Browsing by Author "Brookmeyer, Ron"

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    Pregnancy Does Not Affect HIV Incidence Test Results Obtained Using the BED Capture Enzyme Immunoassay or an Antibody Avidity Assay
    (PLoS One, 2010) Laeyendecker, Oliver; Church, Jessica D.; Oliver, Amy E.; Mwatha, Anthony; Owen, S. Michele; Donnell, Deborah; Brookmeyer, Ron; Musoke, Philippa; Jackson, J. Brooks; Guay, Laura; Nakabiito, Clemesia; Quinn, Thomas C.; Eshleman, Susan H.
    Accurate incidence estimates are needed for surveillance of the HIV epidemic. HIV surveillance occurs at maternal-child health clinics, but it is not known if pregnancy affects HIV incidence testing.We used the BED capture immunoassay (BED) and an antibody avidity assay to test longitudinal samples from 51 HIV-infected Ugandan women infected with subtype A, C, D and intersubtype recombinant HIV who were enrolled in the HIVNET 012 trial (37 baseline samples collected near the time of delivery and 135 follow-up samples collected 3, 4 or 5 years later). Nineteen of 51 women were also pregnant at the time of one or more of the follow-up visits. The BED assay was performed according to the manufacturer's instructions. The avidity assay was performed using a Genetic Systems HIV-1/HIV-2 + O EIA using 0.1M diethylamine as the chaotropic agent.During the HIVNET 012 follow-up study, there was no difference in normalized optical density values (OD-n) obtained with the BED assay or in the avidity test results (%) when women were pregnant (n = 20 results) compared to those obtained when women were not pregnant (n = 115; for BED: p = 0.9, generalized estimating equations model; for avidity: p = 0.7, Wilcoxon rank sum). In addition, BED and avidity results were almost exactly the same in longitudinal samples from the 18 women who were pregnant at only one study visit during the follow-up study (p = 0.6, paired t-test).These results from 51 Ugandan women suggest that any changes in the antibody response to HIV infection that occur during pregnancy are not sufficient to alter results obtained with the BED and avidity assays. Confirmation with larger studies and with other HIV subtypes is needed.
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    Probability of HIV-1 transmission per coital act in monogamous, heterosexual, HIV-1-discordant couples in Rakai, Uganda
    (The Lancet, 2001) Gray, Ronald H.; Wawer, Maria J.; Brookmeyer, Ron; Sewankambo, Nelson K.; Serwadda, David; Wabwire-Mangen, Fred; Lutalo, Tom; Li, Xianbin; vanCott, Thomas; Quinn, Thomas C.
    The probability of HIV-1 transmission per coital act in representative African populations is unknown. We aimed to calculate this probability overall, and to estimate how it is affected by various factors thought to influence infectivity. Methods 174 monogamous couples, in which one partner was HIV-1 positive, were retrospectively identified from a population cohort in Rakai, Uganda. Frequency of intercourse and reliability of reporting within couples was assessed prospectively. HIV-1 seroconversion was determined in the uninfected partners, and HIV-1 viral load was measured in the infected partners. Adjusted rate ratios of transmission per coital act were estimated by Poisson regression. Probabilities of transmission per act were estimated by log-log binomial regression for quartiles of age and HIV-1 viral load, and for symptoms or diagnoses of sexually transmitted diseases (STDs) in the HIV-1-infected partners. Results The mean frequency of intercourse was 8·9 per month, which declined with age and HIV-1 viral load. Members of couples reported similar frequencies of intercourse. The overall unadjusted probability of HIV-1 transmission per coital act was 0·0011 (95% CI 0·0008–0·0015). Transmission probabilities increased from 0·0001 per act at viral loads of less than 1700 copies/mL to 0·0023 per act at 38 500 copies/mL or more (p=0·002), and were 0·0041 with genital ulceration versus 0·0011 without (p=0·02). Transmission probabilities per act did not differ significantly by HIV-1 subtypes A and D, sex, STDs, or symptoms of discharge or dysuria in the HIV-1-positive partner.