Browsing by Author "Mbewe F"

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A color-coded tape for uterine height measurement: a tool to identify preterm pregnancies in low resource settings.
(2015) Althabe F; Berrueta M; Hemingway-Foday J; Mazzoni A; Bonorino CA; Gowdak A; Gibbons L; Bellad MB; Metgud MC; Goudar S; Kodkany BS; Derman RJ; Saleem S; Iqbal S; Ala SH; Goldenberg RL; Chomba E; Manasyan A; Chiwila M; Imenda E; Mbewe F; Tshefu A; Lokomba V; Bose CL; Moore J; Meleth S; McClure EM; Koso-Thomas M; Buekens P; Belizán JM; Department of Community Health Sciences, Aga Khan University, Karachi Pakistan.; Kinshasa School of Public Health, Kinshasa, Democratic Republic of Congo.; Eunice Kennedy Shriver NICHD, Bethesda, Maryland, United States of America.; Department of Obstetrics and Gynecology, Columbia University, New York, New York, United States of America.; Centre for Infectious Disease Research in Zambia, Lusaka, Zambia; University of North Carolina, Chapel Hill, North Carolina, United States of America.; University of North Carolina, Chapel Hill, North Carolina, United States of America.; RTI International; Durham, North Carolina, United States of America.; Institute for Clinical Effectiveness and Health Policy, Buenos Aires, Argentina.; School of Public Health and Tropical Medicine, Tulane University, Louisiana, United States of America.; KLE University's Jawaharlal Nehru Medical College, Belgaum, Karnataka, India.; Department of Obstetrics, Sindh Government Qatar Hospital, Karachi Pakistan.; Christiana Care, Newark, Delaware, United States of America.; University Teaching Hospital, Lusaka, Zambia.; Department of Obstetrics, Sobhraj Maternity Hospital, Karachi, Pakistan.; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
INTRODUCTION: Neonatal mortality associated with preterm birth can be reduced with antenatal corticosteroids (ACS), yet <10% of eligible pregnant women in low-middle income countries. The inability to accurately determine gestational age (GA) leads to under-identification of high-risk women who could receive ACS or other interventions. To facilitate better identification in low-resource settings, we developed a color-coded tape for uterine height (UH) measurement and estimated its accuracy identifying preterm pregnancies. METHODS: We designed a series of colored-coded tapes with segments corresponding to UH measurements for 20-23.6 weeks, 24.0-35.6 weeks, and >36.0 weeks GA. In phase 1, UH measurements were collected prospectively in the Democratic Republic of Congo, India and Pakistan, using distinct tapes to address variation across regions and ethnicities. In phase 2, we tested accuracy in 250 pregnant women with known GA from early ultrasound enrolled at prenatal clinics in Argentina, India, Pakistan and Zambia. Providers masked to the ultrasound GA measured UH. Receiver operating characteristics (ROC) analysis was conducted. RESULTS: 1,029 pregnant women were enrolled. In all countries the tapes were most effective identifying pregnancies between 20.0-35.6 weeks, compared to the other GAs. The ROC areas under the curves and 95% confidence intervals were: Argentina 0.69 (0.63, 0.74); Zambia 0.72 (0.66, 0.78), India 0.84 (0.80, 0.89), and Pakistan 0.83 (0.78, 0.87). The sensitivity and specificity (and 95% confidence intervals) for identifying pregnancies between 20.0-35.6 weeks, respectively, were: Argentina 87% (82%-92%) and 51% (42%-61%); Zambia 91% (86%-95%) and 50% (40%-60%); India 78% (71%-85%) and 89% (83%-94%); Pakistan 63% (55%-70%) and 94% (89%-99%). CONCLUSIONS: We observed moderate-good accuracy identifying pregnancies ≤ 35.6 weeks gestation, with potential usefulness at the community level in low-middle income countries to facilitate the preterm identification and interventions to reduce preterm neonatal mortality. Further research is needed to validate these findings on a population basis.
Addition of single-dose tenofovir and emtricitabine to intrapartum nevirapine to reduce perinatal HIV transmission.
(2008-Jun-01) Chi BH; Chintu N; Cantrell RA; Kankasa C; Kruse G; Mbewe F; Sinkala M; Smith PJ; Stringer EM; Stringer JS; Centre for Infectious Disease Research in Zambia, Lusaka, Zambia. bchi@uab.edu; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
OBJECTIVE: To determine the impact of adjuvant single-dose peripartum tenofovir/emtricitabine (TDF/FTC) on intrapartum/early postpartum HIV transmission. METHODS: In the setting of routine short-course zidovudine (ZDV) and peripartum nevirapine (NVP) for perinatal HIV prevention, participants were randomized to single-dose TDF (300 mg)/FTC (200 mg) or to no intervention in labor. Six-week infant HIV infection was compared according to actual-use drug regimens. RESULTS: Of 397 women randomized, 355 (89%) had infants who were alive and active at 6 weeks postpartum. Of these, 18 (5.1%) were infected in utero and 6 (1.8%) were infected intrapartum/early postpartum. Among the 243 who used ZDV and NVP, intrapartum/early postpartum transmission was not reduced among infants whose mothers received TDF/FTC compared with those who did not (2 of 123 [1.6%] vs. 3 of 109 [2.8%]; P = 0.67). Among the 49 infants whose mothers did not receive antenatal ZDV but who had confirmed NVP ingestion, transmission similarly did not differ (0 of 19 [0%] vs. 1 of 26 [3.4%]). TDF/FTC was not significantly associated with reduced overall transmission (odds ratio [OR] = 0.7, 95% confidence interval [CI]: 0.3 to 1.6), even when other antiretroviral drugs were considered (adjusted OR = 0.8, 95% CI: 0.3 to 1.8). CONCLUSIONS: Adjuvant peripartum single-dose TDF/FTC did not reduce perinatal transmission. Whether a higher dose might be effective remains unknown but should be studied in settings in which NVP is used without antenatal ZDV.
Intrapartum tenofovir and emtricitabine reduces low-concentration drug resistance selected by single-dose nevirapine for perinatal HIV prevention.
(2009-Nov) Chi BH; Ellis GM; Chintu N; Cantrell RA; Sinkala M; Aldrovandi GM; Warrier R; Mbewe F; Nakamura K; Stringer EM; Frenkel LM; Stringer JS; Centre for Infectious Disease Research in Zambia, Lusaka, Zambia. bchi@uab.edu; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
A single dose of tenofovir/emtricitabine (TDF/FTC) during labor significantly reduces peripartum nevirapine-associated viral drug resistance when measured by consensus HIV sequencing. It is unknown whether this effect extends to HIV subpopulations of <25-50%. We conducted a randomized trial of single-dose TDF/FTC added to peripartum nevirapine to reduce drug resistance associated with nonnucleoside reverse transcriptase inhibitors (NNRTIs). To detect mutations for NNRTIs comprising > or = 2% of the viral population, we used an oligonucleotide ligation assay (OLA) at codons 103, 106, 181, and 190 of HIV reverse transcriptase. To assess development of drug resistance mutations to our study intervention, OLA was also performed at codons 65 and 184. Among the 328 women included in the 2-week analysis, those receiving TDF/FTC were less likely to have NNRTI resistance by OLA (RR = 0.40, 95% CI = 0.21-0.77). A similar trend was observed among the 315 women included in the 6-week analysis (RR = 0.45, 95% CI = 0.31-0.66). Only two (1%) specimens had detectable K65R by OLA. Both were at 6 weeks postpartum; one was detected in the intervention arm and one in the control arm (p = 0.96). M184V was not detected. The ability of single-dose TDF/FTC to protect against peripartum NVP-induced NNRTI resistance extends to minority populations. This efficacy is achieved without significant selection of TDF- or FTC-resistant viruses.
Single-dose tenofovir and emtricitabine for reduction of viral resistance to non-nucleoside reverse transcriptase inhibitor drugs in women given intrapartum nevirapine for perinatal HIV prevention: an open-label randomised trial.
(2007-Nov-17) Chi BH; Sinkala M; Mbewe F; Cantrell RA; Kruse G; Chintu N; Aldrovandi GM; Stringer EM; Kankasa C; Safrit JT; Stringer JS; Centre for Infectious Disease Research in Zambia, Lusaka, Zambia. bchi@uab.edu; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
BACKGROUND: Intrapartum and neonatal single-dose nevirapine are essential components of perinatal HIV prevention in resource-constrained settings, but can induce resistance to other non-nucleoside reverse transcriptase inhibitor drugs. We aimed to investigate whether this complication would be reduced with a single peripartum intervention of tenofovir and emtricitabine. METHODS: We randomly assigned 400 HIV-infected pregnant women who sought care at two public-sector primary health facilities in Lusaka, Zambia. One was excluded, 200 were assigned to receive a single oral dose of 300 mg tenofovir disoproxil fumarate with 200 mg emtricitabine under direct observation, and 199 to receive no study drug. Short-course zidovudine and intrapartum nevirapine were offered to all HIV-infected women, according to the local standard of care. Women who met national criteria for antiretroviral therapy were referred for care and not enrolled. Our primary study outcome was resistance to non-nucleoside reverse transcriptase inhibitors at 6 weeks after delivery. We used standard population sequencing to determine HIV genotypes. Analysis was per protocol. This study is registered with ClinicalTrials.gov, number NCT00204308. FINDINGS: Of the 200 women who were randomly assigned to the intervention, 14 were lost to follow-up or withdrew from the study, two did not take study drug according to protocol, and one specimen was lost; 23 of 199 controls were lost to follow-up or withdrew from the study, and three specimens were lost. Women given the intervention were 53% less likely than controls to have a mutation that conferred resistance to non-nucleoside reverse transcriptase inhibitors at 6 weeks after delivery (20/173 [12%] vs 41/166 [25%]; risk ratio [RR] 0.47, 95% CI 0.29-0.76). We noted postpartum anaemia, the most common serious adverse event in mothers, in four women in each group. 20 of 198 (10%) infants in the intervention group and 23 of 199 (12%) controls had a serious adverse event, mostly due to septicaemia (n=22) or pneumonia (n=8); these events did not differ between groups, and none were judged to be caused by the study intervention. INTERPRETATION: A single dose of tenofovir and emtricitabine at delivery reduced resistance to non-nucleoside reverse transcriptase inhibitors at 6 weeks after delivery by half; therefore this treatment should be considered as an adjuvant to intrapartum nevirapine.