Cocaine and HIV/AIDS and Hepatitis C
Cocaine abusers, especially those who inject, are at increased risk for contracting such infectious diseases as human immunodeficiency virus (HIV/AIDS) and hepatitis C. In fact, use and abuse of illicit drugs, including crack cocaine, have become the leading risk factors for new cases of HIV. Drug abuse-related spread of HIV can result from direct transmission of the virus through the sharing of contaminated needles and paraphernalia between injecting drug users. It can also result from indirect transmission, such as a HIV-infected mother transmitting the virus prenataly to her child. This is particularly alarming, given that more than 60 percent of new AIDS cases are women.
Research has also shown that cocaine use can interfere with judgment about risk-taking behavior, and can potentially lead to reduced precautions about having sex, the sharing of needles and injection paraphernalia, and the trading of sex for drugs, by both men and women. Additionally, hepatitis C is spreading rapidly among injection drug users; current estimates indicate infection rates of 65 to 90 percent in the drug injecting population. At present, there is no vaccine for the hepatitis C virus, and the only treatment is expensive, often unsuccessful, and may have serious side effects.
Researchers at the Medical College of Wisconsin have found that up to one-third of cocaine users who thought they were healthy may be infected with hepatitis C. Hepatitis C can lead to chronic hepatitis, cirrhosis of the liver and even liver cancer. It has been suggested by some researchers that hepatitis C infection may be the major cause of liver disease in the United States. The use of alcohol may make the effects of hepatitis C on the liver more severe.
Harold H. Harsch, MD, Associate Professor of Psychiatry at the Medical College of Wisconsin screened cocaine users who volunteered for the study of how the brain reacts to cocaine. Of the 144 people screened, 47 were found to have hepatitis C, while only seven tested positive for hepatitis B and only two for HIV. Of the 144, 56% were African-American, 81% were male, 75% were never-married, and 55% were unemployed. The average age was 36. None of the subjects had ever received a blood transfusion.
Twenty-nine percent who tested negative for hepatitis C reported intravenous drug use, while 77% of those testing positive for the disease reported IV drug use. Those who tested positive for hepatitis C tended to be three to four years older than hepatitis C-free patients.
One of the most surprising findings was that about 14% of those with hepatitis C said they had never used intravenous drugs. This suggests that there are other ways for the spread of the disease among cocaine users, such as sharing straws to snort cocaine, particularly if nosebleeds occur. For hepatitis C to be spread, the virus generally must enter the bloodstream through the skin or mucous membranes. hepatitis C does not spread as easily through sexual contact as hepatitis B or HIV.
Cocaine Speeds HIV'S Spread in Cells
New York -- Experts have long known that cocaine abuse encourages risky behaviors linked to infection with HIV. Now, research in mice suggests the drug may also speed the cell-to-cell spread of the virus by up to 200-times.
"This is important, because cocaine use--specifically crack cocaine--is a significant public health problem, and it's particularly significant in populations at risk for contracting HIV," said researcher Dr. Gayle Baldwin, of the University of California, Los Angeles. Her team published their findings in the March issue of the Journal of Infectious Diseases.
Previous population-based studies have suggested that HIV-related disease progresses faster in drug abusers than in non-users. However, ethical and practical concerns have meant that its nearly impossible to carry out studies that would measure the effects of cocaine on HIV spread at the cellular level.
In their research, Baldwin's team developed a mouse model of human HIV infection. They first transplanted human cells into mice, then infected those cells with HIV. Next, they fed some of the mice cocaine in liquid form, at dosages roughly comparable to those used by human addicts. The rest of the mice received no cocaine.
"What we found was that cocaine use dramatically accelerated the spread of HIV infection," Baldwin told Reuters Health. In fact, the blood cells of mice fed cocaine had nearly 200 times the level of virus of those who did not receive the drug.
Furthermore, cocaine-fed rodents experienced significant injury to their immune systems, as well. "There was a dramatic decrease in the number of CD4+ T cells--these are one of the primary cellular immune defenders, and the target cell of choice for HIV," Baldwin said. According to the researchers, the number of CD4+ cells fell 9 times faster in rats fed cocaine versus those that were not.
The exact mechanisms behind cocaine's impact on HIV and immune health remains unclear. "There certainly are some targets we can look at," Baldwin said. "Cocaine doesn't work by itself...it has a number of byproducts, and these byproducts can act on HIV. These can include things as straightforward as cellular mediators such as cytokines, compounds which have been already shown to have an effect on HIV replication." Cocaine and its byproducts might also help HIV break into cells.
Regardless of the way in which it wreaks havoc with HIV, the message to HIV-positive individuals--or anyone else--seems clear: stay away from cocaine.
"Even if cocaine had no effect on HIV replication, the consequences of use in immune-compromised population is very straightforward," Baldwin noted. But evidence that cocaine could actually speed the spread of HIV within cells may now mean that "the caution against this sort of recreational drug use has now been increased 200-fold," she said.
Source: The Journal of Infectious Diseases, 2002:185:701-705. By E. J. Mundell, Reuters 14 Feb. 2002