Date: Wed, 6 Dec 1995 01:14:08 +0500 From: ghmcleaf{CONTRACTOR/ASPEN/ghmcleaf}%NAC-GATEWAY.ASPEN@ace.aspensys.com Subject: CDC Natl AIDS Hotline Training Bull #163 CENTERS FOR DISEASE CONTROL AND PREVENTION HIV/AIDS PREVENTION CDC NATIONAL AIDS HOTLINE TRAINING BULLETIN ................................................................. October 31, 1995 #163 These are answers from the Centers for Disease Control and Prevention (CDC) to questions concerning a case of possible blood-to-blood transmission of HIV by a human bite. Officials from the Florida State Health Department and a county public health unit conducted an investigation of an incident that suggests blood-to-blood transmission of HIV by a human bite. An adult HIV-positive female with bleeding gums bit an adult male, inflicting extensive tissue damage and causing bleeding. Other possible routes of HIV transmission (for example, drug use and sexual contact) were thoroughly investigated. DNA testing showed that the virus from the woman and the virus from the man were closely related, suggesting person-to-person transmission. The epidemiologic and laboratory evidence support bloodborne transmission of HIV via the bite. 1. Is biting a common route of HIV transmission? There is only one report in the medical literature in which HIV was transmitted by a bite. That report shares certain characteristics with the Florida incident. * Both were characterized by severe trauma--extensive tissue tearing and damage and blood, associated with violent fighting. * In the published report, two adult sisters, one of whom was an HIV-positive injecting drug user, had a violent fight, in which several of the HIV-positive sistergs teeth were broken and knocked out when she was punched in the mouth. She then bit her HIV-negative sister, severely tearing the skin and resulting in blood-to- blood contact. (Lancet, August 29, 1987; page 522) 2. Can HIV be transmitted by saliva? No cases of HIV transmission are clearly attributable only to saliva. In contrast, there are numerous reports of bites that did not cause HIV infection. Those reports do not involve the severe tissue trauma and presence of blood seen in the fight between the sisters and in the Florida incident. 3. How do we know the bite transmitted HIV in the Florida report? The evidence that supports the bite, which caused severe trauma, as the route of transmission is that the man was exposed to the blood of an HIV-infected person, he subsequently seroconverted, and tests show that the viruses in the woman and the man are closely linked. 4. What were the roles of the State health department and CDC in the investigation? The Florida state health department conducted an extensive investigation to determine the route of transmission and concluded it was the bite. CDC worked with the Florida state health department on the DNA sequencing and determined that the viruses were similar. CDC cannot confirm details on specific case investigations of HIV transmission. The Florida state health department has investigated this report and is the best source of information. 5. What are the implications of this report? Current recommendations are not being altered based on this report. Because the transmission in this instance is attributed to a bite, it might raise concerns about the possibility of HIV transmission in settings where biting occurs, such as day care centers. However, the nature of the bite in this instance is unlike most bites that occur among children--whose bites rarely involve blood or breaking the skin. There has been only one previous report, from Germany, in which a bite by a child was suggested as the mode of HIV transmission. But the source and other possible modes of transmission were not thoroughly investigated in that report. 6. Will CDC change its recommendations? This report highlights the need to prevent blood exposures in all settings. However, there is nothing medically unique about this incident that would cause CDC to revise its current recommendations for day care centers, schools, and health care settings. Current guidelines are detailed in these editions of Morbidity and Mortality Weekly Report: MMWR 1985 August 30; 34: 517-21. MMWR 1988 June 24; 37: 377-82, 87-88. MMWR 1989 June 23; 38 (S-6): 1-37. Disclaimer: CDC Hotline Training Bulletins The information in the "CDC Hotline Training Bulletins" is provided by CDC and NIH for use by the CDC National AIDS Hotline in responding to general questions from the public about HIV and AIDS. The bulletins are not intended to be comprehensive discussions of the subject areas. Treatment and drug therapy options change as new research and clinical experiences broaden scientific knowledge. Therefore, persons seeking information on drug therapy should refer to the product information sheet included in all drug packages for the most current and accurate information about a particular drug, especially if the drug is new or infrequently used. HIV-infected individuals should consult their personal physician for specific concerns about their health. For persons desiring more information on a specific topic, public, medical, and university libraries can provide excellent references. The AIDS Clinical Trials Information Service (800-874-2572) can provide information about ongoing HIV/AIDS clinical trials; the HIV/AIDS Treatment Information Service (800-448-0440) can assist with information about the latest treatments for persons with HIV infection or AIDS.