknown status for cirrhosis and liver cancer. Better reporting from health care providers is needed to identify cases with these complications of HCV infection. Using cross-matched analysis between hepatitis C and registered liver cancer, an additional 59 cases were identified through the cancer registry system. Of 319 registered liver cancer individuals, 104 (32.6%) were found in the hepatitis C surveillance system.

Table 2. Reported Hepatitis C Cases by Clinical Data, Washoe County, May 2002 – December 2012.

Reported Hepatitis C Cases by Behavioral Risk Factors

Approximately 31% of cases acknowledged they had injected drugs not prescribed by a physician, and 5% received a blood transfusion prior to 1992. Thirty-three percent (33%, 1191/3647) of cases reported current alcohol use – indicating a need for better education of HCV patients by health care providers. Overall, 45% (1838/4118) of cases had one or more risk factors, 30% (1291/4118) of cases denied risk factors and 25% (1061/4118) had unknown risks. Twelve percent (12%, 1219/4118) of cases had no health insurance. Behavioral risk factor data was obtained via chart review rather than through patient interview.

Table 3. Reported Hepatitis C Cases by Patient Risk Behaviors, Washoe County, May 2002– December 2012.