Rapid Hepatitis C Testing Among Persons at Increased Risk for Infection — Wisconsin, 2012-2013

Lauren J. Stockman, MPH; Sheila M. Guilfoyle; Andrea L. Benoit; James M. Vergeront, MD; Jeffrey P. Davis, MD

Disclosures

Morbidity and Mortality Weekly Report. 2014;63(14):309-311. 

In This Article

Introduction

An estimated 3.2 million persons in the United States have chronic infection with hepatitis C virus (HCV).[1] Most new HCV transmissions occur among persons who inject drugs,[2] often within the first few years of their injection drug use.[3] During 2003–2012, reports of HCV infection increased from 15 to 54 cases per 100,000 among persons aged <30 years in Wisconsin, and 58% of persons in this age group with acute HCV infection reported injecting drugs (Wisconsin Division of Public Health, unpublished data, 2013). To increase detection of HCV infection, the Wisconsin Division of Public Health (WDPH) piloted a program during October 2012–October 2013 that offered rapid HCV testing to clients of four agencies providing outreach testing for HCV and human immunodeficiency virus infection, syringe exchange, counseling, and other harm reduction services to persons with drug dependence. During that period, 1,255 persons were tested using a rapid HCV test, and 246 (20%) of the results were positive. Most (72%) of the infections had not been reported to WDPH. A blood specimen for further testing was collected from 192 (78%) participants with positive HCV test results; among these participants, 183 were tested for HCV RNA using reverse transcription–polymerase chain reaction (RT-PCR), and these results were positive for 128 (70%) participants, indicating active infection. Use of the rapid HCV test detected previously unreported HCV infections and raised awareness of HCV. Persons identified with active HCV infection should be referred to medical care and counseled on ways to prevent HCV transmission to others.

A new cohort of young injection drug users acquiring HCV infection has been recognized nationwide, notably in suburban and rural areas.[4] Most persons infected with HCV are unaware of their infection because it has few, if any, symptoms.* CDC and the United States Preventative Service Task Force recommend that persons who inject drugs receive HCV enzyme immunoassay (EIA) and nucleic acid testing to diagnose current HCV infections.[5,6] Conventional EIA testing requires laboratory equipment, a trained phlebotomist, and long turnaround times to process. However, rapid point-of-care screening tests for HCV antibody using finger-stick capillary blood allow screening to be expanded outside of a clinical setting.[7,8]

WDPH, in partnership with community organizations, supports outreach and overdose prevention services for persons with drug dependence. Four outreach agencies providing these services currently use rapid HIV testing technology and have staff members trained to collect blood specimens for PCR testing. Staff members at each agency were provided with OraQuick rapid HCV test kits (OraSure Technologies). Confirmatory tests using EIA and PCR were conducted at the Wisconsin State Laboratory of Hygiene.

Clients who used services from these agencies during October 2012–October 2013 were offered the OraQuick test and were interviewed to collect information regarding demographic characteristics and risk behaviors. Participants whose OraQuick test results were positive had blood specimens obtained by venipuncture and were asked to return to the outreach site for confirmatory test results. Reactive tests, and confirmatory results, when available, were reported to WDPH. Data from the Wisconsin Electronic Disease Surveillance System were analyzed to determine whether HCV infections detected during this pilot program had been reported previously to WDPH from a laboratory or local health department.

During the pilot program, rapid HCV tests were performed on blood specimens from the 1,255 participants, and results for 246 (20%) were positive. Most participants reported either that they had not been tested previously for HCV (53%) or they did not remember being tested for HCV (10%). Most (72%) of the infections detected during the pilot period were not recorded in the Wisconsin Electronic Disease Surveillance System, indicating they were newly detected HCV infections and not previously reported to WDPH.

Of the 1,255 persons who received rapid HCV tests, the median age was 28 years (range = 17–68 years), and 732 (59%) were male ( Table ). A total of 965 (78%) participants were non-Hispanic white, 81 (7%) were non-Hispanic black, 79 (6%) were non-Hispanic American Indian, and 18 (1%) were of other, mixed, or nonspecified race. A total of 97 (8%) were of Hispanic or Latino ethnicity. Compared with 2012 state data on HCV cases reported to WDPH, the 246 pilot program participants with HCV infection were younger (49% aged <30 years compared with 24%), more likely to be non-Hispanic white (78% compared with 63%), and less likely to be non-Hispanic black (5% compared with 13%) ( Table ).

The most common risk behavior or exposure reported by participants was injection drug use, reported by 1,033 (82%) of the 1,255 participants. A total of 868 (69%) reported injecting drugs within 6 months of testing (Figure); among these participants, the average number of persons with whom they reported injecting drugs was 5.4 (range = zero to 100). Among the participants, 825 (66%) reported sharing drug injection equipment, and 531 (42%) reported sharing equipment within 6 months of testing.

Figure.

Percentage of participants (N = 1,255) reporting selected risk behaviors or exposures,* by period before rapid hepatitis C virus (HCV) testing during a pilot program — four outreach agencies, Wisconsin, 2012–2013
* Participants could report more than one risk behavior or exposure.
From an unlicensed vendor.
§For example, contact with blood during a fight.

A blood specimen for confirmatory testing was collected from 192 (78%) of the 246 participants with positive results from rapid HCV tests. The 54 participants without a blood specimen either refused venipuncture or agency staff members could not access a vein and referred them to a clinic for HCV diagnostic testing. Among participants with a blood specimen, 190 of the 192 were tested for HCV antibody using EIA, and 100% of the results were positive, indicating no false-positive results from the rapid HCV test. A total of 183 of the 192 were tested for HCV RNA using RT-PCR, and 128 (70%) had a positive result, indicating a high proportion of participants with active infection.

* Additional information available at http://www.cdc.gov/hepatitis/hcv/index.htm.

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