Field evaluation of the Determine rapid human immunodeficiency virus diagnostic test in Honduras and the Dominican Republic.

Rapid detection of human immunodeficiency virus (HIV) infection can result in improved patient care and/or faster implementation of public health preventive measures. A new rapid test, Determine (Abbott, Abbott Park, Ill.), detects HIV type 1 (HIV-1) and HIV-2 antibodies within 15 min by using 50 microl of serum or plasma. No specialized equipment or ancillary supplies are required, and results are read visually. A positive result is noted by the appearance of a red line. An operational control (red line) indicates proper test performance. We evaluated the Determine rapid HIV detection test with a group of well-characterized serum samples (CD4 counts and viral loads were known) and serum samples from HIV-positive individuals at field sites in Honduras and the Dominican Republic. In the field evaluations, the results obtained by the Determine assay were compared to those obtained by local in-country HIV screening procedures. We evaluated serum from 100 HIV-positive patients and 66 HIV-negative patients. All samples gave the expected results. In a companion study, 42 HIV-positive samples from a Miami, Fla., serum bank were tested by the Determine assay. The samples had been characterized in terms of CD4 counts and viral loads. Fifteen patients had CD4 counts <200 cells/mm(3), while 27 patients had CD4 counts >200 cells/mm(3). Viral loads ranged from 630 to 873,746 log(10) copies/ml. All samples from the Miami serum bank were positive by the Determine test. Combined results from the multicenter studies indicated that the correct results were obtained by the Determine assay for 100% (142 of 142) of the HIV-positive serum samples and 100% (66 of 66) of the HIV-negative serum samples. The Determine test was simple to perform and the results were easy to interpret. The Determine test provides a valuable new method for the rapid identification of HIV-positive individuals, especially in developing countries with limited laboratory infrastructures.

Seroprevalence of HIV-1 and hepatitis B and C in prostitutes in Albuquerque, New Mexico.

A survey of persons soliciting sex in an area known to be frequented by prostitutes in Albuquerque, NM, included 43 females and 66 males. Seroprevalence rates found in this population-based study were as follows: human immunodeficiency virus type 1 (HIV-1), 3%; hepatitis B, 39%; hepatitis C, 45%. Increased age, intravenous drug use, and condom use were independent risk factors for hepatitis B. Female gender and intravenous drug use were independent risk factors for hepatitis C. Neither sharing injection equipment nor engaging in receptive anal intercourse was independently associated with hepatitis B or C.

Identification of a cell-surface antigen produced by a gene on human chromosome 3 (cen-q22) and not expressed by Rhnull cells.

A monoclonal antibody, 1D8, which recognizes a cell-surface antigen expressed by human chromosome 3 in Chinese hamster-human somatic-cell hybrids, has been produced. Testing of hybrids containing various deletions of chromosome 3 determines that the gene encoding the antigen is regionally localized to 3q (cen-22). This regional mapping is distinct from that elsewhere reported for two other cell-surface antigens assigned to chromosome 3--namely, the human transferrin receptor and the p97 melanoma-associated antigen. In addition, biochemical characterization is different from that elsewhere reported for other chromosome 3-encoded cell-surface antigens. When tested against a panel of rare-phenotype red blood cells, the only cells that failed to react were those of the Rhnull phenotype. The antibody reacts only weakly with homozygous -D- and fetal red cells, in contrast with a previously described antibody, R6A, which does not react with Rhnull cells. Furthermore, R6A does not recognize a cell-surface antigen expressed by chromosome 3 in Chinese hamster-human somatic-cell hybrids. Thus, the monoclonal antibody 1D8 recognizes a previously undescribed cell-surface antigen encoded by human chromosome 3 and not expressed on Rhnull cells. The gene on chromosome 3 regulating expression of this antigen may be that defective in Rhnull disease or may require the normal allele at an unlinked Rhnull locus for expression. Linkage studies will be required to further elucidate this matter.