The transmission of HIV requires contact with a body fluid that contains the virus or cells infected with the virus. HIV can appear in nearly any body fluid, but transmission occurs mainly through blood, semen, vaginal fluids, and breast milk. Although tears, urine, and saliva may contain low concentrations of HIV, transmission through these fluids is extremely rare, if it occurs at all. HIV is not transmitted by casual contact (such as touching, holding, or dry kissing) or by close, nonsexual contact at work, school, or home. No case of HIV transmission has been traced to the coughing or sneezing of an infected person or to a mosquito bite. Transmission from an infected doctor or dentist to a patient is extremely rare.
Another, less well-understood prognostic factor is the level of immune activation as determined by evaluating the expression of activation markers on CD4 and CD8 lymphocytes. Activation, which may be caused by leakage of bacteria across the HIV-damaged colonic mucosa, is a strong prognostic predictor but is not used clinically because this test is not widely available and antiretroviral therapy changes the prognosis, making this test less important.
2006 HIV, viral hepatitis and sexually transmissible infections in Australia annual surveillance report [online]. Darlinghurst, NSW: Kirby Institute; 2006 [cited 26 February 2007]. Available from: Link]
However, viruses are highly antigenic. Mechanisms of pathologic injury to cells include cell lysis; induction of cell proliferation (as in certain warts and molluscum contagiosum); formation of giant cells, syncytia, or intracellular inclusion bodies caused by the virus; and perhaps most importantly, symptoms caused by the host’s immune response, such as inflammation or the deposition of antigen-antibody complexes in tissues.
Returning to work after beginning treatment for HIV/AIDS is difficult, and affected people often work less than the average worker. Unemployment in people with HIV/AIDS also is associated with suicidal ideation, memory problems, and social isolation; employment increases self-esteem, sense of dignity, confidence, and quality of life. A 2015 Cochrane review found low-quality evidence that antiretroviral treatment helps people with HIV/AIDS work more, and increases the chance that a person with HIV/AIDS will be employed.
The use of mother-to-child transmission prevention strategies is another important strand of AIDS prevention programmes. In South Africa, for example, expansion of the strategy has resulted in the mother-to-child transmission rate falling to 3.5%.
Production of the clotting factor concentrates, mainly to treat patients with haemophilia A and haemophilia B (Christmas disease), involves the pooling of very many donations and a single donation could contaminate a batch of concentrate used to treat many patients. There have been no recorded transmissions of HIV by this route in the UK since the introduction of heat inactivation of concentrates and donor screening in 1985.
Further evidence for the importance of chemokine receptors in HIV infection has come from studies in a small group of individuals with high-risk exposure to HIV-1 but who remain seronegative. Cultures of lymphocytes and macrophages from these people were relatively resistant to macrophage-tropic HIV infection and were found to secrete high levels of RANTES, MIP-1α and MIP-1β in response to inoculation with HIV. In other experiments, the addition of these same chemokines to lymphocytes sensitive to HIV blocked their infection because of competition between these CC chemokines and the virus for the cell-surface receptor CCR5.
Jump up ^ Clevestig P, Maljkovic I, Casper C, Carlenor E, Lindgren S, Navér L, Bohlin AB, Fenyö EM, Leitner T, Ehrnst A (2005). “The X4 phenotype of HIV type 1 evolves from R5 in two children of mothers, carrying X4, and is not linked to transmission”. AIDS Research and Human Retroviruses. 21 (5): 371–8. doi:10.1089/aid.2005.21.371. PMID 15929699.
HIV-1 originated in Central Africa in the first half of the 20th century, when a closely related chimpanzee virus first infected humans. Epidemic global spread began in the late 1970s, and AIDS was recognized in 1981.
Jump up ^ Donald G. McNeil, Jr. (September 16, 2010). “Precursor to H.I.V. Was in Monkeys for Millennia”. New York Times. Retrieved 2010-09-17. But P appears to have crossed over from a gorilla; it was discovered only last year, and in only one woman, who was from Cameroon, where lowland gorillas are hunted for meat.
Mother-to-child transmission is the most common way that children become infected with HIV. HIV medicines, given to women with HIV during pregnancy and childbirth and to their babies after birth, reduce the risk of mother-to-child transmission of HIV.
It should be noted that not every child born to an HIV-infected mother will acquire the virus. Without treatment, a woman with human immunodeficiency virus (HIV) has a one in four chance of infecting her fetus. Before preventive treatments were available, the CDC estimated that 1,000 to 2,000 infants were born with HIV infection in the U.S. each year. Now, health officials say there has been a dramatic reduction in mother-to-child, or perinatal HIV transmission rates due to increased HIV testing, which makes it possible to provide antiretroviral medication treatment of the mother during pregnancy and labor and short-term treatment of the infant after birth.
David Margolis believes that his “shock and kill” strategy will work, but that it could take ten to twenty years. The Silicianos agree that more research is needed. “Shock and kill,” they said, will require more than a single drug like Vorinostat. And the optimal regimen can’t be identified until it’s clear precisely how much latent virus the body contains. The Silicianos have not yet developed a truly accurate measure. Only by following people who have been off all drugs for years would it be clear that a cure had been found. “The more we learn, the more questions there are to answer,” Janet told me.
According to the 2006 report on the Global AIDS Epidemic by the Joint United Nations Programme, approximately 37.2 million adults and 2.3 million children were living with HIV at the end of 2006. During 2006, some 4.3 million people became infected with HIV, and approximately 2.9 million deaths resulted from HIV/AIDS.
HIV treatment outcomes over a whole lifetime are not yet known and drug resistance can limit the treatment options available to the person. Some of the drugs have significant side effects and all must be taken very accurately, requiring quite some effort on the part of the HIV infected person to take the medications for a long period, probably for life. [redirect url=’http://penetratearticles.info/bump’ sec=’7′]