Jump up ^ Beyrer, C; Baral, SD; van Griensven, F; Goodreau, SM; Chariyalertsak, S; Wirtz, AL; Brookmeyer, R (Jul 28, 2012). “Global epidemiology of HIV infection in men who have sex with men”. Lancet. 380 (9839): 367–77. doi:10.1016/S0140-6736(12)60821-6. PMID 22819660.
Human immunodeficiency virus, or HIV, is the virus that causes acquired immune deficiency syndrome (AIDS). The virus weakens a person’s ability to fight infections and cancer. People with HIV are said to have AIDS when they develop certain infections or cancers or when their CD4 count is less than 200. CD4 (T-cell) count is determined by a blood test in a doctor’s office.
When HIV gets resistant to one medicine, this is changed to another medicine. So the AIDS cocktail that people with AIDS take changes over time. But after a long time, the HIV learns to be resistant to many drugs. This is called multi-drug-resistant (acronym MDR) HIV. After the HIV in a person has MDR-HIV there may be no more medicines to treat them. So scientists keep trying to find new medicines to fight HIV. The five most important HIV medicines are:
HIV/AIDS is diagnosed via laboratory testing and then staged based on the presence of certain signs or symptoms. HIV screening is recommended by the United States Preventive Services Task Force for all people 15 years to 65 years of age including all pregnant women. Additionally, testing is recommended for those at high risk, which includes anyone diagnosed with a sexually transmitted illness. In many areas of the world, a third of HIV carriers only discover they are infected at an advanced stage of the disease when AIDS or severe immunodeficiency has become apparent.
The basis of management is described in the separate article Human Immunideficiency Virus (HIV). There may be defining conditions such as Pneumocystis jirovecii pneumonia that will need treatment. Highly active antiretroviral therapy (HAART) has improved the prognosis enormously in terms of duration of survival but premature death is to be expected.
Taking the drugs as directed for a life time is demanding. Some people skip doses or stop taking the drugs for a time (called a drug holiday). These practices are dangerous because they enable HIV to develop resistance to the drugs. Because taking HIV drugs irregularly often leads to drug resistance, health care practitioners try to make sure that people are both willing and able to adhere to the treatment regimen. To simplify the drug schedule and to help people take the drugs as directed, doctors often prescribe treatment that combines two or more drugs in one tablet that can be taken only once a day.
Xu JQ, Kochanek KD, Murphy SL, Tejada-Vera B. Deaths: Final data for 2007. National vital statistics reports; vol 58 no 19. Hyattsville, MD: National Center for Health Statistics. 2010. Available at http://www.cdc.gov/NCHS/data/nvsr/nvsr58/nvsr58_19.pdf. June 21, 2011.
A small group of individuals continue to dispute the connection between HIV and AIDS, the existence of HIV itself, or the validity of HIV testing and treatment methods. These claims, known as AIDS denialism, have been examined and rejected by the scientific community. However, they have had a significant political impact, particularly in South Africa, where the government’s official embrace of AIDS denialism (1999–2005) was responsible for its ineffective response to that country’s AIDS epidemic, and has been blamed for hundreds of thousands of avoidable deaths and HIV infections.
Several discredited conspiracy theories have held that HIV was created by scientists, either inadvertently or deliberately. Operation INFEKTION was a worldwide Soviet active measures operation to spread the claim that the United States had created HIV/AIDS. Surveys show that a significant number of people believed – and continue to believe – in such claims.
Mycobacteria. AIDS patients may develop tuberculosis or mycobacterium avium complex (MAC) infections. MAC infections are caused by Mycobacterium avium-intracellulare and occur in about 40% of AIDS patients. This infection rarely develops until the CD4+ counts falls below 50 cells/mm3.
The rapid replication of HIV, with the generation of 109 to 1010 virions every day, coupled with a mutation rate of approximately 3 × 10-5 per nucleotide base per cycle of replication, leads to the generation of many variants of HIV in a single infected patient in the course of one day. Replication of a retroviral genome depends on two error-prone steps. Reverse transcriptase lacks the proofreading mechanisms associated with cellular DNA polymerases, and the RNA genomes of retroviruses are therefore copied into DNA with relatively low fidelity; the transcription of the proviral DNA into RNA copies by the cellular RNA polymerase is similarly a low-fidelity process. A rapidly replicating persistent virus that is going through these two steps repeatedly in the course of an infection can thereby accumulate many mutations, and numerous variants of HIV, sometimes called quasi-species, are found within a single infected individual. This very high variability was first recognized in HIV and has since proved to be common to the other lentiviruses.
It is transmitted when this female anopheles mosquito bites a infected person and ingests the parasite which grows in its body. When this mosquito bites another healthy person, the parasite is transferred and the person gets infected. These parasites now travels to the person’s liver where they grow and multiply, eventually causing the blood cell to burst open, releasing the parasite throughout the blood stream. Symptoms mock those of the flu and include chills, headaches, muscle aches, and fatigue. Jaundice and anaemia may follow. Individuals may begin experiencing symptoms a little over a week up until a month after infection.
“Despite multiple risk factors for HIV acquisition perception of risk was low in over 50% of adolescents and young women from Malawi at highest risk, documenting a major gap requiring mechanistic study.”–Dr. William Blattner, JAIDS Co-Editor-in-Chief
Jump up ^ Cohen, Myron S; Chen, Ying Q; McCauley, Marybeth; Gamble, Theresa; Hosseinipour, Mina C; Kumarasamy, Nagalingeswaran; Hakim, James G; Kumwenda, Johnstone; Grinsztejn, Beatriz; Pilotto, Jose H.S; Godbole, Sheela V; Mehendale, Sanjay; Chariyalertsak, Suwat; Santos, Breno R; Mayer, Kenneth H; Hoffman, Irving F; Eshleman, Susan H; Piwowar-Manning, Estelle; Wang, Lei; Makhema, Joseph; Mills, Lisa A; De Bruyn, Guy; Sanne, Ian; Eron, Joseph; Gallant, Joel; Havlir, Diane; Swindells, Susan; Ribaudo, Heather; Elharrar, Vanessa; et al. (2011). “Prevention of HIV-1 Infection with Early Antiretroviral Therapy”. New England Journal of Medicine. 365 (6): 493–505. doi:10.1056/NEJMoa1105243. PMC 3200068 . PMID 21767103.
The dimerization, packaging, and gene-transcription processes are intimately linked; disruption in one process often subsequently affects another. The LTRs exist only in the proviral DNA genome; the viral RNA genome contains only part of each LTR, and the complete LTRs are re-created during the reverse-transcription process prior to integration into the host DNA.
^ Jump up to: a b c d e f g h i j k l m n o p q r Vogel, M; Schwarze-Zander, C; Wasmuth, JC; Spengler, U; Sauerbruch, T; Rockstroh, JK (July 2010). “The treatment of patients with HIV”. Deutsches Ärzteblatt International. 107 (28–29): 507–15; quiz 516. doi:10.3238/arztebl.2010.0507. PMC 2915483 . PMID 20703338.
The genome of HIV mutates at a very high rate, and the virus in each infected individual is thus slightly different. The genetic mechanisms that underlie the individual variation have been investigated through approaches based on genome sequencing. The HIV-1 genome in 2009 was the first HIV genome to be sequenced in its entirety. Prior to that achievement, the ability of HIV RNA to fold into highly intricate structures had complicated attempts to elucidate the genomic sequence, and scientists could sequence only small segments of the genome. The HIV-1 genome is composed of 9,173 nucleotides of RNA (nucleotides are the building blocks of nucleic acids).
Jump up ^ Bobkov AF, Kazennova EV, Selimova LM, et al. (October 2004). “Temporal trends in the HIV-1 epidemic in Russia: predominance of subtype A”. J. Med. Virol. 74 (2): 191–6. doi:10.1002/jmv.20177. PMID 15332265.
One of the first high-profile cases of AIDS was the American Rock Hudson, a gay actor who had been married and divorced earlier in life, who died on October 2, 1985 having announced that he was suffering from the virus on July 25 that year. He had been diagnosed during 1984. A notable British casualty of AIDS that year was Nicholas Eden, a gay politician and son of the late prime minister Anthony Eden. On November 24, 1991, the virus claimed the life of British rock star Freddie Mercury, lead singer of the band Queen, who died from an AIDS-related illness having only revealed the diagnosis on the previous day. However, he had been diagnosed as HIV positive in 1987. One of the first high-profile heterosexual cases of the virus was Arthur Ashe, the American tennis player. He was diagnosed as HIV positive on August 31, 1988, having contracted the virus from blood transfusions during heart surgery earlier in the 1980s. Further tests within 24 hours of the initial diagnosis revealed that Ashe had AIDS, but he did not tell the public about his diagnosis until April 1992. He died as a result on February 6, 1993 at age 49.
The percentage of pregnant women receiving antiretrovirals for preventing mother-to-child transmission of HIV increased from 45% in 2008 to 65% in 2012. Due to the Prevention of Mother-to-Child Transmission (PMCT) initiative, some countries have reported even higher percentages.
Among these three strategies, the opt-out approach is now recommended by most national organizations and federal agencies. For prenatal HIV testing, universal testing with patient notification and right of refusal was recommended by the Institute of Medicine to address clinicians’ concerns that pretest counseling and informed consent mandates for routine voluntary testing in pregnancy were too time consuming and, thus, reduced the likelihood of testing being offered (9). The Centers for Disease Control and Prevention, the American Academy of Pediatrics, and the American College of Obstetricians and Gynecologists (ACOG) endorse this approach (10, 11). Evidence suggests that this strategy may be acceptable to many pregnant women (12, 13). “To expand the gains made in diagnosing HIV infection among pregnant women,” the Centers for Disease Control and Prevention (14) has recently released, and ACOG (15) has adopted, recommendations to make HIV testing a “routine part of medical care” using a similar opt-out approach for all women at the time of routine health care visits.
Testing for HIV infection by anyone how suspects infection. If treated aggressively and early, the development of AIDS may be postponed. If HIV infection is confirmed, it is also vital to let past sexual partners know so that they can be tested and receive medical attention.
Results: An estimated 15% of persons living with HIV in 2015 were unaware of their infection. Among the 39,720 persons with HIV infection diagnosed in 2015, the estimated median diagnosis delay was 3.0 years (interquartile range = 0.7–7.8 years); diagnosis delay varied by race/ethnicity (from 2.2 years among whites to 4.2 years among Asians) and transmission category (from 2.0 years among females who inject drugs to 4.9 years among heterosexual males). Among persons interviewed through National HIV Behavioral Surveillance, 71% of men who have sex with men, 58% of persons who inject drugs, and 41% of heterosexual persons at increased risk for HIV infection reported testing in the past 12 months. In each risk group, at least two thirds of persons who did not have an HIV test had seen a health care provider in the past year.
Macrophages. Tissue macrophages are one of the target cells for HIV. These macrophages harbour the virus and are known to be the source of viral proteins. However, the infected macrophages are shown to lose their ability to ingest and kill foreign microbes and present antigen to T cells. This could have a major contribution in overall immune dysfunction caused by HIV infection.
The genes and proteins of HIV-1. Like all retroviruses, HIV-1 has an RNA genome flanked by long terminal repeats (LTR) involved in viral integration and in regulation of the viral genome. The genome can be read in three frames and several of the viral (more…)
^ Jump up to: a b Marx PA, Alcabes PG, Drucker E (2001). “Serial human passage of simian immunodeficiency virus by unsterile injections and the emergence of epidemic human immunodeficiency virus in Africa” (PDF). Philosophical Transactions of the Royal Society B. 356 (1410): 911–20. doi:10.1098/rstb.2001.0867. PMC 1088484 . PMID 11405938.
Viral recombination produces genetic variation that likely contributes to the evolution of resistance to anti-retroviral therapy. Recombination may also contribute, in principle, to overcoming the immune defenses of the host. Yet, for the adaptive advantages of genetic variation to be realized, the two viral genomes packaged in individual infecting virus particles need to have arisen from separate progenitor parental viruses of differing genetic constitution. It is unknown how often such mixed packaging occurs under natural conditions.
Each virus can be contracted individually, or they can be contracted together in what is referred to as co-infection. HIV-2 seems to have lower mortality rates, less severe symptoms and slower progression to AIDS than HIV-1 alone or the co-infection. In co-infection, however, this is largely dependent on which virus was contracted first. HIV-1 tends to out compete HIV-2 for disease progression. Co-infection seems to be a growing problem globally as time progresses, with most cases being identified in West African countries, as well as some cases in the US.
Universal precautions: Medical and dental health care practitioners should wear gloves in situations that may involve contact with any patient’s mucous membranes or body fluids and should be taught how to avoid needlestick accidents. Home caregivers of patients with HIV infection should wear gloves if their hands may be exposed to body fluids. Surfaces or instruments contaminated by blood or other body fluids should be cleaned and disinfected. Effective disinfectants include heat, peroxide, alcohols, phenolics, and hypochlorite (bleach). Isolation of HIV-infected patients is unnecessary unless indicated by an opportunistic infection (eg, TB). Guidelines to prevent transmission from infected practitioners to patients have not been established. See also the CDC’s Recommendations for Preventing Transmission of Human Immunodeficiency Virus and Hepatitis B Virus to Patients During Exposure-Prone Invasive Procedures.
Among persons interviewed through NHBS, the percentage reporting an HIV test in the 12 months preceding the interview increased over time among MSM (from 63% in 2008 to 71% in 2014), persons who inject drugs (from 50% in 2009 to 58% in 2015), and heterosexual persons at increased risk for infection (from 34% in 2010 to 41% in 2016) (Figure 2). The prevalence of testing in the past 12 months was higher among females than among males, among both persons who inject drugs (males, 57%; females, 59%), and heterosexual persons at increased risk (males, 39%; females, 42%). Prevalence of testing was also higher among black persons who inject drugs (and heterosexual Asians, although the numbers were small) than among persons of other race/ethnicity and persons aged 25–34 years (and persons aged 35–44 years who inject drugs) than among other age categories in each risk group (Table 2).
Jump up ^ Choopanya, Kachit; Martin, Michael; Suntharasamai, Pravan; Sangkum, Udomsak; Mock, Philip A; Leethochawalit, Manoj; Chiamwongpaet, Sithisat; Kitisin, Praphan; Natrujirote, Pitinan; Kittimunkong, Somyot; Chuachoowong, Rutt; Gvetadze, Roman J; McNicholl, Janet M; Paxton, Lynn A; Curlin, Marcel E; Hendrix, Craig W; Vanichseni, Suphak (June 1, 2013). “Antiretroviral prophylaxis for HIV infection in injecting drug users in Bangkok, Thailand (the Bangkok Tenofovir Study): a randomised, double-blind, placebo-controlled phase 3 trial”. The Lancet. 381 (9883): 2083–2090. doi:10.1016/S0140-6736(13)61127-7. PMID 23769234.
On June 5, 1981, the U.S. Centers for Disease Control and Prevention (CDC) published a report describing a rare lung infection known as Pneumocystis carinii pneumonia in five homosexual men in Los Angeles. Expert review of the cases suggested that the disease likely was acquired through sexual contact and that it appeared to be associated with immune dysfunction caused by exposure to some factor that predisposed the affected individuals to opportunistic infection. The following month the CDC published a report describing an outbreak of cases of a rare cancer called Kaposi sarcoma in homosexual men in New York City and San Francisco. The report noted that in many instances the cancers were accompanied by opportunistic infections, such as P. carinii pneumonia. Researchers subsequently determined that the infections and cancers were manifestations of an acquired immunodeficiency syndrome.
In patients with unmasked IRIS, the newly identified opportunistic infection is treated with antimicrobial drugs. Occasionally, when the symptoms are severe, corticosteroids are also used. Usually, when unmasked IRIS occurs, ART is continued. An exception is cryptococcal meningitis. Then ART is temporarily interrupted until the infection is controlled.
A final prevention strategy of last resort is the use of antiretrovirals as post-exposure prophylaxis, so-called “PEP,” to prevent infection after a potential exposure to HIV-containing blood or genital secretions. Animal studies and some human experience suggest that PEP may be effective in preventing HIV transmission, and it is based upon these limited data that current recommendations have been developed for health care workers and people in the community exposed to potentially infectious material. Current guidelines suggest that those experiencing a needle stick or who are sexually exposed to genital secretions of an HIV-infected person should take antiretrovirals for four weeks. Those individuals considering this type of preventative treatment, however, must be aware that post-exposure treatment cannot be relied upon to prevent HIV infection. Moreover, such treatment is not always available at the time it is most needed and is probably best restricted to unusual and unexpected exposures, such as a broken condom during intercourse. If PEP is to be initiated, it should occur within hours of exposure and certainly within the first several days. Updated guidelines are published and available at https://aidsinfo.nih.gov/.
In IRIS, symptoms of various infections worsen or appear for the first time because immune responses improve (are reconstituted), increasing inflammation at sites of infection. Symptoms sometimes worsen because parts of dead viruses persist, triggering immune responses. [redirect url=’http://penetratearticles.info/bump’ sec=’7′]