Efficacy and Safety of an Ad26.RSV.preF-RSV preF Protein Vaccine in Older Adults.

BACKGROUND: Respiratory syncytial virus (RSV) can cause serious lower respiratory tract disease in older adults, but no licensed RSV vaccine currently exists. An adenovirus serotype 26 RSV vector encoding a prefusion F (preF) protein (Ad26.RSV.preF) in combination with RSV preF protein was previously shown to elicit humoral and cellular immunogenicity. METHODS: We conducted a randomized, double-blind, placebo-controlled, phase 2b, proof-of-concept trial to evaluate the efficacy, immunogenicity, and safety of an Ad26.RSV.preF-RSV preF protein vaccine. Adults who were 65 years of age or older were randomly assigned in a 1:1 ratio to receive vaccine or placebo. The primary end point was the first occurrence of RSV-mediated lower respiratory tract disease that met one of three case definitions: three or more symptoms of lower respiratory tract infection (definition 1), two or more symptoms of lower respiratory tract infection (definition 2), and either two or more symptoms of lower respiratory tract infection or one or more symptoms of lower respiratory tract infection plus at least one systemic symptom (definition 3). RESULTS: Overall, 5782 participants were enrolled and received an injection. RSV-mediated lower respiratory tract disease meeting case definitions 1, 2, and 3 occurred in 6, 10, and 13 vaccine recipients and in 30, 40, and 43 placebo recipients, respectively. Vaccine efficacy was 80.0% (94.2% confidence interval [CI], 52.2 to 92.9), 75.0% (94.2% CI, 50.1 to 88.5), and 69.8% (94.2% CI, 43.7 to 84.7) for case definitions 1, 2, and 3, respectively. After vaccination, RSV A2 neutralizing antibody titers increased by a factor of 12.1 from baseline to day 15, a finding consistent with other immunogenicity measures. Percentages of participants with solicited local and systemic adverse events were higher in the vaccine group than in the placebo group (local, 37.9% vs. 8.4%; systemic, 41.4% vs. 16.4%); most adverse events were mild to moderate in severity. The frequency of serious adverse events was similar in the vaccine group and the placebo group (4.6% and 4.7%, respectively). CONCLUSIONS: In adults 65 years of age or older, Ad26.RSV.preF-RSV preF protein vaccine was immunogenic and prevented RSV-mediated lower respiratory tract disease. (Funded by Janssen Vaccines and Prevention; CYPRESS ClinicalTrials.gov number, NCT03982199.).

Combining rapid diagnostic tests to estimate primary and post-primary dengue immune status at the point of care.

BACKGROUND: Characterising dengue virus (DENV) infection history at the point of care is challenging as it relies on intensive laboratory techniques. We investigated how combining different rapid diagnostic tests (RDTs) can be used to accurately determine the primary and post-primary DENV immune status of reporting patients during diagnosis. METHODS AND FINDINGS: Serum from cross-sectional surveys of acute suspected dengue patients in Indonesia (N:200) and Vietnam (N: 1,217) were assayed using dengue laboratory assays and RDTs. Using logistic regression modelling, we determined the probability of being DENV NS1, IgM and IgG RDT positive according to corresponding laboratory viremia, IgM and IgG ELISA metrics. Laboratory test thresholds for RDT positivity/negativity were calculated using Youden's J index and were utilized to estimate the RDT outcomes in patients from the Philippines, where only data for viremia, IgM and IgG were available (N:28,326). Lastly, the probabilities of being primary or post-primary according to every outcome using all RDTs, by day of fever, were calculated. Combining NS1, IgM and IgG RDTs captured 94.6% (52/55) and 95.4% (104/109) of laboratory-confirmed primary and post-primary DENV cases, respectively, during the first 5 days of fever. Laboratory test predicted, and actual, RDT outcomes had high agreement (79.5% (159/200)). Among patients from the Philippines, different combinations of estimated RDT outcomes were indicative of post-primary and primary immune status. Overall, IgG RDT positive results were confirmatory of post-primary infections. In contrast, IgG RDT negative results were suggestive of both primary and post-primary infections on days 1-2 of fever, yet were confirmatory of primary infections on days 3-5 of fever. CONCLUSION: We demonstrate how the primary and post-primary DENV immune status of reporting patients can be estimated at the point of care by combining NS1, IgM and IgG RDTs and considering the days since symptoms onset. This framework has the potential to strengthen surveillance operations and dengue prognosis, particularly in low resource settings.

Prevention of Respiratory Syncytial Virus Infection in Healthy Adults by a Single Immunization of Ad26.RSV.preF in a Human Challenge Study.

BACKGROUND: Respiratory syncytial virus (RSV) is a significant cause of severe lower respiratory tract disease in children and older adults, but has no approved vaccine. This study assessed the potential of Ad26.RSV.preF to protect against RSV infection and disease in an RSV human challenge model. METHODS: In this double-blind, placebo-controlled study, healthy adults aged 18-50 years were randomized 1:1 to receive 1 × 1011 vp Ad26.RSV.preF or placebo intramuscularly. Twenty-eight days postimmunization, volunteers were challenged intranasally with RSV-A (Memphis 37b). Assessments included viral load (VL), RSV infections, clinical symptom score (CSS), safety, and immunogenicity. RESULTS: Postchallenge, VL, RSV infections, and disease severity were lower in Ad26.RSV.preF (n = 27) vs placebo (n = 26) recipients: median VL area under the curve (AUC) quantitative real-time polymerase chain reaction: 0.0 vs 236.0 (P = .012; predefined primary endpoint); median VL-AUC quantitative culture: 0.0 vs 109; RSV infections 11 (40.7%) vs 17 (65.4%); median RSV AUC-CSS 35 vs 167, respectively. From baseline to 28 days postimmunization, geometric mean fold increases in RSV A2 neutralizing antibody titers of 5.8 and 0.9 were observed in Ad26.RSV.preF and placebo, respectively. Ad26.RSV.preF was well tolerated. CONCLUSIONS: Ad26.RSV.preF demonstrated protection from RSV infection through immunization in a human challenge model, and therefore could potentially protect against natural RSV infection and disease. CLINICAL TRIALS REGISTRATION: NCT03334695; CR108398, 2017-003194-33 (EudraCT); VAC18193RSV2002.

Case-area targeted interventions (CATI) for reactive dengue control: Modelling effectiveness of vector control and prophylactic drugs in Singapore.

BACKGROUND: Targeting interventions to areas that have recently experienced cases of disease is one strategy to contain outbreaks of infectious disease. Such case-area targeted interventions (CATI) have become an increasingly popular approach for dengue control but there is little evidence to suggest how precisely targeted or how recent cases need to be, to mount an effective response. The growing interest in the development of prophylactic and therapeutic drugs for dengue has also given new relevance for CATI strategies to interrupt transmission or deliver early treatment. METHODS/PRINCIPAL FINDINGS: Here we develop a patch-based mathematical model of spatial dengue spread and fit it to spatiotemporal datasets from Singapore. Simulations from this model suggest CATI strategies could be effective, particularly if used in lower density areas. To maximise effectiveness, increasing the size of the radius around an index case should be prioritised even if it results in delays in the intervention being applied. This is partially because large intervention radii ensure individuals receive multiple and regular rounds of drug dosing or vector control, and thus boost overall coverage. Given equivalent efficacy, CATIs using prophylactic drugs are predicted to be more effective than adult mosquito-killing vector control methods and may even offer the possibility of interrupting individual chains of transmission if rapidly deployed. CATI strategies quickly lose their effectiveness if baseline transmission increases or case detection rates fall. CONCLUSIONS/SIGNIFICANCE: These results suggest CATI strategies can play an important role in dengue control but are likely to be most relevant for low transmission areas where high coverage of other non-reactive interventions already exists. Controlled field trials are needed to assess the field efficacy and practical constraints of large operational CATI strategies.

Diagnostic Accuracy of the INSHI Consensus Case Definition for the Diagnosis of Paradoxical Tuberculosis-IRIS.

BACKGROUND: The diagnosis of paradoxical tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS) relies on characteristic clinical features synthesized as the International Network for the Study of HIV-associated IRIS (INSHI) case definition. There is no confirmatory laboratory test. SETTING: Site B HIV-TB clinic in Khayelitsha, Cape Town, South Africa. METHODS: Using data of participants with HIV-associated tuberculosis starting antiretroviral treatment from a prospective trial evaluating prednisone for TB-IRIS prevention, we applied latent class analysis to model a gold standard for TB-IRIS. The model-predicted probability of TB-IRIS for each participant was used to assess the performance of the INSHI case definition and compare its diagnostic accuracy with several adapted case definitions. RESULTS: Data for this analysis were complete for 217 participants; 41% developed TB-IRIS. Our latent class model included the following parameters: respiratory symptoms; night sweats; INSHI major criteria 1, 2, and 4; maximum C-reactive protein >90 mg/L; maximum heart rate >120/min; maximum temperature >37.7°C; and preantiretroviral therapy CD4 count <50 cells/µL. The model estimated a TB-IRIS incidence of 43% and had optimal goodness of fit (χ2 = 337, P = 1.0). The INSHI case definition displayed a sensitivity of 0.77 and a specificity of 0.86. Replacing all the minor INSHI criteria with objectives measures (C-reactive protein elevation, fever, and/or tachycardia) resulted in a definition with better diagnostic accuracy, with a sensitivity of 0.89 and a specificity of 0.88. CONCLUSION: The INSHI case definition identifies TB-IRIS with reasonable accuracy. Amending the case definition by replacing INSHI minor criteria with objective variables improved sensitivity without loss of specificity.

Determinants for progression from asymptomatic infection to symptomatic visceral leishmaniasis: A cohort study.

BACKGROUND: Asymptomatic Leishmania donovani infections outnumber clinical presentations, however the predictors for development of active disease are not well known. We aimed to identify serological, immunological and genetic markers for progression from L. donovani infection to clinical Visceral Leishmaniasis (VL). METHODS: We enrolled all residents >2 years of age in 27 VL endemic villages in Bihar (India). Blood samples collected on filter paper on two occasions 6-12 months apart, were tested for antibodies against L. donovani with rK39-ELISA and DAT. Sero converters, (negative for both tests in the first round but positive on either of the two during the second round) and controls (negative on both tests on both occasions) were followed for three years. At the start of follow-up venous blood was collected for the following tests: DAT, rK39- ELISA, Quantiferon assay, SNP/HLA genotyping and L.donovani specific quantitative PCR. RESULTS: Among 1,606 subjects enrolled,17 (8/476 seroconverters and 9/1,130 controls) developed VL (OR 3.1; 95% CI 1.1-8.3). High DAT and rK39 ELISA antibody titers as well as positive qPCR were strongly and significantly associated with progression from seroconversion to VL with odds ratios of 19.1, 30.3 and 20.9 respectively. Most VL cases arose early (median 5 months) during follow-up. CONCLUSION: We confirmed the strong association between high DAT and/or rK39 titers and progression to disease among asymptomatic subjects and identified qPCR as an additional predictor. Low predictive values do not warrant prophylactic treatment but as most progressed to VL early during follow-up, careful oberservation of these subjects for at least 6 months is indicated.

Four artemisinin-based treatments in African pregnant women with malaria.

BACKGROUND: Information regarding the safety and efficacy of artemisinin combination treatments for malaria in pregnant women is limited, particularly among women who live in sub-Saharan Africa. METHODS: We conducted a multicenter, randomized, open-label trial of treatments for malaria in pregnant women in four African countries. A total of 3428 pregnant women in the second or third trimester who had falciparum malaria (at any parasite density and regardless of symptoms) were treated with artemether-lumefantrine, amodiaquine-artesunate, mefloquine-artesunate, or dihydroartemisinin-piperaquine. The primary end points were the polymerase-chain-reaction (PCR)-adjusted cure rates (i.e., cure of the original infection; new infections during follow-up were not considered to be treatment failures) at day 63 and safety outcomes. RESULTS: The PCR-adjusted cure rates in the per-protocol analysis were 94.8% in the artemether-lumefantrine group, 98.5% in the amodiaquine-artesunate group, 99.2% in the dihydroartemisinin-piperaquine group, and 96.8% in the mefloquine-artesunate group; the PCR-adjusted cure rates in the intention-to-treat analysis were 94.2%, 96.9%, 98.0%, and 95.5%, respectively. There was no significant difference among the amodiaquine-artesunate group, dihydroartemisinin-piperaquine group, and the mefloquine-artesunate group. The cure rate in the artemether-lumefantrine group was significantly lower than that in the other three groups, although the absolute difference was within the 5-percentage-point margin for equivalence. The unadjusted cure rates, used as a measure of the post-treatment prophylactic effect, were significantly lower in the artemether-lumefantrine group (52.5%) than in groups that received amodiaquine-artesunate (82.3%), dihydroartemisinin-piperaquine (86.9%), or mefloquine-artesunate (73.8%). No significant difference in the rate of serious adverse events and in birth outcomes was found among the treatment groups. Drug-related adverse events such as asthenia, poor appetite, dizziness, nausea, and vomiting occurred significantly more frequently in the mefloquine-artesunate group (50.6%) and the amodiaquine-artesunate group (48.5%) than in the dihydroartemisinin-piperaquine group (20.6%) and the artemether-lumefantrine group (11.5%) (P<0.001 for comparison among the four groups). CONCLUSIONS: Artemether-lumefantrine was associated with the fewest adverse effects and with acceptable cure rates but provided the shortest posttreatment prophylaxis, whereas dihydroartemisinin-piperaquine had the best efficacy and an acceptable safety profile. (Funded by the European and Developing Countries Clinical Trials Partnership and others; ClinicalTrials.gov number, NCT00852423.).

Four Artemisinin-Based Treatments in African Pregnant Women with Malaria.

BACKGROUND: Information regarding the safety and efficacy of artemisinin combination treatments for malaria in pregnant women is limited, particularly among women who live in sub-Saharan Africa. METHODS: We conducted a multicenter, randomized, open-label trial of treatments for malaria in pregnant women in four African countries. A total of 3428 pregnant women in the second or third trimester who had falciparum malaria (at any parasite density and regardless of symptoms) were treated with artemether-lumefantrine, amodiaquine-artesunate, mefloquine-artesunate, or dihydroartemisinin-piperaquine. The primary end points were the polymerase-chain-reaction (PCR)-adjusted cure rates (i.e., cure of the original infection; new infections during follow-up were not considered to be treatment failures) at day 63 and safety outcomes. RESULTS: The PCR-adjusted cure rates in the per-protocol analysis were 94.8% in the artemether-lumefantrine group, 98.5% in the amodiaquine-artesunate group, 99.2% in the dihydroartemisinin-piperaquine group, and 96.8% in the mefloquine-artesunate group; the PCR-adjusted cure rates in the intention-to-treat analysis were 94.2%, 96.9%, 98.0%, and 95.5%, respectively. There was no significant difference among the amodiaquine-artesunate group, dihydroartemisinin-piperaquine group, and the mefloquine-artesunate group. The cure rate in the artemether-lumefantrine group was significantly lower than that in the other three groups, although the absolute difference was within the 5-percentage-point margin for equivalence. The unadjusted cure rates, used as a measure of the post-treatment prophylactic effect, were significantly lower in the artemether-lumefantrine group (52.5%) than in groups that received amodiaquine-artesunate (82.3%), dihydroartemisinin-piperaquine (86.9%), or mefloquine-artesunate (73.8%). No significant difference in the rate of serious adverse events and in birth outcomes was found among the treatment groups. Drug-related adverse events such as asthenia, poor appetite, dizziness, nausea, and vomiting occurred significantly more frequently in the mefloquine-artesunate group (50.6%) and the amodiaquine-artesunate group (48.5%) than in the dihydroartemisinin-piperaquine group (20.6%) and the artemether-lumefantrine group (11.5%) (P<0.001 for comparison among the four groups). CONCLUSIONS: Artemether-lumefantrine was associated with the fewest adverse effects and with acceptable cure rates but provided the shortest post-treatment prophylaxis, whereas dihydroartemisinin-piperaquine had the best efficacy and an acceptable safety profile. (Funded by the European and Developing Countries Clinical Trials Partnership and others; ClinicalTrials.gov number, NCT00852423.).

Reasons for Missing Antiretroviral Therapy: Results from a Multi-Country Study in Tanzania, Uganda, and Zambia.

OBJECTIVES: To identify the reasons patients miss taking their antiretroviral therapy (ART) and the proportion who miss their ART because of symptoms; and to explore the association between symptoms and incomplete adherence. METHODS: Secondary analysis of data collected during a cross-sectional study that examined ART adherence among adults from 18 purposefully selected sites in Tanzania, Uganda, and Zambia. We interviewed 250 systematically selected patients per facility (≥ 18 years) on reasons for missing ART and symptoms they had experienced (using the HIV Symptom Index). We abstracted clinical data from the patients' medical, pharmacy, and laboratory records. Incomplete adherence was defined as having missed ART for at least 48 consecutive hours during the past 3 months. RESULTS: Twenty-nine percent of participants reported at least one reason for having ever missed ART (1278/4425). The most frequent reason was simply forgetting (681/1278 or 53%), followed by ART-related hunger or not having enough food (30%), and symptoms (12%). The median number of symptoms reported by participants was 4 (IQR: 2-7). Every additional symptom increased the odds of incomplete adherence by 12% (OR: 1.1, 95% CI: 1.1-1.2). Female participants and participants initiated on a regimen containing stavudine were more likely to report greater numbers of symptoms. CONCLUSIONS: Symptoms were a common reason for missing ART, together with simply forgetting and food insecurity. A combination of ART regimens with fewer side effects, use of mobile phone text message reminders, and integration of food supplementation and livelihood programmes into HIV programmes, have the potential to decrease missed ART and hence to improve adherence and the outcomes of ART programmes.

Design and analysis considerations in the Ebola_Tx trial evaluating convalescent plasma in the treatment of Ebola virus disease in Guinea during the 2014-2015 outbreak.

The Ebola virus disease outbreak in 2014-2015 led to a huge caseload with a high case fatality rate. No specific treatments were available beyond supportive care for conditions such as dehydration and shock. Evaluation of treatment with convalescent plasma from Ebola survivors was identified as a priority. We evaluated this intervention in an emergency setting, where randomization was unacceptable. The original trial design was an open-label study comparing patients receiving convalescent plasma and supportive care to patients receiving supportive care alone. The comparison group comprised patients recruited at the start of the trial before convalescent plasma became available, as well as patients presenting during the trial for whom there was insufficient blood group-compatible plasma or no staffing capacity to provide additional transfusions. However, during the trial, convalescent plasma was available to treat all new patients. The design was changed to use a comparator group comprising patients previously treated at the same Ebola treatment center prior to the start of the trial. In the analysis, it was planned to adjust for any differences in prognostic variables between intervention and comparison groups, specifically baseline polymerase chain reaction cycle threshold and age. In addition, adjustment was planned for other potential confounders, identified in the analysis, such as patient presenting symptoms and time to treatment seeking. Because plasma treatment started up to 3 days after diagnosis and we could not define a similar time-point for the comparator group, patients who died before the third day after confirmation of diagnosis were excluded from both intervention and comparison groups in a per-protocol analysis. Some patients received additional experimental treatments soon after plasma treatment, and these were excluded. We also analyzed mortality including all patients from the time of confirmed diagnosis, irrespective of whether those in the trial series actually received plasma, as an intention-to-treat analysis. Per-protocol and intention-to-treat approaches gave similar conclusions. An important caveat in the interpretation of the findings is that it is unlikely that all potential sources of confounding, such as any variation in supportive care over time, were eliminated. Protocols and electronic data capture systems have now been extensively field-tested for emergency evaluation of treatment with convalescent plasma. Ongoing studies seek to quantify the level of neutralizing antibodies in different plasma donations to determine whether this influences the response and survival of treated patients.

A DNA tool for early detection of vaginal dysbiosis in African women.

A next-generation diagnostic tool for bacterial vaginosis, consisting of quantitative and/or qualitative molecular criteria, has not yet been identified. The optimal diagnostic tool should not only diagnose bacterial vaginosis in diverse populations, but should also detect early signs of transition to dysbiosis. We evaluated a tool based on log10-transformed qPCR data for Lactobacillus crispatus, Lactobacillus iners, Lactobacillus jensenii, Lactobacillus gasseri, Lactobacillus vaginalis, Lactobacillus genus, Atopobium vaginae and Gardnerella vaginalis in vaginal specimens of 426 African women to detect dysbiosis and predict transition to dysbiosis. G. vaginalis (p = 0.204) and A. vaginae (p = 0.001) were more commonly present in women who evolved to an intermediate (Nugent 4-6) or bacterial vaginosis score (Nugent 7-10) compared to women who continued to have a normal Nugent score. The combination of G. vaginalis, A. vaginae and Lactobacillus genus counts performed best for diagnostic accuracy for bacterial vaginosis--sensitivity 93.4% and specificity 83.6%; and for predictive accuracy for bacterial vaginosis--sensitivity 79% and specificity 52%. L. crispatus combinations did not perform well. We conclude that a triple-G. vaginalis-A. vaginae-Lactobacillus genus-qPCR tool holds promise for research in sub-Saharan Africa or when developed as a next-generation clinical diagnostic modality for bacterial vaginosis, ideally engineered as a rapid assay.

Lower Levels of Antiretroviral Therapy Enrollment Among Men with HIV Compared with Women - 12 Countries, 2002-2013.

Equitable access to antiretroviral therapy (ART) for men and women with human immunodeficiency virus (HIV) infection is a principle endorsed by most countries and funding bodies, including the U.S. President's Emergency Plan for AIDS (acquired immunodeficiency syndrome) Relief (PEPFAR) (1). To evaluate gender equity in ART access among adults (defined for this report as persons aged ≥15 years), 765,087 adult ART patient medical records from 12 countries in five geographic regions* were analyzed to estimate the ratio of women to men among new ART enrollees for each calendar year during 2002-2013. This annual ratio was compared with estimates from the Joint United Nations Programme on HIV/AIDS (UNAIDS)(†) of the ratio of HIV-infected adult women to men in the general population. In all 10 African countries and Haiti, the most recent estimates of the ratio of adult women to men among new ART enrollees significantly exceeded the UNAIDS estimates for the female-to-male ratio among HIV-infected adults by 23%-83%. In six African countries and Haiti, the ratio of women to men among new adult ART enrollees increased more sharply over time than the estimated UNAIDS female-to-male ratio among adults with HIV in the general population. Increased ART coverage among men is needed to decrease their morbidity and mortality and to reduce HIV incidence among their sexual partners. Reaching more men with HIV testing and linkage-to-care services and adoption of test-and-treat ART eligibility guidelines (i.e., regular testing of adults, and offering treatment to all infected persons with ART, regardless of CD4 cell test results) could reduce gender inequity in ART coverage.

Use of Pentamidine As Secondary Prophylaxis to Prevent Visceral Leishmaniasis Relapse in HIV Infected Patients, the First Twelve Months of a Prospective Cohort Study.

BACKGROUND: Visceral leishmaniasis (VL) has become an important opportunistic infection in persons with HIV-infection in VL-endemic areas. The co-infection leads to profound immunosuppression and high rate of annual VL recurrence. This study assessed the effectiveness, safety and feasibility of monthly pentamidine infusions to prevent recurrence of VL in HIV co-infected patients. METHODS: A single-arm, open-label trial was conducted at two leishmaniasis treatment centers in northwest Ethiopia. HIV-infected patients with a VL episode were included after parasitological cure. Monthly infusions of 4 mg/kg pentamidine-isethionate diluted in normal-saline were started for 12 months. All received antiretroviral therapy (ART). Time-to-relapse or death was the primary end point. RESULTS: Seventy-four patients were included. The probability of relapse-free survival at 6 months and at 12 months was 79% and 71% respectively. Renal failure, a possible drug-related serious adverse event, occurred in two patients with severe pneumonia. Forty-one patients completed the regimen taking at least 11 of the 12 doses. Main reasons to discontinue were: 15 relapsed, five died and seven became lost to follow-up. More patients failed among those with a CD4+cell count ≤ 50 cells/µl, 5/7 (71.4%) than those with counts above 200 cells/µl, 2/12 (16.7%), (p = 0.005). CONCLUSION: Pentamidine secondary prophylaxis led to a 29% failure rate within one year, much lower than reported in historical controls (50%-100%). Patients with low CD4+cell counts are at increased risk of relapse despite effective initial VL treatment, ART and secondary prophylaxis. VL should be detected and treated early enough in patients with HIV infection before profound immune deficiency installs.

Determinants of Weight Evolution Among HIV-Positive Patients Initiating Antiretroviral Treatment in Low-Resource Settings.

BACKGROUND: In resource-limited settings, clinical parameters, including body weight changes, are used to monitor clinical response. Therefore, we studied body weight changes in patients on antiretroviral treatment (ART) in different regions of the world. METHODS: Data were extracted from the "International Epidemiologic Databases to Evaluate AIDS," a network of ART programmes that prospectively collects routine clinical data. Adults on ART from the Southern, East, West, and Central African and the Asia-Pacific regions were selected from the database if baseline data on body weight, gender, ART regimen, and CD4 count were available. Body weight change over the first 2 years and the probability of body weight loss in the second year were modeled using linear mixed models and logistic regression, respectively. RESULTS: Data from 205,571 patients were analyzed. Mean adjusted body weight change in the first 12 months was higher in patients started on tenofovir and/or efavirenz; in patients from Central, West, and East Africa, in men, and in patients with a poorer clinical status. In the second year of ART, it was greater in patients initiated on tenofovir and/or nevirapine, and for patients not on stavudine, in women, in Southern Africa and in patients with a better clinical status at initiation. Stavudine in the initial regimen was associated with a lower mean adjusted body weight change and with weight loss in the second treatment year. CONCLUSIONS: Different ART regimens have different effects on body weight change. Body weight loss after 1 year of treatment in patients on stavudine might be associated with lipoatrophy.

Diagnostic accuracy of rK28-based immunochromatographic rapid diagnostic tests for visceral leishmaniasis: a prospective clinical cohort study in Sudan.

BACKGROUND: Rapid diagnostic tests (RDTs) for visceral leishmaniasis (VL) based on rK39 antigen showed suboptimal sensitivity in East Africa. A prospective clinical cohort study in Sudan was designed to validate a novel rK28-based RDT for Leishmania donovani VL. METHODS: Patients (n=285) suspected of VL by residency, fever for ≥2 weeks, splenomegaly with no prior reported VL, and negative for malaria were consecutively enrolled at three Sudanese sites in 2012-2013 and informed consent obtained. Two human readers, who were blinded to the clinical status and other RDT results, evaluated patient whole blood (WB) and serum on the rK28 RDT. Based on Leishmania parasite detection in lymph node or bone marrow aspirates (Giemsa-stained smears or culture in Novy-MacNeal-Nicolle medium), patients were categorized as VL cases (n=200) or VL controls (n=85). RESULTS: The rK28 RDT had high specificity using either WB (100% [85/85]) or serum (97.6% [83/85]) and exhibited greater sensitivity (WB, 92.5% [185/200]; serum, 94.5% [189/200]) than a direct agglutination test performed with the same sera (92.9% [79/85] and 83.5% [167/200] for specificity and sensitivity, respectively). Two blinded readers scored a given WB or serum sample the same on the rK28 RDT 99.6% and 100% of the time, respectively. A reader scored each individual donor's paired WB and serum rK28 RDT results the same 97.2% of the time. CONCLUSIONS: An inexpensive rK28 RDT that performs robustly with WB or serum will be valuable for diagnosing cases of VL in East Africa.

Arsenic, antimony, and Leishmania: has arsenic contamination of drinking water in India led to treatment- resistant kala-azar?

BACKGROUND: In Bihar state, India, the cure rate of antimonial compounds (eg, sodium stibogluconate) in the treatment of visceral leishmaniasis (VL) has fallen from more than 85% to less than 50%. This reduction has been attributed to long-term, widespread misuse of antimonial drugs within the Indian private health-care system. We aimed to test the hypothesis that exposure to arsenic in drinking water in this region has resulted in antimony-resistant Leishmania parasites. METHODS: L donovani parasites were serially passaged in mice exposed to environmentally relevant concentrations of arsenic in drinking water. Arsenic concentrations in murine organs were quantified and the sensitivity of L donovani to sodium stibogluconate assessed at each passage. A retrospective field study on a cohort of antimony-treated patients with VL was performed in an arsenic-contaminated area of Bihar to assess risk of treatment failure and death in people exposed to arsenic. FINDINGS: Arsenic accumulation in organs of exposed mice was proportional to exposure level. After five passages, isolated parasites were refractory to sodium stibogluconate in in-vitro drug sensitivity assays. Treatment of arsenic exposed, infected mice with this drug confirmed that these parasites retained resistance in vivo. In the field work study, 110 patients with VL treated with sodium stibogluconate, failure rate was 59%. Patients using well water with high mean arsenic concentrations had a higher risk of treatment failure than patients using wells with arsenic levels of less than 10 µg/L (odds ratio 1·78, 95% CI 0·7-4·6, p=0·23). 21 patients died, 16 directly as a result of their disease. Mean arsenic concentrations of more than 10 µg/L increased the risk of all-cause and VL-related mortality (hazard ratio 3·27, 95% CI 1·4-8·1, and 2·65, 0·96-7·65, respectively). INTERPRETATION: These data suggest that arsenic contamination might have contributed to the development of antimonial resistance in Leishmania parasites in Bihar. Our epidemiological study was underpowered and retrospective in nature, so firm conclusions cannot be made. Further research into the associations between arsenic exposure and antimonial treatment failure and death in the leishmaniases is warranted. FUNDING: Wellcome Trust.

A general framework for comparative Bayesian meta-analysis of diagnostic studies.

BACKGROUND: Selecting the most effective diagnostic method is essential for patient management and public health interventions. This requires evidence of the relative performance of alternative tests or diagnostic algorithms. Consequently, there is a need for diagnostic test accuracy meta-analyses allowing the comparison of the accuracy of two or more competing tests. The meta-analyses are however complicated by the paucity of studies that directly compare the performance of diagnostic tests. A second complication is that the diagnostic accuracy of the tests is usually determined through the comparison of the index test results with those of a reference standard. These reference standards are presumed to be perfect, i.e. allowing the classification of diseased and non-diseased subjects without error. In practice, this assumption is however rarely valid and most reference standards show false positive or false negative results. When an imperfect reference standard is used, the estimated accuracy of the tests of interest may be biased, as well as the comparisons between these tests. METHODS: We propose a model that allows for the comparison of the accuracy of two diagnostic tests using direct (head-to-head) comparisons as well as indirect comparisons through a third test. In addition, the model allows and corrects for imperfect reference tests. The model is inspired by mixed-treatment comparison meta-analyses that have been developed for the meta-analysis of randomized controlled trials. As the model is estimated using Bayesian methods, it can incorporate prior knowledge on the diagnostic accuracy of the reference tests used. RESULTS: We show the bias that can result from using inappropriate methods in the meta-analysis of diagnostic tests and how our method provides more correct estimates of the difference in diagnostic accuracy between two tests. As an illustration, we apply this model to a dataset on visceral leishmaniasis diagnostic tests, comparing the accuracy of the RK39 dipstick with that of the direct agglutination test. CONCLUSIONS: Our proposed meta-analytic model can improve the comparison of the diagnostic accuracy of competing tests in a systematic review. This is however only true if the studies and especially information on the reference tests used are sufficiently detailed. More specifically, the type and exact procedures used as reference tests are needed, including any cut-offs used and the number of subjects excluded from full reference test assessment. If this information is lacking, it may be better to limit the meta-analysis to direct comparisons.

Trypanosome infection in dromedary camels in Eastern Ethiopia: Prevalence, relative performance of diagnostic tools and host related risk factors.

A cross-sectional study was conducted in Chifra and Dewe districts of Afar region, Eastern Ethiopia, to determine the prevalence, agreement between diagnostic tests and host related risk factors of trypanosome infection in camel. An overall prevalence of 2%, 24.1%, 21.3%, 9.5% and 7.8% was recorded with respectively Giemsa stained thin blood smear, CATT/T. evansi, RoTat1.2 PCR, 18S PCR and ITS-1PCR in a cohort of 399 animals. Only one T. vivax infection was confirmed by TvPRAC PCR indicating T. evansi as the predominant species affecting camels in the study area. No single animal was positive when tested with T. evansi type B specific EVAB PCR. There was slight agreement between the CATT/T. evansi and the molecular tests. Among the PCR methods, RoTat 1.2 PCR yielded a significantly higher positivity rate compared to 18S PCR and ITS-1 PCR. There was no significant difference in the positivity rate observed in each gender of camels (p>0.05). The positivity rate was significantly higher in camels with poor body condition and in older animals when tested using the CATT/T.evansi or RoTat 1.2 PCR (p>0.05). Camels that tested positive with all tests had significantly lower PCV's (p<0.05). This study provides further evidence that T. evansi is endemic in the Afar region of Ethiopia. The latent class analysis indicated an estimate overall prevalence of 19% (95% CI: 13-28). Moreover, the model indicated low sensitivity of CATT/T. evansi (43%) and the PCR tests (39-53%) but higher specificity of the PCR tests (86-99%) and low specificity of CATT/T. evansi (80%). This study suggests that improved sensitivity and reliability of the tests would help diagnosis of trypanosomosis. Further studies are required to determine the prevalence of clinical disease and losses due to trypanosomosis.

Correlates of the molecular vaginal microbiota composition of African women.

BACKGROUND: Sociodemographic, behavioral and clinical correlates of the vaginal microbiome (VMB) as characterized by molecular methods have not been adequately studied. VMB dominated by bacteria other than lactobacilli may cause inflammation, which may facilitate HIV acquisition and other adverse reproductive health outcomes. METHODS: We characterized the VMB of women in Kenya, Rwanda, South Africa and Tanzania (KRST) using a 16S rDNA phylogenetic microarray. Cytokines were quantified in cervicovaginal lavages. Potential sociodemographic, behavioral, and clinical correlates were also evaluated. RESULTS: Three hundred thirteen samples from 230 women were available for analysis. Five VMB clusters were identified: one cluster each dominated by Lactobacillus crispatus (KRST-I) and L. iners (KRST-II), and three clusters not dominated by a single species but containing multiple (facultative) anaerobes (KRST-III/IV/V). Women in clusters KRST-I and II had lower mean concentrations of interleukin (IL)-1α (p < 0.001) and Granulocyte Colony Stimulating Factor (G-CSF) (p = 0.01), but higher concentrations of interferon-γ-induced protein (IP-10) (p < 0.01) than women in clusters KRST-III/IV/V. A lower proportion of women in cluster KRST-I tested positive for bacterial sexually transmitted infections (STIs; ptrend = 0.07) and urinary tract infection (UTI; p = 0.06), and a higher proportion of women in clusters KRST-I and II had vaginal candidiasis (ptrend = 0.09), but these associations did not reach statistical significance. Women who reported unusual vaginal discharge were more likely to belong to clusters KRST-III/IV/V (p = 0.05). CONCLUSION: Vaginal dysbiosis in African women was significantly associated with vaginal inflammation; the associations with increased prevalence of STIs and UTI, and decreased prevalence of vaginal candidiasis, should be confirmed in larger studies.

The significance of Lactobacillus crispatus and L. vaginalis for vaginal health and the negative effect of recent sex: a cross-sectional descriptive study across groups of African women.

BACKGROUND: Women in sub-Saharan Africa are vulnerable to acquiring HIV infection and reproductive tract infections. Bacterial vaginosis (BV), a disruption of the vaginal microbiota, has been shown to be strongly associated with HIV infection. Risk factors related to potentially protective or harmful microbiota species are not known. METHODS: We present cross-sectional quantitative polymerase chain reaction data of the Lactobacillus genus, five Lactobacillus species, and three BV-related bacteria (Gardnerella vaginalis, Atopobium vaginae, and Prevotella bivia) together with Escherichia coli and Candida albicans in 426 African women across different groups at risk for HIV. We selected a reference group of adult HIV-negative women at average risk for HIV acquisition and compared species variations in subgroups of adolescents, HIV-negative pregnant women, women engaging in traditional vaginal practices, sex workers and a group of HIV-positive women on combination antiretroviral therapy. We explored the associations between presence and quantity of the bacteria with BV by Nugent score, in relation to several factors of known or theoretical importance. RESULTS: The presence of species across Kenyan, South African and Rwandan women was remarkably similar and few differences were seen between the two groups of reference women in Kenya and South Africa. The Rwandan sex workers and HIV-positive women had the highest G. vaginalis presence (p = 0.006). Pregnant women had a higher Lactobacillus genus mean log (7.01 genome equivalents (geq)/ml) compared to the reference women (6.08 geq/ml). L. vaginalis (43%) was second to L. iners (81.9%) highly present in women with a normal Nugent score. Recent sexual exposure negatively affected the presence of L. crispatus (<0.001), L. vaginalis (p = 0.001), and Lactobacillus genus (p < 0.001). Having more than one sexual partner in the last three months was associated with an increased prevalence of G. vaginalis (p = 0.044) and L. iners (p = 0.001). CONCLUSIONS: Although the composition of species across the studied African countries was similar, the presence of protective species i.e. L. crispatus and L. vaginalis in women with a normal Nugent score appeared lower compared to non-African studies. Furthermore, Lactobacillus species were negatively affected by sexual behavioural. Strategies to support protective Lactobacillus species are urgently needed. TRIAL REGISTRATION: The study is registered at the Trial Registration at the National Health Research Ethics Council South Africa with the number DOH2709103223.