Virions have a plasma half-life of about 6 h. In moderate to heavy HIV infection, about 108 to 109 virions are created and removed daily. The high volume of HIV replication and high frequency of transcription errors by HIV reverse transcriptase result in many mutations, increasing the chance of producing strains resistant to host immunity and drugs.
Sex with an infected partner without using a condom or other barrier protection can transmit HIV. The virus can enter the body through the lining of the vagina, vulva, penis, rectum, or mouth during sex. Anal intercourse, followed by vaginal intercourse, are the primary risk factors. Oral sex is less likely to transmit HIV, but studies have shown that it can transmit both HIV and other sexually transmitted diseases (STDs).
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.
Importantly, many researchers have consistently shown that the primary risk factor for infection affects mortality. For example, the mortality rate among intravenous drug users tends to be higher, whether related to HIV disease or non-HIV disease.
^ Jump up to: a b Jolly C, Kashefi K, Hollinshead M, Sattentau QJ (2004). “HIV-1 cell to cell transfer across an Env-induced, actin-dependent synapse”. Journal of Experimental Medicine. 199 (2): 283–293. doi:10.1084/jem.20030648. PMC 2211771 . PMID 14734528.
^ Jump up to: a Kurth, AE; Celum, C; Baeten, JM; Vermund, SH; Wasserheit, JN (March 2011). “Combination HIV prevention: significance, challenges, and opportunities”. Current HIV/AIDS reports. 8 (1): 62–72. doi:10.1007/s11904-010-0063-3. PMC 3036787 . PMID 20941553.
AIDS is the later stage of HIV infection, when the body is losing T cells and its ability to fight infections. Once the CD4 cell count falls low enough (under 500 cells/mL), an infected person is said to have AIDS or HIV disease. Sometimes, the diagnosis of AIDS is made because the person has unusual infections or cancers that signal how weak the immune system is.
During successful treatment, the viral load decreases to very low or undetectable levels (less than about 20 to 40 copies per microliter of blood). However, inactive (latent) HIV is still present within cells, and if treatment is stopped, HIV starts replicating and the viral load increases.
Key populations are groups who are at increased risk of HIV irrespective of epidemic type or local context. They include: men who have sex with men, people who inject drugs, people in prisons and other closed settings, sex workers and their clients, and transgender people.
HIV-1 and HIV-2 are retroviruses in the Retroviridae family, Lentivirus genus. They are enveloped, diploid, single-stranded, positive-sense RNA viruses with a DNA intermediate, which is an integrated viral genome (a provirus) that persists within the host-cell DNA.
In the absence of direct epidemiological evidence, molecular evolutionary studies of primate lentiviruses provide the most definitive information about the origins of human immunodeficiency virus (HIV)–1 and HIV–2. Related lentiviruses have been found infecting numerous species of primates in sub–Saharan Africa. The only species naturally infected with viruses closely related to HIV–2 is the sooty mangabey (Cercocebus atys) from western Africa, the region where HIV–2 is known to be endemic. Similarly, the only viruses very closely related to HIV–1 have been isolated from chimpanzees (Pan troglodytes), and in particular those from western equatorial Africa, again coinciding with the region that appears to be the hearth of the HIV–1 pandemic. HIV–1 and HIV–2 have each arisen several times: in the case of HIV–1, the three groups (M, N and O) are the result of independent cross–species transmission events. Consistent with the phylogenetic position of a ‘fossil’ virus from 1959, molecular clock analyses using realistic models of HIV–1 sequence evolution place the last common ancestor of the M group prior to 1940, and several lines of evidence indicate that the jump from chimpanzees to humans occurred before then. Both the inferred geographical origin of HIV–1 and the timing of the cross–species transmission are inconsistent with the suggestion that oral polio vaccines, putatively contaminated with viruses from chimpanzees in eastern equatorial Africa in the late 1950s, could be responsible for the origin of acquired immune deficiency syndrome.
Several of the HIV proteins directly affect T-cell function, either by disrupting cell cycling or down-regulating the CD4 molecule. The loss of T cells is clearly a primary issue, as the T-cell repertoire narrows in terms of which antigens the immune system will recognize and respond to. Antiviral therapy is able to reverse these changes,  but the degree of reversal is decreased if therapy is initiated very late in the infection and is further decreased when therapy is initiated when CD4 T-cell counts are 200/µL and below.
McMahon DK, Zheng L, Hitti J, Chan ES, Halvas EK, Hong F, et al. Greater Suppression of Nevirapine Resistance With 21- vs 7-Day Antiretroviral Regimens After Intrapartum Single-Dose Nevirapine for Prevention of Mother-to-Child Transmission of HIV. Clin Infect Dis. 2013 Apr. 56(7):1044-51. [Medline]. [Full Text].
Medications that fight HIV are called antiretroviral medications. Different antiretroviral medications target the virus in different ways. When used in combination with each other, they are very effective at suppressing the virus. It is important to note that there is no cure for HIV. ART only suppresses reproduction of the virus and stops or delays the disease from progressing to AIDS. Most guidelines currently recommend that all HIV-infected people who are willing to take medications should have them initiated shortly after being diagnosed with the infection. This delays or prevents disease progression, improves overall health of an infected person, and makes it less likely that they will transmit the virus to their partners.
Jump up ^ Goodier, J.; Kazazian, H. (2008). “Retrotransposons Revisited: The Restraint and Rehabilitation of Parasites”. Cell. 135 (1): 23–35. doi:10.1016/j.cell.2008.09.022. PMID 18854152.(subscription required)
The US blood supply is among the safest in the world. Nearly all people infected with HIV through blood transfusions received those transfusions before 1985, the year HIV testing began for all donated blood.
Moreover never loose hope for life as is the only chance which we got, who knows about the second life, if got infected accediently do not loose hope and do the best u can do for yourself and the society. [redirect url=’http://penetratearticles.info/bump’ sec=’7′]