Emergent HCV epidemic among young, non-urban people who inject drugs in the United States

Incidence of acute hepatitis C virus (HCV) infection increased significantly among young, non-urban people who inject drugs in the United States between 2006 and 2012, investigators report in the online edition of Clinical Infectious Diseases.

“The incidence of reported acute hepatitis C among young persons has significantly increased during 2006-12, with annual increases over two times greater in non-urban compared to urban jurisdictions,” write the authors. “Reported incidence was greater in 2012 than 2006 in at least 30 states, most notably in non-urban jurisdictions east of the Mississippi River in or nearby Appalachian counties.” The authors call for a comprehensive plan to tackle this “worrisome” emergent epidemic.

HCV now surpasses HIV as a cause of death in the US. Incidence of acute HCV infection was falling before 2003 but has been increasing since 2006, especially among younger people (under 30 years of age) who inject drugs. Data from individual states suggests that there are emergent HCV epidemics among younger non-urban people who inject drugs, with the infections linked to the injecting of prescription opioids.

Glossary

acute infection

The very first few weeks of infection, until the body has created antibodies against the infection. During acute HIV infection, HIV is highly infectious because the virus is multiplying at a very rapid rate. The symptoms of acute HIV infection can include fever, rash, chills, headache, fatigue, nausea, diarrhoea, sore throat, night sweats, appetite loss, mouth ulcers, swollen lymph nodes, muscle and joint aches – all of them symptoms of an acute inflammation (immune reaction).

trend

In everyday language, a general movement upwards or downwards (e.g. every year there are more HIV infections). When discussing statistics, a trend often describes an apparent difference between results that is not statistically significant. 

representative sample

Studies aim to give information that will be applicable to a large group of people (e.g. adults with diagnosed HIV in the UK). Because it is impractical to conduct a study with such a large group, only a sub-group (a sample) takes part in a study. This isn’t a problem as long as the characteristics of the sample are similar to those of the wider group (e.g. in terms of age, gender, CD4 count and years since diagnosis).

epidemiology

The study of the causes of a disease, its distribution within a population, and measures for control and prevention. Epidemiology focuses on groups rather than individuals.

treatment as prevention (TasP)

A public health strategy involving the prompt provision of antiretroviral treatment in people with HIV in order to reduce their risk of transmitting the virus to others through sex.

To see if this was representative of a wider national trend, investigators analysed data collected by the Centers for Disease Control and Prevention (CDC) on the epidemiology of acute HCV infections between 2006 and 2012. Detailed data from 2011-12 were examined to see if there were any specific risk factors associated with new HCV infections among younger people who inject drugs.

A total of 7169 acute HCV infections were reported between 2006 and 2012; information on age was available for 7077 cases, and 44% of patients were aged 30 years or younger. In 2006, 36% of infections involved younger people, increasing to 49% in 2012. Annual incidence among younger people was significantly higher in 2012 compared to 2006 (p = 0.002).

Of the 34 states and territories reporting to the CDC, 30 (88%) reported a higher incidence of acute HCV in 2012 compared to 2006. Half of these states had an increases of over 200%. The five states with the most cases in 2012 were Kentucky, Tennessee, Georgia, Indiana and Florida. The authors note all are east of the Mississippi River, in or near Appalachian jurisdictions.

Of the 102 counties reporting an incidence of acute HCV above 10 cases per 100,000 in 2012, 89% were east of the Mississippi River, most commonly in the Appalachians.

Of the young people with acute HCV, 69% lived in urban settings and 31% in non-urban counties. The incidence of acute HCV increased by 13% overall with a 170% increase between 2006 and 2012 in non-urban jurisdictions (p = 0.003).

Between 2006 and 2012, the highest annual incidence was in 2012 for both non-urban (1.22 per 100,000) and urban (0.55 per 100,000) jurisdictions.

Supplemental data for 2011-12 were available for 1202 people. Over half (52%) were female, 56% lived outside large metropolitan areas, 85% were white and 44% were aged in their early 20s.

Approximately three quarters were insured and had undergone treatment for alcohol or drug abuse. A third reported being in jail in the year before their infection with HCV. Over three quarters (77%) reported ever injecting drugs. Of these, 57% said they had shared needles or syringes and 82% reported the sharing of other drug-use paraphernalia.

Interviews with the younger patients revealed that 84% had ever used drugs (alcohol included) with 76% reporting use of prescription opioids. Average age of first use of an injectable drug was a little under 20 years. Over half (54%) said they used both prescription opioids and heroin, with use of prescription opioids initiated an average of two years before injecting of heroin.

“A comprehensive approach is needed to address the increases in HCV infection among young persons,” comment the investigators. “The early abuse of prescription opioids presents an opportunity to mitigate high-risk behaviors.” The authors also call for surveillance of the HCV epidemic to be strengthened and for HCV testing and preventing services to be offered at drug and alcohol services and in prisons. They also suggest the expanded use of newer anti-HCV drugs offers the promise of “treatment as prevention” with models suggesting “even modest increases in HCV treatment among people who inject drugs can reduce prevalence.”

The authors conclude, “reducing HCV incidence among young persons is achievable, but requires a comprehensive, integrative strategy in response to this emergent threat.”

References

Suryaprasad AG et al. Emerging epidemic of hepatitis C virus infections among young non-urban persons who inject drugs in the United States, 2006-2012. Clin Infect Dis, online edition, 2014.