CIDRZ Research
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The CIDRZ Research Repository serves as an open-access archive for peer-reviewed publications, conference papers, and other scholarly outputs from CIDRZ researchers. Our goal is to promote the dissemination of knowledge and support evidence-based public health initiatives.
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Item HIVCorps: using volunteers to rapidly expand HIV health services across Zambia.(2006-May) Chi BH; Fusco H; Goma FM; Zulu I; Simmers E; Stringer JS; Centre for Infectious Disease Research in Zambia, Lusaka, Zambia. bchi@cidrz.org; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)In 2004, we created HIVCorps, an international volunteer program to involve pre-medical, medical, and public health students in the scale-up of HIV care and prevention services in Zambia. In our first year, we used 27 American and Zambian volunteers to assist with the administrative and logistical aspects of program implementation. Ten volunteers were based in the capital Lusaka; the remaining 17 were stationed across five rural districts. Supervision was provided by local health care providers, district officials, and hospital administrators. In our setting, the use of volunteers has proven feasible and effective for program support. Depending on a program's immediate needs, use of many basic field personnel may be more beneficial than employment of one to two trained clinicians. Formal volunteer programs like HIVCorps should be developed alongside initiatives focused on deploying more specialized, experienced healthcare workers aboard.Item Field performance of a thin-layer chromatography assay for detection of nevirapine in umbilical cord blood.(2006) Chi BH; Lee A; Acosta EP; Westerman LE; Sinkala M; Stringer JS; Centre for Infectious Disease Research in Zambia, Lusaka, Zambia. bchi@cidrz.org; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)PURPOSE: Although cord blood surveillance can measure the effectiveness of nevirapine (NVP)-based programs for the prevention of mother-to-child HIV transmission (PMTCT), it requires the ability to detect nevirapine in plasma. At present, the only validated method is high-performance liquid chromatography (HPLC), a technique poorly suited for most resource-constrained settings. METHOD: We evaluated the field performance for a simple and inexpensive thin-layer chromatography (TLC) assay for NVP detection. We developed a conditional probability model to compare 2 testing algorithms: HPLC alone, and TLC screening followed by HPLC confirmation of negative results. RESULTS: When compared to HPLC, sensitivity of TLC was 0.67 (95% confidence interval [CI] 0.49-0.84) and specificity was 0.84 (95% CI 0.69-0.95). In this sample - where overall NVP coverage was 49% - positive predictive value was 0.80 and negative predictive value was 0.72. At baseline with population NVP coverage of 33%, cost per specimen was lower in the TLC-HPLC testing algorithm (40 dollars vs. 50 dollars), and the proportion of false results was acceptable (11%). As population NVP coverage increased, cost-efficiency improved and error rate dropped substantially. CONCLUSION: TLC is reasonably sensitive and specific for NVP detection. A 2-step testing algorithm incorporating TLC and HPLC provides cost-efficiency at little expense to test performance.Item Early clinical and immune response to NNRTI-based antiretroviral therapy among women with prior exposure to single-dose nevirapine.(2007-May-11) Chi BH; Sinkala M; Stringer EM; Cantrell RA; Mtonga V; Bulterys M; Zulu I; Kankasa C; Wilfert C; Weidle PJ; Vermund SH; Stringer JS; Centre for Infectious Disease Research in Zambia, Zambia. bchi@cidrz.org; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)OBJECTIVE: To determine whether prior exposure to single-dose nevirapine (NVP) for prevention of mother-to-child HIV transmission (PMTCT) is associated with attenuated CD4 cell response, death, or clinical treatment failure in women starting antiretroviral therapy (ART) containing non-nucleoside reverse transcriptase inhibitors (NNRTI). METHODS: Open cohort evaluation of outcomes for women in program sites across Zambia. HIV treatment was provided according to Zambian/World Health Organization guidelines. RESULTS: Peripartum NVP exposure status was known for 6740 women initiating NNRTI-containing ART, of whom 751 (11%) reported prior use of NVP for PMTCT. There was no significant difference in mean CD4 cell change between those exposed or unexposed to NVP at 6 (+202 versus +182 cells/microl; P = 0.20) or 12 (+201 versus +211 cells/microl; P = 0.60) months. Multivariable analyses showed no significant differences in mortality [adjusted hazard ratio (HR), 1.2; 95% confidence interval (CI), 0.8-1.8] or clinical treatment failure (adjusted HR, 1.1; 95% CI, 0.8-1.5). Comparison of recent NVP exposure with remote exposure suggested a less favorable CD4 cell response at 6 (+150 versus +219 cells/microl; P = 0.06) and 12 (+149 versus +215 cells/microl; P = 0.39) months. Women with recent NVP exposure also had a trend towards elevated risk for clinical treatment failure (adjusted HR, 1.6; 95% CI, 0.9-2.7). CONCLUSION: Exposure to maternal single-dose NVP was not associated with substantially different short-term treatment outcomes. However, evidence was suggestive that exposure within 6 months of ART initiation may be a risk factor for poor treatment outcomes, highlighting the importance of ART screening and initiation early in pregnancy.Item A randomized trial of the intrauterine contraceptive device vs hormonal contraception in women who are infected with the human immunodeficiency virus.(2007-Aug) Stringer EM; Kaseba C; Levy J; Sinkala M; Goldenberg RL; Chi BH; Matongo I; Vermund SH; Mwanahamuntu M; Stringer JS; Centre for Infectious Disease Research in Zambia, Lusaka, Zambia. eli@uab.edu; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)OBJECTIVE: The purpose of this study was to determine whether the intrauterine contraceptive device (IUD) is effective and safe among women who are infected with the human immunodeficiency virus (HIV). STUDY DESIGN: We randomly assigned 599 postpartum, HIV-infected women in Zambia to receive either a copper IUD or hormonal contraception and followed them for at least 2 years. RESULTS: Women who were assigned randomly to hormonal contraception were more likely to become pregnant than those who were assigned randomly to receive an IUD (rate, 4.6/100 vs 2.0/100 woman-years; hazards ratio, 2.4; 95% CI, 1.3-4.7). One woman who was assigned to the IUD experienced pelvic inflammatory disease (crude rate, 0.16/100 woman-years; 95% CI, 0.004-868); there was no pelvic inflammatory disease among those women who were assigned to hormonal contraception. Clinical disease progression (death or CD4+ lymphocyte count dropping below 200 cells/microL) was more common in women who were allocated to hormonal contraception (13.2/100 woman-years) than in women who were allocated to the IUD (8.6/100 woman-years; hazard ratio, 1.5; 95% CI, 1.04-2.1). CONCLUSION: The IUD is effective and safe in HIV-infected women. The unexpected observation that hormonal contraception was associated with more rapid HIV disease progression requires urgent further study.Item Use of traditional medicine among pregnant women in Lusaka, Zambia.(2007) Banda Y; Chapman V; Goldenberg RL; Stringer JS; Culhane JF; Sinkala M; Vermund SH; Chi BH; University of Zambia School of Medicine, Lusaka, Zambia. yolan.banda@cidrz.org; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)OBJECTIVE: We studied the prevalence of and predictors for traditional medicine use among pregnant women seeking care in the Lusaka, Zambia public health system. SUBJECTS: We surveyed 1128 pregnant women enrolled in a clinical trial of perinatal human immunodeficiency virus (HIV) prevention strategies at two district delivery centers. OUTCOME MEASURES: Postpartum questionnaires were administered to determine demographic characteristics, behavioral characteristics, HIV knowledge, and prior use of traditional medicines. RESULTS: Of the 1128 women enrolled, 335 (30%) reported visiting a traditional healer in the past; 237 (21%) reported using a traditional healer during the current pregnancy. Overall, 54% believed that admitting to a visit to a traditional healer would result in worse medical care. When women who had used traditional medicines were compared to those who had not, no demographic differences were noted. However, women who reported use of traditional medicine were more likely to drink alcohol during pregnancy, have >or=2 sex partners, engage in "dry sex," initiate sex with their partner, report a previously treated sexually transmitted disease, and use contraception (all p < 0.01). HIV-infected women who reported using traditional healers were also less likely to adhere to a proven medical regimen to reduce HIV transmission to their infant (25% versus 50%, p = 0.048). CONCLUSIONS: Use of traditional medicine during pregnancy is common, stigmatized, and may be associated with nonadherence to antiretroviral regimens. Health care providers must open lines of communication with traditional healers and with pregnant women themselves to maximize program success.Item Clinical outcomes and CD4 cell response in children receiving antiretroviral therapy at primary health care facilities in Zambia.(2007-Oct-24) Bolton-Moore C; Mubiana-Mbewe M; Cantrell RA; Chintu N; Stringer EM; Chi BH; Sinkala M; Kankasa C; Wilson CM; Wilfert CM; Mwango A; Levy J; Abrams EJ; Bulterys M; Stringer JS; Centre for Infectious Disease Research in Zambia, Lusaka.; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)CONTEXT: The Zambian Ministry of Health provides pediatric antiretroviral therapy (ART) at primary care clinics in Lusaka, where, despite scale-up of perinatal prevention efforts, many children are already infected with the human immunodeficiency virus (HIV). OBJECTIVE: To report early clinical and immunologic outcomes of children enrolled in the pediatric treatment program. DESIGN, SETTING, AND PATIENTS: Open cohort assessment using routinely collected clinical and outcome data from an electronic medical record system in use at 18 government primary health facilities in Lusaka, Zambia. Care was provided primarily by nurses and clinical officers ("physician extenders" akin to physician assistants in the United States). Patients were children (<16 years of age) presenting for HIV care between May 1, 2004, and June 29, 2007. INTERVENTION: Three-drug ART (zidovudine or stavudine plus lamivudine plus nevirapine or efavirenz) for children who met national treatment criteria. MAIN OUTCOME MEASURES: Survival, weight gain, CD4 cell count, and hemoglobin response. RESULTS: After enrollment of 4975 children into HIV care, 2938 (59.1%) started ART. Of those initiating ART, the median age was 81 months (interquartile range, 36-125), 1531 (52.1%) were female, and 2087 (72.4%) with World Health Organization stage information were in stage III or IV. At the time of analysis, 158 children (5.4%) had withdrawn from care and 382 (13.0%) were at least 30 days late for follow-up. Of the remaining 2398 children receiving ART, 198 (8.3%) died over 3018 child-years of follow-up (mortality rate, 6.6 deaths per 100 child-years; 95% confidence interval [CI], 5.7-7.5); of these deaths, 112 (56.6%) occurred within 90 days of therapy initiation (early mortality rate, 17.4/100 child-years; post-90-day mortality rate, 2.9/100 child-years). Mortality was associated with CD4 cell depletion, lower weight-for-age, younger age, and anemia in multivariate analysis. The mean CD4 cell percentage at ART initiation among the 1561 children who had at least 1 repeat measurement was 12.9% (95% CI, 12.5%-13.3%) and increased to 23.7% (95% CI, 23.1%-24.3%) at 6 months, 27.0% (95% CI, 26.3%-27.6%) at 12 months, 28.0% (95% CI, 27.2%-28.8%) at 18 months, and 28.4% (95% CI, 27.4%-29.4%) at 24 months. CONCLUSIONS: Care provided by clinicians such as nurses and clinical officers can result in good outcomes for HIV-infected children in primary health care settings in sub-Saharan Africa. Mortality during the first 90 days of therapy is high, pointing to a need for earlier intervention.Item Do targeted HIV programs improve overall care for pregnant women?: Antenatal syphilis management in Zambia before and after implementation of prevention of mother-to-child HIV transmission programs.(2008-Jan-01) Potter D; Goldenberg RL; Chao A; Sinkala M; Degroot A; Stringer JS; Bulterys M; Vermund SH; Schools of Public Health and Medicine, University of Alabama at Birmingham, Birmingham, AL, USA. dara.potter@cidrz.org; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)BACKGROUND: The implementation of disease-specific research or service programs may have an ancillary beneficial or harmful impact on routine clinical services. METHODS: We reviewed the records of 5801 first visits to 22 antenatal clinics from 1997 to 2004 in Lusaka, Zambia and examined documented syphilis rapid plasma reagin (RPR) screening and syphilis treatment before and after implementation of research and/or service programs in prevention of mother-to-child (PMTCT) HIV transmission. FINDINGS: Compared with before PMTCT program implementation, the prevalence odds ratios (PORs) and 95% confidence intervals (CIs) for documented RPR screening were 0.9 (0.7 to 1.1) after implementation of research, 0.7 (0.6 to 0.8) after service, and 2.5 (2.1 to 3.0) after research and service programs. CONCLUSIONS: Documented RPR screening was improved after implementation of PMTCT research and service were operating simultaneously and not with research or service alone. Health policy makers and researchers should plan explicitly for how the targeted HIV programs, service, and/or research can have a broader primary care impact.Item Monitoring effectiveness of programmes to prevent mother-to-child HIV transmission in lower-income countries.(2008-Jan) Stringer EM; Chi BH; Chintu N; Creek TL; Ekouevi DK; Coetzee D; Tih P; Boulle A; Dabis F; Shaffer N; Wilfert CM; Stringer JS; Centre for Infectious Disease Research in Zambia, Lusaka, Zambia. eli@uab.edu; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)Ambitious goals for paediatric AIDS control have been set by various international bodies, including a 50% reduction in new paediatric infections by 2010. While these goals are clearly appropriate in their scope, the lack of clarity and consensus around how to monitor the effectiveness of programmes to prevent mother-to-child HIV transmission (PMTCT) makes it difficult for policy-makers to mount a coordinated response. In this paper, we develop the case for using population HIV-free child survival as a gold standard metric to measure the effectiveness of PMTCT programmes, and go on to consider multiple study designs and source populations. Finally, we propose a novel community survey-based approach that could be implemented widely throughout the developing world with minor modifications to ongoing Demographic and Health Surveys.Item 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.Item 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.