Browsing by Author "Mwatha, Anthony"

Now showing 1 - 7 of 7
  • Thumbnail Image
    Item
    Analysis of HIV Diversity Using a High-Resolution Melting Assay
    (AIDS research and human retroviruses, 2010) Towler, William I.; James, Maria M.; Ray, Stuart C.; Wang, Lei; Donnell, Deborah; Mwatha, Anthony; Guay, Laura; Nakabiito, Clemensia; Musoke, Philippa; Jackson, J. Brooks; Eshleman, Susan
    HIV viruses are usually genetically homogeneous shortly after infection, and become more heterogeneous over time. We developed a high-resolution melting (HRM) assay to analyze HIV diversity without sequencing. Plasma samples from the HIVNET 012 trial were obtained from nine Ugandan mother–infant pairs. DNA amplified from the HIV gag region was analyzed to determine the number of degrees over which the DNA melted (HRM score). HRM gag DNA was also cloned and sequenced (50 clones/mother; 20 clones/infant). The median HRM score for infants (4.3, range 4.2–5.3) was higher than that for control plasmids (3.4, range 3.2–3.8, p < 0.001) and lower than that for mothers (5.7, range 4.4–7.7, p = 0.005, exact Wilcoxon rank sum test). The intraclass correlation coefficient reflecting assay reproducibility was 94% (95% CI: 89–98%). HRM scores were also compared to sequenced-based measures of HIV diversity; higher HRM scores were associated with higher genetic diversity (p < 0.001), complexity (p = 0.009), and Shannon entropy (p = 0.022), but not with length variation (p = 0.111). The HRM assay provides a novel, rapid method for assessing HIV diversity without sequencing. This assay could be applied to any region of the HIV genome or to other genetic systems that exhibit DNA diversity.
  • Thumbnail Image
    Item
    Analysis of HIV tropism in Ugandan infants
    (Current HIV research, 2010) Church, Jessica D.; Huang, Wei; Mwatha, Anthony; Musoke, Philippa; Jackson, J. Brooks; Bagenda, Danstan; Omer, Saad B.; Donnell, Deborah; Nakabiito, Clemensia; Eure, Chineta; Guay, Laura A.; Taylor, Allan; Bakaki, Paul M.; Matovu, Flavia; McConnell, Michelle; Fowler, Mary Glenn; Eshleman, Susan H.
    HIV-infected infants may have CXCR4-using (X4-tropic) HIV, CCR5-using (R5-tropic) HIV, or a mixture of R5-tropic and X4-tropic HIV (dual/mixed, DM HIV). The level of infectivity for R5 virus (R5-RLU) varies among HIV-infected infants. HIV tropism and R5-RLU were measured in samples from HIV-infected Ugandan infants using a commercial assay. DM HIV was detected in 7/72 (9.7%) infants at the time of HIV diagnosis (birth or 6–8 weeks of age, 4/15 (26.7%) with subtype D, 3/57 (5.3 %) with other subtypes, P=0.013). A transition from R5-tropic to DM HIV was observed in only two (6.7%) of 30 infants over 6–12 months. Six (85.7%) of seven infants with DM HIV died, compared to 21/67 (31.3%) infants with R5-tropic HIV (p=0.09). Higher R5- RLU at 6–8 weeks was not associated with decreased survival. Infants with in utero infection had a higher median R5-RLU than infants who were HIV-uninfected at birth (p=0.025).
  • Thumbnail Image
    Item
    Characterization of Nevirapine Resistance Mutations in Women With Subtype A Vs. D HIV-1 6–8 Weeks After Single-Dose Nevirapine (HIVNET 012)
    (JAIDS Journal of Acquired Immune Deficiency Syndromes, 2004) Eshleman, Susan H.; Guay, Laura A.; Mwatha, Anthony; Brown, Elizabeth R.; Cunningham, Shawn P.; Musoke, Philippa; Mmiro, Francis; Jackson, J. Brooks
    To compare the number and type of nevirapine (NVP) resistance mutations detected in Ugandan women with subtype A vs.D HIV-1 infection after single-dose NVP prophylaxis.In the HIVNET 012 trial, a higher rate of NVP resistance (NVPR) was seen in women with subtype D than A after single-dose NVP. In this study, the number and type of NVPR mutations detected 6–8 weeks after NVP were compared in women with subtypes A vs. D.Plasma samples were available for 282 (92%) of 306 women who received NVP in HIVNET 012. Samples were analyzed with the ViroSeq HIV-1 Genotyping System (Applied Biosystems, Foster City, CA). Subtyping was performed by phylogenetic analysis of pol region sequences. Results were obtained for 279 women, including 147 with subtype A, 98 with subtype D, 6 with subtype C, and 28 with recombinant HIV-1. NVPR mutations were detected in 70 (25%) of 279 women. NVPR was more common in women with subtype D vs. A (35.7 vs. 19%, P = 0.0035). Complex patterns of NVPR mutations were detected in both subtypes. Among women with NVPR, 43% of women with subtype A and 46% of women with subtype D had 2 NVPR mutations. The mean number and pattern of NVPR mutations detected in women with subtypes A and D were similar. This study confirms a higher rate of NVPR in women with subtype D than A and further defines the pattern of NVPR mutations that emerge 6–8 weeks after single-dose NVP prophylaxis in these subtypes.
  • Thumbnail Image
    Item
    Comparison of HIV-1 Mother-to-Child Transmission After Single-Dose Nevirapine Prophylaxis Among African Women With Subtypes A, C, and D
    (JAIDS Journal of Acquired Immune Deficiency Syndromes, 2006) Eshleman, Susan; Church, Jessica; Guay, Laura A.; Mwatha, Anthony; Fiscus, Susan A.; Mmiro, Francis; Musoke, Philippa; Kumwenda, Newton; Jackson, J. Brooks; Taha, Taha E.; Hoover, Donald R.
    The HIVNET 012 trial in Uganda showed that mother-to-child transmission (MTCT) of HIV-1 can be prevented by providing pregnant women and their infants with a single dose (SD) of the antiretroviral drug, nevirapine (NVP).1,2 Safety and efficacy of 1- or 2-dose NVP prophylaxis for prevention of MTCT have been documented in other studies. We have shown that NVP resistance emerges in some women after SD NVP prophylaxis3 and that the portion of women with NVP resistance is influenced by HIV-1 subtype.4 At 6 to 8 weeks after SD NVP, NVP resistance was more common in women with subtype C (69.2%) than in women with subtype D (36.1%, P < 0.0001) or subtype A (19.4%, P < 0.0001).4 Selection of NVP-resistant HIV-1 variants in women after NVP dosing could theoretically lower the efficacy of NVP prophylaxis for prevention of HIV transmission by breast-feeding in the first few weeks after birth. In the HIVNET 012 trial, most women were infected with HIV-1 subtype A or D. Risk of MTCT was slightly (but not statistically) higher in women with subtype D.5 In this report, we combined data from the HIVNET 012 and NVAZ trials6 to compare the risk of MTCT in women with subtype C to the risk of MTCT in women with subtypes A and D in the setting of SD NVP prophylaxis.
  • Thumbnail Image
    Item
    Intrapartum and neonatal single-dose nevirapine compared with zidovudine for prevention of mother-to-child transmission of HIV-1 in Kampala, Uganda: 18-month follow-up of the HIVNET 012 randomised trial
    (The Lancet, 2003) Jackson, J. Brooks; Musoke, Philippa; Fleming, Thomas; Guay, Laura A.; Bagenda, Danstan; Allen, Melissa; Nakabiito, Clemensia; Sherman, Joseph; Bakaki, Paul; Owor, Maxensia; Ducar, Constance; Deseyve, Martina; Mwatha, Anthony; Emel, Lynda; Duefield, Corey; Mirochnick, Mark; Glenn Fowler, Mary; Mofenson, Lynne; Miotti, Paolo; Gigliotti, Maria; Bray, Dorothy; Mmiro, Francis
    In 1999, we reported safety and efficacy data for short-course nevirapine from a Ugandan perinatal HIV-1 prevention trial when 496 babies were followed up to age 14–16 weeks. Safety and efficacy data are now presented for all babies followed up to 18 months of age. Methods From November, 1997, to April, 1999, HIV-1 infected pregnant women in Kampala, Uganda, were randomly assigned nevirapine (200 mg at labour onset and 2 mg/kg for babies within 72 h of birth; regimen A) or zidovudine (600 mg orally at labour onset and 300 mg every 3 h until delivery, and 4 mg/kg orally twice daily for babies for 7 days, regimen B). Infant HIV-1 testing was done at birth, age 6–8 and 14–16 weeks, and age 12 months by HIV-1 RNA PCR, and by HIV-1 antibody at 18 months. HIV-1 transmission and HIV-1-free survival were assessed using Kaplan-Meier analysis. We recorded adverse experiences through 6–8 weeks postpartum for mothers, and 18 months for babies. Efficacy analyses were by intention to treat. Findings We enrolled 645 mothers to the study: 313 were assigned regimen A, 313 regimen B, and 19 placebo. Eight mothers were lost to follow-up before delivery. 99% of babies were breastfed (median duration 9 months). Estimated risks of HIV-1 transmission in the zidovudine and nevirapine groups were 10·3% and 8·1% at birth (p=0·35); 20·0% and 11·8% by age 6–8 weeks (p=0·0063); 22·1% and 13·5% by age 14–16 weeks (p=0·0064); and 25·8% and 15·7% by age 18 months (p=0·0023). Nevirapine was associated with a 41% (95% CI 16–59) reduction in relative risk of transmission through to age 18 months. Both regimens were well-tolerated with few serious side-effects. Interpretation Intrapartum/neonatal nevirapine significantly lowered HIV-1 transmission risk in a breastfeeding population in Uganda compared with a short intrapartum/neonatal zidovudine regimen. The absolute 8·2% reduction in transmission at 6–8 weeks was sustained at age 18 months (10·1% [95% CI 3·5–16·6]). This simple, inexpensive, welltolerated regimen has the potential to significantly decrease HIV-1 perinatal transmission in less-developed countries.
  • Thumbnail Image
    Item
    Long Term Follow-up of Children in the HIVNET 012 Perinatal HIV Prevention Trial: Five-Year Growth and Survival
    (Journal of acquired immune deficiency syndromes, 2013) Owor, Maxensia; Mwatha, Anthony; Donnell, Deborah; Musoke, Philippa; Mmiro, Francis; Allen, Melissa; Jackson, J. Brooks; Fowler, Mary Glenn; Laura A; Guay, Laura A.
    To describe five year growth, survival and long-term safety among children exposed to nevirapine or zidovudine in an African perinatal prevention trial, HIVNET 012.All study children who were alive at eighteen months of age were eligible for an extended follow-up study. Children whose families consented were enrolled and evaluated every six months from 24 to 60 months. At each visit, history, physical exam and growth measures were taken. From these measurements Z scores based on World Health Organization (WHO) standards were computed. Serious adverse event data were collected. Data from the initial and extended follow-up cohorts were included in the analysis.528 study children were alive at age 18 months, and 491 (426 HIV uninfected; 65 infected) were enrolled into the follow-up study. Both exposed but uninfected children and HIV infected children were substantially below WHO growth standards for weight and height. Head circumference Z scores for uninfected children were comparable to WHO norms. Five-year survival rates were 93% for uninfected children versus 43% for infected children. Long-term safety and growth outcomes in the two study arms were similar.Both infected and uninfected children in the five-year HIVNET 012 follow-up showed poor height and weight growth outcomes, underscoring the need for early nutritional interventions to improve long-term growth of all infants born to HIV-infected women in resource limited settings. Likewise, the low five year survival among HIV infected children support the importance of early initiation of antiretroviral therapy. Both peripartum nevirapine and zidovudine were safe.
  • Thumbnail Image
    Item
    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.