November 30, 2015
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Human Immunodeficiency Virus (HIV) (cont.)

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What are risk factors for an HIV infection?

The most common modes of transmission in the United States are via

  • anal or vaginal sexual intercourse
  • use of illicit, injectable drugs where needles/syringes/materials are contaminated through sharing them with an HIV-infected person.

Thus, the main risk factors for HIV infection are having nonmonogamous sexual intercourse, having unprotected sex (not using condoms), or the use of injectable illicit drugs. Transmission through oral sex is less common but is still possible.

There is also a risk of transmission from infected mother to unborn child during pregnancy or delivery. Appropriate use of anti-HIV medications can significantly reduce this risk (see below) and has dramatically reduced the incidence of HIV in newborns in the United States. There is also some risk in the perinatal period because breast milk may harbor HIV, and infected mothers in the United States are counseled not to breastfeed. In developing countries, alternatives to breast milk may be lacking and recommendations may differ. Currently, there are approximately 200 new HIV cases per year in the U.S. in children younger than 13 years of age, and most (75%) were infected after birth.

Other less common modes of transmission include accidental needle stick or sharps injuries in health-care workers and splashes of contaminated material onto mucous membranes or nonintact skin. Risk factors include unsafe practices for handling used needles or sharps, inappropriate disposal of needles/sharps, and inadequate use of personal protective measures such as gloves, masks, and eye protection when there is a chance of splashing.

The blood supply in the United States is tested for HIV before use and the risk of acquiring HIV infection from a transfusion is less than one in 1.5 million.

Casual contact (shaking hands, sneezing, coughing, sharing drinking glasses, sharing a toilet, exposure to saliva from social kissing, etc.) does not pose a threat for HIV infection.

Medically Reviewed by a Doctor on 3/3/2014


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