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Though not officially part of the federal initiative to end the HIV epidemic by 2030, an HIV outbreak among injection drug users in West Virginia proved such outbreaks can be managed using the four outlined pillars of this initiative, researchers found.

Cabell County, in the southwestern part of the state, experienced the largest increase in HIV infections over relative baseline in its 2018-2019 outbreak among people who inject drugs since Indiana's highly publicized outbreak in Scott County in 2015, reported Robert McClung, MD, of the CDC in Atlanta.

Responding quickly to a potential HIV outbreak is one of the four pillars of ending the HIV epidemic, which the CDC and state and local public health departments accomplished by utilizing the other three pillars of the plan: diagnosing all people with infection; treating them rapidly and getting them virally suppressed; and preventing new transmission through increased access to pre-exposure prophylaxis (PrEP).

In a late-breaking presentation at the virtual Conference on Retroviruses and Opportunistic Infections (CROI), McClung described Cabell County as part of a metropolitan area with 350,000 people residing in West Virginia, Ohio, and Kentucky, which was "severely affected by the opioid crisis." It was further identified to be at "high risk" for outbreaks of both HIV and hepatitis C (HCV), with 1,900 injection drug users as of 2018.

McClung noted the "strong public health infrastructure" in the county, including a large academic medical center, a large network of community health centers, and a "growing capacity to treat substance use disorder," such as a syringe service program in place since 2015.

The county had averaged 2 cases per year among injection drug users, which jumped when 15 new cases were diagnosed among the population since January 2018, 9 since October 2018, McClung said. He said that molecular cluster analyses identified a cluster of infections, "which suggested rapid transmission."

At that point, public health officials moved quickly, developing a case definition comprised of all HIV diagnoses after January 2018 among people who inject drugs residing in or receiving care in Cabell County, their sex or injecting partners, and people who were linked with the HIV sequence.

In total, 82 total cases were identified through October 2019. According to available data, nearly all cases were injection drug users, 91% were white, 40% were women, and the median age was 33. Nearly nine out of 10 had evidence of HCV infection, and the majority reported either homelessness or unstable housing and sharing injection equipment, McClung said. Nearly half had a history of incarceration.

Median CD4 count was 594, he noted, which was "much higher than the statewide median for [injection drug users] with HIV diagnosis." The molecular cluster was 47 of 51 cases with an available sequence, and of those, over 90% inferred transmission occurred after January 2018, and 60% occurred during 2019.

Overall, the outbreak had 72 infections per 100 person years, or 18 times the estimated national rate, McClung noted.

Public health officials then employed interventions "from across the spectrum of HIV prevention and care."

They moved to quickly diagnose people, which was a "focal point early in the response due to concerns many cases had not been detected." CDC deployed disease intervention specialists to support those in West Virginia with rapid identification of cases and contacts. McClung noted testing was held in "jails, community centers, and residential areas."

For the treat aspect of the response, the goal was to "treat people with HIV rapidly and effectively to reach sustained viral suppression," working to improve linkage to care and addressing barriers to retention in care, including linkage to medication assisted treatment for opioid use disorder. Soon, viral suppression increased from 16% to 43%.

Prevention interventions, such as pre-exposure prophylaxis (PrEP), were scaled up, with McClung saying they worked with "area healthcare systems to train over 100 providers to assist with PrEP implementation."

"Our approach to this outbreak reflects key elements of the Respond pillar [in the federal initiative] ... it takes proven interventions from the other three pillars and delivers them quickly and creatively to communities experiencing rapid transmission," he said.

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