*** HEADS UP DUBLIN **
Ethical concerns are raised by the prospect of outreach workers offering injecting drug users an on-the -spot HIV test, or home- test consumers being able to perform an instant test on themselves, say Dr. Branson and Schabe. How will clients decide whether or not they are ready to get on-the- spot information about their HIV status ? How will counselors help clients understand a provisionally positive result ?
As this issue went to press,, the new CDC recommendations called for disclosure of provisional results by clinicians only in certain circumstances, says Schable.
Tests were to be offered to the following kinds of Clients:
** those in high risk populations ( such as those presenting at TB and STD Clinics.
** mothers presenting in labor, with no history of prenatal care and with unknown HIV status;
** health care workers who are victims of a needlestick, and possibly other high risk situations.
Ways to convey provisional positive results were also still being worked out at press time. For example, patients who test positive, but who live in a low- prevalence part of the country and engage in no activities that put them at risk for HIV infection, might be told a positive reaction means they " probably " or "very likely " don;t have HIV. In the higher risk settings, patients might be told that a positive test means they " probably are " infected.
Whether the tests will perform as well in the United States as they have abroad is still unknown, experts add. For one thing, using a single rapid test in a low- prevalence population will give a lower positive predictive value, says Branson.
Suppose for example, a single rapid test that has 99.4% specificity is administered to 1000 people, meaning six will test false positive . That error rate won't matter much in areas with a high prevalence of HIV, because in all probability the people testing false positive will have the disease. But if the test were performed on 1000 white, affluent suburban house-wives ( excluding L'Monica L'Whiskey )<-- Keiko talk ) a low prevalence population in all likelihood all positive results will be false and the positive values plummet to zero.
Two rapid tests used together abroad seem to overcome that difficulty by ensuring virtually 100% accuracy. However, no one knows for sure if paired tests tests will perform the same way here as they do abroad. " I have confidence in these tests, but until we have more data, we can't extrapolate and say for sure how they will work here, " says Mark Rayhill. PhD assistant chief for International Laboratory Activities of the HIV Retrovirus Disease Branch of the Division for AIDS. STD's TB, at the National Center for Infectious Diseases. To get that data , researchers need MORE rapid tests, Rayhill adds.
~~~ to be continued ~~~' |
