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 Antiretroviral therapy in sub-Saharan Africa: adherence lessons from tuberculosis and leprosy.(2004-Nov) Reid SE; Reid CA; Vermund SH; Centre for Infectious Disease Research in Zambia, PO Box 34681, Plot 5977 Benakale Road, Northmead, Lusaka, Zambia. stewart@cidrz.org; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)Declining drug costs and increases in international donor interest are leading to greater availability of antiretroviral treatment programmes for persons living with the human immunodeficiency virus in parts of sub-Saharan Africa. Ensuring adequate adherence to antiretroviral drug therapy is one of the principal challenges facing successful implementation in Africa, where 70% of the world's infected persons live. Tuberculosis and leprosy are two diseases of global importance whose control programmes can provide important lessons for developing antiretroviral drug adherence strategies. This paper examines various approaches used in tuberculosis and leprosy control which could help enhance adherence to antiretroviral therapy in resource-limited settings.Item Perceptions toward HIV, HIV screening, and the use of antiretroviral medications: a survey of maternity-based health care providers in Zambia.(2004-Oct) Chi BH; Chansa K; Gardner MO; Sangi-Haghpeykar H; Goldenberg RL; Sinkala M; Muchimba M; Stringer JS; Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, Texas, USA. Bchi@cidrz.org; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)Mother-to-child transmission of HIV (MTCT) is a major contributor to Zambia's HIV burden. Based on our experience in Zambia, we felt that provider perceptions, knowledge base, and practice patterns toward HIV-positive mothers may pose as significant obstacles to preventing MTCT. Two hundred and twenty-five health care providers throughout Zambia were surveyed in 2002. Providers reported widespread stigma associated with HIV. Physicians (OR = 1.9), providers with research affiliations (OR = 2.3), and those located in Lusaka (OR = 9.0) were more likely to offer HIV testing. Only 30% routinely prescribed antiretroviral treatment (ART) to reduce MTCT. Practitioners from district facilities, those from Lusaka, and those employed at research facilities were more likely to prescribe ART routinely (OR = 2.8, 10.1 and 3.4 respectively). Among those never prescribing ART, most cited a lack of availability (83%). Our results highlight the need for further provider education, critical appraisal of the current system for HIV testing, and widespread distribution of ART.Item Effectiveness of a city-wide program to prevent mother-to-child HIV transmission in Lusaka, Zambia.(2005-Aug-12) Stringer JS; Sinkala M; Maclean CC; Levy J; Kankasa C; Degroot A; Stringer EM; Acosta EP; Goldenberg RL; Vermund SH; Schools of Medicine and Public Health, University of Alabama at Birmingham, USA. stringer@cidrz.org; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)OBJECTIVE: To determine the population effectiveness of a city-wide perinatal HIV prevention program. DESIGN: An anonymous surveillance of newborn cord blood for HIV serology and nevirapine (NVP). METHODS: All 10 public-sector delivery centers in Lusaka, Zambia participated. All mother-infant pairs delivering during the 12-week surveillance period at the participating centers and who received antenatal care at a public-sector facility in Lusaka were included in the study. The main outcome measure was population NVP coverage, defined as the proportion of HIV-infected women and HIV-exposed infants in the population that ingested NVP. RESULTS: Of 8787 women in the surveillance population, 7204 (82%) had been offered antenatal HIV testing, of which 5149 (71%) had accepted, and of which 5129 (99%) had received a result. Overall, 2257 of 8787 (26%) were cord seropositive. Of the 1246 (55%) cord blood seropositive women who received an antenatal HIV test result, 1112 (89%) received a positive result; the other 134 comprise seroconverters and clerical errors. Only 751 of 1112 (68%) women who received a positive antenatal test result and a NVP tablet for ingestion at labor onset had NVP detected in the cord blood (i.e., maternal non-adherence rate was 32%). A total of 675 infants born to 751 adherent mothers (90%) received NVP before discharge. Thus, only 675 of 2257 (30%) seropositive mother-infant pairs in the surveillance population received both a maternal and infant dose of NVP. CONCLUSIONS: Successful perinatal HIV prevention requires each mother-infant pair to negotiate a cascade of events that begins with offering HIV testing and continues through adherence to the prescribed regimen. This novel surveillance demonstrates that failures occur at each step, resulting in reduced coverage and diminished program effectiveness.Item Timing of maternal and neonatal dosing of nevirapine and the risk of mother-to-child transmission of HIV-1: HIVNET 024.(2005-Nov-04) Chi BH; Wang L; Read JS; Sheriff M; Fiscus S; Brown ER; Taha TE; Valentine M; Goldenberg R; University of Alabama at Birmingham, Department of Obstetrics & Gynecology, Birmingham, Alabama, USA. bchi@cidrz.org; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)OBJECTIVE: Despite a growing emphasis worldwide on complex and potent antiretroviral drug regimens for the prevention of mother-to-child transmission of HIV-1 (MTCT), two-dose nevirapine (NVP) prophylaxis remains an important choice in many settings. We analyzed data from a multicenter clinical trial to determine whether timing of maternal or infant NVP was associated with MTCT between delivery and 6 weeks of age (intrapartum/early postnatal transmission; I/EP). METHODS: HIVNET 024 was a placebo-controlled, double-blind trial of empiric antibiotics to reduce chorioamnionitis-associated MTCT. This secondary analysis used data collected in the original randomized trial. Enrolled women were instructed to self-administer NVP at labor onset; infants were to receive a dose within 72 h of birth. RESULTS: Data regarding 1491 mother-infant pairs were analyzed. The overall I/EP HIV-1 transmission rate was 8.1% at 6 weeks. Almost all women (93%) ingested NVP within 24 h of delivery; 90% of infants were given NVP within 48 h after delivery. Variations in mother or infant dose timing did not influence transmission rates, even when the combined pattern of both was taken into account through multivariate analysis. In the subset of women ingesting NVP or= 4 h). CONCLUSION: Variations in the timing of maternal and infant NVP doses (within reasonable proximity to delivery) do not appear to affect the risk of MTCT.Item Cost and enrollment implications of targeting different source population for an HIV treatment program.(2005-Nov-01) Chi BH; Fusco H; Sinkala M; Goldenberg RL; Stringer JS; Centre for Infectious Disease Research in Zambia, Lusaka, Zambia. bchi@uab.edu; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)BACKGROUND: Rapid scale-up of antiretroviral therapy (ART) is a worldwide priority, and ambitious targets for numbers on ART have been set. Antenatal clinics (ANCs) and tuberculosis (TB) clinics have been targeted as entry points into HIV care. METHODS: We developed a conditional probability model to evaluate the effects of ANC and TB clinic populations on ART program enrollment. RESULTS: To start 1 individual on ART, 3 TB patients have to be screened at a crude program cost of 36 US dollars per patient initiated on therapy. By contrast, 48 ANC patients have to be screened at a cost of US 214 US dollars per patient on therapy. In an incremental analysis in which ANC HIV testing was borne by a program to prevent mother-to-child transmission, recruitment efficiency increased (8 screened per patient starting ART) and cost decreased (114 US dollars per patient on therapy). Absolute numbers starting ART, however, remained fixed. If all 60,000 ANC patients seen yearly in the Lusaka District were screened, 1247 would start ART. Approaching the district's 35,000 annual TB patients would generate 11,947 patients on ART. CONCLUSION: In areas with high HIV prevalence, targeting chronically ill populations for HIV treatment may have significant short-term benefits in cost savings and recruitment efficiency.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 Isolation and characterization of a new simian rotavirus, YK-1.(2006-May-31) Westerman LE; Jiang B; McClure HM; Snipes-Magaldi LJ; Griffin DD; Shin G; Gentsch JR; Glass RI; Viral Gastroenteritis Team, Respiratory and Enteric Viruses Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA. larry@cidrz.org; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)BACKGROUND: To effectively analyze the requirements for protection to rotavirus infection, a reliable animal model that reasonably mimics infection and disease in humans is needed. A requirement for an effective animal model is the availability of appropriate rotavirus stocks for challenge. RESULTS: A new simian rotavirus, designated YK-1, was isolated from a 2-year-old immunodeficient pigtailed macaque with chronic diarrhea. YK-1 was distinguishable by electropherotype from the other simian rotavirus strains, SA11 and RRV. One variant of YK-1, clone 311, which was isolated after adaptation and plaque purification in cell cultures, displayed an unusual RNA electropherotype with an abnormally migrating gene 11 segment. Sequence analysis demonstrated a genetic rearrangement that involved a partial duplication of the gene 11 ORF encoding NSP5. YK-1 was identified as a Group A rotavirus belonging to subgroup 1. To further characterize the YK-1 strain, the genes encoding VP4, VP7, and NSP4 were sequenced. Analysis of VP4 and VP7 gene fragments suggests that this strain is a G3P3 rotavirus and is closely related to the simian rotavirus strain RRV. Serotype analysis also identified YK-1 as a G3 rotavirus. The NSP4 genotype of YK-1 is C, the same genotype as RRV. CONCLUSION: This newly isolated rotavirus, YK-1, is being used to establish a nonhuman primate model for studying the infectivity, immunity, and pathogenesis of rotavirus and for evaluating candidate rotavirus vaccines.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 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.