Browsing by Author "Chintu NT"

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Comparative outcomes of tenofovir-based and zidovudine-based antiretroviral therapy regimens in Lusaka, Zambia.
(2011-Dec-15) Chi BH; Mwango A; Giganti MJ; Sikazwe I; Moyo C; Schuttner L; Mulenga LB; Bolton-Moore C; Chintu NT; Sheneberger R; 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)
BACKGROUND: Although tenofovir (TDF) is a common component of antiretroviral therapy (ART), recent evidence suggests inferior outcomes when it is combined with nevirapine (NVP). METHODS: We compared outcomes among patients initiating TDF + emtricitabine or lamivudine (XTC) + NVP, TDF + XTC + efavirenz (EFV), zidovudine (ZDV) + lamuvidine (3TC) + NVP, and ZDV + 3TC + EFV. We categorized drug exposure by initial ART dispensation by a time-varying analysis that accounted for drug substitutions and by predominant exposure (>75% of drug dispensations) during an initial window period. Risks for death and program failure were estimated using Cox proportional hazard models. All regimens were compared with ZDV + 3TC + NVP. RESULTS: Between July 2007 and November 2010, 18,866 treatment-naive adults initiated ART: 18.2% on ZDV + 3TC + NVP, 1.8% on ZDV + 3TC + EFV, 36.2% on TDF + XTC + NVP, and 43.8% on TDF + XTC + EFV. When exposure was categorized by initial prescription, patients on TDF + XTC + NVP [adjusted hazard ratio (AHR): 1.45; 95% confidence interval (CI): 1.03 to 2.06] had a higher post-90-day mortality. TDF + XTC + NVP was also associated with an elevated risk for mortality when exposure was categorized as time-varying (AHR: 1.51; 95% CI: 1.18 to 1.95) or by predominant exposure over the first 90 days (AHR: 1.91, 95% CI: 1.09 to 3.34). However, these findings were not consistently observed across sensitivity analyses or when program failure was used as a secondary outcome. CONCLUSION: TDF + XTC + NVP was associated with higher mortality when compared with ZDV + 3TC + NVP but not consistently across sensitivity analyses. These findings may be explained in part by inherent limitations to our retrospective approach, including residual confounding. Further research is urgently needed to compare the effectiveness of ART regimens in use in resource-constrained settings.
Implementation of the Zambia electronic perinatal record system for comprehensive prenatal and delivery care.
(2011-May) Chi BH; Vwalika B; Killam WP; Wamalume C; Giganti MJ; Mbewe R; Stringer EM; Chintu NT; Putta NB; Liu KC; Chibwesha CJ; Rouse DJ; Stringer JS; Centre for Infectious Disease Research in Zambia, Lusaka, Zambia. bchi@cidrz.org; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
OBJECTIVE: To characterize prenatal and delivery care in an urban African setting. METHODS: The Zambia Electronic Perinatal Record System (ZEPRS) was implemented to record demographic characteristics, past medical and obstetric history, prenatal care, and delivery and newborn care for pregnant women across 25 facilities in the Lusaka public health sector. RESULTS: From June 1, 2007, to January 31, 2010, 115552 pregnant women had prenatal and delivery information recorded in ZEPRS. Median gestation age at first prenatal visit was 23weeks (interquartile range [IQR] 19-26). Syphilis screening was documented in 95663 (83%) pregnancies: 2449 (2.6%) women tested positive, of whom 1589 (64.9%) were treated appropriately. 111108 (96%) women agreed to HIV testing, of whom 22% were diagnosed with HIV. Overall, 112813 (98%) of recorded pregnancies resulted in a live birth, and 2739 (2%) in a stillbirth. The median gestational age was 38weeks (IQR 35-40) at delivery; the median birth weight of newborns was 3000g (IQR 2700-3300g). CONCLUSION: The results demonstrate the feasibility of using a comprehensive electronic medical record in an urban African setting, and highlight its important role in ongoing efforts to improve clinical care.
Nonvirologic algorithms for predicting HIV infection among HIV-exposed infants younger than 12 weeks of age.
(2013-Feb) Chi BH; Limbada MI; Giganti MJ; Li MS; Bweupe M; Musonda P; Bubala P; Mubiana-Mbewe M; Chintu NT; Bolton-Moore C; Stringer JS; Centre for Infectious Disease Research in Zambia, Lusaka, Zambia. bchi@cidrz.org; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
BACKGROUND: Early initiation of antiretroviral therapy has been shown to reduce mortality among perinatally HIV-infected infants, but availability of virologic testing remains limited in many settings. METHODS: We collected cross-sectional data from mother-infant pairs in three primary care clinics in Lusaka, Zambia, to develop predictive models for HIV infection among infants younger than 12 weeks of age. We evaluated algorithm performance for all possible combinations of selected characteristics using an iterative approach. In primary analysis, we identified the model with the highest combined sensitivity and specificity. RESULTS: Between July 2009 and May 2011, 822 eligible HIV-infected mothers and their HIV-exposed infants were enrolled; of these, 44 (5.4%) infants had HIV diagnosed. We evaluated 382,155,260 different characteristic combinations for predicting infant HIV infection. The algorithm with the highest combined sensitivity and specificity required 5 of the following 7 characteristic thresholds: infant CD8 percentage >22; infant CD4 percentage ≤44; infant weight-for-age Z score ≤0; infant CD4 ≤1600 cells/µL; infant CD8 >2200 cells/µL; maternal CD4 ≤600 cells/µL; and mother not currently using antiretroviral therapy for HIV treatment. This combination had a sensitivity of 90.3%, specificity of 78.4%, positive predictive value of 22.4%, negative predictive value of 99.2% and area under the curve of 0.844. CONCLUSION: Predicting HIV infection in HIV-exposed infants in this age group is difficult using clinical and immunologic characteristics. Expansion of polymerase chain reaction capacity in resource-limited settings remains urgently needed.
Universal combination antiretroviral regimens to prevent mother-to-child transmission of HIV in rural Zambia: a two-round cross-sectional study.
(2014-Aug-01) Chi BH; Musonda P; Lembalemba MK; Chintu NT; Gartland MG; Mulenga SN; Bweupe M; Turnbull E; Stringer EM; Stringer JS; Department of Medical Statistics, University of East Anglia, Norwich, England .; University of North Carolina at Chapel Hill School of Medicine, Campus Box 7570, 130 Farm Mason Road, Chapel Hill, NC 27599, United States of America (USA).; Centre for Infectious Disease Research in Zambia, Lusaka, Zambia .; Zambian Ministry of Health, Lusaka, Zambia .; Vanderbilt University School of Medicine, Nashville, USA .; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
OBJECTIVE: To evaluate if a pilot programme to prevent mother-to-child transmission (PMTCT) of the human immunodeficiency virus (HIV) was associated with changes in early childhood survival at the population level in rural Zambia. METHODS: Combination antiretroviral regimens were offered to pregnant and breastfeeding, HIV-infected women, irrespective of immunological status, at four rural health facilities. Twenty-four-month HIV-free survival among children born to HIV-infected mothers was determined before and after PMTCT programme implementation using community surveys. Households were randomly selected and women who had given birth in the previous 24 months were asked to participate. Mothers were tested for HIV antibodies and children born to HIV-infected mothers were tested for viral deoxyribonucleic acid. Multivariable models were used to determine factors associated with child HIV infection or death. FINDINGS: In the first survey (2008-2009), 335 of 1778 women (18.8%) tested positive for HIV. In the second (2011), 390 of 2386 (16.3%) tested positive. The 24-month HIV-free survival in HIV-exposed children was 0.66 (95% confidence interval, CI: 0.63-0.76) in the first survey and 0.89 (95% CI: 0.83-0.94) in the second. Combination antiretroviral regimen use was associated with a lower risk of HIV infection or death in children (adjusted hazard ratio: 0.33, 95% CI: 0.15-0.73). Maternal knowledge of HIV status, use of HIV tests and use of combination regimens during pregnancy increased between the surveys. CONCLUSION: The PMTCT programme was associated with an increased HIV-free survival in children born to HIV-infected mothers. Maternal utilization of HIV testing and treatment in the community also increased.