HIV Prevention

It is well-known that administration of antiretroviral therapy to pregnant women who have HIV significantly prevents transmission to the baby.  In health care settings where an employee may suffer a needlestick or other sharp instrument injury, immediate post-exposure administration of antiretroviral agents to the health care worker may prevent the acquisition of this medical condition.  This naturally applies to cases in which the sharp instrument contains blood from a patient who is HIV-positive [1].

The contagiousness of an individual with HIV infection will vary with the stage of the illness.  For example, the first phase lasts for several weeks after acquisition of the virus, and levels of the microbe are extraordinarily high.  This is when the virus infects billions of human cells within three weeks.  If the patient has unprotected sex during this period with someone who does not have the disease, the risk of transmission is very high [1]. 

The third and final stage of the disease is where the patient develops acquired immunodeficiency syndrome (AIDS).  He or she will be quite infectious during these final few years of life unless antiretroviral medication improves the medical condition.

The longest stage is the chronic or latent phase, and the degree of contagiousness is lower than the first or third stages of HIV infection.  Nevertheless, transmission can still occur during the 8 years or more that may comprise the chronic stage.  Moreover, since this latent phase continues for so many years, it is conceivable that many transmissions take place during that time. 

In other words, the HIV-positive patient may have more sexual encounters during the phase which lasts the most years than the other two stages [1].

A study in Africa demonstrated that seropositive sexual partners who took antiretroviral medication were 92 percent less likely to transmit the disease to seronegative persons than when the seropositive individual did not receive those therapeutic agents [1].  The medication maintains the HIV RNA plasma levels to an acceptable range so the seronegative partner does not acquire the infection despite exposure to the virus.

There has been much progress in the use of medication to control the HIV pandemic.  Education of sexually active individuals and further research are necessary.

1. Mayer, K. and Venkatesh, K.  (2010).  Antiretroviral therapy as HIV prevention:  Status and prospects.  American Journal of Public Health, 100, 1867-1876.
2. The photograph is a thin-section transmission electron micrograph of several human immunodeficiency virus particles.  Reprinted with permission from Centers for Disease Control/Dr. A. Harrison/Dr. P. Feorino.

The information contained in this article is for educational purposes only and should not be used for diagnosis or to guide treatment without the opinion of a health professional. Any reader who is concerned about his or her health should contact their physician for advice.