Strategies used during HIV, HCV outbreak in Indiana may prevent future epidemics
BOSTON — Interventions and surveillance techniques used to control the HIV and hepatitis C epidemic in Scott County, Indiana, may prevent future outbreaks in other states and local health jurisdictions that are threatened by an increasing trend in injection drug use, according to two presentations at CROI 2016.
In early 2015, Indiana state health officials began investigating an HIV outbreak among syringe-sharing members of a rural community in Scott County. The outbreak was traced primarily to IV drug use of Opana (oxymorphone, Endo Pharmaceuticals), John T. Brooks, MD, medical epidemiologist for the CDC’s Division of HIV/AIDS Prevention, said during a press conference. The investigation also revealed a high prevalence of HCV infection within the community, with 23% of HCV cases coinfected with HIV, according to CDC investigator Sumathi Ramachandran, PhD.
John T. Brooks
As of Feb. 1, there have been 188 new HIV infections reported in Scott County, with an estimated 400 to 500 injection drug users (IDUs) in the community of 4,200. On average, one to six needle-sharing partners injected drugs four to 15 times daily.
In an “enormous effort," federal, state and local health agencies implemented a variety of interventions to identify new infections, provide treatment and help patients address addiction issues, Brooks said.
“Our first priority in this outbreak was getting people onto treatment, because that’s the most potent intervention for reducing new infections,” he said. “As we began to get treatment into place, we then began to focus on [pre-exposure prophylaxis]. It was prescribed to sexual partners of IDUs and people who were injecting drugs.”
As health officials examined the epidemiology of the outbreak, they found that many of the factors that fueled the epidemic, such as high unemployment rates, a lack of medical services and no health insurance, are seen on a national scale.
Harold W. Jaffe
“Our stereotype that this is a problem concentrated in the inner city involving primarily racial minority groups is no longer correct,” Harold W. Jaffe, MD, associate director for science at the CDC, said during the conference. “This outbreak occurred in a very rural area, it occurred almost entirely in whites, and it was imminently related to the overuse of opioid pain medications, [which is] a problem across the United States.”
HCV surveillance predicts injection drug use patterns
To prevent similar epidemics, Brooks recommended that state and local health jurisdictions monitor the prevalence of acute hepatitis C in their areas to determine whether communities are vulnerable to outbreaks linked to IDUs. He also suggested that jurisdictions establish HCV testing in locations where IDUs are likely to be found such as substance abuse treatment centers, jails/prisons and hospitals.
“The events that occurred were entirely preventable,” Brooks said. “We learned a lot from this as a result, and we hope that we’ll be able to prevent this from happening again. Hepatitis C surveillance is a great way to monitor injection drug use.”
During the press conference, Ramachandran introduced a new bioinformatics toolkit developed by CDC’s Division of Viral Hepatitis called Global Hepatitis Outbreak and Surveillance Technology (GHOST), which was employed for the first time in Indiana to track HCV strains and complex transmission networks using existing lab sequencing capabilities.
“The GHOST tool takes data from the lab tests and drops it into a web-based software that identifies the transmission pattern of different cases of hepatitis,” Ramachandran said. “The tool provides local health departments an in-depth data knowledge of where the transmissions are taking place in a user-friendly, cost-effective, sustainable and real-time manner.”
With the tool, Ramachandran and colleagues were able to determine that multiple, independent introductions of HCV occurred among IDUs over several years before the HIV outbreak was detected.
The researchers analyzed 492 HCV antibody reactive specimens, 334 of which were HCV-RNA positive and included genotypes 1a (69.8%), 1b (2.4%), 2b (5.1%) and 3a (22.8%). A phylogenetic analysis identified one major cluster of genotype 1a and two clusters of genotype 3, all with more than 93% homology.
Among the cases, 240 were further analyzed by GHOST, which revealed that 70 HCV cases were infected with more than one HCV strain and 46 were infected with more than one genotype. In one case, a patient was infected with five strains of genotypes 1a, 1b, 3 and 6, according to the researchers. They discovered 335 HCV strains using next-generation sequencing, and found that 65% of strains were organized into 19 transmission clusters with a median cluster size of 3. The largest transmission cluster involved 92 cases of HCV.
Ramachandran and colleagues concluded that state and local health departments can implement GHOST to identify transmission clusters and target interventions in those areas to avoid future epidemics.
Syringe service programs help control outbreaks
A key intervention that helped to control the HIV and HCV outbreak was a temporary syringe service program, according to Brooks. He defended the use of such programs despite the contrasting belief that they may promote injection drug use.
“We have interventions that can keep needles out of people’s arms,” Brooks said. “If they get into a program where they can receive medication-assisted therapy in the form of either methadone, Suboxone, or naltrexone, that can be a very potent way of getting [users] off that before or shortly after they move to injection drug use.
You’re supporting the person’s habit, but you’re interacting with them every day. They’ve got to come in to get this drug and that provides an opportunity to work with the person [and] to help them move slowly down the road to where they don’t need that drug anymore.”
Monita R. Patel
A positive impact of syringe programs was previously demonstrated by Monita R. Patel, PhD, MPH, from the CDC, and colleagues at IDWeek 2015. During their investigation, Patel and colleagues compared injection-related risk behaviors reported over time by 148 (62%) of its clients. Each participant received sterile syringes, a wound kit, harm reduction education and referrals to health and substance use treatment services, and completed surveys about current risk behaviors.
The proportion of IDUs who shared syringes decreased from 18% at the first visit to 2% at the last visit (P < .001). The median frequency of IDUs reusing the same syringe also decreased from two times at the first visit to one time at the last visit (P < .001). The median number of syringes returned increased (0 to 57; P < .001), as did the number of new syringes distributed (35 to 63; P < .001). The researchers also saw a decrease in the percentage of IDUs sharing syringes to divide drugs (19% to 4%; P < .001) and the sharing of other injection equipment (24% to 5%; P < .001). However, the frequency of reported injections per day increased over time (5 to 9; P < .001).
Brooks concluded that the outcomes of service syringe programs are “in significant contrast to under-the–table injection drug use that takes place.” – by Stephanie Viguers
Brooks JT. Abstract 132. Presented at: Conference on Retroviruses and Opportunistic Infections; Feb. 22-25, 2016; Boston.
Patel MR, et al. Abstract 638a. Presented at: IDWeek; Oct. 7-11, 2015; San Diego.
Ramachandran S, et al. Abstract 149. Presented at: Conference on Retroviruses and Opportunistic Infections; Feb. 22-25, 2016; Boston.
Disclosures: The researchers report no relevant financial disclosures.