Longitudinal estimation of Plasmodium falciparum prevalence in relation to malaria prevention measures in six sub-Saharan African countries.

BACKGROUND: Plasmodium falciparum prevalence (PfPR) is a widely used metric for assessing malaria transmission intensity. This study was carried out concurrently with the RTS,S/AS01 candidate malaria vaccine Phase III trial and estimated PfPR over ≤ 4 standardized cross-sectional surveys. METHODS: This epidemiology study (NCT01190202) was conducted in 8 sites from 6 countries (Burkina Faso, Gabon, Ghana, Kenya, Malawi, and Tanzania), between March 2011 and December 2013. Participants were enrolled in a 2:1:1 ratio according to age category: 6 months-4 years, 5-19 years, and ≥ 20 years, respectively, per year and per centre. All sites carried out surveys 1-3 while survey 4 was conducted only in 3 sites. Surveys were usually performed during the peak malaria parasite transmission season, in one home visit, when medical history and malaria risk factors/prevention measures were collected, and a blood sample taken for rapid diagnostic test, microscopy, and haemoglobin measurement. PfPR was estimated by site and age category. RESULTS: Overall, 6401 (survey 1), 6411 (survey 2), 6400 (survey 3), and 2399 (survey 4) individuals were included in the analyses. In the 6 months-4 years age group, the lowest prevalence (assessed using microscopy) was observed in 2 Tanzanian centres (4.6% for Korogwe and 9.95% for Bagamoyo) and Lambaréné, Gabon (6.0%), while the highest PfPR was recorded for Nanoro, Burkina Faso (52.5%). PfPR significantly decreased over the 3 years in Agogo (Ghana), Kombewa (Kenya), Lilongwe (Malawi), and Bagamoyo (Tanzania), and a trend for increased PfPR was observed over the 4 surveys for Kintampo, Ghana. Over the 4 surveys, for all sites, PfPR was predominantly higher in the 5-19 years group than in the other age categories. Occurrence of fever and anaemia was associated with high P. falciparum parasitaemia. Univariate analyses showed a significant association of anti-malarial treatment in 4 surveys (odds ratios [ORs]: 0.52, 0.52, 0.68, 0.41) and bed net use in 2 surveys (ORs: 0.63, 0.68, 1.03, 1.78) with lower risk of malaria infection. CONCLUSION: Local PfPR differed substantially between sites and age groups. In children 6 months-4 years old, a significant decrease in prevalence over the 3 years was observed in 4 out of the 8 study sites. Trial registration Clinical Trials.gov identifier: NCT01190202:NCT. GSK Study ID numbers: 114001.

CPAP IMPACT: a protocol for a randomised trial of bubble continuous positive airway pressure versus standard care for high-risk children with severe pneumonia using adaptive design methods.

INTRODUCTION: Pneumonia is a leading cause of mortality among children in low-resource settings. Mortality is greatest among children with high-risk conditions including HIV infection or exposure, severe malnutrition and/or severe hypoxaemia. WHO treatment recommendations include low-flow oxygen for children with severe pneumonia. Bubble continuous positive airway pressure (bCPAP) is a non-invasive support modality that provides positive end-expiratory pressure and oxygen. bCPAP is effective in the treatment of neonates in low-resource settings; its efficacy is unknown for high-risk children with severe pneumonia in low-resource settings. METHODS AND ANALYSIS: CPAP IMPACT is a randomised clinical trial comparing bCPAP to low-flow oxygen in the treatment of severe pneumonia among high-risk children 1-59 months of age. High-risk children are stratified into two subgroups: (1) HIV infection or exposure and/or severe malnutrition; (2) severe hypoxaemia. The trial is being conducted in a Malawi district hospital and will enrol 900 participants. The primary outcome is in-hospital mortality rate of children treated with standard care as compared with bCPAP. ETHICS AND DISSEMINATION: CPAP IMPACT has approval from the Institutional Review Boards of all investigators. An urgent need exists to determine whether bCPAP decreases mortality among high-risk children with severe pneumonia to inform resource utilisation in low-resource settings. TRIAL REGISTRATION NUMBER: NCT02484183; Pre-results.

RTS,S/AS01 Malaria Vaccine Efficacy is Not Modified by Seasonal Precipitation: Results from a Phase 3 Randomized Controlled Trial in Malawi.

The World Health Organization has selected Malawi as one of three sites to pilot the roll-out of RTS,S/AS01 in phase 4 trials. As policy discussions for the expanded use of RTS,S/AS01 continue, it will be critical to determine the performance of the vaccine according to seasonal patterns of malaria transmission in regions of Africa. Given waning vaccine efficacy over time, this secondary analysis demonstrates that administering the vaccine to children in the months prior to malaria season could maximize impact of the vaccine. We followed children (5-17 months) and infants (6-12 weeks) assigned to one of three groups: (1) vaccine with four doses; (2) vaccine with three doses; (3) control. The primary endpoint was defined as episodes of clinical malaria. During the 4-years of follow-up, 658 of 1544 (42.6%) children and infants had at least one episode of clinical malaria. With each 1-inch increase in rainfall per month there was an associated increase in the rate of malaria by 12.6% (95% CI 9.6%, 15.6%, P < 0.0001) among children and 15.9% (95% CI 12.8%, 18.9%, P < 0.0001) among infants. There was no evidence of effect modification of vaccine efficacy by precipitation (89% power).

Effects of community-level bed net coverage on malaria morbidity in Lilongwe, Malawi.

BACKGROUND: The protective effect of insecticide-treated bed nets against individual-level malaria transmission is well known, however community-level effects are less understood. Protective effects from community-level bed net use against malaria transmission have been observed in clinical trials, however, the relationship is less clear outside of a controlled research setting. The objective of this research was to investigate the effect of community-level bed net use against malaria transmission outside of a bed net clinical trial setting in Lilongwe, Malawi following national efforts to scale-up ownership of long-lasting, insecticide-treated bed nets. METHODS: An annual, cross-sectional, household-randomized, malaria transmission intensity survey was conducted in Lilongwe, Malawi (2011-2013). Health, demographic, and geographic-location data were collected. Participant blood samples were tested for Plasmodium falciparum presence. The percentage of people sleeping under a bed net within 400-m and 1-km radii of all participants was measured. Mixed effects logistic regression models were used to measure the relationship between malaria prevalence and surrounding bed net coverage. Each year, 800 people were enrolled (400 <5 years; 200 5-19 years; 200 ≥20 years; total n = 2400). RESULTS: From 2011 to 2013, malaria prevalence declined from 12.9 to 5.6%, while bed net use increased from 53.8 to 78.6%. For every 1% increase in community bed net coverage, malaria prevalence decreased among children under 5 years old [adjusted odds ratio: 0.98 (0.96, 1.00)]. Similar effects were observed in participants 5-19 years [unadjusted odds ratio: 0.98 (0.97, 1.00)]; the effect was attenuated after adjusting for individual-level bed net use. Community coverage was not associated with malaria prevalence among adults ≥20 years. Supplemental analyses identified more pronounced indirect protective effects from community-level bed net use against malaria transmission among children under 5 years who were sleeping under a bed net [adjusted odds ratio: 0.97 (0.94, 0.99)], compared to children who were not sleeping under a bed net [adjusted odds ratio: 0.99 (0.97, 1.01)]. CONCLUSIONS: Malawi's efforts to scale up ownership of long-lasting, insecticide-treated bed nets are effective in increasing reported use. Increased community-level bed net coverage appears to provide additional protection against malaria transmission beyond individual use in a real-world context.

Effect of Postnatal HIV Treatment on Clinical Mastitis and Breast Inflammation in HIV-Infected Breast-feeding Women.

BACKGROUND: The relationship between mastitis and antiretroviral therapy among HIV-positive, breast-feeding women is unclear. METHODS: In the Breastfeeding, Antiretrovirals, and Nutrition (BAN) study, conducted in Lilongwe, Malawi, 2369 mother-infant pairs were randomized to a nutritional supplement group and to one of three treatment groups: maternal antiretroviral therapy (ART), infant nevirapine (NVP) or standard of care for 24 weeks of exclusive breast-feeding and 4 weeks of weaning. Among 1472 HIV-infected women who delivered live infants between 2004 and 2007, we estimated cumulative incidence functions and sub-distribution hazard ratios (HR) of mastitis or breast inflammation comparing women in maternal ART (n = 487) or infant nevirapine (n = 492) groups to the standard of care (n = 493). Nutritional supplement groups (743 took, 729 did not) were also compared. RESULTS: Through 28-weeks post-partum, 102 of 1472 women experienced at least one occurrence of mastitis or breast inflammation. The 28-week risk was higher for maternal ART (risk difference (RD) 4.5, 95% confidence interval (CI) 0.9, 8.1) and infant NVP (RD 3.6, 95% CI 0.3, 6.9) compared to standard of care. The hazard of late-appearing mastitis or breast inflammation (from week 5-28) was also higher for maternal ART (HR 6.7, 95% CI 2.0, 22.6) and infant NVP (HR 5.1, 95% CI 1.5, 17. 5) compared to the standard of care. CONCLUSIONS: Mastitis or breast inflammation while breast-feeding is a possible side effect for women taking prophylactic ART and women whose infants take NVP, warranting additional research in the context of postnatal HIV transmission.

Information management in Malawi's prevention of Mother-to-Child Transmission (PMTCT) Program: Health workers' perspectives.

Aim: Health workers are the key drivers for strengthening Prevention of Mother-to-Child Transmission (PMTCT) program information management in the health facilities. Thus understanding how health workers perceive information management can enlighten areas that require interventions to improve information management processes in the health facilities. The purpose is to assess health workers' perceptions toward PMTCT program information management and factors affecting information management in the health facilities. Methods: The study was conducted in five out of forty-three health facilities providing PMTCT services in Lilongwe district and thirty out of sixty-eight health workers were recruited across the study sites. Purposive and convenience sampling were used. Semi-structured questionnaires and in-depth interviews were used to collect demographic information and health workers' perceptions toward information management, respectively. Thematic and content analysis techniques were employed for qualitative data, while descriptive statistics were used for quantitative data. Results: Most health workers perceived information management tasks as part of their job description, but less important to provision of clinical services. For many, use of information technology tools was viewed as beneficial and valuable, whereas the paper-based system was perceived as tedious and difficult to manage. In addition, some believed lack of feedback, information sharing, and poor attitude toward information management tasks were challenges. Conclusion: Based on the study findings, there is need to find ways of motivating data quality improvement practises in the health facilities, as health workers view this as a tangential, non-essential part of their job. Health facility leadership needs to promote an information culture through enforcement of meetings, supervision and provision of feedback. The government and its partners should continue rolling out and enhancing competence of health workers on EMR in the health facilities whilst also addressing challenges mentioned in the study.

Benefits and Risks of Antiretroviral Therapy for Perinatal HIV Prevention.

BACKGROUND: Randomized-trial data on the risks and benefits of antiretroviral therapy (ART) as compared with zidovudine and single-dose nevirapine to prevent transmission of the human immunodeficiency virus (HIV) in HIV-infected pregnant women with high CD4 counts are lacking. METHODS: We randomly assigned HIV-infected women at 14 or more weeks of gestation with CD4 counts of at least 350 cells per cubic millimeter to zidovudine and single-dose nevirapine plus a 1-to-2-week postpartum "tail" of tenofovir and emtricitabine (zidovudine alone); zidovudine, lamivudine, and lopinavir-ritonavir (zidovudine-based ART); or tenofovir, emtricitabine, and lopinavir-ritonavir (tenofovir-based ART). The primary outcomes were HIV transmission at 1 week of age in the infant and maternal and infant safety. RESULTS: The median CD4 count was 530 cells per cubic millimeter among 3490 primarily black African HIV-infected women enrolled at a median of 26 weeks of gestation (interquartile range, 21 to 30). The rate of transmission was significantly lower with ART than with zidovudine alone (0.5% in the combined ART groups vs. 1.8%; difference, -1.3 percentage points; repeated confidence interval, -2.1 to -0.4). However, the rate of maternal grade 2 to 4 adverse events was significantly higher with zidovudine-based ART than with zidovudine alone (21.1% vs. 17.3%, P=0.008), and the rate of grade 2 to 4 abnormal blood chemical values was higher with tenofovir-based ART than with zidovudine alone (2.9% vs. 0.8%, P=0.03). Adverse events did not differ significantly between the ART groups (P>0.99). A birth weight of less than 2500 g was more frequent with zidovudine-based ART than with zidovudine alone (23.0% vs. 12.0%, P<0.001) and was more frequent with tenofovir-based ART than with zidovudine alone (16.9% vs. 8.9%, P=0.004); preterm delivery before 37 weeks was more frequent with zidovudine-based ART than with zidovudine alone (20.5% vs. 13.1%, P<0.001). Tenofovir-based ART was associated with higher rates than zidovudine-based ART of very preterm delivery before 34 weeks (6.0% vs. 2.6%, P=0.04) and early infant death (4.4% vs. 0.6%, P=0.001), but there were no significant differences between tenofovir-based ART and zidovudine alone (P=0.10 and P=0.43). The rate of HIV-free survival was highest among infants whose mothers received zidovudine-based ART. CONCLUSIONS: Antenatal ART resulted in significantly lower rates of early HIV transmission than zidovudine alone but a higher risk of adverse maternal and neonatal outcomes. (Funded by the National Institutes of Health; PROMISE ClinicalTrials.gov numbers, NCT01061151 and NCT01253538 .).

Long-term follow-up of HIV seroconverters in microbicide trials - rationale, study design, and challenges in MTN-015.

BACKGROUND: As the effect of biomedical prevention interventions on the natural history of HIV-1 infection in participants who seroconvert is unknown, the Microbicide Trials Network (MTN) established a longitudinal study (MTN-015) to monitor virologic, immunological, and clinical outcomes, as well as behavioral changes among women who become HIV-infected during MTN trials. We describe the rationale, study design, implementation, and enrollment of the initial group of participants in the MTN seroconverter cohort. METHODS: Initiated in 2008, MTN-015 is an ongoing observational cohort study enrolling participants who acquire HIV-1 infection during effectiveness studies of candidate microbicides. Eligible participants from recently completed and ongoing MTN trials are enrolled after seroconversion and return for regular follow-up visits with clinical and behavioral data collection. Biologic samples including blood and genital fluids are stored for future testing. RESULTS: MTN-015 was implemented initially at six African sites and enrolled 100/139 (72%) of eligible women who seroconverted in HIV Prevention Trials Network protocol 035 (HPTN 035, conducted by the MTN). The median time from seroconversion in HPTN 035 to enrollment in MTN-015 was 18 months. Retention was good with >70% of visits completed. Implementation challenges included regulatory reviews, translation, and testing of questionnaires, and site readiness. CONCLUSIONS: Enrollment of HIV-seroconverters into a longitudinal observational follow-up study is feasible and acceptable to participants. Data and samples collected in this protocol will be used to assess safety of investigational HIV microbicides and answer other important public health questions for HIV infected women.

Estimation of Plasmodium falciparum Transmission Intensity in Lilongwe, Malawi, by Microscopy, Rapid Diagnostic Testing, and Nucleic Acid Detection.

Estimates of malaria transmission intensity (MTI) typically rely upon microscopy or rapid diagnostic testing (RDT). However, these methods are less sensitive than nucleic acid amplification techniques and may underestimate parasite prevalence. We compared microscopy, RDT, and polymerase chain reaction (PCR) for the diagnosis of Plasmodium falciparum parasitemia as part of an MTI study of 800 children and adults conducted in Lilongwe, Malawi. PCR detected more cases of parasitemia than microscopy or RDT. Age less than 5 years predicted parasitemia detected by PCR alone (adjusted odds ratio = 1.61, 95% confidence interval = 1.09-2.38, Wald P = 0.02). In addition, we identified one P. falciparum parasite with a false-negative RDT result due to a suspected deletion of the histidine-rich protein 2 (hrp2) gene and used a novel, ultrasensitive PCR assay to detect low-level parasitemia missed by traditional PCR. Molecular methods should be considered for use in future transmission studies as a supplement to RDT or microscopy.

Recruiting the social contacts of patients with STI for HIV screening in Lilongwe, Malawi: process evaluation and assessment of acceptability.

OBJECTIVES: To explore acceptability of recruiting social contacts for HIV and sexually transmitted infection (STI) screening in Lilongwe, Malawi. METHODS: In this observational study, three groups of 'seed' patients were enrolled: 45 HIV-infected patients with STI, 45 HIV-uninfected patients with STI and 45 community controls, who were also tested for HIV as part of the study. Each seed was given five coupons and asked to recruit up to five social contacts to the STI clinic. Seeds were told the programme for contacts would include HIV testing, STI screening and general health promotion. Seeds were asked to return after 1 month to report on the contact recruitment process. Seeds received $2 for each successfully recruited contact. RESULTS: Eighty-nine seeds (66%) returned for 1-month follow-up with no difference between the three seed groups (p=0.9). Returning seeds reported distributing most of their coupons (mean=4.1) and discussing each feature of the programme with most contacts-HIV testing (90%), STI screening (87%) and health promotion (91%). Seeds reported discussing their own HIV status with most contacts (52%), with a lower proportion of HIV-infected seeds discussing their HIV status (22%) than HIV-uninfected seeds (81%) or community seeds (64%) (p<0.001). Contact recruitment did not vary with socioeconomic status. CONCLUSIONS: Most seeds distributed all coupons and reported describing all aspects of the programme to most contacts. Patients with STI are able to act as health promoters within their social networks and may be a critical link to increasing STI and HIV status awareness among high-risk groups.

Safety, Acceptability and Adherence of Dapivirine Vaginal Ring in a Microbicide Clinical Trial Conducted in Multiple Countries in Sub-Saharan Africa.

BACKGROUND: This was the first microbicide trial conducted in Africa to evaluate an antiretroviral-containing vaginal ring as an HIV prevention technology for women. OBJECTIVES: The trial assessed and compared the safety, acceptability and adherence to product use of a 4-weekly administered vaginal ring containing the antiretroviral microbicide, dapivirine, with a matching placebo ring among women from four countries in sub-Saharan Africa. METHODS: 280 Healthy, sexually active, HIV-negative women, aged 18 to 40 years were enrolled with 140 women randomised to a dapivirine vaginal ring (25 mg) and 140 women to a matching placebo ring, inserted 4-weekly and used over a 12-week period. Safety was evaluated by pelvic examination, colposcopy, clinical laboratory assessments, and adverse events. Blood samples for determination of plasma concentrations of dapivirine were collected at Weeks 0, 4 and 12. Residual dapivirine levels in returned rings from dapivirine ring users were determined post-trial. Participant acceptability and adherence to ring use were assessed by self-reports. RESULTS: No safety concerns or clinically relevant differences were observed between the dapivirine and placebo ring groups. Plasma dapivirine concentrations immediately prior to ring removal were similar after removal of the first and third ring, suggesting consistent ring use over the 12-week period. No clear relationship was observed between the residual amount of dapivirine in used rings and corresponding plasma concentrations. Self-reported adherence to daily use of the vaginal rings over the 12-week trial period was very high. At the end of the trial, 96% of participants reported that the ring was usually comfortable to wear, and 97% reported that they would be willing to use it in the future if proven effective. CONCLUSIONS: The dapivirine vaginal ring has a favourable safety and acceptability profile. If proven safe and effective in large-scale trials, it will be an important component of combination HIV prevention approaches for women. TRIAL REGISTRATION: ClinicalTrials.gov NCT01071174.

Use of a Vaginal Ring Containing Dapivirine for HIV-1 Prevention in Women.

BACKGROUND: Antiretroviral medications that are used as prophylaxis can prevent acquisition of human immunodeficiency virus type 1 (HIV-1) infection. However, in clinical trials among African women, the incidence of HIV-1 infection was not reduced, probably because of low adherence. Longer-acting methods of drug delivery, such as vaginal rings, may simplify use of antiretroviral medications and provide HIV-1 protection. METHODS: We conducted a phase 3, randomized, double-blind, placebo-controlled trial of a monthly vaginal ring containing dapivirine, a non-nucleoside HIV-1 reverse-transcriptase inhibitor, involving women between the ages of 18 and 45 years in Malawi, South Africa, Uganda, and Zimbabwe. RESULTS: Among the 2629 women who were enrolled, 168 HIV-1 infections occurred: 71 in the dapivirine group and 97 in the placebo group (incidence, 3.3 and 4.5 per 100 person-years, respectively). The incidence of HIV-1 infection in the dapivirine group was lower by 27% (95% confidence interval [CI], 1 to 46; P=0.046) than that in the placebo group. In an analysis that excluded data from two sites that had reduced rates of retention and adherence, the incidence of HIV-1 infection in the dapivirine group was lower by 37% (95% CI, 12 to 56; P=0.007) than that in the placebo group. In a post hoc analysis, higher rates of HIV-1 protection were observed among women over the age of 21 years (56%; 95% CI, 31 to 71; P<0.001) but not among those 21 years of age or younger (-27%; 95% CI, -133 to 31; P=0.45), a difference that was correlated with reduced adherence. The rates of adverse medical events and antiretroviral resistance among women who acquired HIV-1 infection were similar in the two groups. CONCLUSIONS: A monthly vaginal ring containing dapivirine reduced the risk of HIV-1 infection among African women, with increased efficacy in subgroups with evidence of increased adherence. (Funded by the National Institutes of Health; ClinicalTrials.gov number, NCT01617096 .).

Oral and injectable contraceptive use and HIV acquisition risk among women in four African countries: a secondary analysis of data from a microbicide trial.

OBJECTIVE: To assess the effect of oral and injectable contraceptive use compared to nonhormonal contraceptive use on HIV acquisition among Southern African women enrolled in a microbicide trial. STUDY DESIGN: This is a prospective cohort study using data from women enrolled in HIV Prevention Trials Network protocol 035. At each quarterly visit, participants were interviewed about self-reported contraceptive use and sexual behaviors and underwent HIV testing. Cox proportional hazards regression was used to assess the effect of injectable and oral hormonal contraceptive use on HIV acquisition. RESULTS: The analysis included 2830 participants, of whom 106 became HIV infected (4.07 per 100 person-years). At baseline, 1546 (51%) participants reported using injectable contraceptives and 595 (21%) reported using oral contraceptives. HIV incidence among injectable, oral and nonhormonal contraceptive method users was 4.72, 2.68 and 3.83 per 100 person-years, respectively. Injectable contraceptive use was associated with a nonstatistically significant increased risk of HIV acquisition [adjusted hazard ratio (aHR)=1.17; 95% confidence interval (CI) 0.70, 1.96], while oral contraceptive use was associated with a nonstatistically significant decreased risk of HIV acquisition (aHR=0.76; 95% CI 0.37,1.55). CONCLUSION: In this secondary analysis of randomized trial data, a marginal, but nonstatistically significant, increase in HIV risk among women using injectable hormonal contraceptives was observed. No increased HIV risk was observed among women using oral contraceptives. Our findings support the World Health Organization's recommendation that women at high risk for acquiring HIV, including those using progestogen-only injectable contraception, should be strongly advised to always use condoms and other HIV prevention measures. IMPLICATIONS: Among Southern African women participating in an HIV prevention trial, women using injectable hormonal contraceptives had a modest increased risk of HIV acquisition; however, this association was not statistically significant. Continued research on the relationship between widely used hormonal contraceptive methods and HIV acquisition is essential.

Pooled Amplicon Deep Sequencing of Candidate Plasmodium falciparum Transmission-Blocking Vaccine Antigens.

Polymorphisms within Plasmodium falciparum vaccine candidate antigens have the potential to compromise vaccine efficacy. Understanding the allele frequencies of polymorphisms in critical binding regions of antigens can help in the designing of strain-transcendent vaccines. Here, we adopt a pooled deep-sequencing approach, originally designed to study P. falciparum drug resistance mutations, to study the diversity of two leading transmission-blocking vaccine candidates, Pfs25 and Pfs48/45. We sequenced 329 P. falciparum field isolates from six different geographic regions. Pfs25 showed little diversity, with only one known polymorphism identified in the region associated with binding of transmission-blocking antibodies among our isolates. However, we identified four new mutations among eight non-synonymous mutations within the presumed antibody-binding region of Pfs48/45. Pooled deep sequencing provides a scalable and cost-effective approach for the targeted study of allele frequencies of P. falciparum candidate vaccine antigens.

Immunogenicity of the RTS,S/AS01 malaria vaccine and implications for duration of vaccine efficacy: secondary analysis of data from a phase 3 randomised controlled trial.

BACKGROUND: The RTS,S/AS01 malaria vaccine targets the circumsporozoite protein, inducing antibodies associated with the prevention of Plasmodium falciparum infection. We assessed the association between anti-circumsporozoite antibody titres and the magnitude and duration of vaccine efficacy using data from a phase 3 trial done between 2009 and 2014. METHODS: Using data from 8922 African children aged 5-17 months and 6537 African infants aged 6-12 weeks at first vaccination, we analysed the determinants of immunogenicity after RTS,S/AS01 vaccination with or without a booster dose. We assessed the association between the incidence of clinical malaria and anti-circumsporozoite antibody titres using a model of anti-circumsporozoite antibody dynamics and the natural acquisition of protective immunity over time. FINDINGS: RTS,S/AS01-induced anti-circumsporozoite antibody titres were greater in children aged 5-17 months than in those aged 6-12 weeks. Pre-vaccination anti-circumsporozoite titres were associated with lower immunogenicity in children aged 6-12 weeks and higher immunogenicity in those aged 5-17 months. The immunogenicity of the booster dose was strongly associated with immunogenicity after primary vaccination. Anti-circumsporozoite titres wane according to a biphasic exponential distribution. In participants aged 5-17 months, the half-life of the short-lived component of the antibody response was 45 days (95% credible interval 42-48) and that of the long-lived component was 591 days (557-632). After primary vaccination 12% (11-13) of the response was estimated to be long-lived, rising to 30% (28-32%) after a booster dose. An anti-circumsporozoite antibody titre of 121 EU/mL (98-153) was estimated to prevent 50% of infections. Waning anti-circumsporozoite antibody titres predict the duration of efficacy against clinical malaria across different age categories and transmission intensities, and efficacy wanes more rapidly at higher transmission intensity. INTERPRETATION: Anti-circumsporozoite antibody titres are a surrogate of protection for the magnitude and duration of RTS,S/AS01 efficacy, with or without a booster dose, providing a valuable surrogate of effectiveness for new RTS,S formulations in the age groups considered. FUNDING: UK Medical Research Council.

Supporting Option B+ scale up and strengthening the prevention of mother-to-child transmission cascade in central Malawi: results from a serial cross-sectional study.

BACKGROUND: We established Safeguard the Family (STF) to support Ministry of Health (MoH) scale-up of universal antiretroviral therapy (ART) for HIV-infected pregnant and breastfeeding women (Option B+) and to strengthen the prevention of mother-to-child transmission (PMTCT) cascade from HIV testing and counseling (HTC) through maternal ART provision and post-delivery early infant HIV diagnosis (EID). To these ends, we implemented the following interventions in 5 districts: 1) health worker training and mentorship; 2) couples' HTC and male partner involvement; 3) women's psychosocial support groups; and 4) health and laboratory system strengthening for EID. METHODS: We conducted a serial cross-sectional study using facility-level quarterly (Q) program data and individual-level infant HIV-1 DNA PCR data to evaluate STF performance on PMTCT indicators for project years (Y) 1 (April-December 2011) through 3 (January-December 2013), and compared these results to national averages. RESULTS: Facility-level uptake of HTC, ART, infant nevirapine prophylaxis, and infant DNA PCR testing increased significantly from quarterly baselines of 66 % (n/N = 32,433/48,804), 23 % (n/N = 442/1,958), 1 % (n/N = 10/1,958), and 52 % (n/N = 1,385/2,644) to 87 % (n/N = 39,458/45,324), 96 % (n/N = 2,046/2,121), 100 % (n/N = 2,121/2,121), and 62 % (n/N = 1,462/2,340), respectively, by project end (all p < 0.001). Quarterly HTC, ART, and infant nevirapine prophylaxis uptake outperformed national averages over years 2-3. While transitioning EID laboratory services to MoH, STF provided first-time HIV-1 DNA PCR testing for 2,226 of 11,261 HIV-exposed infants (20 %) tested in the MoH EID program in STF districts from program inception (Y2) through Y3. Of these, 78 (3.5 %) tested HIV-positive. Among infants with complete documentation (n = 608), median age at first testing decreased from 112 days (interquartile range, IQR: 57-198) in Y2 to 76 days (IQR: 46-152) in Y3 (p < 0.001). During Y3 (only year with national data for comparison), non-significantly fewer exposed infants tested HIV-positive (3.6 %) at first testing in STF districts than nationally (4.1 %) (p = 0.4). CONCLUSIONS: STF interventions, integrated within the MoH Option B+ program, achieved favorable HTC, maternal ART, infant prophylaxis, and EID services uptake, and a low proportion of infants found HIV-infected at first DNA PCR testing. Continued investments are needed to strengthen the PMTCT cascade, particularly around EID.

Characteristics of Women Enrolled into a Randomized Clinical Trial of Dapivirine Vaginal Ring for HIV-1 Prevention.

INTRODUCTION: Women in sub-Saharan Africa are a priority population for evaluation of new biomedical HIV-1 prevention strategies. Antiretroviral pre-exposure prophylaxis is a promising prevention approach; however, clinical trials among young women using daily or coitally-dependent products have found low adherence. Antiretroviral-containing vaginal microbicide rings, which release medication over a month or longer, may reduce these adherence challenges. METHODS: ASPIRE (A Study to Prevent Infection with a Ring for Extended Use) is a phase III, randomized, double-blind, placebo-controlled trial testing the safety and effectiveness of a vaginal ring containing the non-nucleoside reverse transcriptase inhibitor dapivirine for prevention of HIV-1 infection. We describe the baseline characteristics of African women enrolled in the ASPIRE trial. RESULTS: Between August 2012 and June 2014, 5516 women were screened and 2629 HIV-1 seronegative women between 18-45 years of age were enrolled from 15 research sites in Malawi, South Africa, Uganda, and Zimbabwe. The median age was 26 years (IQR 22-31) and the majority (59%) were unmarried. Nearly 100% of participants reported having a primary sex partner in the prior three months but 43% did not know the HIV-1 status of their primary partner; 17% reported additional concurrent partners. Nearly two-thirds (64%) reported having disclosed to primary partners about planned vaginal ring use in the trial. Sexually transmitted infections were prevalent: 12% had Chlamydia trachomatis, 7% Trichomonas vaginalis, 4% Neisseria gonorrhoeae, and 1% syphilis. CONCLUSIONS: African HIV-1 seronegative women at risk of HIV -1 infection were successfully enrolled into a phase III trial of dapivirine vaginal ring for HIV-1 prevention.

Sampling at community level by using satellite imagery and geographical analysis.

PROBLEM: Traditional random sampling at community level requires a list of every individual household that can be randomly selected in the study community. The longitudinal demographic surveillance systems often used as sampling frames are difficult to create in many resource-poor settings. APPROACH: We used Google Earth imagery and geographical analysis software to develop a sampling frame. Every household structure within the catchment area was digitized and assigned coordinates. A random sample was then generated from the list of households. LOCAL SETTING: The sampling took place in Lilongwe, Malawi and formed a part of an investigation of the intensity of Plasmodium falciparum transmission in a multi-site Phase III trial of a candidate malaria vaccine. RELEVANT CHANGES: Creation of a complete list of household coordinates within the catchment area allowed us to generate a random sample representative of the population. Once the coordinates of the households in that sample had been entered into the hand-held receivers of a global positioning system device, the households could be accurately identified on the ground and approached. LESSONS LEARNT: In the development of a geographical sampling frame, the use of Google Earth satellite imagery and geographical software appeared to be an efficient alternative to the use of a demographic surveillance system. The use of a complete list of household coordinates reduced the time needed to locate households in the random sample. Our approach to generate a sampling frame is accurate, has utility beyond morbidity studies and appears to be a cost-effective option in resource-poor settings.

Assessment of peer-based and structural strategies for increasing male participation in an antenatal setting in Lilongwe, Malawi.

In sub-Saharan Africa, although male involvement in antenatal care is associated with positive outcomes for HIV-infected women and their infants, men rarely accompany female partners. We implemented a project to increase the number of male partners attending an antenatal clinic at Bwaila Hospital in Lilongwe, Malawi. We evaluated changes in the proportion of women who came with a partner over three periods. During period 1 (January 2007 - June 2008) there was didactic peer education. During period 2 (July 2008 - September 2009) a peer-led male-involvement drama was introduced into patient waiting areas. During period 3 (October 2009 - December 2009) changes to clinical infrastructure were introduced to make the clinic more male-friendly. The proportion of women attending ANC with a male partner increased from 0.7% to 5.7%, to 10.7% over the three periods. Peer education through drama and male-friendly hospital infrastructure coincided with substantially greater male participation, although further gains are necessary.