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Norfloxacin Is Inferior to Chloroquine for Falciparum Malaria in Northwestern Zambia: A Comparative Clinical Trial
(1992-5-1) McClean, Karen L.; Hitchman, Derek; Shafran, Stephen D.
An Outbreak of Plague in Northwestern Province, Zambia
(1995-9-1) McClean K. L.
Europe to create new centre for communicable disease
(2003-6) Orellana, Claudia
Ethiopia loses HIV research centre
(2003-8) Ahmad, Khabir
Antiretroviral therapy in sub-Saharan Africa: adherence lessons from tuberculosis and leprosy.
(2004-Nov) Reid SE; Reid CA; Vermund SH
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.
Perceptions toward HIV, HIV screening, and the use of antiretroviral medications: a survey of maternity-based health care providers in Zambia.
(2004-Oct) Chi, Benjamin H.; Chansa, Kayula; Gardner, Michael O.; Sangi-Haghpeykar, Haleh; Goldenberg, Robert L.; Sinkala, Moses; Muchimba, Maureen; Stringer, Jeffrey S.
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.
Lusaka, Zambia
(2005-4-7) Nave Ari
Effectiveness of a city-wide program to prevent mother-to-child HIV transmission in Lusaka, Zambia.
(2005-Aug-12) Stringer, Jeffrey S.; Sinkala, Moses; Maclean, Courtney C.; Levy, Jens; Kankasa, Chipepo; Degroot, Alain; Stringer, Elizabeth M.; Acosta, Edward P.; Goldenberg, Robert L.; Vermund, Sten H.
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.
Cost and enrollment implications of targeting different source population for an HIV treatment program.
(2005-Nov-01) Chi, Benjamin H.; Fusco, Harmony; Sinkala, Moses; Goldenberg, Robert L.; Stringer, Jeffrey S.
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.
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, Benjamin H.; Wang, Lei; Read, Jennifer S.; Sheriff, Muhsin; Fiscus, Susan; Brown, Elizabeth R.; Taha, Taha E.; Valentine, Megan; Goldenberg, Robert
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.
Field performance of a thin-layer chromatography assay for detection of nevirapine in umbilical cord blood.
(2006) Chi, Benjamin H.; Lee, Alison; Acosta, Edward P.; Westerman, Larry E.; Sinkala, Moses; Stringer, Jeffrey S.
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.
HIVCorps: using volunteers to rapidly expand HIV health services across Zambia.
(2006-May) Chi, Benjamin H.; Fusco, Harmony; Goma, Fastone M.; Zulu, Isaac; Simmers, Erin; Stringer, Jeffrey S.
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.
Isolation and characterization of a new simian rotavirus, YK-1.
(2006-May-31) Westerman, Larry E.; Jiang, Baoming; McClure, Harold M.; Snipes-Magaldi, Lauren J.; Griffin, Dixie D.; Shin, Gary; Gentsch, Jon R.; Glass, Roger I.
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.
Use of traditional medicine among pregnant women in Lusaka, Zambia.
(2007) Banda, Yolan; Chapman, Victoria; Goldenberg, Robert L.; Stringer, Jeffrey S.; Culhane, Jennifer F.; Sinkala, Moses; Vermund, Sten H.; Chi, Benjamin H.
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.
New US Lyme disease research centre opens
(2007-6) Senior, Kathryn
Opportunities for Increased Production, Utilization and Income Generation from African Leafy Vegetables in Zambia
(2007-7-7) Ng'uni, Dickson; Mwila, Godfrey
In order to promote the production and marketing of African Leafy Vegetables (ALVs) and help realize their potential as sources of food and income, a case study was undertaken under the IPGRI programme on ALVs. The study was aimed at determining the priority ALVs and assessing their status in terms of genetic diversity, production, processing and marketing through a household survey. Three communities of Hoffmeyer, Subcentre and Chikumbi in Nyimba, Siavonga and Chibombo districts respectively were covered. Information was gathered from 280 households across the communities through participatory rural appraisal using guided household interviews and focused group discussions. Amaranthus spp. Wild spinach (English) Bboonko (Tonga), Libondwe (Lenje), Bondwe (Nyanja); Cleome gynandra Cat’s whiskers, spiderplant (English), Shungwa/ Luyuni-yuni (Tonga), Lubanga (Lenje), Suntha (Nyanja); Abelmoschus esculentus, Okra (English), Mudelele/ Mutezi (Tonga), Delele/ Mulembwe (Lenje), Delele (Nyanja); Brassica carinata, Ethiopian Mustard (English) Tanta a chulu/ Chishu chituba (Tonga), Mupilu/ Nchembele (Lenje), Mupilu (Nyanja) and Cucurbita spp., Pumpkin (English) Bboobbo, Lutanga, Muchile (Tonga), Buchisa bwa nyungu (Lenje), Chiwawa, Mthopo (Njanja) were identified as priority ALVs. It was found that within species variability based on morphological markers of the target ALVs was generally low except for Abelmoschus esculentus and Cucurbita spp which had more than three known varieties. Although 63% of households cultivated both ALVs and exotic vegetables, 33% of the households cultivated ALVs while only 4% exclusively grew exotic vegetables. Farm saved seed for all ALVs except Abelmoschus esculentus was used by 81% of households across communities while 10% obtained their seed from neighbours/relatives within their communities. Direct sowing was the commonest planting method while the application of organic manure to the crop was prominent in Subcentre followed by Chikumbi. Application of mineral fertilizers to ALVs was uncommon practice except in Abelmoschus esculentus. It was revealed that the most preserved ALVs were Abelmoschus esculentus and Cucurbita spp. Open markets and supermarkets in Lusaka sold ALVs such as Abelmoschus esculentus, Amaranthus spp and Cucurbita spp. The main sources of these vegetables in Lusaka were local farmers in the peri-urban areas of the town. A total of 33 different recipes and eleven preservation methods for ALVs were documented across communities while 7 recipes were documented from commercial restaurants. The ALVs play an increasing role in the diets and as source of income for many households and efforts required for stimulating production include improvements in access to improved varieties and availability of urban markets.
A randomized trial of the intrauterine contraceptive device vs hormonal contraception in women who are infected with the human immunodeficiency virus.
(2007-Aug) Stringer, Elizabeth M.; Kaseba, Christine; Levy, Jens; Sinkala, Moses; Goldenberg, Robert L.; Chi, Benjamin H.; Matongo, Inutu; Vermund, Sten H.; Mwanahamuntu, Mulindi; Stringer, Jeffrey S.
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.
Early clinical and immune response to NNRTI-based antiretroviral therapy among women with prior exposure to single-dose nevirapine.
(2007-May-11) Chi, Benjamin H.; Sinkala, Moses; Stringer, Elizabeth M.; Cantrell, Ronald A.; Mtonga, Velepi; Bulterys, Marc; Zulu, Isaac; Kankasa, Chipepo; Wilfert, Catherine; Weidle, Paul J.; Vermund, Sten H.; Stringer, Jeffrey S.
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.
Predictors of stillbirth in sub-saharan Africa.
(2007-Nov) Chi, Benjamin H.; Wang, Lei; Read, Jennifer S.; Taha, Taha E.; Sinkala, Moses; Brown, Elizabeth R.; Valentine, Megan; Martinson, Francis; Goldenberg, Robert L.
OBJECTIVE: To describe the incidence and predictors of stillbirth in a predominantly human immunodeficiency virus (HIV)-infected African cohort. METHODS: Human Immunodeficiency Virus (HIV) Prevention Trials Network (HPTN) 024 was a randomized controlled trial of empiric antibiotics to reduce chorioamnionitis-related perinatal HIV transmission. A proportion of HIV-uninfected individuals were enrolled to reduce community-based stigma surrounding the trial. For this analysis, only women who gave birth to singleton infants were included. RESULTS: Of 2,659 women enrolled, 2,434 (92%) mother- child pairs met inclusion criteria. Of these, 2,099 (86%) infants were born to HIV-infected women, and 335 (14%) were born to HIV-uninfected women. The overall stillbirth rate was 32.9 per 1,000 deliveries (95% confidence interval [CI] 26.1-40.7). In univariable analyses, predictors for stillbirth included previous stillbirth (odds ratio [OR] 2.3, 95% CI 1.2-4.3), antenatal hemorrhage (OR 14.4, 95% CI 4.3-47.9), clinical chorioamnionitis (OR 20.9, 95% CI 5.1-86.2), and marked polymorphonuclear infiltration on placental histology (OR 2.9, 95% CI 1.7-5.2). When compared with pregnancies longer than 37 weeks, those at 34-37 weeks (OR 1.7, 95% CI 0.8-3.4) and those at less than 34 weeks (OR 22.8, 95% CI 13.6-38.2) appeared more likely to result in stillborn delivery. Human immunodeficiency virus infection was not associated with a greater risk for stillbirth in either univariable (OR 1.5, 95% CI 0.7-3.0) or multivariable (adjusted OR 1.11, 95% CI 0.38-3.26) analysis. Among HIV-infected women, however, decreasing CD4 cell count was inversely related to stillbirth risk (P=.009). CONCLUSION: In this large cohort, HIV infection was not associated with increased stillbirth risk. Further work is needed to elucidate the relationship between chorioamnionitis and stillbirth in African populations. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, www.clinicaltrials.gov, NCT00021671 LEVEL OF EVIDENCE: II.
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, Benjamin H.; Sinkala, Moses; Mbewe, Felistas; Cantrell, Ronald A.; Kruse, Gina; Chintu, Namwinga; Aldrovandi, Grace M.; Stringer, Elizabeth M.; Kankasa, Chipepo ; Safrit, Jeffrey T.; Stringer, Jeffrey S.
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.