Supported in part by an educational grant from Bristol-Myers Squibb. Supported in part by an educational grant from Bristol-Myers Squibb. CROI: HCV

Supported in part by an educational grant from Bristol-Myers Squibb.
Supported in part by an educational grant from Bristol-Myers Squibb.

CROI: HCV Spread Abetted by Needle Type
By Crystal Phend, Senior Staff Writer, MedPage Today
Published: February 20, 2010
Reviewed by Barry S. Zingman, MD; Professor of Clinical Medicine, Albert Einstein College of Medicine, Bronx, NY and
Dorothy Caputo, MA, RN, BC-ADM, CDE, Nurse Planner Earn CME/CE credit
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Action Points

* Explain to interested patients that hepatitis C virus remains viable longer in high-volume syringes and at lower temperatures.


* Note that this study was published as an abstract and presented at a conference. These data and conclusions should be considered preliminary until published in a peer-reviewed journal.

SAN FRANCISCO -- Among injection drug users, the type of needle used and the temperature it's stored at can substantially affect the risk of transmitting hepatitis C virus (HCV), researchers found.

Syringes with detachable needles appeared by far the most likely to transmit the virus, Elijah Paintsil, MD, of Yale, and colleagues showed in a laboratory study.

And lower temperatures kept HCV viable for up to 63 days in the syringes with a high void volume, they reported here at the Conference on Retroviruses and Opportunistic Infections.

The bottom line is that sharing needles is a bad idea no matter what the conditions, although there may be implications for prevention, Paintsil said at a press conference.

Needle sharing programs typically offer users whatever kind they want, noted co-author Robert Heimer, PhD, also of Yale.

But changing that to offer only types less associated with transmission may help cut down on what has become an epidemic among injection drug users, he said.

These kind of programs aimed at harm reduction have been much more effective in reducing incidence of HIV, which is 10-fold less transmissible than HCV.

By comparison, HCV is a hardy virus -- a grenade to HIV's firecracker of transmissibility, said David Thomas, MD, of Johns Hopkins, moderator of the press conference at which the results were presented.

The researchers investigated why by loading a variety of syringes with HCV-spiked blood and then storing them at different temperatures.

After a delay of up to 63 days, they recovered the virus and tested its infectivity in cell cultures.

At room temperature (22°C, or 72°F), HCV dropped off sharply in activity over the first few hours but then decayed slowly over the next three days.

Whereas the low, 2-μL volume syringe of the sort usually used for insulin administration maintained viable HVC out to three days at room temperature, it extended to seven days at 4ºC (39°F).

For a high, 32-μL volume syringe with detachable needle, some degree of viability was maintained at all temperatures out to 63 days, although again low temperatures maintained greater viability.

Most needles used by injection drug users stay in circulation up to 23 days, a period during which the virus remained at high viral titers, Paintsil said.

The researchers cautioned that this simulation in the laboratory under carefully controlled conditions might not accurately replicate what would happen among intravenous drug users.

It's also possible that other genotypes or strains of the virus would have different survival characteristics.

While these findings suggest increased transmissibility, effects on population level transmission now need to be determined by epidemiologic studies, Paintsil said.

"This is just the first step," but one that may help inform prevention efforts, Thomas concluded at the press conference.

The study was funded by grants from the Yale Center for Interdisciplinary Research on AIDS and National Institute on Drug Abuse.

Paintsil and Thomas reported no conflicts of interest. Heimer provided no information on conflicts of interest.

Primary source: Conference on Retroviruses and Opportunistic Infections
Source reference:
Paintsil E, et al "Survival of HCV in syringes: Implication for HCV transmission among injection drug users" CROI 2010; Abstract 168.