Jaya Bansal

Seroprevalence of human immunodeficiency virus, hepatitis B virus, hepatitis C virus, and rapid plasma reagin in a trauma population. Discussion

We evaluated the presence of human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV), and rapid plasma reagin (RPR) among patients admitted to our trauma unit from April 15 to June 30, 1993. Of 984 patients tested, we found 255 (26%) had evidence of exposure to one or more of these agents: HIV, 4%; HBV, 20%; HCV, 14%; and RPR, 1%. Thirty-eight percent of patients had more than one positive serology, 75% of the HIV patients, 49% of the HBV patients, and 66% of the HCV patients. There was no difference between penetrating and nonpenetrating trauma with respect to any of the viruses. The risk factors for HIV-positive patients were non-White race, positive drug screen, positive alcohol screen, and city resident. Risk factors for HBV patients were non-White race, positive drug screen, and city resident. Risk factors for HBC patients were male sex, non-White race, positive alcohol screen, positive drug screen, and city resident. The risk of blood-borne infections in this group of patients is substantial.

Enhanced chemiluminescence as a means of increasing the sensitivity of Western blot assays for HIV antibody

Chemiluminescence indicator systems offer several advantages for diagnostic assays and have been used successfully to increase the sensitivity of antibody and antigen assays. A technique of enhanced chemiluminescence (ECL) was applied as a replacement for routine chromogenic substrates on HIV-1 Western blots. The results indicated that the enhanced chemiluminescence detection system increased the sensitivity by greater than 10-fold over routine chromogenic indicator systems when testing diluted, reactive sera. When testing 9 seroconversion panels, the use of ECL indicated that early detection of HIV infection was elicited in six panels up to 31 days (average 11.4 days) prior to detection by routine FDA-licensed Western blots, and could be detected in all panels up to 43 days (average 18.8 days) prior to detection by in-house Western blots. In no case was the ECL Western blot system less sensitive than any of the chromogenic Western blots, and in several cases the maximum potential of the ECL system for early detection of antibody could not be determined. The ECL system was capable of detecting antibodies to envelope antigens at a 20-fold increase over chromogenic Western blots. The time of detection of seropositivity by the ECL Western blot was equal to that of most ELISAs in 5 panels and was 31 days earlier than ELISA in one panel. Permanent documentation of Western blot profiles was accomplished using a simple instamatic camera system capable of detecting the chemiluminescence signal, and blots could be re-probed using a second sample.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of five hepatitis C virus screening tests and two supplemental assays: performance when testing sera from sexually transmitted diseases clinic attendees in the USA.

The performances of five screening tests (recombinant peptide-based first and second generation tests from Abbott and Ortho, and a synthetic peptide-based test from Biochem Immunosystems) and two supplemental tests: recombinant peptide- based, Abbott neutralization test and Chiron second generation recombinant immunoblot assay (RIBA 2), were evaluated for their ability to detect hepatitis C virus (HCV) antibodies in a population of 276 individuals attending a sexually transmitted diseases (STD) clinic in the USA. Although the five screening tests produced a variable number (35-62) of repeatedly reactive samples, only 13% (36/276) were classified as true positives by the supplemental tests. Thirty-four of the 36 were reactive by all screening tests and 32 of the true positives were reactive by both supplemental tests, while 2 did not neutralize but were reactive in the RIBA 2 test. Of the remaining 2 of the true positives which were discordant by several of the screening assays, 1 was confirmed by both supplemental assays but the other required a chemiluminescent enhancement technique to show positivity in RIBA 2. The sensitivities of the first and second generation Abbott and Ortho tests ranged from 97% to 100% and that of the Biochem test was 94%. The specificities of these tests ranged from 89.2% to 99.6%. The second generation Ortho test presented 9.4% (26/276) false positives. The use of second generation Ortho as a screening test would lead to an excessive number of confirmatory false positives. the positive predictive values of the screening tests ranged from 58.1% to 97.1%. Although the synthetic peptide based Biochem test exhibited the best overall indices, the presence of 2 false negative results would prevent its use as a singular screening test. Nevertheless its high specificity may lend itself to be used as a second screening test before confirmatory testing with RIBA 2.

Multiple blood-borne and sexually transmitted infections in sexually transmitted disease clinic and hospital emergency room patient populations.

The degree of coinfections with blood-borne or sexually transmitted pathogens (HIV-1, HTLV-I/II, HBV, HCV, HDV, and Treponema pallidum) were assessed in individuals attending sexually transmitted diseases (STD) clinic and patients admitted to a hospital through the emergency room in Baltimore. Enzyme-linked immunosorbent assays (ELISA), immunoblots, and card tests were used to screen the sera. Nearly one third of the individuals in both populations were infected with one or more pathogens. With some minor exceptions, all individuals with dual or multiple infections had antibodies reactive with the HBV core antigen. There was a strong overall association between the presence of antibodies to HIV-1 and the presence of antibodies to HBV core and HCV in both populations. Additionally, the presence of HIV-1 antibodies was significantly associated with the presence of HTLV-I/II antibodies and HBV surface antigen in the STD population and with a positive RPR test result in the H/ER population. We suggest that HIV-1 and/or HTLV-I/II infected individuals in STD clinic and emergency rooms are highly likely to have had past infections with HBV or HCV.