Increases in Hepatitis C Virus Infection Related to Injection Drug Use Among Persons Aged ≤30 Years — Kentucky, Tennessee, Virginia, and West Virginia, 2006–2012

Jon E. Zibbell, PhD; Kashif Iqbal, MPH; Rajiv C. Patel, MPH; Anil Suryaprasad, MD; Kathy J. Sanders, MSN; Loretta Moore-Moravian; Jamie Serrecchia, MPA; Steven Blankenship, MS; John W. Ward, MD; Deborah Holtzman, PhD

Disclosures

Morbidity and Mortality Weekly Report. 2015;64(17):453-458. 

In This Article

Introduction

Hepatitis C virus (HCV) infection is the most common blood-borne infection in the United States, with approximately three million persons living with current infection.[1] Percutaneous exposure to contaminated blood is the most efficient mode of transmission, and in the United States, injection drug use (IDU) is the primary risk factor for infection. State surveillance reports from the period 2006–2012 reveal a nationwide increase in reported cases of acute HCV infection, with the largest increases occurring east of the Mississippi River, particularly among states in central Appalachia.[2] Demographic and behavioral data accompanying these reports show young persons (aged ≤30 years) from nonurban areas contributed to the majority of cases, with about 73% citing IDU as a principal risk factor. To better understand the increase in acute cases of HCV infection and its correlation to IDU, CDC examined surveillance data for acute case reports in conjunction with analyzing drug treatment admissions data from the Treatment Episode Data Set-Admissions (TEDS-A) among persons aged ≤30 years in four states (Kentucky, Tennessee, Virginia, and West Virginia) for the period 2006–2012. During this period, significant increases in cases of acute HCV infection were found among persons in both urban and nonurban areas, with a substantially higher incidence observed each year among persons residing in nonurban areas. During the same period, the proportion of treatment admissions for opioid dependency increased 21.1% in the four states, with a significant increase in the proportion of persons admitted who identified injecting as their main route of drug administration (an increase of 12.6%). Taken together, these increases indicate a geographic intersection among opioid abuse, drug injecting, and HCV infection in central Appalachia and underscore the need for integrated health services in substance abuse treatment settings to prevent HCV infection and ensure that those who are infected receive medical care.

Confirmed cases of acute HCV infection* and associated demographic and risk characteristics were obtained from the National Notifiable Disease Surveillance System (NNDSS) for Kentucky, Tennessee, Virginia, and West Virginia for the period 2006–2012 for persons aged ≤30 years. Surveillance case reports met the clinical and laboratory markers of confirmed cases of acute HCV infection as defined by CDC/CSTE.§ A case report was classified as "urban" if the person lived in a metropolitan county with ≥50,000 population and as "nonurban" if the person lived in a nonmetropolitan county with <50,000 population. The percentage of cases reported for the period 2006–2012 among persons aged ≤30 years in the four states were examined by demographic and risk characteristics (IDU versus non-IDU) and by urbanicity. In addition, using the number of cases reported through NNDSS as the numerator and the mid-year (July) population estimates for persons aged ≤30 years from U.S. Census Bureau as the denominator, annual incidence rates for the period 2006–2012 were calculated and analyzed by urbanicity. Linear trends in annual incidence were determined by the Spearman correlation trend test and were considered statistically significant at p<0.05.

TEDS-A contains data on admissions to substance abuse treatment facilities in the United States, by year and state, among patients aged ≥12 years.** For each admission, up to three "substances of abuse" with a corresponding route of administration and demographic characteristics might be reported. TEDS-A classifies opioids into three categories: heroin, nonprescription methadone, and opiates and synthetics. For this report, three types of admissions were defined: heroin admission, prescription opioid admission (includes nonprescription methadone and opiates and synthetics), and any opioid admission (includes heroin and prescription opioids). In addition, two types of drug injection were defined: any opioid injection (includes injection of heroin and/or prescription opioids) and nonopioid injection (includes injection of any substance not classified as an opioid [e.g., cocaine]). The annual percentage of patient admissions among persons aged 12–29 years in Kentucky, Tennessee, Virginia, and West Virginia was calculated by type of admission and by drug injection for the period 2006–2012. Denominators for all percentages were the total number of reported treatment admissions for persons aged 12–29 years in that year in the four states. Further, the difference in the percentage of each admission type from 2006 to 2012 was calculated. Significance of a monotonic trend for any-opioid and nonopioid injection was determined by the Mann-Kendall test. Trends were considered statistically significant at p<0.05.

During 2006–2012, a total of 1,377 cases of acute HCV infection were reported to CDC from Kentucky, Tennessee, Virginia, and West Virginia. Of the 1,374 cases with a recorded age and classified as either urban or nonurban, 616 (44.8%) were among persons aged ≤30 years. The median age of persons with acute infection was 25 years in both nonurban (range = 6–30 years) and urban (range = 6–30 years) counties ( Table ). Of the number of cases in persons aged ≤30 years in nonurban counties, 247 (78.4%) were in non-Hispanic whites, and 156 (49.5%) in males; in urban counties, 249 (82.7%) cases were in non-Hispanic whites, and 155 (51.5%) were in males. Among the 265 (43.0%) cases in both urban and nonurban counties with identified risks for HCV infection, 196 (73.1%) were among persons who reported IDU, with similar percentages by urbanicity (urban = 99 [71.7%], nonurban 95 [74.8%]). During 2006–2012, a significant increase occurred in the incidence of acute HCV infection among young persons in both nonurban (p=0.007) and urban counties (p<0.001) in the four states (Figure 1). However, in each year, incidence was more than twice the rate among persons who resided in nonurban compared with urban areas.

Figure 1.

Incidence of acute hepatitis C among persons aged ≤30 years, by urbanicity and year — Kentucky, Tennessee, Virginia, and West Virginia, 2006–2012
* 95% confidence interval.

Among all treatment admissions for persons aged 12–29 years in the four states, the change in the proportion of any-opioid admissions increased by 21.1% from 2006 to 2012 (Figure 2). In addition, increases of 16.8% and 7.4% were observed in the proportion of prescription opioid admissions and heroin admissions, respectively. Further, from 2006 to 2012, the proportion of admissions related to any-opioid injection increased by 12.6%, and the proportion of admissions of a patient reporting nonopioid injection increased by 2.1%. Both trends (any-opioid and nonopioid injections) were significant (p<0.05) over the 7-year period (Figure 3).

Figure 2.

Percentage of all admissions to substance abuse treatment centers by persons aged 12–29 years (N = 217,789) attributed to the use of opioids, prescription opioids, and heroin, by year — Kentucky, Tennessee, Virginia, and West Virginia, 2006–2012
*Any opioids include heroin and prescription opioids.
Prescription opioids includes buprenorphine, codeine, hydrocodone, hydromorphone, meperidine, morphine, opium, oxycodone, pentazocine, propoxyphene, tramadol, illicitly obtained methadone, and any other drug with morphine-like effects.

Figure 3.

Percentage of all admissions to substance abuse treatment centers by persons aged 12–29 years (N = 217,789) attributed to the injection of opioids and other drugs, by year — Kentucky, Tennessee, Virginia, and West Virginia, 2006–2012
*Any opioids include heroin and prescription opioids.
Other drugs include cocaine/crack, alcohol, phencyclidine, other hallucinogens, methamphetamine, other amphetamines, other stimulants, benzodiazepines, other non-benzodiazepine tranquilizers, barbiturates, other non-barbiturate sedatives or hypnotics, over the counter medications, and other drugs not listed.

*From 2006 to 2012, acute hepatitis C was defined for surveillance as laboratory-confirmed infection with acute illness of discreet onset. Acute illness was considered as the presence of any sign or symptom of acute viral hepatitis plus either jaundice or elevated alanine aminotransferase >400 IU/L. In 2012, the surveillance case definition was expanded to include cases with negative HCV antibody followed by positive antibody within 6 months.
Information available at https://wwwn.cdc.gov/nndss/conditions/hepatitis-c-acute/case-definition/2012.
§Information available at https://www.cdc.gov/hepatitis/Statistics/2011Surveillance/PDFs/2011HepSurveillanceRpt.pdf.
Information available at https://www.cdc.gov/nchs/data/series/sr_02/sr02_154.pdf.
**Information available at https://doi.org/10.3886/ICPSR25221.v9.

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