Office of Technology Assessment

Do Insects Transmit Aids? Office of Technology Assessment

Infections of HIV (Human Immunodeficiency Virus), the virus that causes AIDS, are spreading rapidly among intravenous drug users, and there have been rare occasions in which health care workers became infected after being accidentally stuck with contaminated needles. If infection can occur by these routes, is it possible for the AIDS virus to be transmitted from an infected to an uninfected person by biting insects? What evidence is there for actual transmission by insects? If insect transmission is possible, how serious is the threat, and what research is being conducted and could be conducted that could answer these questions? Inquiries into whether insect transmission of HIV could occur fall into two general categories. First, field and laboratory studies of insects can determine: 1) whether their feeding/biting habits are compatible with their possible role as vectors of HIV transmission, 2) whether these insects are capable of drawing up and transmitting enough virus to cause infection, and 3) whether the microbiology of the virus in the insect is conducive to transmission. Second, epidemiological studies can be conducted among populations who live in environmental conditions favorable to insect transmission, to see if there are HIV infection patterns: 1 ) that cannot be explained by established risk factors (such as sexual transmission or intravenous drug use), and 2) that are consistent with transmission through insect vectors. The insects of primary interest as possible vectors in the spread of HIV infections are biting flies, mosquitoes, and bedbugs. Other possible insect vectors include lice and fleas. In this Office of Technology Assessment (OTA) Staff Paper: 1) the evidence for the possibility of insect transmission of HIV infection is summarized, and 2) areas for further investigation are identified.