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[This corrects the article DOI: 10.1371/journal.pmed.1003279.].
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Background and Aims: In Myanmar, public sector treatment programs for hepatitis C virus (HCV) infection were nonexistent until June 2017. WHO highlights the importance of simplification of HCV service delivery through task-shifting among health workers and decentralization to the primary health care level. Between November 2016 and November 2017, a study was conducted to describe the epidemiological data and real-world outcomes of treating HIV/HCV coinfected patients with generic direct acting antiviral (DAA) based regimens in the three HIV clinics run by nonspecialist medical doctors in Myanmar. Methods: HCV co-infection among people living with HIV (PLHIV) from two clinics in Yangon city and one clinic in Dawei city was screened by rapid diagnostic tests and confirmed by testing for viral RNA. Nonspecialist medical doctors prescribed sofosbuvir and daclatasvir based regimens (with or without ribavirin) for 12 or 24 weeks based on the HCV genotype and liver fibrosis status. Sustained virologic response at 12 weeks after treatment (SVR12) was assessed to determine cure. Results: About 6.5% (1417/21,777) of PLHIV were co-infected with HCV. Of 864 patients enrolled in the study, 50.8% reported history of substance use, 27% history of invasive medical procedures and 25.6% history of incarceration. Data on treatment outcomes were collected from 267 patients of which 257 (96.3%) achieved SVR12, 7 (2.6%) failed treatment, 2 (0.7%) died and 1 (0.4%) became loss to follow-up. Conclusion: The study results support the integration of hepatitis C diagnosis and treatment with DAA-based regimens into existing HIV clinics run by nonspecialist medical doctors in a resource-limited setting. Epidemiological data on HIV/HCV co-infection call for comprehensive HCV care services among key populations like drug users and prisoners in Yangon and Dawei.
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BACKGROUND: The burden of advanced HIV disease (AHD) and predictors of outcomes among people living with HIV (PLHIV) re-engaging in care are not well known. METHODS: We conducted a retrospective cohort study of PLHIV who re-engaged in care after being lost to follow-up (LFU), from 2003 to 2019, in Myanmar. We calculated the incidence rates of attrition after re-engagement and performed Cox regression to identify risk factors for attrition. RESULTS: Of 44 131 PLHIV who started antiretroviral treatment, 12 338 (28.0%) were LFU at least once: 7608 (61.6%) re-engaged in care, 4672 (61.4%) with AHD at re-engagement. The death and LFU rates were 2.21-fold (95% CI 1.82 to 2.67) and 1.46-fold (95% CI 1.33 to 1.61) higher among patients who re-engaged with AHD (p>0.001). Death in patients who re-engaged with AHD was associated with male sex (adjusted HR [aHR] 2.63; 95% CI 1.31 to 5.26; p=0.006), TB coinfection (aHR 2.26; 95% CI 1.23 to 4.14; p=0.008) and sex work (aHR 7.49, 95% CI 2.29 to 22.52; p<0.001). History of intravenous drug use was identified as a predictor of being LFU. CONCLUSIONS: Re-engagement in HIV care in Myanmar is frequent and those who re-engage carry a high burden of AHD. As AHD at re-engagement is associated with higher attrition rates, implementation of differentiated interventions that enable earlier linkage to care and prompt identification and management of AHD in this population is necessary.
Subject(s)
Anti-HIV Agents , HIV Infections , Humans , Male , Retrospective Studies , Myanmar/epidemiology , CD4 Lymphocyte Count , HIV Infections/drug therapy , HIV Infections/epidemiology , Risk Factors , Anti-HIV Agents/therapeutic useABSTRACT
Studies reporting vaccine effectiveness against COVID-19 outcomes concentrate mainly on estimates of one single type of vaccine and variant, seldom considering waning effects. We aimed to estimate the effectiveness of the overall COVID-19 vaccination programme implemented in the Apulia region of Italy at preventing SARS-CoV-2 infections, COVID-19-related hospital admissions and deaths during alpha and delta variant dominant periods. We conducted a retrospective cohort study using electronic health records of persons 16 years and older resident in the Apulia region, assessing the effectiveness of the combined use of BNT162b2, mRNA-1273, ChAdOx1-S and Ad26.COV2.S vaccines against confirmed COVID-19 infections, hospitalisations and deaths, for fully and partially vaccinated persons as well as by time since vaccination and variants. Cox regression models yielding hazard ratios were used to calculate the overall vaccination programme effectiveness. From 1 January to 1 December 2021, we included 3,530,967 eligible persons in the cohort, of whom 2,770,299 were fully vaccinated and 158,313 were COVID-19 positive at the end of the study period. The effectiveness of the programme over the entire study period for fully vaccinated persons against COVID-19 infection, hospitalisation and death were 87.69% (CI95% 87.73-88.18), 94.08% (93.58-94.54) and 95.95% (CI95% 95.26-96.54), respectively. The effectiveness against COVID-19 infection of fully vaccinated subjects during the alpha and delta period was respectively 88.20% (CI95% 87.60-99.78) and 59.31% (CI95% 57.91-60.67), against hospitalisation 93.89% (CI95% 92.67-94.90) and 88.32% (CI95% 86.50-89.90) and against death 93.83% (CI95% 91.65-95.45) and 85.91 (CI95% 79.98-90.09). The waning effects of the programme regarding COVID-19 infection during the delta period were stronger than for alpha, with 75.85% (CI95% 74.38-77.24) effectiveness after 1-2 months and 8.35% (CI95% 3.45-13.01) after 5-6 months after full vaccination. The effectiveness against hospitalisation and death during the delta period waned rapidly and at 7-8-months after the full vaccination respectively decreased to 27.67% (CI95% 7.48-43.45) and 48.47 (CI95% 53.97-34.82). Our study suggests that the COVID-19 vaccination program in Apulia was strongly protective against COVID-19 infection, hospitalisation, and death due to alpha as well as delta variants, although its effectiveness is reduced over time.
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COVID-19 , Cross Infection , Humans , COVID-19/epidemiology , COVID-19/prevention & control , COVID-19 Vaccines/therapeutic use , Program Evaluation , Retrospective Studies , Ad26COVS1 , BNT162 Vaccine , SARS-CoV-2 , Vaccination , Hospitalization , Cohort StudiesABSTRACT
Soil-transmitted helminths, such as Ascaris lumbricoides, are the most prevalent parasites globally. Optimal anthelmintic treatment for A. lumbricoides in endemically infected communities is challenged by several host-related and environmental factors influencing infection acquisition. We assessed the risk of A. lumbricoides (re)infection after treatment in a Venezuelan rural community. Individual merthiolate-iodine-formaldehyde-fixed faecal samples were collected from 224 persons before a single-dose pyrantel treatment and at 1, 3, 6, 9 and 15 months after treatment. Effects of age, sex and socioeconomic status (SES) on A. lumbricoides prevalence, eggs/gram faeces (EPG) and infection (re)acquisition were assessed using both generalised linear mixed-effects models and survival analysis. Pre-treatment A. lumbricoides prevalence was 39.7%. Higher prevalence was associated with younger age and lower SES. Higher EPG values were observed among young children. Median time to A. lumbricoides infection was six months after treatment: at 1, 3, 6, 9 and 15 months post-treatment, cumulative incidence was 6.7%, 18.9%, 34.6%, 42.2%, and 52.6%, respectively. Younger age, lower SES, and pre-treatment A. lumbricoides infection status showed significantly elevated hazard ratios. Mass drug administration protocols would benefit from considering these factors in selective treatment strategies and possibly more than just annual or biannual treatments in the target population.
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Ascariasis , Helminthiasis , Animals , Ascariasis/drug therapy , Ascariasis/epidemiology , Ascariasis/parasitology , Ascaris lumbricoides , Child , Child, Preschool , Feces/parasitology , Helminthiasis/epidemiology , Helminthiasis/parasitology , Humans , Prevalence , Rural Population , Soil/parasitology , Venezuela/epidemiologyABSTRACT
INTRODUCTION: Data have suggested that SARS-CoV-2 infection causes an antibody response at least as strong as one BNT162b2 vaccine dose. Nevertheless, some aspects require further investigation to better understand the immunogenicity of one vaccine dose among infected individuals. Thus, we evaluated how previous SARS-CoV-2 infection may influence the humoral immunity after a single Pfizer BNT162b mRNA vaccine dose in a sample of healthcare workers (HCWs). METHODS: As part of the routine surveillance activity conducted among HCWs of the Policlinico Riuniti Foggia Hospital (Apulia region, Italy), we conducted a retrospective serosurvey in the period January-March 2021. We compared specific antibody titres (anti-spike IgGs measured by enzyme-linked immunoassay, ELISA) after SARS-CoV-2 infection and after the first dose of the BNT162b2 vaccine, analysing the impact of sex, age, time since infection, and presence of symptoms on the humoral response. RESULTS: We included in the study 58 HCWs (mean age 44.1 years, 48.2% male) with anti-spike IgG titres available before and after the first BNT162b2 vaccine dose. Among these, we observed higher titres in previously infected cases (N = 21) than in COVID-19-naïve subjects (N = 37) (medians 1510 vs. 0.68; p < 0.001). A statistically significant difference in anti-spike IgG titres was also observed among previously infected HCWs before vaccine dose in comparison with post-dose infection-naïve HCWs (medians 18.37 vs. 0.68, p < 0.001). Among infected individuals, no differences by sex, age, or time since infection were reported (p > 0.05). Post-dose titres of symptomatic and asymptomatic infected HCWs slightly differed (medians = 1900 vs. 1090; p = 0.048). CONCLUSION: Our data support the viable hypothesis of a single-dose vaccine regimen in individuals with a history of COVID-19, but no conclusion on duration of protection in this group can be drawn from our study.
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BACKGROUND: In response to the rising global NCD burden, humanitarian actors have rapidly scaled-up NCD services in crisis-affected low-and-middle income countries. Using the RE-AIM implementation framework, we evaluated a multidisciplinary, primary level model of NCD care for Syrian refugees and vulnerable Jordanians delivered by MSF in Irbid, Jordan. We examined the programme's Reach, Effectiveness, Adoption and acceptance, Implementation and Maintenance over time. METHODS: This mixed methods retrospective evaluation, undertaken in 2017, comprised secondary analysis of pre-existing cross-sectional household survey data; analysis of routine cohort data from 2014 to 2017; descriptive costing analysis of total annual, per-patient and per-consultation costs for 2015-2017 from the provider-perspective; a clinical audit; a medication adherence survey; and qualitative research involving thematic analysis of individual interviews and focus group discussions. RESULTS: The programme enrolled 23% of Syrian adult refugees with NCDs in Irbid governorate. The cohort mean age was 54.7 years; 71% had multi-morbidity and 9.9% self-reported a disability. The programme was acceptable to patients, staff and stakeholders. Blood pressure and glycaemic control improved as the programme matured and by 6.6 mmHg and 1.12 mmol/l respectively within 6 months of patient enrolment. Per patient per year cost increased 23% from INT$ 1424 (2015) to 1751 (2016), and by 9% to 1904 (2017). Cost per consultation increased from INT$ 209 to 253 (2015-2017). Staff reported that clinical guidelines were usable and patients' self-reported medication adherence was high. Individual, programmatic and organisational challenges to programme implementation and maintenance included the impact of war and the refugee experience on Syrian refugees' ability to engage; inadequate low-cost referral options; and challenges for MSF to rapidly adapt to operating in a highly regulated and complex health system. Essential programme adaptations included refinement of health education, development of mental health and psychosocial services and addition of essential referral pathways, home visit, physiotherapy and social worker services. CONCLUSION: RE-AIM proved a valuable tool in evaluating a complex intervention in a protracted humanitarian crisis setting. This multidisciplinary programme was largely acceptable, achieving good clinical outcomes, but for a limited number of patients and at relatively high cost. We propose that model simplification, adapted procurement practices and use of technology could improve cost effectiveness without reducing acceptability, and may facilitate replication.
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Noncommunicable Diseases , Refugees , Adult , Cross-Sectional Studies , Humans , Jordan/epidemiology , Middle Aged , Retrospective Studies , SyriaABSTRACT
BACKGROUND: Progress toward the global target for 95% virological suppression among those on antiretroviral treatment (ART) is still suboptimal. We describe the viral load (VL) cascade, the incidence of virological failure and associated risk factors among people living with HIV receiving first-line ART in an HIV cohort in Myanmar treated by the Médecins Sans Frontières in collaboration with the Ministry of Health and Sports Myanmar. METHODS: We conducted a retrospective cohort study, including adult patients with at least one HIV viral load test result and having received of at least 6 months' standard first-line ART. The incidence rate of virological failure (HIV viral load ≥ 1000 copies/mL) was calculated. Multivariable Cox's regression was performed to identify risk factors for virological failure. RESULTS: We included 25,260 patients with a median age of 33.1 years (interquartile range, IQR 28.0-39.1) and a median observation time of 5.4 years (IQR 3.7-7.9). Virological failure was documented in 3,579 (14.2%) participants, resulting in an overall incidence rate for failure of 2.5 per 100 person-years of follow-up. Among those who had a follow-up viral load result, 1,258 (57.1%) had confirmed virological failure, of which 836 (66.5%) were switched to second-line treatment. An increased hazard for failure was associated with age ≤ 19 years (adjusted hazard ratio, aHR 1.51; 95% confidence intervals, CI 1.20-1.89; p < 0.001), baseline tuberculosis (aHR 1.39; 95% CI 1.14-1.49; p < 0.001), a history of low-level viremia (aHR 1.60; 95% CI 1.42-1.81; p < 0.001), or a history of loss-to-follow-up (aHR 1.24; 95% CI 1.41-1.52; p = 0.041) and being on the same regimen (aHR 1.37; 95% CI 1.07-1.76; p < 0.001). Cumulative appointment delay was not significantly associated with failure after controlling for covariates. CONCLUSIONS: VL monitoring is an important tool to improve programme outcomes, however limited coverage of VL testing and acting on test results hampers its full potential. In our cohort children and adolescents, PLHIV with history of loss-to-follow-up or those with low-viremia are at the highest risk of virological failure and might require more frequent virological monitoring than is currently recommended.
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Anti-HIV Agents , HIV Infections , Adolescent , Adult , Anti-HIV Agents/therapeutic use , Child , Cohort Studies , HIV Infections/drug therapy , HIV Infections/epidemiology , Humans , Infant, Newborn , Myanmar/epidemiology , Retrospective StudiesABSTRACT
BACKGROUND: Little is known about the content or quality of non-communicable disease (NCD) care in humanitarian settings. Since 2014, Médecins Sans Frontières (MSF) has provided primary-level NCD services in Irbid, Jordan, targeting Syrian refugees and vulnerable Jordanians who struggle to access NCD care through the overburdened national health system. This retrospective cohort study explored programme and patient-level patterns in achievement of blood pressure and glycaemic control, patterns in treatment interruption, and the factors associated with these patterns. METHODS AND FINDINGS: The MSF multidisciplinary, primary-level NCD programme provided facility-based care for cardiovascular disease, diabetes, and chronic respiratory disease using context-adapted guidelines and generic medications. Generalist physicians managed patients with the support of family medicine specialists, nurses, health educators, pharmacists, and psychosocial and home care teams. Among the 5,045 patients enrolled between December 2014 and December 2017, 4,044 eligible adult patients were included in our analysis, of whom 72% (2,913) had hypertension and 63% (2,546) had type II diabetes. Using visits as the unit of analysis, we plotted the following on a monthly basis: mean blood pressure among hypertensive patients, mean fasting blood glucose and HbA1c among type II diabetic patients, the proportion of each group achieving control, mean days of delayed appointment attendance, and the proportion of patients experiencing a treatment interruption. Results are presented from programmatic and patient perspectives (using months since programme initiation and months since cohort entry/diagnosis, respectively). General linear mixed models explored factors associated with clinical control and with treatment interruption. Mean age was 58.5 years, and 60.1% (2,432) were women. Within the programme's first 6 months, mean systolic blood pressure decreased by 12.4 mm Hg from 143.9 mm Hg (95% CI 140.9 to 146.9) to 131.5 mm Hg (95% CI 130.2 to 132.9) among hypertensive patients, while fasting glucose improved by 1.12 mmol/l, from 10.75 mmol/l (95% CI 10.04 to 11.47) to 9.63 mmol/l (95% CI 9.22 to 10.04), among type II diabetic patients. The probability of achieving treatment target in a visit was 63%-75% by end of 2017, improving with programme maturation but with notable seasonable variation. The probability of experiencing a treatment interruption declined as the programme matured and with patients' length of time in the programme. Routine operational data proved useful in evaluating a humanitarian programme in a real-world setting, but were somewhat limited in terms of data quality and completeness. We used intermediate clinical outcomes proven to be strongly associated with hard clinical outcomes (such as death), since we had neither the data nor statistical power to measure hard outcomes. CONCLUSIONS: Good treatment outcomes and reasonable rates of treatment interruption were achieved in a multidisciplinary, primary-level NCD programme in Jordan. Our approach to using continuous programmatic data may be a feasible way for humanitarian organisations to account for the complex and dynamic nature of interventions in unstable humanitarian settings when undertaking routine monitoring and evaluation. We suggest that frequency of patient contact could be reduced without negatively impacting patient outcomes and that season should be taken into account in analysing programme performance.
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Health Services Accessibility , Noncommunicable Diseases/prevention & control , Primary Health Care/organization & administration , Refugees , Adult , Aged , Altruism , Female , Humans , Jordan/epidemiology , Male , Middle Aged , Noncommunicable Diseases/epidemiology , Retrospective Studies , Syria/ethnologyABSTRACT
BACKGROUND: Odour baits can attract host-seeking Anopheles mosquitoes indoors and outdoors. We assessed the effects of mass deployment of odour-baited traps on malaria transmission and disease burden. METHODS: We installed solar-powered odour-baited mosquito trapping systems (SMoTS) to households on Rusinga Island, Lake Victoria, western Kenya (mean population 24â879), in a stepped-wedge cluster-randomised trial. All residents in the completed health and demographic surveillance system were eligible to participate. We used the travelling salesman algorithm to assign all households to a cluster (50 or 51 geographically contiguous households); nine contiguous clusters formed a metacluster. Initially, no cluster had SMoTS (non-intervened). During the course of the intervention roll-out SMoTS were gradually installed cluster by cluster until all clusters had SMoTS installed (intervened). We generated 27 cluster randomisations, with the cluster as unit of randomisation, to establish the order to install the traps in the clusters until all had a SMoTS installed. Field workers and participants were not masked to group allocation. The primary outcome of clinical malaria was monitored through repeated household visits covering the entire population, once before roll-out (baseline) and five times throughout the 2-year roll-out. We measured clinical malaria as fever plus a positive result with a rapid diagnostic test. The SolarMal project was registered on the Dutch Trial Register (NTR 3496). FINDINGS: We enrolled 34â041 participants between April 25, 2012, and March 23, 2015, to 81 clusters and nine metaclusters. 4358 households were provided with SMoTS during roll-out between June 3, 2013, and May 16, 2015. 23 clinical malaria episodes were recorded in intervened clusters and 33 episodes in non-intervened clusters (adjusted effectiveness 40·8% [95% CI -172·8 to 87·1], p=0·5) during the roll-out. Malaria prevalence measured by rapid diagnostic test was 29·8% (95% CI 20·9-38·0) lower in SMoTS clusters (prevalence 23·7%; 1552 of 6550 people) than in non-intervened clusters (prevalence 34·5%; 2002 of 5795 people). INTERPRETATION: The unexpectedly low clinical incidence of malaria during roll-out led to an imprecise estimate of effectiveness from the clinical incidence data. The substantial effect on malaria prevalence is explained by reduction in densities of Anopheles funestus. Odour-baited traps might be an effective malaria intervention. FUNDING: COmON Foundation.
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Anopheles , Cost of Illness , Insecticide-Treated Bednets , Malaria/epidemiology , Malaria/prevention & control , Mosquito Control/methods , Odorants , Animals , Evidence-Based Medicine , Female , Humans , Incidence , Insect Vectors , Insecticide-Treated Bednets/statistics & numerical data , Kenya , Malaria/diagnosis , Malaria/transmission , Male , Prevalence , Research Design , Treatment OutcomeABSTRACT
BACKGROUND: Increasing levels of insecticide resistance as well as outdoor, residual transmission of malaria threaten the efficacy of existing vector control tools used against malaria mosquitoes. The development of odour-baited mosquito traps has led to the possibility of controlling malaria through mass trapping of malaria vectors. Through daily removal trapping against a background of continued bed net use it is anticipated that vector populations could be suppressed to a level where continued transmission of malaria will no longer be possible. METHODS/DESIGN: A stepped wedge cluster-randomised trial design was used for the implementation of mass mosquito trapping on Rusinga Island, western Kenya (the SolarMal project). Over the course of 2 years (2013-2015) all households on the island were provided with a solar-powered mosquito trapping system. A continuous health and demographic surveillance system combined with parasitological surveys three times a year, successive rounds of mosquito monitoring and regular sociological studies allowed measurement of intervention outcomes before, during and at completion of the rollout of traps. Data collection continued after achieving mass coverage with traps in order to estimate the longer term effectiveness of this novel intervention. Solar energy was exploited to provide electric light and mobile phone charging for each household, and the impacts of these immediate tangible benefits upon acceptability of and adherence to the use of the intervention are being measured. DISCUSSION: This study will be the first to evaluate whether the principle of solar-powered mass mosquito trapping could be an effective tool for elimination of malaria. If proven to be effective, this novel approach to malaria control would be a valuable addition to the existing strategies of long-lasting insecticide-treated nets and case management. Sociological studies provide a knowledge base for understanding the usage of this novel tool. TRIAL REGISTRATION: Trialregister.nl: NTR3496 - SolarMal. Registered on 20 June 2012.
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Culicidae/parasitology , Disease Vectors , Malaria/prevention & control , Mosquito Control/methods , Odorants , Solar Energy , Animals , Humans , Incidence , Kenya/epidemiology , Malaria/epidemiology , Malaria/parasitology , Malaria/transmission , Prevalence , Research Design , Time FactorsABSTRACT
BACKGROUND: Many interventions against infectious diseases have geographically diffuse effects. This leads to contamination between arms in cluster-randomized trials (CRTs). Pathogen elimination is the goal of many intervention programs against infectious agents, but contamination means that standard CRT designs and analyses do not provide inferences about the potential of interventions to interrupt pathogen transmission at maximum scale-up. METHODS: A generic model of disease transmission was used to simulate infections in stepped wedge cluster-randomized trials (SWCRTs) of a transmission-reducing intervention, where the intervention has spatially diffuse effects. Simulations of such trials were then used to examine the potential of such designs for providing generalizable causal inferences about the impact of such interventions, including measurements of the contamination effects. The simulations were applied to the geography of Rusinga Island, Lake Victoria, Kenya, the site of the SolarMal trial on the use of odor-baited mosquito traps to eliminate Plasmodium falciparum malaria. These were used to compare variants in the proposed SWCRT designs for the SolarMal trial. RESULTS: Measures of contamination effects were found that could be assessed in the simulated trials. Inspired by analyses of trials of insecticide-treated nets against malaria when applied to the geography of the SolarMal trial, these measures were found to be robust to different variants of SWCRT design. Analyses of the likely extent of contamination effects supported the choice of cluster size for the trial. CONCLUSIONS: The SWCRT is an appropriate design for trials that assess the feasibility of local elimination of a pathogen. The effects of incomplete coverage can be estimated by analyzing the extent of contamination between arms in such trials, and the estimates also support inferences about causality. The SolarMal example illustrates how generic transmission models incorporating spatial smoothing can be used to simulate such trials for a power calculation and optimization of cluster size and randomization strategies. The approach is applicable to a range of infectious diseases transmitted via environmental reservoirs or via arthropod vectors.
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Communicable Disease Control/methods , Communicable Diseases/transmission , Disease Vectors , Endemic Diseases/prevention & control , Models, Theoretical , Randomized Controlled Trials as Topic/methods , Research Design , Animals , Computer Simulation , Humans , Insect Vectors , Kenya/epidemiology , Malaria, Falciparum/epidemiology , Malaria, Falciparum/parasitology , Malaria, Falciparum/prevention & control , Malaria, Falciparum/transmission , Mosquito Control/methods , Mosquito Nets , Odorants , Plasmodium falciparum/pathogenicity , Time FactorsABSTRACT
The health and demographic surveillance system on Rusinga Island, Western Kenya, was initiated in 2012 to facilitate a malaria intervention trial: the SolarMal project. The project aims to eliminate malaria from Rusinga Island using the nationwide adopted strategy for malaria control (insecticide-treated bed nets and case management) augmented with mass trapping of anopheline mosquitoes. The main purpose of the health and demographic surveillance is to measure the effectiveness of the trial on clinical malaria incidence, and to monitor demographic, environmental and malaria-related data variables. At the end of 2014, the 44 km(2) island had a population of approximately 25 000 individuals living in 8746 residential structures. Three times per year, all individuals are followed up and surveyed for clinical malaria. Following each round of surveillance, a randomly selected cross-section of the population is subject to a rapid diagnostic test to measure malaria. Additionally, extensive monitoring of malaria vectors is performed. Data collection and management are conducted using the OpenHDS platform, with tablet computers and applications with advanced software connected to a centralized database. Besides the general demographic information, other health-related data are collected which can be used to facilitate a range of other studies within and outside the current project. Access to the core dataset can be obtained on request from the authors.
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Health Surveys , Malaria/epidemiology , Malaria/prevention & control , Malaria/transmission , Mosquito Control/methods , Adolescent , Adult , Aged , Aged, 80 and over , Case Management , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Insecticide-Treated Bednets , Kenya/epidemiology , Male , Middle Aged , Population Surveillance , Sex Distribution , Young AdultABSTRACT
BACKGROUND: Large reductions in malaria transmission and mortality have been achieved over the last decade, and this has mainly been attributed to the scale-up of long-lasting insecticidal bed nets and indoor residual spraying with insecticides. Despite these gains considerable residual, spatially heterogeneous, transmission remains. To reduce transmission in these foci, researchers need to consider the local demographical, environmental and social context, and design an appropriate set of interventions. Exploring spatially variable risk factors for malaria can give insight into which human and environmental characteristics play important roles in sustaining malaria transmission. METHODS: On Rusinga Island, western Kenya, malaria infection was tested by rapid diagnostic tests during two cross-sectional surveys conducted 3 months apart in 3632 individuals from 790 households. For all households demographic data were collected by means of questionnaires. Environmental variables were derived using Quickbird satellite images. Analyses were performed on 81 project clusters constructed by a traveling salesman algorithm, each containing 50-51 households. A standard linear regression model was fitted containing multiple variables to determine how much of the spatial variation in malaria prevalence could be explained by the demographic and environmental data. Subsequently, a geographically-weighted regression (GWR) was performed assuming non-stationarity of risk factors. Special attention was taken to investigate the effect of residual spatial autocorrelation and local multicollinearity. RESULTS: Combining the data from both surveys, overall malaria prevalence was 24%. Scan statistics revealed two clusters which had significantly elevated numbers of malaria cases compared to the background prevalence across the rest of the study area. A multivariable linear model including environmental and household factors revealed that higher socioeconomic status, outdoor occupation and population density were associated with increased malaria risk. The local GWR model improved the model fit considerably and the relationship of malaria with risk factors was found to vary spatially over the island; in different areas of the island socio-economic status, outdoor occupation and population density were found to be positively or negatively associated with malaria prevalence. DISCUSSION: Identification of risk factors for malaria that vary geographically can provide insight into the local epidemiology of malaria. Examining spatially variable relationships can be a helpful tool in exploring which set of targeted interventions could locally be implemented. Supplementary malaria control may be directed at areas, which are identified as at risk. For instance, areas with many people that work outdoors at night may need more focus in terms of vector control. TRIAL REGISTRATION: Trialregister.nl NTR3496-SolarMal, registered on 20 June 2012.
Subject(s)
Malaria/epidemiology , Adolescent , Child , Child, Preschool , Cross-Sectional Studies , Family Characteristics , Female , Humans , Infant , Infant, Newborn , Kenya/epidemiology , Male , Mosquito Control/statistics & numerical data , Risk Factors , Socioeconomic FactorsABSTRACT
BACKGROUND: Health in low and middle income countries is on one hand characterized by a high burden associated with preventable communicable diseases and on the other hand considered to be under-documented due to improper basic health and demographic record-keeping. health and demographic surveillance systems (HDSSs) have provided researchers, policy makers and governments with data about local population dynamics and health related information. In order for an HDSS to deliver high quality data, effective organization of data collection and management are vital. HDSSs impose a challenging logistical process typically characterized by door to door visits, poor navigational guidance, conducting interviews recorded on paper, error prone data entry, an extensive staff and marginal data quality management possibilities. METHODS: A large trial investigating the effect of odour-baited mosquito traps on malaria vector populations and malaria transmission on Rusinga Island, western Kenya, has deployed an HDSS. By means of computer tablets in combination with Open Data Kit and OpenHDS data collection and management software experiences with time efficiency, cost effectiveness and high data quality are illustrate. Step by step, a complete organization of the data management infrastructure is described, ranging from routine work in the field to the organization of the centralized data server. RESULTS AND DISCUSSION: Adopting innovative technological advancements has enabled the collection of demographic and malaria data quickly and effectively, with minimal margin for errors. Real-time data quality controls integrated within the system can lead to financial savings and a time efficient work flow. CONCLUSION: This novel method of HDSS implementation demonstrates the feasibility of integrating electronic tools in large-scale health interventions.
Subject(s)
Demography , Health Status Indicators , Malaria/epidemiology , Population Surveillance , Geographic Information Systems , Humans , Kenya/epidemiologyABSTRACT
Malaria continues to place a disease burden on millions of people throughout the tropics, especially in sub-Saharan Africa. Although efforts to control mosquito populations and reduce human-vector contact, such as long-lasting insecticidal nets and indoor residual spraying, have led to significant decreases in malaria incidence, further progress is now threatened by the widespread development of physiological and behavioural insecticide-resistance as well as changes in the composition of vector populations. A mosquito-directed push-pull system based on the simultaneous use of attractive and repellent volatiles offers a complementary tool to existing vector-control methods. In this study, the combination of a trap baited with a five-compound attractant and a strip of net-fabric impregnated with micro-encapsulated repellent and placed in the eaves of houses, was tested in a malaria-endemic village in western Kenya. Using the repellent delta-undecalactone, mosquito house entry was reduced by more than 50%, while the traps caught high numbers of outdoor flying mosquitoes. Model simulations predict that, assuming area-wide coverage, the addition of such a push-pull system to existing prevention efforts will result in up to 20-fold reductions in the entomological inoculation rate. Reductions of such magnitude are also predicted when mosquitoes exhibit a high resistance against insecticides. We conclude that a push-pull system based on non-toxic volatiles provides an important addition to existing strategies for malaria prevention.