Human Immunodeficiency Virus

HIV is an enveloped genome of two identical, single-stranded RNA molecules. HIV, classified as a retrovirus in the subfamily lentivirus, replicates in activated CD4 T lymphocytes. There are two types of human lentiviruses: HIV-1, the predominant HIV type in most parts of the world, and HIV-2, primarily found in West Africa. 58 As of December 1996, the Joint United Nations Programme on HIV/AIDS estimated that there were a total of 27 million adults and 2.6 million children with HIV infection. Of these cases, 62 percent occurred in sub-Saharan Africa and 23 percent in South and Southeast Asia. 59 As of 1996, there were at least five African nations with adult prevalence of HIV greater than 10 percent. In 1996, there were over 32,000 deaths in the United States due to HIV and/or AIDS, ranking it the eighth leading cause of death in the nation.60 The capacity of HIV to recombine and generate mosaic genotypes confounds treatment efforts and vaccine development. The virus mutates at varying rates over time in various individuals, and data suggest that the host's ongoing immune response is a driving force for genetic variation.

More than 70 percent of HIV infections are due to unprotected heterosexual intercourse. Other important modes of transmission include unprotected homosexual intercourse, injected drug use, mother-infant vertical transmission, and blood transfusions. Blood screening, use of a voluntary donor pool, and more rational use of blood products has greatly reduced transfusions as a means of infection.

Percutaneous injury with exposure to HIV-infected blood in health care workers accounts for 80 percent of occupational exposures. 17 The average risk of HIV infection from all types of percutaneous exposures to HIV-infected blood is 0.3 percent. 61 Risk of infection is increased for deep injury, injury by a device previously placed in the source patient's artery or vein, visible blood on the device causing the injury, and death of the source patient as a result of AIDS within 60 days postexposure. The risks of acquiring HIV after mucous membrane and skin exposure to HIV-infected blood are approximately 0.1 percent and less than 0.1 percent respectively. 17 As previously mentioned, large-volume exposures, increased viral titer in the source patient, large surface area of contact, and loss of integrity in mucous membranes or skin may increase the risks of acquiring HIV. Chemoprophylaxis should be recommended to exposed workers after occupational exposures associated with highest risk for HIV transmission. The US Public Health Service has published guidelines for the management of health care workers exposed to HIV with recommendations for postexposure prophylaxis (Table 148:6, I§b].§..,148:Z, and Table...l48:8)62 Chemoprophylaxis should begin as soon as possible after the exposure, ideally within 1

to 2 h. Animal studies show that antiretrovirals are not effective if started later than 24 to 36 h after the exposure event. No vaccine for HIV currently exists. Preventive measures for health care providers include the use of standard precautions. Postexposure medical examination, counseling, treatment (antivirals based on risk evaluation), and follow-up should be readily available to health care personnel.

TABLE 148-6 Determine Exposure Code (EC)

TABLE 148-7 Determine HIV Status Code (HIV SC)

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The term vaginitis is one that is applied to any inflammation or infection of the vagina, and there are many different conditions that are categorized together under this ‘broad’ heading, including bacterial vaginosis, trichomoniasis and non-infectious vaginitis.

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