HIV outbreak linked to change in injectable drug use pattern
BRUSSELS — A large-scale outbreak of HIV among injectable drug users in Tel Aviv was directly associated with a transition from heroin to a cathinone derivative — also known as “bath salts” — injected in combination with the opioid substitute buprenorphine, according to a presenter here at EACS 2013.
Previous reports indicated a plateau in the incidence of HIV infection among drug users in Tel Aviv who participated in government-funded risk reduction programs, including syringe exchange and methadone/buprenorphine substitution therapy.
However, a recent considerable increase in the rate of primary HIV infection among experienced injectable drug users prompted Eugene Katchman, MD, of the infectious diseases unit at Tel Aviv Sourasky Medical Center in Israel, and colleagues to carry out an active surveillance and risk factor analysis.
Researchers collected demographic, clinical and laboratory data and completed field visits and interviews with injectable drug users. The researchers also determined HIV genotyping and phylogenetic relationships among viral sequences.
According to study results, the rate of primary HIV infection increased sixfold after May 2012 (outbreak period; 5.9 cases per month vs. 1 case per month; P<.0001) and was associated with injectable drug use (50.7% vs. 0%; P=.0001).
The researchers found that all injectable drug users with primary HIV infection had recently switched from heroin use to injecting a combination of cathinone and buprenorphine, known locally as “hagigat.” No cases of primary HIV infection were observed among drug users who continued to inject heroin.
Researchers observed that severe bacterial coinfections were frequent among injectable drug users and represented the most common reason for hospitalization: all injectable drug users were coinfected with hepatitis C, whereas 33% were coinfected with hepatitis B.
The mortality rate among drug users was 7.5% within 3 months after diagnosis of primary HIV infection. All HIV isolates were a variant of subtype A/CRF01-AE.
“This outbreak of primary HIV infection is characterized by significant morbidity and mortality, mainly due to severe bacterial infections,” Katchman said. “The tight clustering of HIV isolates suggests a single source of infection.”
According to Katchman, unlike heroin, hagigat represents a cheaper drug alternative that can be dissolved in water rather than boiled before usage, which increases the risk for blood infections and severe abscesses.
In addition, because of its comparatively short-acting effect, hagigat users increased frequency of injections (up to 30 injections daily vs. one to two injections daily with heroin) and reported increased incidence of sharing the same syringe with other drug users who were not intimate friends.
“This outbreak was directly associated with the shift in illicit drug use practices, in which drug users switched from heroin to cathinone, sometimes together with buprenorphine injections, causing a failure of the previously efficient risk-reduction program,” Katchman said. “To address this outbreak, dynamic and non-standard multidisciplinary efforts are necessary.”
For more information:
Katchman E. #PS 11/4. Presented at: 14th European AIDS Conference; Oct. 16-19, 2013; Brussels.