Geospatial joint modeling of vector and parasite serology to microstratify malaria transmission.

The World Health Organization identifies a strong surveillance system for malaria and its mosquito vector as an essential pillar of the malaria elimination agenda. Anopheles salivary antibodies are emerging biomarkers of exposure to mosquito bites that potentially overcome sensitivity and logistical constraints of traditional entomological surveys. Using samples collected by a village health volunteer network in 104 villages in Southeast Myanmar during routine surveillance, the present study employs a Bayesian geostatistical modeling framework, incorporating climatic and environmental variables together with Anopheles salivary antigen serology, to generate spatially continuous predictive maps of Anopheles biting exposure. Our maps quantify fine-scale spatial and temporal heterogeneity in Anopheles salivary antibody seroprevalence (ranging from 9 to 99%) that serves as a proxy of exposure to Anopheles bites and advances current static maps of only Anopheles occurrence. We also developed an innovative framework to perform surveillance of malaria transmission. By incorporating antibodies against the vector and the transmissible form of malaria (sporozoite) in a joint Bayesian geostatistical model, we predict several foci of ongoing transmission. In our study, we demonstrate that antibodies specific for Anopheles salivary and sporozoite antigens are a logistically feasible metric with which to quantify and characterize heterogeneity in exposure to vector bites and malaria transmission. These approaches could readily be scaled up into existing village health volunteer surveillance networks to identify foci of residual malaria transmission, which could be targeted with supplementary interventions to accelerate progress toward elimination.

Adaptive NK Cells Rapidly Expand during Acute HIV Infection and Persist Despite Early Initiation of Antiretroviral Therapy.

HIV is associated with NK cell dysfunction and expansion of adaptive-like NK cells that persist despite antiretroviral therapy (ART). We investigated the timing of NK cell perturbations during acute HIV infection and the impact of early ART initiation. PBMCs and plasma were obtained from people with HIV (PWH; all men who have sex with men; median age, 26.0 y) diagnosed during Fiebig stages I, II, III, or IV/V. Participants initiated ART a median of 3 d after diagnosis, and immunophenotyping was performed at diagnosis and longitudinally after ART. Anti-CMV Abs were assessed by ELISA. Samples from matched HIV-uninfected males were also analyzed. Proportions of adaptive NK cells (A-NKs; defined as Fcε-Receptor-1γ-) were expanded at HIV diagnosis at all Fiebig stages (pooled median 66% versus 25% for controls; p < 0.001) and were not altered by early ART initiation. Abs to CMV immediate early protein were elevated in PWH diagnosed in Fiebig stages III and IV/V (p < 0.03 for both). Proportions of A-NKs defined as either Fcε-Receptor-1γ- or NKG2C+/CD57+ were significantly associated with HIV DNA levels at diagnosis (p = 0.046 and 0.029, respectively) and trended toward an association after 48 wk of ART. Proportions of activated HLA-DR+/CD38+ NK cells remained elevated in PWH despite early ART initiation. NK cell activation and A-NK expansion occur very early after HIV transmission, before T cell activation, and are not altered by ART initiation during acute infection. A-NKs may contribute to HIV control and thus be useful for HIV cure.

Characteristics of attrition within the SuperMIX cohort of people who inject drugs: a multiple event discrete-time survival analysis.

BACKGROUND: Compared to the general population, people who inject drugs have poor health and wellbeing. Longitudinal studies can provide insight into factors driving these worse health outcomes but are subject to methodological challenges, such as cohort attrition. The aim of this study was to assess and characterise attrition in a prospective cohort of people who inject drugs in Victoria, Australia. METHODS: Using annually collected self-reported data from The Melbourne Injecting Drug User Cohort Study (SuperMIX) from September 2008 to January 2021, we estimated the incidence of participants being lost-to-follow-up (LTFU), with an episode of being LTFU defined as participants not undertaking a follow-up interview within two years of their last interview. We utilised a multiple event discrete-time survival analysis on participant period-observation data to estimate the associations between key factors and LTFU. Key areas of exposure measurement in analyses were sociodemographic, drug use and mental health. RESULTS: A total of n = 1328 SuperMIX participants completed a baseline interview, with n = 489 (36.8%) LTFU, i.e. not completing a follow-up interview in the following two years. Increased attrition was observed among SuperMIX participants who were: born outside Australia, younger than 30 years, reporting having completed fewer years of education, not residing in stable accommodation, not in stable employment and not on opioid agonist therapy (OAT). CONCLUSIONS: The attrition rate of the SuperMIX cohort has largely been stable throughout the duration of the study. Higher attrition rates among individuals at greater sociodemographic disadvantage and not on OAT suggest that additional efforts are required to retain these participants. Findings also suggest that SuperMIX might not be capturing data on adverse health and wellbeing outcomes among subpopulations at high risk of harm.

Reactive surveillance and response strategies for malaria elimination in Myanmar: a literature review.

Myanmar, a country in Greater Mekong Sub-region, aims to eliminate malaria by 2030. To achieve malaria elimination, Myanmar adopted a reactive surveillance and response strategy of malaria case notification within 1 day and case investigation, foci investigation and response activities within 7 days. A literature review was conducted to gain a better understanding of how the reactive surveillance and response strategies are being implemented in Myanmar including enablers and barriers to their implementation. Only two assessments of the completeness and timeliness of reactive surveillance and response strategy in Myanmar have been published to date. The proportion of positive cases notified within one day was 27.9% and the proportion of positive cases investigated within 7 days as recommended by the national guidelines varied from 32.5 to 91.8% under different settings in reported studies. Strong collaboration between the National Malaria Control Programme and implementing partners, and adequate human resource and financial support contributed to a successful and timely implementation of reactive surveillance and response strategy. Documented enablers for successful implementation of reactive surveillance and response strategy included frontline health workers having good knowledge of reactive surveillance and response activities and availability of Basic Health Staff for timely implementation of foci response activities. Barriers for implementation of reactive surveillance and response activities were also identified, including shortage of human resources especially in hard-to-reach settings, limited mobile phone network services and internet coverage leading to delays in timely notification of malaria cases, lengthy and complex case investigation forms and different reporting systems between Basic Health Staff and volunteers.

Performance and feasibility of reactive surveillance and response strategies for malaria elimination in Vietnam: a mixed-methods study.

BACKGROUND: To enhance malaria elimination, Vietnam adopted a Reactive Surveillance and Response (RASR) Strategy in which malaria case notification and investigation must be completed within 2 days followed by a focus investigation within 7 days. The nationwide performance of Vietnam's RASR strategy has yet to be evaluated. This study aims to evaluate the performance and feasibility of RASR in Vietnam, thereby providing recommendations for improved RASR. METHODS: To assess malaria RASR in Vietnam, a mixed-methods study of (1) secondary data analysis of nationwide malaria case-based dataset from 2017 to 2021; (2) a quantitative survey, and (3) qualitative in-depth interviews and focus group discussions administered to central, provincial and district level stakeholders/staff and to the commune and community level front line health services providers was conducted. RESULTS: In Vietnam, there are guidelines and procedures for implementation of each step of RASR. The completeness of case notification on the reported monthly aggregated data was very high in both the paper-based (12,463/12,498, 99.7% in 2017-2020) and electronic reporting systems (467/467, 100% in 2021 when electronic reporting was introduced); however, there were delays in notification while using the paper-based system (timely notification-7,978/12,498, 63.8%). In 2021, the completeness (453/467, 97.0%) and timeliness (371/467, 79.4%) of case investigation were found to be high. Reactive case detection was the major focus investigation response, with fever screening achievement of 88.6% (11,481 / 12,965) and 88.5% (11,471 / 12,965) among index case and neighbouring household members, respectively. CONCLUSIONS: Overall, there was policy commitment for implementation of RASR in Vietnam. The completeness and timeliness of case notification and case investigation were high and improved after the introduction of the electronic reporting system. More evidence is required for reactive case detection in defining the screening area or population.

Anopheles diversity, biting behaviour and transmission potential in forest and farm environments of Gia Lai province, Vietnam.

BACKGROUND: Despite recent reductions in Vietnam, malaria transmission persists in some areas in forests and farmlands where a high density of Anopheles mosquitoes relative to other environments occurs. To inform effective malaria control measures, it is important to understand vector bionomics and the malaria transmission role of Anopheles spp. in the highland regions of Vietnam. This study was conducted to quantify the abundance, composition and biting behaviour of the Anopheles mosquito population, and the proportion of Plasmodium spp. infected mosquitoes collected from forest and agricultural farm sites in Gia Lai province, Vietnam. METHODS: Forest and agricultural farm sites in Gia Lai province were selected for mosquito collections (total eight sites). Mosquito collection was performed by Human-baited Double Net Trap (HDNT), animal-baited traps (ABT) using cattle, and CDC light traps. Captured mosquitoes were identified morphologically, and salivary glands of Anopheles mosquitoes were examined for sporozoites using microscopy. Plasmodium infection was determined by Polymerase Chain Reaction (PCR), and identification of blood meal type was determined by PCR and diffuse serum agglutination assay. RESULTS: A total of 1815 Anopheles mosquitoes belonging to 19 species were collected by ABT (n = 1169), HDNT (n = 471) and CDC light trap (n = 175). Anopheles abundance and diversity varied by district and environment. Capture by HDNT of Anopheles of vectorial concern was observed between early evening and early morning. Plasmodium vivax infection was determined by PCR in two Anopheles dirus specimens captured by HDNT in forest sites. Blood from a range of hosts could, including human blood, could be detected in species considered primary and secondary vectors An. dirus, and Anopheles aconitus, and Anopheles maculatus, respectively. CONCLUSIONS: A low number of Anopheles spp. considered primary vectors of concern and very low numbers of Plasmodium spp. infected Anopheles mosquitoes were captured at the end of the rainy season in the Central Highlands of Vietnam. However, capture species of vectorial concern by HDNT throughout the early to late evening demonstrates that use of additional personal protective measures could supplement current preventative measures, such as bed nets to prevent exposure to vectors of concern in this region.

Union and Complication Rates After Total Wrist Arthrodesis: A Systematic Review and Meta-Analysis.

PURPOSE: Total wrist arthrodesis (TWA) has been performed using various techniques. We aimed to provide pooled prevalence estimates of union and complications of TWA by technique. A secondary aim was to provide estimates of union and complication rates by treatment of the carpometacarpal joint (CMCJ) in TWA using plates. Given the widespread adoption of wrist arthrodesis plates (WAP), we hypothesized that these implants would result in higher union and lower complication rates. We also hypothesized that TWA with CMCJ arthrodesis would improve these outcomes. METHODS: Online databases including PubMed, Medline, Embase, and Cochrane were searched. Studies reporting union and/or complication rates of 10 or more TWA performed with a similar technique (analyzed as bone graft only, bone graft with minimal fixation, intramedullary, augmented intramedullary, plate, WAP, and other) were included. Studies with fewer than 10 TWA, studies reporting TWA where union or complications could not be analyzed separately, and studies without union and complication rates were excluded. Data extraction was performed independently by two English-speaking reviewers with a translator where required. Pooled prevalence estimates were made using a random-effects meta-analysis model and presented as a percent prevalence with 95% confidence and prediction intervals. RESULTS: One hundred and thirty-six studies with a total of 3,517 patients and 3,969 TWA were analyzed. No differences in union and complication prevalence were observed between TWA techniques and in TWA with different treatments of the CMCJ using plates and WAP. CONCLUSION: Using meta-analysis, we found no difference in union and complication prevalence between TWA techniques and TWA with different treatments of the CMCJ with plates and WAP. It must be acknowledged that this research included low-quality studies with high heterogeneity, and confidence in the precision of the estimates is low. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic IV.

Correlates of poor oral health related quality of life in a cohort of people who use methamphetamine in Australia.

OBJECTIVES: Methamphetamine use impacts oral health, but little is known about its impacts on oral health related quality of life (OHRQoL). In this study we examined OHRQoL in a cohort of people who use methamphetamine and assessed associations with sociodemographic, behavioural, psychosocial and dental service utilisation correlates. A secondary aim was to examine the relationship between methamphetamine route of administration and OHRQoL, to test whether smoking the drug is associated with reduced OHRQoL. METHODS: Cross-sectional analysis was performed, using data from VMAX, a cohort of people who use methamphetamine at least monthly in Victoria, Australia (n = 194). Utilising the oral health impact profile (OHIP-14), we assessed three OHRQoL outcomes: OHIP-14 prevalence, OHIP-14 extent and OHIP-14 severity. Regression analyses examined associations between independent variables and the three OHIP-14 outcome measures. RESULTS: A significant segment of the cohort (35%) reported poor OHRQoL. Overall, no statistically significant association was detected between methamphetamine route of administration and the three OHIP-14 outcomes. Participants living in rural areas, with moderate-to-severe self-reported depression and with methamphetamine dependence had significantly worse OHRQoL levels, which persisted after adjusting for other covariates. CONCLUSION: Overall, VMAX cohort participants reported reduced OHRQoL levels. Our findings highlight the need for upstream interventions to improve the OHRQoL of people who use methamphetamine, with specific focus on those living in rural locations. Further research on the links between OHRQoL and mental health among people who use methamphetamine is required.

Induction, decay, and determinants of functional antibodies following vaccination with the RTS,S malaria vaccine in young children.

BACKGROUND: RTS,S is the first malaria vaccine recommended for implementation among young children at risk. However, vaccine efficacy is modest and short-lived. Antibodies play the major role in vaccine-induced immunity, but knowledge on the induction, decay, and determinants of antibody function is limited, especially among children. Antibodies that promote opsonic phagocytosis and other cellular functions appear to be important contributors to RTS,S immunity. METHODS: We studied a phase IIb trial of RTS,S/AS02 conducted in young children in malaria-endemic regions of Mozambique. We evaluated the induction of antibodies targeting the circumsporozoite protein (CSP, vaccine antigen) that interact with Fcγ-receptors (FcRγs) and promote phagocytosis (neutrophils, monocytes, THP-1 cells), antibody-dependent respiratory burst (ADRB) by neutrophils, and natural killer (NK) cell activity, as well as the temporal kinetics of responses over 5 years of follow-up (ClinicalTrials.gov registry number NCT00197041). RESULTS: RTS,S vaccination induced CSP-specific IgG with FcγRIIa and FcγRIII binding activity and promoted phagocytosis by neutrophils, THP-1 monocytes, and primary human monocytes, neutrophil ADRB activity, and NK cell activation. Responses were highly heterogenous among children, and the magnitude of neutrophil phagocytosis by antibodies was relatively modest, which may reflect modest vaccine efficacy. Induction of functional antibodies was lower among children with higher malaria exposure. Functional antibody magnitude and the functional activity of antibodies largely declined within a year post-vaccination, and decay were highest in the first 6 months, consistent with the decline in vaccine efficacy over that time. Decay rates varied for different antibody parameters and decay was slower for neutrophil phagocytosis. Biostatistical modelling suggested IgG1 and IgG3 contribute in promoting FcγR binding and phagocytosis, and IgG targeting the NANP-repeat and C-terminal regions CSP were similarly important for functional activities. CONCLUSIONS: Results provide new insights to understand the modest and time-limited efficacy of RTS,S in children and the induction of antibody functional activities. Improving the induction and maintenance of antibodies that promote phagocytosis and cellular functions, and combating the negative effect of malaria exposure on vaccine responses are potential strategies for improving RTS,S efficacy and longevity.

Reducing malaria transmission in forest-going mobile and migrant populations in Lao PDR and Cambodia: protocol for stepped-wedge cluster-randomised controlled trial.

BACKGROUND: Countries of the Greater Mekong Sub-region aim to achieve malaria elimination by 2030. In the region, malaria is concentrated in high-risk areas and populations such as forest-going mobile and migrant populations (MMPs). However, routine protective measures such as long-lasting insecticidal nets do not prevent all infectious bites in these high-risk populations. Evidence for the effectiveness of a personal protection package tailored to forest-going MMPs which is acceptable, feasible, and cost-effective for reducing malaria transmission is required to inform the malaria elimination toolkit in the region. METHODS: A personal protection package consisting of long-lasting insecticidal hammock net, insect repellent and health communication pamphlet was developed in consultation with relevant implementing partners from Cambodia and Lao PDR. An open stepped-wedge cluster-randomised controlled trial will be conducted over a period of 12 months in a minimum of 488 villages (~ 428 in Lao PDR and ~ 60 in Cambodia) to evaluate the effectiveness of the personal protection package. Villages will be randomised into 11 blocks, with blocks transitioned in random order from control to intervention states at monthly intervals, following a 1-month baseline period. The primary outcome of the trial is the prevalence of Plasmodium spp. infection diagnosed by rapid diagnostic test. Difference in prevalence of malaria infection will be estimated across intervention and control periods using generalized linear mixed modelling. Nested within the stepped-wedge cluster-randomised controlled trial is a mixed-methods study to explore the acceptability of the personal protection package, feasibility of implementing a personal protection package as a vector control intervention, and knowledge, attitude and practice of MMPs regarding malaria prevention; and cost-analysis to determine the cost-effectiveness of implementing a personal protection package. DISCUSSION: This study, using a rigorous design and mixed-methods methodology, will evaluate whether a personal protection package can reduce residual malaria transmission among forest-going MMPs in Cambodia and Lao PDR. It will also measure implementation research outcomes such as effectiveness of the intervention package, cost-effectiveness, acceptability, and feasibility, in order to inform potential national and regional policy. Trial registration This trial was prospectively registered on ClinicalTrials.gov (NCT05117567) on 11th November 2021.

Correlates of anxiety and depression in a community cohort of people who smoke methamphetamine.

OBJECTIVE: Anxiety and depression are the most common mental health disorders experienced by Australians. These disorders are commonly found in people who use methamphetamine; however, much of this research has involved participants recruited from treatment settings who inject methamphetamine. We therefore explored (1) the prevalence of moderate to severe anxiety and depression in a community-recruited cohort who smoked methamphetamine and (2) examined potential factors associated with moderate to severe anxiety or depression in this cohort. METHOD: Data were derived from baseline surveys of 725 participants of the prospective 'VMAX' study, recruited from metropolitan and non-metropolitan areas of Victoria, Australia, via snowball and respondent-driven sampling. Anxiety and depression were measured using the Generalized Anxiety Disorder-7 and the Patient Health Questionnaire-9 instruments. Independent associations between moderate to severe scores on these measures and demographic, socio-economic, substance use and other health and social characteristics were examined using multivariable logistic regression. RESULTS: More than half (60%) of the participants were classified as experiencing moderate to severe anxiety and/or depression. In the multivariable models, having poor/very poor self-rated health, methamphetamine dependence and being unemployed were associated with higher odds of experiencing both moderate to severe depression and moderate to severe anxiety. Living in a large rural town, identifying as Aboriginal and Torres Strait Islander and smoking methamphetamine were associated with lower odds of experiencing moderate to severe depression. Being female was associated with higher odds of experiencing moderate to severe anxiety. CONCLUSION: The high rates of anxiety and/or depression found in the VMAX cohort were associated with demographic, socio-economic, substance use and other health and social factors. The prevalence of moderate to severe anxiety is a novel finding that warrants further study. Further work is needed to determine how anxiety and depression change over time among people who smoke methamphetamine, to help identify key intervention points.

Community-based molecular and serological surveillance of subclinical malaria in Myanmar.

BACKGROUND: In the Greater Mekong Subregion (GMS), current malaria surveillance strategies rely on a network of village health volunteers (VHVs) reporting the results of rapid diagnostic tests (RDTs), known to miss many asymptomatic infections. Integration of more sensitive diagnostic molecular and serological measures into the VHV network may improve surveillance of residual malaria transmission in hard-to-reach areas in the region and inform targeted interventions and elimination responses. However, data on residual malaria transmission that would be captured by these measures in the VHV-led testing and treatment surveillance network in the GMS is unknown. METHODS: A total of 114 VHVs were trained to collect dried blood spots from villagers undergoing routine RDTs as part of VHV-led active and passive case detection from April 2015 to June 2016. Samples were subjected to molecular testing (quantitative polymerase chain reaction [qPCR]) to determine Plasmodium falciparum and P. vivax infection and serological testing (against P. falciparum and P. vivax antigens) to determine exposure to P. falciparum and P. vivax. RESULTS: Over 15 months, 114 VHVs performed 32,194 RDTs and collected samples for molecular (n = 13,157) and serological (n = 14,128) testing. The prevalence of molecular-detectable P. falciparum and P. vivax infection was 3.2% compared to the 0.16% prevalence of Plasmodium spp. by RDT, highlighting the large burden of infections undetected by standard surveillance. Peaks in anti-P. falciparum, but not P. vivax, merozoite IgG seroprevalence coincided with seasonal P. falciparum transmission peaks, even in those with no molecularly detectable parasites. At the individual level, antibody seropositivity was associated with reduced odds of contemporaneous P. falciparum (OR for PfCSP 0.51 [95%CI 0.35, 0.76], p = 0.001, PfAMA1 0.70 [95%CI 0.52, 0.93], p = 0.01, and PfMSP2 0.81 [95%CI 0.61, 1.08], p = 0.15), but not P. vivax infection (OR PvAMA1 1.02 [95%CI 0.73, 1.43], p = 0.89) indicating a potential role of immunity in protection against molecular-detectable P. falciparum parasitaemia. CONCLUSIONS: We demonstrated that integration and implementation of sample collection for molecular and serological surveillance into networks of VHV servicing hard-to-reach populations in the GMS is feasible, can capture significant levels of ongoing undetected seasonal malaria transmission and has the potential to supplement current routine RDT testing. Improving malaria surveillance by advancing the integration of molecular and serological techniques, through centralised testing approaches or novel point-of-contact tests, will advance progress, and tracking, towards malaria elimination goals in the GMS.

A mobile phone application for malaria case-based reporting to advance malaria surveillance in Myanmar: a mixed methods evaluation.

BACKGROUND: To achieve malaria elimination in the Greater Mekong Subregion, including Myanmar, it is necessary to ensure all malaria cases are detected, treated, and reported in a timely manner. Mobile phone-based applications for malaria reporting, case management, and surveillance implemented at a community-level may overcome reporting limitations associated with current paper-based reporting (PBR), but their effectiveness in this context is unknown. METHODS: A mixed methods evaluation study was undertaken to determine the effectiveness of a national Malaria Case-Based Reporting (MCBR) mobile phone application in improving malaria case reporting compared to the existing PBR reporting system in Myanmar. Methods included secondary analysis of malaria case report data, questionnaires, focus group discussions and field observations of community volunteers, interviews and direct observations of malaria programme stakeholders, and cost analysis. Using a combination of these approaches the following areas were investigated: data quality and completeness, data access and usage, capacity for timely reporting, the acceptability, functionality, and ease of use of the application and facilitators and barriers to its use, and the relative cost of MCBR compared to the PBR system. RESULTS: Compared to PBR, MCBR enabled more accurate and complete data to be reported in a much timelier manner, with 63% of MCBR users reporting they transmit rapid diagnostic test outcomes within 24 h, compared to 0% of PBR users. MCBR was favoured by integrated community malaria volunteers and their supervisors because of its efficiency. However, several technical and operational challenges associated with internet coverage, data transmission, and e-literacy were identified and stakeholders reported not being confident to rely solely on MCBR data for programmatic decision-making. CONCLUSIONS: Implementation of MCBR provided timely and accurate data for malaria surveillance. Findings from this evaluation study will enable the optimization of an application-based reporting system for malaria monitoring and surveillance in the Greater Mekong Subregion and advance systems to track progress towards, and certify, the achievement of malaria elimination targets.

Sustainability of a mobile phone application-based data reporting system in Myanmar's malaria elimination program: a qualitative study.

BACKGROUND: Strengthening surveillance systems to collect near-real-time case-based data plays a fundamental role in achieving malaria elimination in the Greater Mekong Subregion (GMS). With the advanced and widespread use of digital technology, mHealth is increasingly taking a prominent role in malaria surveillance systems in GMS countries, including Myanmar. In Myanmar's malaria elimination program, an mHealth system called Malaria Case-based Reporting (MCBR) has been applied for case-based reporting of malaria data by integrated community malaria volunteers (ICMVs). However, the sustainability of such mHealth systems in the context of existing malaria elimination programs in Myanmar is unknown. METHODS: Focus group discussions were conducted with ICMVs and semi-structured in-depth interviews were conducted with malaria program stakeholders from Myanmar's Ministry of Health and Sports and its malaria program implementing partners. Thematic (deductive followed by inductive) analysis was undertaken using a qualitative descriptive approach. RESULTS: Technological and financial constraints such as inadequate internet access, software errors, and insufficient financial resources to support mobile phone-related costs have hampered users' access to MCBR. Poor system integrity, unpredictable reporting outcomes, inadequate human resources for system management, and inefficient user support undermined the perceived quality of the system and user satisfaction, and hence its sustainability. Furthermore, multiple parallel systems with functions overlapping those of MCBR were in use. CONCLUSIONS: Despite its effectiveness and efficiency in malaria surveillance, the sustainability of nationwide implementation of MCBR is uncertain. To make it sustainable, stakeholders should deploy a dedicated human workforce with the necessary technical and technological capacities; secure sustainable, long-term funding for implementation of MCBR; find an alternative cost-effective plan for ensuring sustainable system access by ICMVs, such as using volunteer-owned mobile phones for reporting rather than supporting new mobile phones to them; and find a solution to the burden of multiple parallel systems. TRIAL REGISTRATION: Not applicable.

Outcomes of Treatment for Hepatitis C in Primary Care, Compared to Hospital-based Care: A Randomized, Controlled Trial in People Who Inject Drugs.

BACKGROUND: To achieve the World Health Organization hepatitis C virus (HCV) elimination targets, it is essential to increase access to direct-acting antivirals (DAAs), especially among people who inject drugs (PWID). We aimed to determine the effectiveness of providing DAAs in primary care, compared with hospital-based specialist care. METHODS: We randomized PWID with HCV attending primary care sites in Australia or New Zealand to receive DAAs at their primary care site or local hospital (standard of care [SOC]). The primary outcome was to determine whether people treated in primary care had a noninferior rate of sustained virologic response at Week 12 (SVR12), compared to historical controls (consistent with DAA trials at the time of the study design); secondary outcomes included comparisons of treatment initiation, SVR12 rates, and the care cascade by study arm. RESULTS: We recruited 140 participants and randomized 136: 70 to the primary care arm and 66 to the SOC arm. The SVR12 rate (100%, 95% confidence interval [CI] 87.7-100) of people treated in primary care was noninferior when compared to historical controls (85% assumed). An intention-to-treat analysis revealed that the proportion of participants commencing treatment in the primary care arm (75%, 43/57) was significantly higher than in the SOC arm (34%, 18/53; P < .001; relative risk [RR] 2.48, 95% CI 1.54-3.95), and the proportion of participants with SVR12 was significantly higher in the primary care arm, compared to in the SOC arm (49% [28/57] and 30% [16/53], respectively; P = .043; RR 1.63, 95% CI 1.0-2.65). CONCLUSIONS: Providing HCV treatment in primary care increases treatment uptake and cure rates. Approaches that increase treatment uptake among PWID will accelerate elimination strategies. CLINICAL TRIALS REGISTRATION: NCT02555475.

Evaluation of the effectiveness of topical repellent distributed by village health volunteer networks against Plasmodium spp. infection in Myanmar: A stepped-wedge cluster randomised trial.

BACKGROUND: The World Health Organization has yet to endorse deployment of topical repellents for malaria prevention as part of public health campaigns. We aimed to quantify the effectiveness of repellent distributed by the village health volunteer (VHV) network in the Greater Mekong Subregion (GMS) in reducing malaria in order to advance regional malaria elimination. METHODS AND FINDINGS: Between April 2015 and June 2016, a 15-month stepped-wedge cluster randomised trial was conducted in 116 villages in Myanmar (stepped monthly in blocks) to test the effectiveness of 12% N,N-diethylbenzamide w/w cream distributed by VHVs, on Plasmodium spp. infection. The median age of participants was 18 years, approximately half were female, and the majority were either village residents (46%) or forest dwellers (40%). No adverse events were reported during the study. Generalised linear mixed modelling estimated the effect of repellent on infection detected by rapid diagnostic test (RDT) (primary outcome) and polymerase chain reaction (PCR) (secondary outcome). Overall Plasmodium infection detected by RDT was low (0.16%; 50/32,194), but infection detected by PCR was higher (3%; 419/13,157). There was no significant protection against RDT-detectable infection (adjusted odds ratio [AOR] = 0.25, 95% CI 0.004-15.2, p = 0.512). In Plasmodium-species-specific analyses, repellent protected against PCR-detectable P. falciparum (adjusted relative risk ratio [ARRR] = 0.67, 95% CI 0.47-0.95, p = 0.026), but not P. vivax infection (ARRR = 1.41, 95% CI 0.80-2.47, p = 0.233). Repellent effects were similar when delayed effects were modelled, across risk groups, and regardless of village-level and temporal heterogeneity in malaria prevalence. The incremental cost-effectiveness ratio was US$256 per PCR-detectable infection averted. Study limitations were a lower than expected Plasmodium spp. infection rate and potential geographic dilution of the intervention. CONCLUSIONS: In this study, we observed apparent protection against new infections associated with the large-scale distribution of repellent by VHVs. Incorporation of repellent into national strategies, particularly in areas where bed nets are less effective, may contribute to the interruption of malaria transmission. Further studies are warranted across different transmission settings and populations, from the GMS and beyond, to inform WHO public health policy on the deployment of topical repellents for malaria prevention. TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Registry (ACTRN12616001434482).

Pregnancy-specific malarial immunity and risk of malaria in pregnancy and adverse birth outcomes: a systematic review.

BACKGROUND: In endemic areas, pregnant women are highly susceptible to Plasmodium falciparum malaria characterized by the accumulation of parasitized red blood cells (pRBC) in the placenta. In subsequent pregnancies, women develop protective immunity to pregnancy-associated malaria and this has been hypothesized to be due to the acquisition of antibodies to the parasite variant surface antigen VAR2CSA. In this systematic review we provide the first synthesis of the association between antibodies to pregnancy-specific P. falciparum antigens and pregnancy and birth outcomes. METHODS: We conducted a systematic review and meta-analysis of population-based studies (published up to 07 June 2019) of pregnant women living in P. falciparum endemic areas that examined antibody responses to pregnancy-specific P. falciparum antigens and outcomes including placental malaria, low birthweight, preterm birth, peripheral parasitaemia, maternal anaemia, and severe malaria. RESULTS: We searched 6 databases and identified 33 studies (30 from Africa) that met predetermined inclusion and quality criteria: 16 studies contributed estimates in a format enabling inclusion in meta-analysis and 17 were included in narrative form only. Estimates were mostly from cross-sectional data (10 studies) and were heterogeneous in terms of magnitude and direction of effect. Included studies varied in terms of antigens tested, methodology used to measure antibody responses, and epidemiological setting. Antibody responses to pregnancy-specific pRBC and VAR2CSA antigens, measured at delivery, were associated with placental malaria (9 studies) and may therefore represent markers of infection, rather than correlates of protection. Antibody responses to pregnancy-specific pRBC, but not recombinant VAR2CSA antigens, were associated with trends towards protection from low birthweight (5 studies). CONCLUSIONS: Whilst antibody responses to several antigens were positively associated with the presence of placental and peripheral infections, this review did not identify evidence that any specific antibody response is associated with protection from pregnancy-associated malaria across multiple populations. Further prospective cohort studies using standardized laboratory methods to examine responses to a broad range of antigens in different epidemiological settings and throughout the gestational period, will be necessary to identify and prioritize pregnancy-specific P. falciparum antigens to advance the development of vaccines and serosurveillance tools targeting pregnant women.

Understanding the interactions between iron supplementation, infectious disease and adverse birth outcomes is essential to guide public health recommendations.

Pregnant women are highly susceptible to anaemia and iron deficiency due to the increased demands of pregnancy as well as other factors. Iron supplementation is recommended in pregnancy, yet the benefits on newborn outcomes are variable between populations, most likely due to the heterogeneity in the prevalence of iron deficiency, detrimental birth outcomes and infectious diseases. Furthermore, there are concerns regarding iron supplementation in malaria-endemic areas due to reports of increased risk of malaria in those receiving iron. This is compounded by limited knowledge of how iron deficiency, anaemia, malaria, and other infections may interact to influence birth outcomes. In a recent cohort study in Papua New Guinea, where there is a high burden of infections and iron deficiency, we found that iron deficiency in pregnancy was associated with a reduced risk of adverse birth outcomes. However, this effect could not be wholly explained by interactions between iron deficiency and malaria. We proposed that iron deficiency may confer a degree of protection against other infectious pathogens, which in turn caused improvements in birthweight. We argue that further studies in multiple populations are crucial to elucidate interactions between iron status, iron supplementation and birthweight as well as to understand the context-specific benefits of iron supplementation in pregnancy and inform public policy. Focus should be given to haematological studies on anaemia, haemodilution and iron absorption, as well as investigating infectious diseases and other nutritional deficiencies. This is a particular priority in resource-constrained settings where the prevalence of iron deficiency, poor nutrition, infections and poor birth outcomes are high. While current recommendations of iron supplementation and malaria prophylaxis to reduce the burden of poor pregnancy outcomes should be supported, the strength of evidence underpinning these must be improved and new insights should be garnered in order to maximise improvements in maternal and child health.Please see related article: https://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-018-1146-z .Please see related article: https://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-019-1375-9 .

Induction and decay of functional complement-fixing antibodies by the RTS,S malaria vaccine in children, and a negative impact of malaria exposure.

BACKGROUND: Leading malaria vaccine, RTS,S, is based on the circumsporozoite protein (CSP) of sporozoites. RTS,S confers partial protection against malaria in children, but efficacy wanes relatively quickly after primary immunization. Vaccine efficacy has some association with anti-CSP IgG; however, it is unclear how these antibodies function, and how functional antibodies are induced and maintained over time. Recent studies identified antibody-complement interactions as a potentially important immune mechanism against sporozoites. Here, we investigated whether RTS,S vaccine-induced antibodies could function by interacting with complement. METHODS: Serum samples were selected from children in a phase IIb trial of RTS,S/AS02A conducted at two study sites of high and low malaria transmission intensity in Manhiça, Mozambique. Samples following primary immunization and 5-year post-immunization follow-up time points were included. Vaccine-induced antibodies were characterized by isotype, subclass, and epitope specificity, and tested for the ability to fix and activate complement. We additionally developed statistical methods to model the decay and determinants of functional antibodies after vaccination. RESULTS: RTS,S vaccination induced anti-CSP antibodies that were mostly IgG1, with some IgG3, IgG2, and IgM. Complement-fixing antibodies were effectively induced by vaccination, and targeted the central repeat and C-terminal regions of CSP. Higher levels of complement-fixing antibodies were associated with IgG that equally recognized both the central repeat and C-terminal regions of CSP. Older age and higher malaria exposure were significantly associated with a poorer induction of functional antibodies. There was a marked decay in functional complement-fixing antibodies within months after vaccination, as well as decays in IgG subclasses and IgM. Statistical modeling suggested the decay in complement-fixing antibodies was mostly attributed to the waning of anti-CSP IgG1, and to a lesser extent IgG3. CONCLUSIONS: We demonstrate for the first time that RTS,S can induce complement-fixing antibodies in young malaria-exposed children. The short-lived nature of functional responses mirrors the declining vaccine efficacy of RTS,S over time. The negative influence of age and malaria exposure on functional antibodies has implications for understanding vaccine efficacy in different settings. These findings provide insights into the mechanisms and longevity of vaccine-induced immunity that will help inform the future development of highly efficacious and long-lasting malaria vaccines.

Field Performance and Diagnostic Accuracy of a Low-Cost Instrument-Free Point-of-Care CD4 Test (Visitect CD4) Performed by Different Health Worker Cadres among Pregnant Women.

Measuring CD4 counts remains an important component of HIV care. The Visitect CD4 is the first instrument-free low-cost point-of-care CD4 test with results interpreted visually after 40 min, providing a result of ≥350 CD4 cells/mm3 The field performance and diagnostic accuracy of the test was assessed among HIV-infected pregnant women in South Africa. A nurse performed testing at the point-of-care using both venous and finger-prick blood, and a counselor and laboratory staff tested venous blood in the clinic laboratory (four Visitect CD4 tests/participant). Performance was compared to the mean CD4 count from duplicate flow cytometry tests on venous blood (FACSCalibur Trucount). In 2017, 156 patients were enrolled, providing a total of 624 Visitect CD4 tests (468 venous and 156 finger-prick samples). Of 624 tests, 28 (4.5%) were inconclusive. Generalized linear mixed modeling showed better performance of the test on venous blood (sensitivity = 81.7%; 95% confidence interval [CI] = 72.3 to 91.1]; specificity = 82.6%, 95% CI = 77.1 to 88.1) than on finger-prick specimens (sensitivity = 60.7%; 95% CI = 45.0 to 76.3; specificity = 89.5%, 95% CI = 83.2 to 95.8; P = 0.001). No difference in performance was detected by cadre of health worker (P = 0.113) or between point-of-care versus laboratory-based testing (P = 0.108). Adequate performance of Visitect CD4 with different operators and at the point of care, with no need of electricity or instrument, shows the potential utility of this device, especially for facilitating decentralization of CD4 testing services in rural areas.