HIV TRANSMISSION RISK FROM SEXUAL CONTACT,MOTHER TO CHILD,DRUG INJECTORS OR BLOOD CONTAMINATIONS-A STUDY

PROF.DRRAM ,HIV/AIDS,SEX Diseases,Deaddiction & Hepatitis Expert 
profdrram@gmail.com,+917838059592,+919832025033,DELHI,INDIA
HIV/ AIDS,CANCER MODERN MEDICINES AVAILABLE AT CHEAP RATE.
FOLLOW ON FACE BOOK:www.facebook.com/ramkumar 
FOLLOW ON TWITTER:www.twitter.com/profdrram

This study provides a synthesis of the current scientific evidence on the risk of transmission of human immunodeficiency virus (HIV) associated with sexual activities, injection and other drug use, and mother-to-child (vertical) transmission.But it is common understanding that if infected source highly infective or VIRAL LOAD is high.more is chance of transmission but beside this presence of other STDs and circumcision of male partner also matter.
Sexual transmission of HIV :-------
Although there are challenges in quantifying risk by sex act, all studies consistently reported that anal intercourse is a higher risk act than vaginal intercourse, which in turn is a higher risk act than oral intercourse. There is also an increased risk associated with receptive intercourse (both vaginal and anal) compared with insertive intercourse.
The risk estimates for the sexual transmission of HIV, per sex act, range widely, from 0.5% to 3.38% (with mid-range estimates of 1.4% to 1.69%) for receptive anal intercourse; 0.06% to 0.16% for insertive anal intercourse; 0.08% to 0.19% for receptive vaginal intercourse (i.e., male-to-female); and approximately 0.05% to 0.1% for insertive vaginal intercourse (i.e., female-to-male). The risk of transmission from unprotected oral intercourse (whether penile-oral or vaginal-oral) is markedly lower than for anal or vaginal intercourse, and findings suggest a low but non-zero transmission probability. The risk of transmission to the receptive partner increases with ejaculation and the presence of oral ulcers and sexually transmitted infections (STIs) in the oropharynx.
Male circumcision decreases the risk of female-to-male sexual transmission of HIV by 50% to 60%. However, there is little epidemiological evidence to suggest that circumcision reduces the risk of transmission to female partners of circumcised men or is effective in the prevention of HIV among men who have sex with men (MSM).
The presence of a concomitant STI has also been found to affect HIV transmission. STIs increase susceptibility to HIV by a factor of 2 to 4 and increase transmissibility 2 to 3 times.
HIV transmission among people who use drugs :---
For people who inject drugs, the risk of transmission per injection from a contaminated needle has been estimated to be between 0.7% and 0.8%. However, studies of contact with improperly discarded needles outside of the healthcare setting suggest that such exposures represent a low risk for HIV transmission, likely due to the low viability of the virus outside the body.Sharing ancillary injecting equipment such as filters or cookers during injection drug use has been shown to increase the risk of transmission, even in the absence of sharing needles and syringes.
People using non-injection drugs are also at risk of HIV infection. Drug use can alter sexual behaviours by increasing risk taking. In addition, several drugs have been reported to be independent risk factors for HIV transmission.Blood direct transfer cause 100% transmission.
Mother-to-child transmission of HIV:---
In the absence of any preventive intervention, for example, highly active antiretroviral treatment (HAART), mother-to-child transmission (also known as “vertical” transmission) ranges from about 15% to 45% depending on whether breastfeeding alternatives are available.since the introduction of HAART, studies indicate that there are probably no additional benefits to elective caesarean section for women with low viral loads.Obstetric events, including prolonged rupture of membranes and intrapartum use of fetal scalp electrodes or fetal scalp pH sampling, have been found to increase the risk of perinatal transmission of HIV.

Mother-to-child HIV transmission can also occur through breastfeeding. The probability of transmission of HIV through breastfeeding is in the range of 9% to 16%.