Human immunodeficiency virus (HIV) is one of the greatest worldwide public health challenges of the last century. Since being identified over 20 years ago, HIV has claimed an estimated 25 million lives. Currently, an estimated 33 million individuals are living with HIV/AIDS. Although it causes infections worldwide, this virus has especially targeted areas of the developing world, with prevalence rates nearing 50% among women of child-bearing age in some areas of sub-Saharan Africa. Primary infection may be characterized by an acute viral syndrome or may be entirely asymptomatic, and individuals are often unaware of their infection. Symptomatic illness usually occurs several years after infection, and is manifested by significant-to-severe immune suppression. Although antiretroviral therapy (ART) is generally effective at suppressing viral replication, treatment is not universally available and is often associated with serious side effects. Also, due to the high rate of mutation during viral replication, ART may become ineffective in noncompliant individuals. The structure, genetics, and replication characteristics of HIV make it a challenging pathogen. HIV is a remarkably diverse virus, with two major types, and multiple subtypes and recombinant forms circulating worldwide. The viral envelope varies considerably from isolate to isolate, and has few conserved regions that can be effectively targeted by host antibody responses. Glycosylation of protein structures on the envelope coating hinder access by neutralizing antibodies, and widespread mutational change within the genome permits escape from cellular immune mechanisms. HIV preferentially infects activated host immune cells, which are diverted from normal cellular biosynthetic pathways to produce virus particles, and undergo premature apoptosis. However, infected CD41 T cells may also remain transcriptionally silent, leaving the incorporated proviral HIV genome dormant for many years. This results in a reservoir of infected cells that persists despite apparently effective therapy.The development of an HIV vaccine that is protective and easily and economically deliverable is a daunting endeavor for scientists, public health officials, and government agencies. The field of HIV vaccine development has met with a number of recent disappointments. Both the VAXGEN antibody-based vaccine and the Merck adenovirus T-cell-stimulating vaccine showed no efficacy in protecting from infection or reducing viral loads. In fact, the Merck product, tested in the Americas and South Africa, may have led to an increased susceptibility to HIV infection in individuals with evidence of preexisting serological immunity to the adenovirus vector.A new paradigm of HIV vaccine effectiveness may need to be considered. This paradigm includes vaccines that may: (1) prevent infection; (2) allow infection that is subsequently cleared without clinical disease; (3) delay clinical progression in the vaccinated individual; or (4) minimally impact disease in the infected individual, but reduce infection of others. Several new approaches are actively being tested in HIV vaccine development. DNA and peptide-based vaccines, heterologous prime-boost regimens, and alternative viral vector are under consideration and development. Scientists continue to use many different methodologies to optimize immunogenic HIV insert sequences in order to overcome the tremendous variability presented by potential infecting viruses. Other approaches seek to increase the recognition of viral antigens through the use of adjuvants and optimized modes of immunogen delivery. The next decade will provide opportunities for these hurdles to be overcome, and will likely see the emergence of new challenges as second- and third-generation vaccines are developed. Multidisciplinary approaches to vaccination may ultimately lead to complete control of this pandemic.
He told me, “I’m no longer that concerned about the virus itself. I’m more concerned about my internal organs and premature aging.” In 1999, at fifty, he learned that fatty deposits had substantially constricted the blood flow in a major artery that supplies the heart’s left ventricle. He began to experience crippling pain when he walked, because the blood supply to his bone tissue had diminished—a condition called avascular necrosis. In 2002, he had his first hip replacement, and the second in 2010. His muscles have shrunk, and sitting can be uncomfortable, so he sometimes wears special foam-padded underwear. Every other year, he has his face injected with poly-L-lactic acid, which replaces lost connective tissue.
Sub-Saharan Africa is the region most affected. In 2010, an estimated 68% (22.9 million) of all HIV cases and 66% of all deaths (1.2 million) occurred in this region. This means that about 5% of the adult population is infected and it is believed to be the cause of 10% of all deaths in children. Here in contrast to other regions women compose nearly 60% of cases. South Africa has the largest population of people with HIV of any country in the world at 5.9 million. Life expectancy has fallen in the worst-affected countries due to HIV/AIDS; for example, in 2006 it was estimated that it had dropped from 65 to 35 years in Botswana. Mother-to-child transmission, as of 2013, in Botswana and South Africa has decreased to less than 5% with improvement in many other African nations due to improved access to antiretroviral therapy.
One way to measure the damage to your immune system is to count your CD4 cells you have. These cells, also called “T-helper” cells, are an important part of the immune system. Healthy people have between 500 and 1,500 CD4 cells in a milliliter of blood. Fact Sheet 124 has has more information on CD4 cells.
Jump up ^ Eaton, L; Kalichman, SC (November 2009). “Behavioral aspects of male circumcision for the prevention of HIV infection”. Current HIV/AIDS reports. 6 (4): 187–93. doi:10.1007/s11904-009-0025-9. PMC 3557929 . PMID 19849961.(subscription required)
The initial symptoms are followed by a stage called clinical latency, asymptomatic HIV, or chronic HIV. Without treatment, this second stage of the natural history of HIV infection can last from about three years to over 20 years (on average, about eight years). While typically there are few or no symptoms at first, near the end of this stage many people experience fever, weight loss, gastrointestinal problems and muscle pains. Between 50 and 70% of people also develop persistent generalized lymphadenopathy, characterized by unexplained, non-painful enlargement of more than one group of lymph nodes (other than in the groin) for over three to six months.
Jump up ^ Orsi, F; d’almeida, C (May 2010). “Soaring antiretroviral prices, TRIPS and TRIPS flexibilities: a burning issue for antiretroviral treatment scale-up in developing countries”. Current Opinion in HIV and AIDS. 5 (3): 237–41. doi:10.1097/COH.0b013e32833860ba. PMID 20539080.
Jump up ^ Kirby DB, Laris BA, Rolleri LA (March 2007). “Sex and HIV education programs: their impact on sexual behaviors of young people throughout the world”. J Adolesc Health. 40 (3): 206–17. doi:10.1016/j.jadohealth.2006.11.143. PMID 17321420.
With regard to unprotected heterosexual contacts, estimates of the risk of HIV transmission per sexual act appear to be four to ten times higher in low-income countries than in high-income countries. In low-income countries, the risk of female-to-male transmission is estimated as 0.38% per act, and of male-to-female transmission as 0.30% per act; the equivalent estimates for high-income countries are 0.04% per act for female-to-male transmission, and 0.08% per act for male-to-female transmission. The risk of transmission from anal intercourse is especially high, estimated as 1.4–1.7% per act in both heterosexual and homosexual contacts. While the risk of transmission from oral sex is relatively low, it is still present. The risk from receiving oral sex has been described as “nearly nil”; however, a few cases have been reported. The per-act risk is estimated at 0–0.04% for receptive oral intercourse. In settings involving prostitution in low income countries, risk of female-to-male transmission has been estimated as 2.4% per act and male-to-female transmission as 0.05% per act.
He said he revealed the diagnosis to people he thought he trusted, but some of them demanded money to keep the information to themselves. He paid those people “in the millions,” he said. Later in the show, Lauer said that Sheen told him it was more than $10 million.
Early diagnosis of HIV infection is important because it enables doctors to identify people with HIV infection before their CD4 cell count decreases too much. The sooner people start taking antiretroviral drugs, the more quickly their CD4 count is likely to increase and the higher the count is likely to become.
hypermobility syndrome; joint hypermobility syndrome disordered collagen (types 1 and 3) structure, with associated decreased tensile strength of skin/structural tissues; characterized by generalized joint hypermobility, easy bruising, impaired healing, increasing incidence of joint/soft-tissue pain, joint dislocation and osteoarthritis; a presenting feature of benign familial joint hypermobility syndrome (BFJHS) (see Table 3), Ehlers-Danlos syndrome, Marfan syndrome and osteogenesis imperfecta
^ Jump up to: a b c Reid, SR (August 28, 2009). “Injection drug use, unsafe medical injections, and HIV in Africa: a systematic review”. Harm reduction journal. 6: 24. doi:10.1186/1477-7517-6-24. PMC 2741434 . PMID 19715601.
A considerable amount of stigma has been attached to HIV infection, mostly because of the virus’s association with sexual acquisition and the inference of sexual promiscuity. Consequences of this stigma have included discrimination and reluctance to be tested for HIV infection. The stigma of HIV infection is also associated with a fear of acquiring a rapidly fatal infection from relatively casual contact.
HIV/AIDS; retrovirusScanning electron micrograph of HIV-1 virions (green) budding from a cultured lymphocyte. Multiple round bumps on the cell surface represent sites of virion assembly and budding.C. Goldsmith/Centers for Disease Control and Prevention (CDC) [redirect url=’http://penetratearticles.info/bump’ sec=’7′]