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HIV Risk, Singapore - Shim Clinic

The risk of being infected by the human immunodeficiency virus (HIV), depends on the type of exposure that occured between partners, and whether a condom was used.

Proper and consistent use of condoms reduces the risk of HIV transmission. Unless there was condom failure like condom break, slip, or no condom was used.

HIV Risk (2014 figures)

Estimated Per-Act Probability of Acquiring HIV from an Infected Source, by Exposure Act*

Type of Exposure Risk per 10,000 Exposures
Parenteral3
Blood Transfusion 9,250
Needle-sharing during injection drug use 63
Percutaneous (needle-stick) 23
Sexual3
Receptive anal intercourse 138
Insertive anal intercourse 11
Receptive penile-vaginal intercourse 8
Insertive penile-vaginal intercourse 4
Receptive oral intercourse low
Insertive oral intercourse low
Other^
Biting negligible4
Spitting negligible
Throwing body fluids (including semen or saliva) negligible
Sharing sex toys negligible

* Factors that may increase the risk of HIV transmission include sexually transmitted diseases, acute and late-stage HIV infection, and high viral load. Factors that may decrease the risk include condom use, male circumcision, antiretroviral treatment, and pre-exposure prophylaxis. None of these factors are accounted for in the estimates presented in the table.

^ HIV transmission through these exposure routes is technically possible but unlikely and not well documented.

References

1 Cohen MS, Chen YQ, McCauley M, et al; HPTN 052 Study Team. Prevention of HIV-1 Infection with early antiretroviral therapy. N Engl J Med 2011;365(6):493-505.

2 Weller SC, Davis-Beaty K. Condom effectiveness in reducing heterosexual HIV transmission (Review). The Cochrane Collaboration. Wiley and Sons, 2011.

3 Patel P, Borkowf CB, Brooks JT. Et al. Estimating per-act HIV transmission risk: a systematic review. AIDS. 2014. doi: 10.1097/QAD.0000000000000298.

4 Pretty LA, Anderson GS, Sweet DJ. Human bites and the risk of human immunodeficiency virus transmission. Am J Forensic Med Pathol 1999;20(3):232-239.

HIV Transmission Risk
http://www.cdc.gov/hiv/policies/law/risk.html

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HIV Risk (2009 figures)

Estimated HIV transmission risk per exposure for specific activities and events

Activity Risk-per-exposure
Vaginal sex, female-to-male, studies in high-income countries 0.04% (1:2380)
Vaginal sex, male-to-female, studies in high-income countries 0.08% (1:1234)
Vaginal sex, female-to-male, studies in low-income countries 0.38% (1:263)
Vaginal sex, male-to-female, studies in low-income countries 0.30% (1:333)
Vaginal sex, source partner is asymptomatic 0.07% (1:1428)
Vaginal sex, source partner has late-stage disease 0.55% (1:180)
Receptive anal sex amongst gay men, partner unknown status 0.27% (1:370)
Receptive anal sex amongst gay men, partner HIV positive 0.82% (1:123)
Receptive anal sex with condom, gay men, partner unknown status 0.18% (1:555)
Insertive anal sex, gay men, partner unknown status 0.06% (1:1666)
Insertive anal sex with condom, gay men, partner unknown status 0.04% (1:2500)
Receptive fellatio Estimates range from 0.00% to 0.04% (1:2500)
Mother-to-child, mother takes at least two weeks antiretroviral therapy 0.8% (1:125)
Mother-to-child, mother takes combination therapy, viral load below 50 0.1% (1:1000)
Injecting drug use Estimates range from 0.63% (1:158) to 2.4% (1:41)
Needlestick injury, no other risk factors 0.13% (1:769)
Blood transfusion with contaminated blood 92.5% (9:10)

Sources: vaginal sex;1 anal sex;2 fellatio;3 2 mother-to-child;4 other activities.5

References

  1. Boily MC et al. Heterosexual risk of HIV-1 infection per sexual act: systematic review and meta-analysis of observational studies. Lancet Infect Dis 9(2): 118-129, 2009
  2. Vittinghoff E et al. Per-contact risk of human immunodeficiency virus transmission between male sexual partners. American Journal of Epidemiology 150: 306-311, 1999
  3. Del Romero J et al. Evaluating the risk of HIV transmission through unprotected orogenital sex. AIDS 16(9): 1296-1297, 2002
  4. Townsend C et al. Low rates of mother-to-child transmission of HIV following effective pregnancy interventions in the United Kingdom and Ireland, 2000-2006. AIDS 22: 973-981, 2008
  5. Baggaley RF et al. Risk of HIV-1 transmission for parenteral exposure and blood transfusion. AIDS 20: 805-812, 2006
  6. HIV & AIDS Information :: How transmission occurs – Estimated risk per exposure

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HIV Risk (2005 figures)

Estimated per-act risk for acquisition of HIV, by exposure route*

Exposure route Risk per 10,000 exposures to an infected source %
Blood transfusion 9000 90
Needle-sharing injection-drug use 67 0.67
Receptive anal intercourse 50 0.5
Percutaneous needle stick 30 0.3
Receptive penile-vaginal intercourse 10 0.1
Insertive anal intercourse 6.5 0.065
Insertive penile-vaginal intercourse 5 0.05
Receptive oral intercourse† 1 0.01
Insertive oral intercourse† 0.5 0.005

*Estimates of risk for transmission from sexual exposures assume no condom use.
†Source refers to oral intercourse performed on a man.

References

At risk of HIV? Get HIV PEP treatment!

HIV risk (2002 figures)

HIV Risk Statistics (chances of getting HIV)

HIV Risk Factors HIV Transmission Probability
Needle stick injury3 1/300
Receptive anal intercourse4 1/100
Receptive vaginal intercourse5 1/1000
Insertive vaginal intercourse4 1/2000
Insertive anal intercourse4 1/2500
Receptive fellatio with ejaculation4 1/2500
Sharing needles6 1/150

References

  1. Cardo DM, Culver DH, Ciesielski CA, et al. A Case-Control Study of HIV Seroconversion in Health Care Workers after Percutaneous Exposure. N Engl J Med. 1997;337:1485-1490.
  2. Katz MH, Gerberding JL. Management of occupational and nonoccupational postexposure HIV prophylaxis. Current Inf Dis Reports. 2002;4:543-549.
  3. Gerberding JL. Prophylaxis for Occupational Exposure to HIV. Ann Intern Med. 1996;6:497-501
  4. Vitinghoff E, Douglas J, Judon F, et al. Per-Contact Risk of Human Immunodificiency Virus Transmision between Male Sexual Partners. Am J Epidemiol. 1999;150:306-311.
  5. Peterman TA, Stoneburner RL, Allen JR, et al. Risk of Human Immunodeficiency Virus Transmission From Heterosexual Adults With Transfusion-Associated Infections. JAMA. 1988;259:55-58. [Erratum. JAMA. 1989;262:502]
  6. Kaplan EH, Heimer R. A Model-Based Estimate of HIV Infectivity via Needle Sharing. J Acquir Immune Defic Syndr. 1992;5:1116-1118.

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Blog articles about #HIVrisk


Related Concepts

Sexual risk (of HIV/STD/pregnancy), and what you can do before and after exposure.

Timeline HIV STD Pregnancy
Before exposure
Abstain from sex, Be faithful, or Condom use
Circumcision (males only)
Contraception
(females only)
HIV PrEP (pre-exposure prophylaxis)
– Stop HIV infection before exposure
STD vaccine:
Hepatitis vaccine
HPV vaccine
STD / HIV exposure
Unsafe sex / unprotected sex:
No condom / Condom broke / Condom slip
0-72 hours HIV PEP (post-exposure prophylaxis)
– Stop HIV infection after exposure
STD testing *
Screening test
– to look for asymptomatic infections
– from previous exposures
Emergency contraception
with the
morning-after pill
(females only)
2 weeks HIV DNA Test
1 month HIV 4th Generation Test
SD Bioline HIV Ag/Ab Combo
– Fingerprick blood sampling.
20 minutes to results
3 months HIV 3rd Generation Test
OraQuick® HIV-1/2 Antibody
– Oral fluid or
– Fingerprick blood sampling.
20 minutes to results
STD testing *
– Full & comprehensive
diagnostic test
– to look for current infections
Watch for HIV Symptoms STD Symptoms
If infected HIV Treatment STD Treatment Abortion

* Males: Do not urinate for at least 4 hours before arriving.
* Females: testing is more accurate when you are not menstruating.


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