Home > Encyclopedia of Drugs, Alcohol, and Addictive Behavior > Parasitic Diseases And Drugs Of Abuse

A long historical awareness exists regarding the association between heavy ALCOHOL use and an increased risk or severity of symptoms caused by infectious diseases. In the United States, this awareness can be traced back to the medical literature of the late 1700s. It continues to evolve in ongoing research. Historically, most infectious diseases were viral and bacterial and caused death, such as tuberculosis. Some intestinal diseases have been also noted, especially cholera. This is an acute infectious disease of epedemic proportion caused by Vibrio cholerae (a gram-negative bacillus) that produces a soluble toxin in the intestinal tract, with profuse watery diarrhea, extreme loss of fluid and electrolytes, and a state of dehydration and collapse with death often following.

Modern research in immunosuppressed humans and animals has isolated a protozoan parasite, Cryptosporidium parvum, that affects the gastrointestinal tract. In immunocompetent hosts the disease is self-limiting and recovery is accompanied by resistance to reinfection. Cryptosporidium is, however, common in patients with acquired immunodeficiency syndrome (AIDS). It has been noted in 16 to 50 percent of cases, but is rarely manifested in HIV-positive people before loss of CD4 cells. Research with alcohol and COCAINE in AIDS-com-promised animals has indicated lessened resistance to Cryptosporidium. This is true as well with similar AIDS-compromised animals having colonies of trophozoites (a vegetative protozoan) of Giardia muris infecting the small intestine. The reason parasite infections in addition to some cancers and certain other diseases are more common in heavy or chronic alcohol users relates significantly to suppression of host defenses. Alcohol use lowers production of antibodies. Cocaine suppresses the functioning of T-lymphocytes, critical to the activation of immune defenses. Some infections, particularly parasitic ones, require a substantial lowering of natural immunity and resistance to be able to grow for more than a few days. Alcohol and drugs of abuse are strong suppressors of resistance mechanisms. Thus, their adverse effects are even more pronounced in the elderly, AIDS patients, transplant recipients, and others with damage to their immune system. In addition, alcohol and drugs of abuse lower intakes and tissue levels of antioxidant vitamins and nutrients, important for optimum functioning of host defense systems. Supplementation with antioxidant vitamins helps overcome some of the damage due to AIDS, age, and drug abuse.