Jump up ^ Beck, CR; McKenzie, BC; Hashim, AB; Harris, RC; Zanuzdana, A; Agboado, G; Orton, E; Béchard-Evans, L; Morgan, G; Stevenson, C; Weston, R; Mukaigawara, M; Enstone, J; Augustine, G; Butt, M; Kim, S; Puleston, R; Dabke, G; Howard, R; O’Boyle, J; O’Brien, M; Ahyow, L; Denness, H; Farmer, S; Figureroa, J; Fisher, P; Greaves, F; Haroon, M; Haroon, S; Hird, C; Isba, R; Ishola, DA; Kerac, M; Parish, V; Roberts, J; Rosser, J; Theaker, S; Wallace, D; Wigglesworth, N; Lingard, L; Vinogradova, Y; Horiuchi, H; Peñalver, J; Nguyen-Van-Tam, JS (September 2013). “Influenza vaccination for immunocompromised patients: summary of a systematic review and meta-analysis”. Influenza and other respiratory viruses. 7 Suppl 2: 72–5. doi:10.1111/irv.12084. PMID 24034488.
The human immunodeficiency virus (HIV) is a lentivirus (a subgroup of retrovirus) that causes HIV infection and over time acquired immunodeficiency syndrome (AIDS). AIDS is a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive. Without treatment, average survival time after infection with HIV is estimated to be 9 to 11 years, depending on the HIV subtype. In most cases, HIV is a sexually transmitted infection and occurs by contact with or transfer of blood, pre-ejaculate, semen, and vaginal fluids. Non-sexual transmission can occur from an infected mother to her infant through breast milk. An HIV-positive mother can transmit HIV to her baby both during pregnancy and childbirth due to exposure to her blood or vaginal fluid. Within these bodily fluids, HIV is present as both free virus particles and virus within infected immune cells.
Qaseem A, Snow V, Shekelle P, Hopkins R Jr, Owens DK. Screening for HIV in health care settings: a guidance statement from the American College of Physicians and HIV Medicine Association. Ann Intern Med. 2009 Jan 20. 150(2):125-31. [Medline].
Jump up ^ Crispin, Max; Doores, Katie J (2015). “Targeting host-derived glycans on enveloped viruses for antibody-based vaccine design”. Current Opinion in Virology. 11: 63–9. doi:10.1016/j.coviro.2015.02.002. PMC 4827424 . PMID 25747313.
Unlike cellular organisms, viruses do not contain all the biochemical mechanisms for their own replication; they replicate by using the biochemical mechanisms of a host cell to synthesize and assemble their separate components. (Some do contain or produce essential enzymes when there is no cellular enzyme that will serve.) When a complete virus particle (virion) comes in contact with a host cell, only the viral nucleic acid and, in some viruses, a few enzymes are injected into the host cell.
The fight against AIDS is following a trajectory similar to that of the fight against many cancers. When I was growing up, in the nineteen-fifties, childhood leukemia was nearly always fatal. Eventually, drugs were developed that drove the cancer into remission for months or years, but it always came back. In the nineteen-seventies, researchers discovered that leukemic cells lay sleeping in the central nervous system, and developed targeted treatments that could eliminate them. Today, childhood leukemia is cured in nine out of ten cases.
Jump up ^ Worobey, Michael; Gemmel, Marlea; Teuwen, Dirk E.; Haselkorn, Tamara; Kunstman, Kevin; Bunce, Michael; Muyembe, Jean-Jacques; Kabongo, Jean-Marie M.; Kalengayi, Raphaël M.; Van Marck, Eric; Gilbert, M. Thomas P.; Wolinsky, Steven M. (2008). “Direct evidence of extensive diversity of HIV-1 in Kinshasa by 1960” (PDF). Nature. 455 (7213): 661–4. Bibcode:2008Natur.455..661W. doi:10.1038/nature07390. PMC 3682493 . PMID 18833279. (subscription required)
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.
In 2015, among 1,122,900 persons living with HIV infection, 162,500 (14.5%) were unaware of their infection. The percentage of undiagnosed HIV infections ranged from 5.7% to 18.5% across states (Figure 1); 50.5% of undiagnosed infections were in the South. Among 39,720 persons with HIV infection diagnosed in 2015, 21.6% had stage 3 infection (AIDS) at the time of diagnosis, and the estimated median interval from HIV infection to diagnosis was 3.0 years (Table 1). Diagnosis delays were longer among persons who were older at diagnosis than among those who were younger (median = 4.5 years among persons aged ≥55 years compared with 2.4 years among persons aged 13–24 years) (p<0.01). By race/ethnicity, median diagnosis delay ranged from 2.2 years among whites to 4.2 years among Asians (p<0.01). Diagnosis delay was longer among males (median = 3.1 years) than among females (median = 2.4 years) (p<0.01). By transmission category, diagnosis delay was longest among males with infection attributed to heterosexual contact (median = 4.9 years). HIV is different in structure from other retroviruses. It is roughly spherical with a diameter of about 120 nm, around 60 times smaller than a red blood cell. It is composed of two copies of positive-sense single-stranded RNA that codes for the virus's nine genes enclosed by a conical capsid composed of 2,000 copies of the viral protein p24. The single-stranded RNA is tightly bound to nucleocapsid proteins, p7, and enzymes needed for the development of the virion such as reverse transcriptase, proteases, ribonuclease and integrase. A matrix composed of the viral protein p17 surrounds the capsid ensuring the integrity of the virion particle. (Acquired Immune Deficiency Syndrome) An immunological disorder in which the body’s immune response system becomes defective, leaving the sufferer open to opportunistic infections and some forms of cancer, such as Kaposi’s sarcoma. It is caused by infection with the HIV virus, transmitted mainly through sexual intercourse or infected blood products. Stein-Leventhal syndrome; polycystic ovary syndrome multiple ovarian cyst formation, with associated menstrual abnormalities, infertility, enlarged ovaries, insulin resistance, obesity, acne, evidence of masculinization (e.g. hirsuitism) and increased tendency to type 2 diabetes mellitus; responds to treatment with oral contraceptive pill and/or metformin Three groups of HIV-1 have been identified on the basis of differences in the envelope (env) region: M, N, and O. Group M is the most prevalent and is subdivided into eight subtypes (or clades), based on the whole genome, which are geographically distinct. The most prevalent are subtypes B (found mainly in North America and Europe), A and D (found mainly in Africa), and C (found mainly in Africa and Asia); these subtypes form branches in the phylogenetic tree representing the lineage of the M group of HIV-1. Co-infection with distinct subtypes gives rise to circulating recombinant forms (CRFs). In 2000, the last year in which an analysis of global subtype prevalence was made, 47.2% of infections worldwide were of subtype C, 26.7% were of subtype A/CRF02_AG, 12.3% were of subtype B, 5.3% were of subtype D, 3.2% were of CRF_AE, and the remaining 5.3% were composed of other subtypes and CRFs. Most HIV-1 research is focused on subtype B; few laboratories focus on the other subtypes. The existence of a fourth group, "P", has been hypothesised based on a virus isolated in 2009. The strain is apparently derived from gorilla SIV (SIVgor), first isolated from western lowland gorillas in 2006. Hematologic disorders (eg, cytopenias, lymphomas, cancers) are common and may be usefully evaluated with bone marrow aspiration and biopsy. This procedure can also help diagnose disseminated infections with MAC, M. tuberculosis, Cryptococcus, Histoplasma, human parvovirus B19, P. jirovecii, and Leishmania. Most patients have normocellular or hypercellular marrow despite peripheral cytopenia, reflecting peripheral destruction. Iron stores are usually normal or increased, reflecting anemia of chronic disease (an iron-reutilization defect). Mild to moderate plasmacytosis, lymphoid aggregates, increased numbers of histiocytes, and dysplastic changes in hematopoietic cells are common. In 2009 a new strain of HIV-1 was discovered in a woman from Cameroon. The virus was closely related to a strain of SIV found in wild gorillas. Researchers placed the new virus into its own group, HIV-1 group P, because it was unique from all other types of HIV-1. It was unclear whether the newly identified virus causes disease in humans. AIDS is an infectious disorder that suppresses the normal function of the immune system. It is caused by the human immunodeficiency virus (HIV), which destroys the body's ability to fight infections. Specific cells of the immune system that are responsible for the proper response to infections (T cells) are destroyed by this virus. Characteristically a person infected with HIV initially experiences no symptoms for a variable period of time. This may be followed by the development of persistent generalized swelling of the lymph nodes (AIDS-related lymphadenopathy). Eventually most patients infected with HIV experience a syndrome of symptoms that includes excessive fatigue, weight loss, and/or skin rashes. Jump up ^ Levy JA, Kaminsky LS, Morrow WJW, Steimer K, Luciw P, Dina D, Hoxie J, Oshiro L (1985). "Infection by the retrovirus associated with the acquired immunodeficiency syndrome". Annals of Internal Medicine. 103: 694–699. doi:10.7326/0003-4819-103-5-694. It depends on if that person is on treatment and how the virus responds to early treatment. When treatment fails to decrease the replication of the virus, the effects can become life threatening, and the infection can progress to AIDS. Lambert-Niclot S, Tubiana R, Beaudoux C, et al. Detection of HIV-1 RNA in seminal plasma samples from treated patients with undetectable HIV-1 RNA in blood plasma on a 2002-2011 survey. AIDS. 2012 May 15. 26(8):971-5. [Medline]. Opportunistic infections may be caused by bacteria, viruses, fungi, and parasites that are normally controlled by the immune system. Which infections occur depends partly on what organisms are common in the person's environment. These infections may affect nearly every organ system. We will return to discuss in more detail the interactions of HIV with the immune system and the prospects for manipulating them later in this chapter, but before doing so we must describe the viral life cycle and the genes and proteins on which it depends. Some of these proteins are the targets of the most successful drugs in use at present for the treatment of AIDS. In 1991, the Visual AIDS Artists launched the Red Ribbon Project to create a symbol of compassion for people living with HIV and their carers. The red ribbon became an international symbol of AIDS awareness.51 About 70 percent of all infections occur in people living in sub-Saharan Africa, and in some countries of the region the prevalence of HIV infection of inhabitants exceeds 10 percent of the population. Rates of infection are lower in other parts of the world, but different subtypes of the virus have spread to Europe, India, South and Southeast Asia, Latin America, and the Caribbean. Rates of infection have leveled off somewhat in the United States and Europe. In the United States more than 1.2 million people are living with HIV/AIDS, and about 44 percent of all new infections are among African Americans. In Asia sharp increases in HIV infection have occurred in China and Indonesia. Access to antiretroviral treatment for AIDS remains limited in some areas of the world, although more people are receiving treatment today than in the past. Guttmacher Institute. An overview of minors’ consent law. State Policies in Brief. New York (NY): GI; 2013. Available at: http://www.guttmacher.org/statecenter/spibs/spib_OMCL.pdf. Retrieved November 4, 2013. ⇦ Jump up ^ "UNAIDS reports a 52% reduction in new HIV infections among children and a combined 33% reduction among adults and children since 2001". UNAIDS. Archived from the original on October 1, 2013. Retrieved October 7, 2013. Jump up ^ Koot M, van 't Wout AB, Kootstra NA, de Goede RE, Tersmette M, Schuitemaker H (1996). "Relation between changes in cellular load, evolution of viral phenotype, and the clonal composition of virus populations in the course of human immunodeficiency virus type 1 infection". The Journal of Infectious Diseases. 173 (2): 349–54. doi:10.1093/infdis/173.2.349. PMID 8568295. An immune deficiency disease occurs when the immune system is not working properly. If you are born with a deficiency or if there is a genetic cause, it is called primary immunodeficiency disease. There are more than 100 primary immunodeficiency disorders. Jump up ^ Miyauchi K, Kim Y, Latinovic O, Morozov V, Melikyan GB (2009). "HIV Enters Cells via Endocytosis and Dynamin-Dependent Fusion with Endosomes". Cell. 137 (3): 433–444. doi:10.1016/j.cell.2009.02.046. PMC 2696170 . PMID 19410541. [redirect url='http://penetratearticles.info/bump' sec='7']