Seroconversion Time Frame


Mr. Sawadsky- What percent of people (who eventually become HIV+) seroconvert between 3 and 6 months? Could you provide any sources or statistical studies for the basis of your answer. Would HIV serology be negative or indeterminate during this time frame, if not testing positive by three months. You mentioned that legal prostitutes in Nevada are tested for HIV monthly. Given the controlled environment and mandatory use of Latex condoms, in your experience, what percent of legal prostitutes seroconvert? Thanks for you for taking the time to answer my questions!!


Hi. Thank you for your questions.

There have been many studies (not just one) looking at when persons seroconvert for HIV infection. It is difficult to come up with one specific statistic as to the accuracy of the test between 3 and 6 months. At 3 months, most persons (>90%) infected with HIV will already show positive on the test, however we do know that there are persons who have taken as long as 6 months to show positive. There are also case reports of persons taking longer than 6 months to seroconvert, but these cases are extremely rare, so rare in fact, that they were published in medical journals. What we can definitively say is that by 6 months, more than 99 percent of infected persons will show positive on the antibody tests. Studies looking at the window period for HIV infection generally refer to the average window period, the usual window period, and the maximal window period.

The AVERAGE period of time that an infected person will show positive on the test is 25 days. This is an average, so not all people will test positive by this point in time.

The USUAL period of time that an infected person will show positive on the test is 3 months. This means that most (but not all) infected people will show positive on the test by this time.

The MAXIMUM period of time that an infected person will show positive on the test is 6 months. By this point in time, more than 99% of infected persons will show positive on the test. This is as accurate as any test in medicine could ever be.

If an infected person gets tested before the 6 month waiting period, the test may show a positive result, a negative result, or it may come up with an indeterminate result.

Now, in regard to Nevada's legal prostitutes:

First let me emphasize that not all prostitution is legal in Nevada. Prostitution is only legal in licensed brothels, and only in the rural counties. It is NOT legal in Las Vegas, Reno, Lake Tahoe, Laughlin, and Carson City.

Because HIV is a reportable disease in Nevada, if a prostitute were to test positive for HIV, the State Health Division would be notified. To date, no actively working legal prostitute has tested positive for HIV. There have been applicants to the legal brothels who tested positive for HIV. However, because of their HIV status, they are prohibited from working in the brothels for life, and have never worked in the legal brothels. We do know however that there are illegal prostitutes who have tested positive for HIV, but these prostitutes are working illegally, and NOT in the licensed brothels. Legal brothel workers are tested for Chlamydia, Gonorrhea, Syphilis, and HIV prior to employment. If they test negative for all of these, they can then be medically cleared to work. Once they begin work, they are tested weekly for Chlamydia and Gonorrhea, and monthly for Syphilis and HIV. If they test positive for Chlamydia, Gonorrhea, or Syphilis, they are not allowed to work until they are treated and once again test negative. In the case of HIV, they would be prohibited from working in the brothels for life. Once again, no actively working legal prostitute in Nevada has tested positive for HIV to date. In addition, under state law, legal prostitutes must use latex condoms for all sexual activities with all of their clients.

Therefore, if a person goes to an illegal prostitute in Nevada, the risk is the same as if they went to an illegal prostitute anywhere else. However, if they went to a legal prostitute in Nevada, the risk of infection with HIV and other STD's is much lower than an illegal prostitute.
If you have any further questions, please feel free to call the Centers for Disease Control at 1.800.232.4636 (Nationwide). Rick Sowadsky MSPH CDS