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1.
Malar J ; 23(1): 137, 2024 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-38715035

RESUMEN

BACKGROUND: Universal coverage with insecticide-treated nets (ITNs) is important for malaria control and elimination. The emergence and intensification of insecticide resistance threatens progress made through the deployment of these interventions and has required the development of newer, more expensive ITN types. Understanding malaria prevention behaviour, including barriers and facilitators to net access and use, can support effective decision-making for the promotion and distribution of ITNs. METHODS: In-depth interviews and focus group discussions were conducted in 3 to 4 villages per district, in 13 districts across Burkina Faso, Mozambique, Nigeria and Rwanda from 2019 to 2022. Interviews were conducted in the local language, translated and transcribed in English, French or Portuguese. Transcripts were coded and analysed using Nvivo and ATLAS.ti. RESULTS: ITNs were obtained from mass distribution campaigns, antenatal care and immunization visits, and purchased on the private market in some locations. While there were divergent perspectives in whether the number of distributed nets were adequate, participants consistently expressed concerns of bias, discrimination, and a lack of transparency with the distribution process. ITNs were frequently used alongside other malaria prevention methods. The primary motivation for use was malaria prevention. While some participants reported using nets nightly throughout the year, other participants reported seasonal use, both due to the perceived higher density of mosquitoes and discomfort of sleeping under a net in the increased heat. Other barriers to consistent net use included activities that take place away from the home, sleeping patterns and arrangements, and sensitivity to the insecticides on the nets. CONCLUSIONS: ITNs remain an important malaria control intervention. To ensure adequate and increased net access, distribution campaigns should consider family structures, available sleeping spaces, and other bed sharing preferences when identifying the number of nets needed for distribution. In addition, campaigns should allow for multiple options for net distribution points and timing to accommodate households remote to health services. Continuous distribution channels and complimentary distribution through the private sector could help fill gaps in coverage. Solutions are needed for outdoor malaria transmission, including alternative designs for ITNs, and improving access to complementary personal protective measures.


Asunto(s)
Mosquiteros Tratados con Insecticida , Malaria , Control de Mosquitos , Mosquiteros Tratados con Insecticida/estadística & datos numéricos , Nigeria , Malaria/prevención & control , Burkina Faso , Control de Mosquitos/métodos , Control de Mosquitos/estadística & datos numéricos , Humanos , Mozambique , Femenino , Rwanda , Masculino , Adulto , Persona de Mediana Edad , Adulto Joven , Grupos Focales
2.
Blood ; 143(8): 673-684, 2024 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-37883795

RESUMEN

ABSTRACT: CD19-directed chimeric antigen receptor T cells (CAR-T) achieve high response rates in patients with relapsed/refractory mantle cell lymphoma (MCL). However, their use is associated with significant toxicity, relapse concern, and unclear broad tractability. Preclinical and clinical data support a beneficial synergistic effect of ibrutinib on apheresis product fitness, CAR-T expansion, and toxicity. We evaluated the combination of time-limited ibrutinib and CTL019 CAR-T in 20 patients with MCL in the phase 2 TARMAC study. Ibrutinib commenced before leukapheresis and continued through CAR-T manufacture for a minimum of 6 months after CAR-T administration. The median prior lines of therapy was 2; 50% of patients were previously exposed to a Bruton tyrosine kinase inhibitor (BTKi). The primary end point was 4-month postinfusion complete response (CR) rate, and secondary end points included safety and subgroup analysis based on TP53 aberrancy. The primary end point was met; 80% of patients demonstrated CR, with 70% and 40% demonstrating measurable residual disease negativity by flow cytometry and molecular methods, respectively. At 13-month median follow-up, the estimated 12-month progression-free survival was 75% and overall survival 100%. Fifteen patients (75%) developed cytokine release syndrome; 12 (55%) with grade 1 to 2 and 3 (20%) with grade 3. Reversible grade 1 to 2 neurotoxicity was observed in 2 patients (10%). Efficacy was preserved irrespective of prior BTKi exposure or TP53 mutation. Deep responses correlated with robust CAR-T expansion and a less exhausted baseline T-cell phenotype. Overall, the safety and efficacy of the combination of BTKi and T-cell redirecting immunotherapy appears promising and merits further exploration. This trial was registered at www.ClinicalTrials.gov as #NCT04234061.


Asunto(s)
Adenina/análogos & derivados , Linfoma de Células del Manto , Piperidinas , Receptores Quiméricos de Antígenos , Adulto , Humanos , Linfoma de Células del Manto/tratamiento farmacológico , Receptores Quiméricos de Antígenos/uso terapéutico , Recurrencia Local de Neoplasia/tratamiento farmacológico , Linfocitos T , Inmunoterapia Adoptiva/métodos , Antígenos CD19
3.
Malar J ; 22(1): 99, 2023 Mar 17.
Artículo en Inglés | MEDLINE | ID: mdl-36932384

RESUMEN

BACKGROUND: While many malaria-endemic countries have health management information systems that can measure and report malaria trends in a timely manner, these routine systems have limitations. Periodic community cross-sectional household surveys are used to estimate malaria prevalence and intervention coverage but lack geographic granularity and are resource intensive. Incorporating malaria testing for all women at their first antenatal care (ANC) visit (i.e., ANC1) could provide a more timely and granular source of data for monitoring trends in malaria burden and intervention coverage. This article describes a protocol designed to assess if ANC-based surveillance could be a pragmatic tool to monitor malaria. METHODS: This is an observational, cross-sectional study conducted in Benin, Burkina Faso, Mozambique, Nigeria, Tanzania, and Zambia. Pregnant women attending ANC1 in selected health facilities will be tested for malaria infection by rapid diagnostic test and administered a brief questionnaire to capture key indicators of malaria control intervention coverage and care-seeking behaviour. In each location, contemporaneous cross-sectional household surveys will be leveraged to assess correlations between estimates obtained using each method, and the use of ANC data as a tool to track trends in malaria burden and intervention coverage will be validated. RESULTS: This study will assess malaria prevalence at ANC1 aggregated at health facility and district levels, and by gravidity relative to current pregnancy (i.e., gravida 1, gravida 2, and gravida 3 +). ANC1 malaria prevalence will be presented as monthly trends. Additionally, correlation between ANC1 and household survey-derived estimates of malaria prevalence, bed net ownership and use, and care-seeking will be assessed. CONCLUSION: ANC1-based surveillance has the potential to provide a cost-effective, localized measure of malaria prevalence that is representative of the general population and useful for tracking monthly changes in parasite prevalence, as well as providing population-representative estimates of intervention coverage and care-seeking behavior. This study will evaluate the representativeness of these measures and collect information on operational feasibility, usefulness for programmatic decision-making, and potential for scale-up of malaria ANC1 surveillance.


Asunto(s)
Malaria , Atención Prenatal , Embarazo , Femenino , Humanos , Estudios Transversales , Malaria/diagnóstico , Malaria/epidemiología , Malaria/prevención & control , Número de Embarazos , Tanzanía/epidemiología , Estudios Observacionales como Asunto
4.
J Infect Dis ; 227(9): 1084-1087, 2023 04 26.
Artículo en Inglés | MEDLINE | ID: mdl-36221256

RESUMEN

During the 2022 monkeypox (MPX) outbreak, testing has been limited and results delayed, allowing ongoing transmission. Gold-standard quantitative polymerase chain reaction (qPCR) diagnostics are difficult to obtain. This research adapted the June 2022 CDC MPX qPCR assay for broad implementation. Validated using MPX stocks in a matrix with multiple sample types, MPX was detected with cycle threshold (Ct) values 17.46-35.59 and titer equivalents 8.01 × 106 to 2.45 × 100 plaque-forming unit (PFU)/mL. The detection limit was 3.59 PFU/mL. Sensitivity and specificity were both 100%. This qPCR assay can be quickly and broadly implemented in research and public health laboratories to increase diagnostic capacity amid the growing MPX outbreak.


Asunto(s)
Pruebas Diagnósticas de Rutina , Mpox , Reacción en Cadena de la Polimerasa , Humanos , Mpox/diagnóstico , Monkeypox virus/genética , Sensibilidad y Especificidad , Pruebas Diagnósticas de Rutina/métodos , Reproducibilidad de los Resultados
5.
Am J Trop Med Hyg ; 108(2_Suppl): 4-7, 2023 02 02.
Artículo en Inglés | MEDLINE | ID: mdl-35895587

RESUMEN

Most monitoring and evaluation tools for measuring malaria burden, intervention coverage, and impact of interventions use periodic nationally representative cross-sectional household surveys. These provide advantages in terms of selecting a large, unbiased, population-based sample; however, they are infrequently conducted, are resource-intensive, and do not provide longitudinal data with sufficient granularity. Given the heterogeneity of malaria transmission within most endemic countries, systems with the capacity to provide more granular and frequent data would be more actionable by national malaria control programs and local implementing partners. There is increasing interest in using routine health facility data, usually from outpatient department visits, for monitoring malaria burden. Data from pregnant women attending antenatal care (ANC) could minimize bias related to fever care-seeking among outpatient department visits and provide more granular parasite prevalence data. Most pregnant women attend ANC at least once and are thus highly representative of the overall pregnant population. A growing body of evidence suggests that malaria parasitemia in pregnant women is correlated with parasitemia in children aged < 5 years in moderate to high transmission areas, allowing for monitoring parasitemia in real time. Additional data are needed to assess whether pregnant women are sufficiently representative of the overall population to yield valid malaria prevalence and intervention coverage estimates. Although use of routinely collected ANC data faces many of the same challenges experienced by other routinely collected health facility data, the opportunity to improve parasite prevalence monitoring and the associated health benefits to mothers and infants of early detection of parasitemia make these efforts valuable.


Asunto(s)
Malaria , Atención Prenatal , Lactante , Niño , Femenino , Embarazo , Humanos , Parasitemia/parasitología , Estudios Transversales , Malaria/diagnóstico , Malaria/epidemiología , Malaria/prevención & control , Instituciones de Salud , Aceptación de la Atención de Salud
7.
Nat Commun ; 13(1): 3862, 2022 07 05.
Artículo en Inglés | MEDLINE | ID: mdl-35790746

RESUMEN

The cause of malaria transmission has been known for over a century but it is still unclear whether entomological measures are sufficiently reliable to inform policy decisions in human health. Decision-making on the effectiveness of new insecticide-treated nets (ITNs) and the indoor residual spraying of insecticide (IRS) have been based on epidemiological data, typically collected in cluster-randomised control trials. The number of these trials that can be conducted is limited. Here we use a systematic review to highlight that efficacy estimates of the same intervention may vary substantially between trials. Analyses indicate that mosquito data collected in experimental hut trials can be used to parameterize mechanistic models for Plasmodium falciparum malaria and reliably predict the epidemiological efficacy of quick-acting, neuro-acting ITNs and IRS. Results suggest that for certain types of ITNs and IRS using this framework instead of clinical endpoints could support policy and expedite the widespread use of novel technologies.


Asunto(s)
Culicidae , Malaria , Control de Mosquitos , Animales , Culicidae/parasitología , Humanos , Mosquiteros Tratados con Insecticida , Insecticidas , Malaria/epidemiología , Malaria/prevención & control , Control de Mosquitos/métodos , Mosquitos Vectores/parasitología
8.
Malar J ; 21(1): 185, 2022 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-35690756

RESUMEN

BACKGROUND: Malaria is a major cause of morbidity and mortality globally, especially in sub-Saharan Africa. Widespread resistance to pyrethroids threatens the gains achieved by vector control. To counter resistance to pyrethroids, third-generation indoor residual spraying (3GIRS) products have been developed. This study details the results of a multi-country cost and cost-effectiveness analysis of indoor residual spraying (IRS) programmes using Actellic®300CS, a 3GIRS product with pirimiphos-methyl, in sub-Saharan Africa in 2017 added to standard malaria control interventions including insecticide-treated bed nets versus standard malaria control interventions alone. METHODS: An economic evaluation of 3GIRS using Actellic®300CS in a broad range of sub-Saharan African settings was conducted using a variety of primary data collection and evidence synthesis methods. Four IRS programmes in Ghana, Mali, Uganda, and Zambia were included in the effectiveness analysis. Cost data come from six IRS programmes: one in each of the four countries where effect was measured plus Mozambique and a separate programme conducted by AngloGold Ashanti Malaria Control in Ghana. Financial and economic costs were quantified and valued. The main indicator for the cost was cost per person targeted. Country-specific case incidence rate ratios (IRRs), estimated by comparing IRS study districts to adjacent non-IRS study districts or facilities, were used to calculate cases averted in each study area. A deterministic analysis and sensitivity analysis were conducted in each of the four countries for which effectiveness evaluations were available. Probabilistic sensitivity analysis was used to generate plausibility bounds around the incremental cost-effectiveness ratio estimates for adding IRS to other standard interventions in each study setting as well as jointly utilizing data on effect and cost across all settings. RESULTS: Overall, IRRs from each country indicated that adding IRS with Actellic®300CS to the local standard intervention package was protective compared to the standard intervention package alone (IRR 0.67, [95% CI 0.50-0.91]). Results indicate that Actellic®300CS is expected to be a cost-effective (> 60% probability of being cost-effective in all settings) or highly cost-effective intervention across a range of transmission settings in sub-Saharan Africa. DISCUSSION: Variations in the incremental costs and cost-effectiveness likely result from several sources including: variation in the sprayed wall surfaces and house size relative to household population, the underlying malaria burden in the communities sprayed, the effectiveness of 3GIRS in different settings, and insecticide price. Programmes should be aware that current recommendations to rotate can mean variation and uncertainty in budgets; programmes should consider this in their insecticide-resistance management strategies. CONCLUSIONS: The optimal combination of 3GIRS delivery with other malaria control interventions will be highly context specific. 3GIRS using Actellic®300CS is expected to deliver acceptable value for money in a broad range of sub-Saharan African malaria transmission settings.


Asunto(s)
Insecticidas , Malaria , Compuestos Organotiofosforados , Piretrinas , Análisis Costo-Beneficio , Recolección de Datos , Humanos , Malaria/epidemiología , Malí , Control de Mosquitos/métodos
9.
Malar J ; 21(1): 19, 2022 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-35012559

RESUMEN

BACKGROUND: Vector control tools have contributed significantly to a reduction in malaria burden since 2000, primarily through insecticidal-treated bed nets (ITNs) and indoor residual spraying. In the face of increasing insecticide resistance in key malaria vector species, global progress in malaria control has stalled. Innovative tools, such as dual active ingredient (dual-AI) ITNs that are effective at killing insecticide-resistant mosquitoes have recently been introduced. However, large-scale uptake has been slow for several reasons, including higher costs and limited evidence on their incremental effectiveness and cost-effectiveness. The present report describes the design of several observational studies aimed to determine the effectiveness and cost-effectiveness of dual-AI ITNs, compared to standard pyrethroid-only ITNs, at reducing malaria transmission across a variety of transmission settings. METHODS: Observational pilot studies are ongoing in Burkina Faso, Mozambique, Nigeria, and Rwanda, leveraging dual-AI ITN rollouts nested within the 2019 and 2020 mass distribution campaigns in each country. Enhanced surveillance occurring in select study districts include annual cross-sectional surveys during peak transmission seasons, monthly entomological surveillance, passive case detection using routine health facility surveillance systems, and studies on human behaviour and ITN use patterns. Data will compare changes in malaria transmission and disease burden in districts receiving dual-AI ITNs to similar districts receiving standard pyrethroid-only ITNs over three years. The costs of net distribution will be calculated using the provider perspective including financial and economic costs, and a cost-effectiveness analysis will assess incremental cost-effectiveness ratios for Interceptor® G2, Royal Guard®, and piperonyl butoxide ITNs in comparison to standard pyrethroid-only ITNs, based on incidence rate ratios calculated from routine data. CONCLUSIONS: Evidence of the effectiveness and cost-effectiveness of the dual-AI ITNs from these pilot studies will complement evidence from two contemporary cluster randomized control trials, one in Benin and one in Tanzania, to provide key information to malaria control programmes, policymakers, and donors to help guide decision-making and planning for local malaria control and elimination strategies. Understanding the breadth of contexts where these dual-AI ITNs are most effective and collecting robust information on factors influencing comparative effectiveness could improve uptake and availability and help maximize their impact.


Asunto(s)
Costo de Enfermedad , Mosquiteros Tratados con Insecticida/estadística & datos numéricos , Malaria/prevención & control , Control de Mosquitos/estadística & datos numéricos , África del Sur del Sahara/epidemiología , Humanos , Incidencia , Mosquiteros Tratados con Insecticida/clasificación , Malaria/epidemiología , Proyectos Piloto , Prevalencia
10.
Malar J ; 20(1): 143, 2021 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-33691706

RESUMEN

BACKGROUND: As malaria cases increase in some of the highest burden countries, more strategic deployment of new and proven interventions must be evaluated to meet global malaria reduction goals. METHODS: The cost and cost-effectiveness of indoor residual spraying (IRS) with pirimiphos-methyl (Actellic®300 CS) were assessed in a high transmission district (Mopeia) with high access to pyrethroid insecticide-treated nets (ITNs), compared to ITNs alone. The major mosquito vectors in the area were susceptible to primiphos-methyl, but resistant to pyrethoids. A decision analysis approach was followed to conduct deterministic and probabilistic sensitivity analyses in a theoretical cohort of 10,000 children under five years of age (U5) and 10,000 individuals of all ages, separately. Model parameters and distributions were based on prospectively collected cost and epidemiological data from a cluster-randomized control trial and a literature review. The primary analysis used health facility-malaria incidence, while community cohort incidence and cross-sectional prevalence rates were used in sensitivity analyses. Lifetime costs, malaria cases, deaths and disability-adjusted life-years (DALYs) were calculated to determine the incremental costs per DALY averted through IRS. RESULTS: The average IRS cost per person protected was US$8.26 and 51% of the cost was insecticide. IRS averted 46,609 (95% CI 46,570-46,646) uncomplicated and 242 (95% CI 241-243) severe lifetime cases in a theoretical children U5 cohort, yielding an incremental cost-effectiveness ratio (ICER) of US$400 (95% CI 399-402) per DALY averted. In the all-age cohort, the ICER was higher: US$1,860 (95% CI 1,852-1,868) per DALY averted. Deterministic and probabilistic results were consistent. When adding the community protective effect of IRS, the cost per person protected decreased (US$7.06) and IRS was highly cost-effective in children U5 (ICER = US$312) and cost-effective in individuals of all ages (ICER = US$1,431), compared to ITNs alone. CONCLUSION: This study provides robust evidence that IRS with pirimiphos-methyl can be cost-effective in high transmission regions with high pyrethroid ITN coverage where the major vector is susceptible to pirimiphos-methyl but resistant to pyrethroids. The finding that insecticide cost is the main driver of IRS costs highlights the need to reduce the insecticide price without jeopardizing effectiveness. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT02910934 (Registered 22 September 2016). https://clinicaltrials.gov/ct2/show/NCT02910934?term=NCT02910934&draw=2&rank=1.


Asunto(s)
Anopheles , Análisis Costo-Beneficio , Insecticidas , Control de Mosquitos/economía , Mosquitos Vectores , Compuestos Organotiofosforados , Animales , Incidencia , Mosquiteros Tratados con Insecticida/estadística & datos numéricos , Malaria/epidemiología , Malaria/transmisión , Mozambique/epidemiología , Prevalencia
11.
Malar J ; 20(1): 84, 2021 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-33568137

RESUMEN

BACKGROUND: Attaining the goal of reducing the global malaria burden is threatened by recent setbacks in maintaining the effectiveness of vector control interventions partly due to the emergence of pyrethroid resistant vectors. One potential strategy to address these setbacks could be combining indoor residual spraying (IRS) with non-pyrethroids and standard insecticide-treated nets (ITNs). This study aimed to provide evidence on the incremental epidemiological benefit of using third-generation IRS product in a highly endemic area with high ITN ownership. METHODS: A cluster-randomized, open-label, parallel-arms, superiority trial was conducted in the Mopeia district in Zambezia, Mozambique from 2016 to 2018. The district had received mass distribution of alphacypermethrin ITNs two years before the trial and again mid-way. 86 clusters were defined, stratified and randomized to receive or not receive IRS with pirimiphos-methyl (Actellic®300 CS). Efficacy of adding IRS was assessed through malaria incidence in a cohort of children under five followed prospectively for two years, enhanced passive surveillance at health facilities and by community health workers, and yearly cross-sectional surveys at the peak of the transmission season. FINDINGS: A total of 1536 children were enrolled in the cohort. Children in the IRS arm experienced 4,801 cases (incidence rate of 3,532 per 10,000 children-month at risk) versus 5,758 cases in the no-IRS arm (incidence rate of 4,297 per 10,000 children-month at risk), resulting in a crude risk reduction of 18% and an incidence risk ratio of 0.82 (95% CI 0.79-0.86, p-value < 0.001). Facility and community passive surveillance showed a malaria incidence of 278 per 10,000 person-month in the IRS group (43,974 cases over 22 months) versus 358 (95% CI 355-360) per 10,000 person-month at risk in the no-IRS group (58,030 cases over 22 months), resulting in an incidence rate ratio of 0.65 (95% CI 0.60-0.71, p < 0.001). In the 2018 survey, prevalence in children under five in the IRS arm was significantly lower than in the no-IRS arm (OR 0.54, 95% CI, 0.31-0.92, p = 0.0241). CONCLUSION: In a highly endemic area with high ITN access and emerging pyrethroid resistance, adding IRS with pirimiphos-methyl resulted in significant additional protection for children under five years of age. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT02910934, registered 22 September 2016, https://clinicaltrials.gov/ct2/show/NCT02910934?term=NCT02910934&draw=2&rank=1 .


Asunto(s)
Insecticidas/administración & dosificación , Malaria Falciparum/epidemiología , Control de Mosquitos , Compuestos Organotiofosforados/administración & dosificación , Niño , Preescolar , Estudios de Cohortes , Femenino , Humanos , Incidencia , Lactante , Mosquiteros Tratados con Insecticida/estadística & datos numéricos , Masculino , Mozambique/epidemiología , Ensayos Clínicos Controlados Aleatorios como Asunto
12.
Malar J ; 20(1): 54, 2021 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-33478533

RESUMEN

BACKGROUND: The need to develop new products and novel approaches for malaria vector control is recognized as a global health priority. One approach to meeting this need has been the development of new products for indoor residual spraying (IRS) with novel active ingredients for public health. While initial results showing the impact of several of these next-generation IRS products have been encouraging, questions remain about how to best deploy them for maximum impact. To help address these questions, a 2-year cluster-randomized controlled trial to measure the impact of IRS with a microencapsulated formulation of pirimiphos-methyl (PM) in an area with high ownership of long-lasting insecticidal nets (LLINs) was conducted in a high-transmission district of central Mozambique with pyrethroid resistant vectors. Presented here are the results of the vector surveillance component of the trial. METHODS: The 2 year, two-armed trial was conducted in Mopeia District, Zambezia Province, Mozambique. In ten sentinel villages, five that received IRS with PM in October-November 2016 and again in October-November 2017 and five that received no IRS, indoor light trap collections and paired indoor-outdoor human landing collections catches (HLCs) were conducted monthly from September 2016 through October 2018. A universal coverage campaign in June 2017, just prior to the second spray round, distributed 131,540 standard alpha-cypermethrin LLINs across all study villages and increased overall net usage rates in children under 5 years old to over 90%. RESULTS: The primary malaria vector during the trial was Anopheles funestus sensu lato (s.l.), and standard World Health Organization (WHO) tube tests with this population indicated variable but increasing resistance to pyrethroids (including alpha-cypermethrin, from > 85% mortality in 2017 to 7% mortality in 2018) and uniform susceptibility to PM (100% mortality in both years). Over the entire duration of the study, IRS reduced An. funestus s.l. densities by 48% (CI95 33-59%; p < 0.001) in indoor light traps and by 74% (CI95 38-90%; p = 0.010) during indoor and outdoor HLC, though in each study year reductions in vector density were consistently greatest in those months immediately following the IRS campaigns and waned over time. Overall there was no strong preference for An. funestus to feed indoors or outdoors, and these biting behaviours did not differ significantly across study arms: observed indoor-outdoor biting ratios were 1.10 (CI95 1.00-1.21) in no-IRS villages and 0.88 (CI95 0.67-1.15) in IRS villages. The impact of IRS was consistent in reducing HLC exposures both indoors (75% reduction: CI95 47-88%; p = 0. < 0.001) and outdoors (68% reduction: CI95 22-87%; p = 0.012). While substantially fewer Anopheles gambiae s.l. were collected during the study, trends show a similar impact of IRS on this key vector group as well, with a 33% (CI95 7-53%; p = 0.019) reduction in mosquitoes collected in light traps and a non-statistically significant 39% reduction (p = 0.249) in HLC landing rates. CONCLUSION: IRS with PM used in addition to pyrethroid-only LLINs substantially reduced human exposures to malaria vectors during both years of the cluster-randomized controlled trial in Mopeia-a high-burden district where the primary vector, An. funestus s.l., was equally likely to feed indoors or outdoors and demonstrated increasing resistance to pyrethroids. Findings suggest that IRS with PM can provide effective vector control, including in some settings where pyrethroid-only ITNs are widely used. Trial registration clinicaltrials.gov , NCT02910934. Registered 22 September 2016, https://www.clinicaltrials.gov/ct2/show/NCT02910934.


Asunto(s)
Insecticidas/farmacología , Malaria/prevención & control , Control de Mosquitos/métodos , Mosquitos Vectores/efectos de los fármacos , Compuestos Organotiofosforados/farmacología , Animales , Anopheles/efectos de los fármacos , Entomología/métodos , Monitoreo del Ambiente/estadística & datos numéricos , Femenino , Humanos , Mosquiteros Tratados con Insecticida , Mozambique , Propiedad/estadística & datos numéricos , Piretrinas/farmacología
13.
Evolution ; 75(1): 116-129, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-32895932

RESUMEN

Genes with opposing effects on fitness at different life stages are the mechanistic basis for evolutionary theories of aging and life history. Examples come from studies of mutations in model organisms, but there is little knowledge of genetic bases of life history tradeoffs in natural populations. Here, we test the hypothesis that alleles affecting oxygen sensing in Glanville fritillary butterflies have opposing effects on larval versus adult fitness-related traits. Intermediate-frequency alleles in Succinate dehydrogenase d, and to a lesser extent Hypoxia inducible factor 1α, are associated in larvae with variation in metabolic rate and activation of the hypoxia inducible factor (HIF) pathway, which affects tracheal development and delivery of oxygen to adult flight muscles. A dominant Sdhd allele is likely to cause antagonistic pleiotropy for fitness through its opposing effects on larval metabolic and growth rate versus adult flight and dispersal, and may have additional effects arising from sensitivity to low-iron host plants. Prior results in Glanville fritillaries indicate that fitness of alleles in Sdhd and another antagonistically pleiotropic metabolic gene, Phosphoglucose isomerase, depend strongly on the size and distribution of host plant patches. Hence, these intermediate-frequency alleles are involved in ecoevolutionary dynamics involving life history tradeoffs.


Asunto(s)
Mariposas Diurnas/genética , Pleiotropía Genética , Glucosa-6-Fosfato Isomerasa/genética , Rasgos de la Historia de Vida , Succinato Deshidrogenasa/genética , Alelos , Animales , Mariposas Diurnas/enzimología , Femenino , Factor 1 Inducible por Hipoxia/genética , Larva/metabolismo
14.
Malar J ; 19(1): 340, 2020 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-32950056

RESUMEN

BACKGROUND: The National Malaria Control Programme (NMCP) of Mali has had recent success decreasing malaria transmission using 3rd generation indoor residual spraying (IRS) products in areas with pyrethroid resistance, primarily in Ségou and Koulikoro Regions. In 2015, national survey data showed that Mopti Region had the highest under 5-year-old (u5) malaria prevalence at 54%-nearly twice the national average-despite having high access to long-lasting insecticidal nets (LLINs) and seasonal malaria chemoprevention (SMC). Accordingly, in 2016 the NMCP and other stakeholders shifted IRS activities from Ségou to Mopti. Here, the results of a series of observational analyses utilizing routine malaria indicators to evaluate the impact of this switch are presented. METHODS: A set of retrospective, eco-observational time-series analyses were performed using monthly incidence rates of rapid diagnostic test (RDT)-confirmed malaria cases reported in the District Health Information System 2 (DHIS2) from January 2016 until February 2018. Comparisons of case incidence rates were made between health facility catchments from the same region that differed in IRS status (IRS vs. no-IRS) to describe the general impact of the 2016 and 2017 IRS campaigns, and a difference-in-differences approach comparing changes in incidence from year-to-year was used to describe the effect of suspending IRS operations in Ségou and introducing IRS operations in Mopti in 2017. RESULTS: Compared to communities with no IRS, cumulative case incidence rates in IRS communities were reduced 16% in Ségou Region during the 6 months following the 2016 campaign and 31% in Mopti Region during the 6 months following the 2017 campaign, likely averting a total of more than 22,000 cases of malaria that otherwise would have been expected during peak transmission months. Across all comparator health facilities (HFs) where there was no IRS in either year, peak malaria case incidence rates fell by an average of 22% (CI95 18-30%) from 2016 to 2017. At HFs in communities of Mopti where IRS was introduced in 2017, peak incidence fell by an average of 42% (CI95 31-63%) between these years, a significantly greater decrease (p = 0.040) almost double what was seen in the comparator HFCAs. The opposite effect was observed in Ségou Region, where peak incidence at those HFs where IRS was withdrawn after the 2016 campaign increased by an average of 106% (CI95 63-150%) from year to year, also a significant difference-in-differences compared to the comparator no-IRS HFs (p < 0.0001). CONCLUSION: Annual IRS campaigns continue to make dramatic contributions to the seasonal reduction of malaria transmission in communities across central Mali, where IRS campaigns were timed in advance of peak seasonal transmission and utilized a micro-encapsulated product with an active ingredient that was of a different class than the one found on the LLINs used throughout the region and to which local malaria vectors were shown to be susceptible. Strategies to help mitigate the resurgence of malaria cases that can be expected should be prioritized whenever the suspension of IRS activities in a particular region is considered.


Asunto(s)
Control de Enfermedades Transmisibles/estadística & datos numéricos , Erradicación de la Enfermedad/estadística & datos numéricos , Malaria Falciparum/prevención & control , Residuos de Plaguicidas , Humanos , Incidencia , Malaria Falciparum/epidemiología , Malí/epidemiología , Estudios Retrospectivos
15.
Geohealth ; 4(9): e2020GH000254, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32864541

RESUMEN

Significant recent advances in satellite remote sensing allow environmental managers to detect and monitor cyanobacterial harmful algal blooms (cyanoHAB), and these capabilities are being used more frequently in water quality management. A quantitative estimate of the socioeconomic benefits generated from these new capabilities, known as an impact assessment, was missing from the growing literature on cyanoHABs and remote sensing. In this paper, we present an impact assessment framework to characterize the socioeconomic benefits of satellite remote sensing for detecting cyanoHABs and managing recreational advisories at freshwater lakes. We then apply this framework to estimate the socioeconomic benefits of satellite data that were used to manage a 2017 cyanoHAB event in Utah Lake. CyanoHAB events on Utah Lake can pose health risks to people who interact with the blooms through recreation. We find that the availability of satellite data yielded socioeconomic benefits by improving human health outcomes valued at approximately $370,000, though a sensitivity analysis reveals that this central estimate can vary significantly ($55,000-$1,057,000 in benefits) as a result of different assumptions regarding the time delay in posting a recreational advisory, the number of people exposed to the cyanoHAB, the number of people who experience gastrointestinal symptoms, and the cost per case of illness.

16.
Malar J ; 19(1): 293, 2020 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-32799873

RESUMEN

BACKGROUND: Ségou Region in central Mali is an area of high malaria burden with seasonal transmission. The region reports high access to and use of long-lasting insecticidal nets (LLINs), though the principal vector, Anopheles gambiae, is resistant to pyrethroids. From 2011 until 2016, several high-burden districts of Ségou also received indoor residual spraying (IRS), though in 2014 concerns about pyrethroid resistance prompted a shift in IRS products to a micro-encapsulated formulation of the organophosphate insecticide pirimiphos-methyl. Also in 2014, the region expanded a pilot programme to provide seasonal malaria chemoprevention (SMC) to children aged 3-59 months in two districts. The timing of these decisions presented an opportunity to estimate the impact of both interventions, deployed individually and in combination, using quality-assured passive surveillance data. METHODS: A non-randomized, quasi-experimental time series approach was used to analyse monthly trends in malaria case incidence at the district level. Districts were stratified by intervention status: an SMC district, an IRS district, an IRS + SMC district, and control districts that received neither IRS nor SMC in 2014. The numbers of positive rapid diagnostic test (RDT +) results reported at community health facilities were aggregated and epidemiological curves showing the incidence of RDT-confirmed malaria cases per 10,000 person-months were plotted for the total all-ages and for the under 5 year old (u5) population. The cumulative incidence of RDT + malaria cases observed from September 2014 to February 2015 was calculated in each intervention district and compared to the cumulative incidence reported from the same period in the control districts. RESULTS: Cumulative peak-transmission all-ages incidence was lower in each of the intervention districts compared to the control districts: 16% lower in the SMC district; 28% lower in the IRS district; and 39% lower in the IRS + SMC district. The same trends were observed in the u5 population: incidence was 15% lower with SMC, 48% lower with IRS, and 53% lower with IRS + SMC. The SMC-only intervention had a more moderate effect on incidence reduction initially, which increased over time. The IRS-only intervention had a rapid, comparatively large impact initially that waned over time. The impact of the combined interventions was both rapid and longer lasting. CONCLUSION: Evaluating the impact of IRS with an organophosphate and SMC on reducing incidence rates of passive RDT-confirmed malaria cases in Ségou Region in 2014 suggests that combining the interventions had a greater effect than either intervention used individually in this high-burden region of central Mali with pyrethroid-resistant vectors and high rates of household access to LLINs.


Asunto(s)
Anopheles , Antimaláricos/uso terapéutico , Control de Enfermedades Transmisibles/métodos , Insecticidas , Malaria Falciparum/prevención & control , Control de Mosquitos/métodos , Mosquitos Vectores , Compuestos Organotiofosforados , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Animales , Niño , Preescolar , Humanos , Incidencia , Lactante , Malaria Falciparum/epidemiología , Malaria Falciparum/parasitología , Malí/epidemiología , Persona de Mediana Edad , Residuos de Plaguicidas , Adulto Joven
17.
Malar J ; 19(1): 242, 2020 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-32652994

RESUMEN

BACKGROUND: Ghana has been implementing the indoor residual spraying (IRS) of insecticides since 2006, focusing operations in the north. Insecticide resistance concerns prompted a switch from pyrethroids to organophosphates, beginning gradually in 2011 and switching fully to the micro-encapsulated formulation of pirimiphosmethyl (PM CS), Actellic® 300CS, a third-generation indoor residual spraying (3GIRS) product, by 2014. Entomological surveillance studies have shown IRS to be a highly effective malaria control tool, but epidemiological evidence is needed as well. Countrywide prevalence surveys have shown that malaria parasite prevalence in children under 5 years of age in Northern, Upper East, and Upper West Regions had declined to less than 40% in each region by 2016. Similarly, malaria deaths in children under 5 years of age have also been declining nationally since 2009. Although IRS is suspected to have contributed to this decline, stronger evidence is needed to link the IRS interventions to the epidemiological impact. METHODS: To assess the epidemiological impact of Ghana's IRS programmatic activities, a retrospective, observational analysis using routine epidemiological data was conducted to compare malaria incidence rates from IRS and non-IRS districts in Northern, Upper East, and Upper West Regions. Routine epidemiological data consisted of passive malaria case surveillance data reported in the District Health Information System 2 (DHIS2); with cases representing patients with suspected malaria who had sought care in the public health system and had received a confirmatory diagnosis with a positive malaria RDT result. Final routine data were extracted in September 2018. All districts that had received IRS were included in the analysis and compared to all non-IRS districts within the same region. In the Northern Region, only PMI districts were included in the analysis, as they had similar historical data. RESULTS: District-level analysis from Northern Region from 2015 to 2017 of the aggregate malaria incidence reported from IRS districts relative to non-IRS comparator districts showed 39%, 26%, and 58% fewer confirmed malaria cases reported from IRS districts in 2015, 2016, and 2017, respectively. This translates to approximately 257,000 fewer cases than expected over the three years. In Upper East Region, the effect on reported malaria cases of withdrawing IRS from the region was striking; after spray operations were suspended in 2015, incidence increased an average of 485% per district (95% confidence interval: 330% to 640%) compared to 2014. CONCLUSIONS: The current observational analysis results are in line with the entomological studies in demonstrating the positive contribution of IRS with a 3GIRS product to malaria control programmes in northern Ghana and the value of using routine surveillance and implementation data to rapidly assess the impact of vector control interventions in operational settings, even in complex implementation environments.


Asunto(s)
Insecticidas/administración & dosificación , Malaria/epidemiología , Control de Mosquitos/estadística & datos numéricos , Ghana/epidemiología , Humanos , Incidencia , Malaria/prevención & control , Control de Mosquitos/métodos , Estudios Retrospectivos
18.
Malar J ; 18(1): 360, 2019 Nov 11.
Artículo en Inglés | MEDLINE | ID: mdl-31711489

RESUMEN

BACKGROUND: Malaria remains a leading cause of morbidity and mortality in Mozambique. Increased investments in malaria control have reduced the burden, but few studies have estimated the costs of malaria in the country. This paper estimates the economic costs associated with malaria care to households and to the health system in the high burden district of Mopeia in central Mozambique. METHODS: Malaria care-seeking and morbidity costs were routinely collected among 1373 households with at least one child enrolled in an active case detection (ACD) cohort in Mopeia, and through cross-sectional surveys with 824 families in 2017 and 805 families in 2018. Household costs included direct medical expenses, transportation and opportunity costs of the time lost due to illness. Structured questionnaires were used to estimate the health system costs associated with malaria care in all 13 district health facilities. Cost estimations followed an ingredient-based approach with a top-down allocation approach for health system expenses. RESULTS: Among participants in cross-sectional studies, households sought care for nine severe malaria cases requiring hospital admission and for 679 uncomplicated malaria cases. Median household costs associated with uncomplicated malaria among individuals of all ages were US$ 3.46 (IQR US$ 0.07-22.41) and US$ 81.08 (IQR US$ 39.34-88.38) per severe case. Median household costs were lower among children under five (ACD cohort): US$ 1.63 (IQR US$ 0.00-7.79) per uncomplicated case and US$ 64.90 (IQR US$ 49.76-80.96) per severe case. Opportunity costs were the main source of household costs. Median health system costs associated with malaria among patients of all ages were US$ 4.34 (IQR US$ 4.32-4.35) per uncomplicated case and US$ 26.56 (IQR US$ 18.03-44.09) per severe case. Considering household and health system costs, the overall cost of malaria care to society was US$ 7.80 per uncomplicated case and US$ 107.64 per severe case, representing an economic malaria burden of US$ 332,286.24 (IQR US$ 186,355.84-1,091,212.90) per year only in Mopeia. CONCLUSIONS: Despite the provision of free malaria services, households in Mopeia incur significant direct and indirect costs associated with the disease. Furthermore, the high malaria cost on the Mozambican health system underscores the need to strengthen malaria prevention to reduce the high burden and improve productivity in the region.


Asunto(s)
Costo de Enfermedad , Atención a la Salud/economía , Familia , Malaria/economía , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Estudios de Cohortes , Estudios Transversales , Femenino , Humanos , Lactante , Recién Nacido , Malaria/prevención & control , Masculino , Persona de Mediana Edad , Mozambique , Adulto Joven
19.
Am J Trop Med Hyg ; 100(4): 889-898, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30793695

RESUMEN

Although on-site supervision programs are implemented in many countries to assess and improve the quality of care, few publications have described the use of electronic tools during health facility supervision. The President's Malaria Initiative-funded MalariaCare project developed the MalariaCare Electronic Data System (EDS), a custom-built, open-source, Java-based, Android application that links to District Health Information Software 2, for data storage and visualization. The EDS was used during supervision visits at 4,951 health facilities across seven countries in Africa. The introduction of the EDS led to dramatic improvements in both completeness and timeliness of data on the quality of care provided for febrile patients. The EDS improved data completeness by 47 percentage points (42-89%) on average when compared with paper-based data collection. The average time from data submission to a final data analysis product dropped from over 5 months to 1 month. With more complete and timely data available, the Ministry of Health and the National Malaria Control Program (NMCP) staff could more effectively plan corrective actions and promptly allocate resources, ultimately leading to several improvements in the quality of malaria case management. Although government staff used supervision data during MalariaCare-supported lessons learned workshops to develop plans that led to improvements in quality of care, data use outside of these workshops has been limited. Additional efforts are required to institutionalize the use of supervision data within ministries of health and NMCPs.


Asunto(s)
Manejo de Caso/normas , Exactitud de los Datos , Malaria/diagnóstico , Programas Informáticos/normas , África , Análisis de Datos , Instituciones de Salud , Humanos , Organización y Administración , Atención Primaria de Salud
20.
BMJ Glob Health ; 3(1): e000610, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29564161

RESUMEN

BACKGROUND: Most of the reduction in malaria prevalence seen in Africa since 2000 has been attributed to vector control interventions. Yet increases in the distribution and intensity of insecticide resistance and higher costs of newer insecticides pose a challenge to sustaining these gains. Thus, endemic countries face challenging decisions regarding the choice of vector control interventions. METHODS: A cluster randomised trial is being carried out in Mopeia District in the Zambezia Province of Mozambique, where malaria prevalence in children under 5 is high (68% in 2015), despite continuous and campaign distribution of long-lasting insecticide-treated nets (LLINs). Study arm 1 will continue to use the standard, LLIN-based National Malaria Control Programme vector control strategy (LLINs only), while study arm 2 will receive indoor residual spraying (IRS) once a year for 2 years with a microencapsulated formulation of pirimiphos-methyl (Actellic 300 CS), in addition to the standard LLIN strategy (LLINs+IRS). Prior to the 2016 IRS implementation (the first of two IRS campaigns in this study), 146 clusters were defined and stratified per number of households. Clusters were then randomised 1:1 into the two study arms. The public health impact and cost-effectiveness of IRS intervention will be evaluated over 2 years using multiple methods: (1) monthly active malaria case detection in a cohort of 1548 total children aged 6-59 months; (2) enhanced passive surveillance at health facilities and with community health workers; (3) annual cross-sectional surveys; and (4) entomological surveillance. Prospective microcosting of the intervention and provider and societal costs will be conducted. Insecticide resistance status pattern and changes in local Anopheline populations will be included as important supportive outcomes. DISCUSSION: By evaluating the public health impact and cost-effectiveness of IRS with a non-pyrethroid insecticide in a high-transmission setting with high LLIN ownership, it is expected that this study will provide programmatic and policy-relevant data to guide national and global vector control strategies. TRIAL REGISTRATION NUMBER: NCT02910934.

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