Testing for antibody has a small but definite rate of both false positives and false negatives. Either one can have devastating consequences. A number of conditions, including liver disease, cancer, autoimmunity, and other infections can cause false positives. High risk individuals who test negative should be retested for antibody at six month intervals. Testing in newborns represents a specific challenge.
Maternal antibodies cross the placenta confounding antibody testing.
Methods exist for detection of virus in newborns, but are expensive so are not applicable to screening. These include HIV culture, PCR, and immune complex-dissociated p24. AIDS testing requires informed consent and counseling. Testing without consent can result in legal complications. Psychological, social, and medical counseling is necessary.