Demographic information obtained from the patient at the time of testing as part of the pilot testing will be recorded on a data collection sheet. Data collected will include risk factors for HIV, ethnicity, sex, age, payer status, zip code, homeless status, prior testing status (and dates of prior testing), co-morbid medical conditions possibly related to HIV diagnosis and chief complaint on presentation to ED. In addition, general demographic information about patients admitted to the ED during the study period will be requested and de-identified and, if appropriate, will be extrapolated for calculation of seroprevalence e.g. the characteristics of the patients tested for HIV will be compared to the overall ED population in order to ascertain whether the tested sample is representative of the ED population.