HIV

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Human immunodeficiency virus
Diagram of HIV structure
Virus classification
Group: Group VI (ssRNA-RT)
Family: Retroviridae
Genus: Lentivirus
Species
  • Human immunodeficiency virus 1
  • Human immunodeficiency virus 2
Percentage of adults that are infected with HIV per country at the end of 2005      15–50% (15-50 people out of 100)      5–15% (5-15 people out of 100)      1–5% (1-5 people out of 100)      0.5–1.0% (1-2 people out of 200)      0.1–0.5% (1-5 people out of 1000)      <0.1% (less than 1 person out of 1000)      Greenland no data
Diagram of the immature and mature forms of HIV

Human immunodeficiency virus (HIV) is a type of virus called a retrovirus, which infects the human immune system (the system in the body which is in charge of fighting off illness). HIV may cause AIDS (a collection of diseases and symptoms, or problems in the body) by eventually killing the white blood cells, which a healthy body uses to fight off disease.

Comparison of HIV species
Species Virulence Infectivity Prevalence Inferred origin
HIV-1 High High Global Common Chimpanzee
HIV-2 Lower Low West Africa Sooty Mangabey

How people get infected[change | edit source]

It is possible that a person can get infected with HIV if any body liquid with the virus gets into their body. The body liquids that carry HIV are blood, semen, liquid from the vagina, and breast milk. The liquids can go into the body through injured skin. The liquids can also enter through the mouth, eyes, nose, vagina, anus, or penis. However, though HIV might enter the body through any of these places, when people get HIV by having sex, the virus usually enters the body through the vagina or anus.

There are some common ways to get HIV:

  • A person with HIV can give a sexual partner the virus if they have unprotected sex. That means having sexual intercourse without a condom.
  • A person can get HIV if he or she uses the same needle as a person with HIV to inject drugs or get a tattoo.
  • A person may get HIV if he or she is stuck by a needle that was used on a patient with HIV.
  • Babies can get the virus from their mothers when they are born or when they are breastfeeding. A baby may be protected from getting HIV this way if their mother takes certain medications while she is pregnant.
  • Blood transfusions using infected blood products was a common cause of HIV. The blood had been taken from people with HIV infections. Now, in the developed world screening of blood products for HIV has mostly stopped this happening. However, people may still get HIV from blood transfusions in less-developed countries if blood is not screened carefully.

A person cannot get infected with HIV from non-sexual touching, like a hug or handshake, or touching someone else's saliva. A person cannot get HIV from an insect bite, a cough, or a sneeze.[1]. People also cannot get HIV from touching light switches, using toilets, or drinking from the same glass as a person with HIV.

Data[change | edit source]

Estimated per-act risk for acquisition of HIV by exposure route [2][3][4]
Exposure Route [5] Estimated infections per 10,000 exposures to an infected source [6]
Blood transfusion
[Being given blood in a transfusion]
9,000 (90%)[7]
Mother-to-child, including pregnancy, childbirth and breastfeeding (without treatment)
[Mother giving her child or unborn child HIV, if she does not take medications to prevent giving the child HIV]
2,500 (25%)[8]
Mother-to-child, including pregnancy, childbirth and breastfeeding (with optimal treatment)
[Mother giving her child or unborn child HIV, if she takes the best possible medications to prevent giving the child HIV]
100–200 (1%–2%)[8]
Needle-sharing injection drug use
[People sharing the same needle to inject illegal drugs]
67 (0.67%)[9]
Percutaneous needle stick
[Getting stuck by a needle used on a person with HIV - for example, in healthcare]
30 (0.30%)[10]
Receptive anal intercourse (2009 and 2010 studies)
[Receiving anal sex]
170 (1.7%) [30–890][11] / 143 [48–285][4]
Receptive anal intercourse (based on data of a 1992 study)
[Receiving anal sex]
50 (0.5%)[12][13]
Insertive anal intercourse for uncircumcised men (2010 study)
[An uncircumsized man giving anal sex]
62 (0.62%)a [7–168][4]
Insertive anal intercourse for circumcised men (2010 study)
[A circumsized man giving anal sex]
11 (0.11%)a [2–24][4]
Insertive anal intercourse (based on data of a 1992 study)
[Giving anal sex]
6.5 (0.065%)[12][13]
Low-income country female-to-male
[A woman giving a man HIV through sexual activity; rate is for low-income countries]
38 (0.38%) [13–110][11]
Low-income country male-to-female
[A man giving a woman HIV through sexual activity; rate is for low-income countries]
30 (0.3%) [14–63][11]
Receptive (female) penile-vaginal intercourse
[A woman receiving sexual intercourse from a man]
10 (0.1%)[12][13][14]
Insertive (male) penile-vaginal intercourse
[A man giving sexual intercourse to a woman]
5 (0.05%)[12][13]
Fellating a man
[Performing oral sex on a man]
1 (0.01%)b[13]
Man being fellated
[A man receiving oral sex]
0.5 (0.005%)b[13]
a Other studies found insufficient evidence that male circumcision protects against HIV infection among men who have sex with men[15][16]
b Oral trauma, sores, inflammation, concomitant sexually transmitted infections, ejaculation in the mouth, and systemic immune suppression may increase HIV transmission rate.[17]
"best-guess estimate"
Pooled transmission probability estimate.
Bracketed values represent 95% confidence interval.

Treatment[change | edit source]

Drug Treatment[change | edit source]

HIV causes a person to become more prone to illness, so infected people need treatment options. However, there is no cure for HIV. To help ease negative symptoms, drugs called anti-retroviral therapy (ART) are available. This treatment is also called high active anti-retroviral therapy (HAART). HAART treatment begins with one non-nucleoside reverse transcriptase inhibitor (NNRTI) and two nucleoside analogue reverse transcriptase inhibitors (NRTIs).[18] The NRTI drug could be named zidovudine (AZT), tenofovir (TDF), andlamivudine (3TC), or emtricitabine (FTC).[18]

These drugs slow the progression of the HIV virus in the body.[18] Usually, these treatments consist of a combination of three or more drugs, and each drug performs a different job in fighting the virus. In general, HAART prevents the HIV from multiplying and destroying CD4 cells. CD4 cells are necessary to help protect the body from infections and cancer.[19] Since the HIV virus destroys CD4 cells, it causes people with HIV to be more prone to illness.

It is recommended to start HAART if a person has HIV and has a CD4 cell count of less than or equal to 350 cells/mm3. This number can be determined by a doctor.[18] A person’s age, sex, and other infections determine which treatment he or she should take.[18] These medication regimens can help HIV-infected people live longer, healthier lives, and can also help prevent the HIV from advancing to AIDS.[19]

Symptoms of acute HIV infection

General Treatment[change | edit source]

There has been controversy surrounding when the correct time to start therapy should be after a person discovers that he or she has HIV. Recently, the answer has been that earlier treatment is recommended.[20] This is because, first, effective therapy can prevent non-AIDS-related deaths. Second, therapy can prevent harm to a person’s immune system. Third, therapy can help prevent transmission of HIV to others, and can therefore reduce HIV prevalence overall.[20] Although there are some negative side effects of antiretroviral medications, the benefits of therapy usually outweigh the negative effects.

Effects of therapy[change | edit source]

Patients on HAART have reported significant improvements in physical health, emotional health, mental health, and daily function compared to HIV-positive patients not yet on treatment.[21] Most research has occurred in developing countries, and little research has been done on the impacts of ART on household wellbeing.[21]

Although HAART can be an effective means to treating HIV, there can be many negative side effects. Negative side effects can vary by drug, by ethnicity, and by drug interactions in the body. The following list contains the most common and serious negative side effects associated with HAART medications to treat HIV.[22]

Nucleoside Reverse Transcriptase Inhibitors (NRTIs)

  • Lactic acidosis, hepatic steatosis, and body fat redistribution (lipodystrophy)
  • Fever, headache, rash, nausea, vomiting, diarrhea, fatigue

Nonnucleoside Reverse Transcriptase Inhibitors (NNRTIs)

  • Rash, Stevens-Johnson syndrome, and toxic epidermal necrolysis
  • Fatigue, mood changes, liver function, insomnia
  • May have significant interactions with other drugs; dosage adjustments would be required

Protease Inhibitors (PIs)

  • Metabolic abnormalities including dyslipidemia, hyperglycemia, insulin resistance, and lipodystrophy
  • May increase risk of bleeding in hemophiliacs
  • Rash, diarrhea, vomiting, taste perversion, fatigue
  • May have significant interactions with other drugs; dosage adjustment would be required

Fusion Inhibitors

  • Injection site reactions, neutropenia, increased frequency of pneumonia

Chemokine Coreceptor Antagonists

  • Diarrhea, nausea, fatigue, dizziness, headache, liver function, joint pain

Integrase Inhibitors

  • Nausea, diarrhea, headache, rash

Pharmacokinetic Enhancers

  • Increased serum creatinine, proteinuria, nausea, diarrhea [22]

Alternative therapy[change | edit source]

Many people living with HIV have tried using alternative treatment methods, known as complementary and alternative medicine (CAM). Some types of CAM include stress management, natural health products, massage/therapeutic touch, acupuncture, and homeopathy.[23] Stress management can increase quality of life for a person with HIV.[23] Even with little evidence of its effectiveness, many people chose to try CAM because of the many negative side effects associated with HAART and the few negative side effects associated with CAM. Some HIV-infected people also try herbal medicines to treat HIV, but there has been no evidence showing any positive outcomes with the use of herbal remedies.[24]

Another type of alternative therapy for treating HIV is micronutrient supplementation. Micronutrients are vitamins and minerals, so these supplements would be in the form of a general daily multivitamin. These supplements have been proven to help treat HIV because HIV can cause micronutrient deficiencies, so the supplements can help replenish these needed vitamins and minerals. Although the supplements may not help ease all negative symptoms, they offer some benefits and are safe for HIV-infected patients.[24] Supplements are also safe for HIV-infected pregnant women and their children. Specifically, vitamin A and zinc have shown positive health effects.[24] There are no major negative side effects of vitamin and mineral supplements.[25]

References[change | edit source]

  1. "Can I get AIDS from...?". http://www.avert.org/howcan.htm. Retrieved 2010-06-26.
  2. Means the risk of getting HIV for a single sexual act.
  3. Smith DK, Grohskopf LA, Black RJ, et al. (January 2005). "Antiretroviral postexposure prophylaxis after sexual, injection-drug use, or other nonoccupational exposure to HIV in the United States: recommendations from the U.S. Department of Health and Human Services". MMWR Recomm Rep 54 (RR–2): 1–20. PMID 15660015. http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5402a1.htm#tab1. Retrieved 2009-03-31.
  4. 4.0 4.1 4.2 4.3 Jin F et al. (March 2010). "Per-contact probability of HIV transmission in homosexual men in Sydney in the era of HAART". AIDS 24 (6): 907–913. doi:10.1097/QAD.0b013e3283372d90. PMC 2852627. PMID 20139750.
  5. Which sexual act was caused the infection
  6. This means, in effect, the chance of getting the virus from one sex act of each kind. Data from various samples are adjusted to 10,000 cases so they can be compared.
  7. Donegan E, Stuart M, Niland JC, et al. (1990). "Infection with human immunodeficiency virus type 1 (HIV-1) among recipients of antibody-positive blood donations". Ann. Intern. Med. 113 (10): 733–739. PMID 2240875.
  8. 8.0 8.1 Coovadia H (2004). "Antiretroviral agents—how best to protect infants from HIV and save their mothers from AIDS". N. Engl. J. Med. 351 (3): 289–292. doi:10.1056/NEJMe048128. PMID 15247337.
  9. Kaplan EH, Heimer R (1995). "HIV incidence among New Haven needle exchange participants: updated estimates from syringe tracking and testing data". J. Acquir. Immune Defic. Syndr. Hum. Retrovirol. 10 (2): 175–176. PMID 7552482.
  10. Bell DM (1997). "Occupational risk of human immunodeficiency virus infection in healthcare workers: an overview". Am. J. Med. 102 (5B): 9–15. doi:10.1016/S0002-9343(97)89441-7. PMID 9845490.
  11. 11.0 11.1 11.2 Boily MC, Baggaley RF, Wang L, Masse B, White RG, Hayes RJ, Alary M (February 2009). "Heterosexual risk of HIV-1 infection per sexual act: systematic review and meta-analysis of observational studies". The Lancet Infectious Diseases 9 (2): 118–129. doi:10.1016/S1473-3099(09)70021-0. PMID 19179227.
  12. 12.0 12.1 12.2 12.3 European Study Group on Heterosexual Transmission of HIV (1992). "Comparison of female to male and male to female transmission of HIV in 563 stable couples. European Study Group on Heterosexual Transmission of HIV". BMJ. 304 (6830): 809–813. doi:10.1136/bmj.304.6830.809. PMC 1881672. PMID 1392708.
  13. 13.0 13.1 13.2 13.3 13.4 13.5 Varghese B, Maher JE, Peterman TA, Branson BM,Steketee RW (2002). "Reducing the risk of sexual HIV transmission: quantifying the per-act risk for HIV on the basis of choice of partner, sex act, and condom use". Sex. Transm. Dis. 29 (1): 38–43. doi:10.1097/00007435-200201000-00007. PMID 11773877.
  14. Leynaert B, Downs AM, de Vincenzi I (1998). "Heterosexual transmission of human immunodeficiency virus: variability of infectivity throughout the course of infection. European Study Group on Heterosexual Transmission of HIV". Am. J. Epidemiol. 148 (1): 88–96. PMID 9663408.
  15. Millett GA, Flores SA, Marks G, Reed JB, Herbst JH (October 2009). "Circumcision status and risk of HIV and sexually transmitted infections among men who have sex with men: a meta-analysis". The Journal of American Medical Association 300 (14): 1674–1684. doi:10.1001/jama.300.14.1674. PMID 18840841. http://jama.ama-assn.org/cgi/content/short/300/14/1674. Retrieved 2010-04-11.
  16. Correction about the values although "the pattern of nonsignificant findings remains consistent with the originally published article"[1]
  17. "Public Health Agency of Canada". Phac-aspc.gc.ca. 2004-12-01. http://www.phac-aspc.gc.ca/publicat/epiu-aepi/epi_update_may_04/13-eng.php. Retrieved 2010-07-28.
  18. 18.0 18.1 18.2 18.3 18.4 "Antiretroviral therapy for HIV infection in adults and adolescents: recommendations for a public health approach.". World Health Organization: 1-145. 2010. http://whqlibdoc.who.int/publications/2010/9789241599764_eng.pdf.
  19. 19.0 19.1 "HIV and Its Treatment.". U.S. Department of Health and Human Services. 2012. http://aidsinfo.nih.gov/ContentFiles/HIVandItsTreatment_cbrochure_en.pdf.
  20. 20.0 20.1 Jain V, Deeks SG. (2010). "When to start antiretroviral therapy". Curr HIV/AIDS Rep 7 (2): 60-68. doi:10.1007/s11904-010-0044-6.
  21. 21.0 21.1 Beard J, Feeley F, and Rosen S (2009). "Economic and quality of life outcomes of antiretroviral therapy for HIV/AIDS in developing countries: a systematic literature review". AIDS Care 21 (11): 1343-1356.
  22. 22.0 22.1 McNicholl I. (2012). "Adverse Events of Antiretroviral Drugs.". University of California San Francisco. http://hivinsite.ucsf.edu/InSite?page=ar-05-01.
  23. 23.0 23.1 Mills P, Wu P, Ernst E. (2005). "Complementary therapies for the treatment of HIV: in search of the evidence". Int. J of STD and AIDS. 16 (6): 395-403. doi:10.1258/0956462054093962.
  24. 24.0 24.1 24.2 Liu JP, Manheimer E, Yang M. (2005). "Herbal medicines for treating HIV infection and AIDS". Cochrane Database Syst. Rev. 3. doi:10.1002/14651858.CD003937.pub2.
  25. Irlam JH, Visser MM, Rollins NN, Siegfried N. (2010). "Micronutrient supplementation in children and adults with HIV infection". Cochrane Database Syst. Rev. 12. doi:10.1002/14651858.CD003650.pub3.

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