RESUMO
Objective To determine if the prevalence of schistosomiasis in children aged 912 years is associated with the prevalence in 58-year-olds and adults after preventive chemotherapy in schools or the community. Methods We combined data from four community-randomized, preventive chemotherapy trials in treatment-naïve populations in Côte d'Ivoire, Kenya and the United Republic of Tanzania during 20102016 according to the number of praziquantel treatments and the delivery method. Schistosoma mansoni infection was sought on two slides prepared from each participant's first stool using the KatoKatz technique. We assessed associations between S. mansoni prevalence in 912-year-olds and 58-year-olds and adults in the community before and after treatment using Bayesian regression models. Findings Stool samples from 47 985 58-year-olds, 81 077 912-year-olds and 20 492 adults were analysed. We found associations between the prevalence in 912-year-olds and that in 58-year-olds and adults after preventive treatment, even when only school-age children were treated. When the prevalence in 912-year-olds was under 10%, the prevalence in 58-year-olds was consistently under 10%. When the prevalence in 912-year-olds was under 50%, the prevalence in adults after two or four rounds of preventive chemotherapy was 10%15% lower than before chemotherapy. Post-chemotherapy age-group associations were consistent with pre-chemotherapy associations in this analysis and previous studies. Conclusion The prevalence of S. mansoni infection in 912-year-olds was associated with the prevalence in other age groups and could be used to guide community treatment decisions.
Assuntos
Tanzânia , Tratamento Farmacológico , QuêniaRESUMO
[ABSTRACT]. Objective. Systematize the experience and identify challenges and lessons learned in the implementation of an initiative for integrated serosurveillance of communicable diseases using a multiplex bead assay in coun- tries of the Americas. Methods. Documents produced in the initiative were compiled and reviewed. These included concept notes, internal working papers, regional meetings reports, and survey protocols from the three participating countries (Mexico, Paraguay, and Brazil) and two additional countries (Guyana and Guatemala) where serology for sev- eral communicable diseases was included in neglected tropical diseases surveys. Information was extracted and summarized to describe the experience and the most relevant challenges and lessons learned. Results. Implementing integrated serosurveys requires interprogrammatic and interdisciplinary work teams for the design of survey protocols to respond to key programmatic questions aligned to the needs of the countries. Valid laboratory results are critical and rely on the standardized installment and roll-out of laboratory tech- niques. Field teams require adequate training and supervision to properly implement survey procedures. The analysis and interpretation of serosurveys results should be antigen-specific, contextualizing the responses for each disease, and triangulated with programmatic and epidemiological data for making decisions tailored to specific population socioeconomic and ecologic contexts. Conclusions. Integrated serosurveillance as a complementary tool for functional epidemiological surveil- lance systems is feasible to use and key components should be considered: political engagement, technical engagement, and integrated planning. Aspects such as designing the protocol, selecting target populations and diseases, laboratory capacities, anticipating the capacities to analyze and interpret complex data, and how to use it are key.
[RESUMEN]. Objetivo. Sistematizar la experiencia y determinar los desafíos y las enseñanzas obtenidas durante la apli- cación de una iniciativa de serovigilancia integrada de enfermedades transmisibles mediante un ensayo de perlas múltiples en países de la Región de las Américas. Métodos. Se recopilaron y revisaron los documentos generados en el marco de la iniciativa. Estos incluían notas conceptuales, documentos de trabajo internos, informes de reuniones regionales y protocolos de encuesta de los tres países participantes (Brasil, México y Paraguay) y otros dos países (Guatemala y Guyana) donde en las encuestas sobre enfermedades tropicales desatendidas también se incluía la serología para varias enfermedades transmisibles. Se recabó y resumió la información para describir tanto la experiencia como los desafíos y las enseñanzas de mayor relevancia. Resultados. La realización de encuestas serológicas integradas requiere equipos de trabajo interprogramáti- cos e interdisciplinarios para la elaboración de protocolos de encuesta que permitan responder a cuestiones programáticas fundamentales y ajustadas a las necesidades de los países. Es imprescindible contar con resultados de laboratorio válidos, para lo que es preciso que sus técnicas e instalaciones estén estandariza- das. Para que los equipos de campo puedan ejecutar correctamente los procedimientos de la encuesta, deben contar con una formación y supervisión adecuadas. El análisis y la interpretación de los resultados de las encuestas serológicas deben ser específicos para cada antígeno, situar las respuestas en el contexto de cada enfermedad y triangularse con los datos programáticos y epidemiológicos para tomar decisiones adaptadas a los contextos socioeconómicos y ecológicos específicos de la población. Conclusiones. Es uso de la vigilancia serológica integrada como una herramienta complementaria en los sistemas funcionales de vigilancia epidemiológica es algo posible; para esto deben tenerse en cuenta ciertos elementos fundamentales: el compromiso político, el compromiso técnico y la planificación integrada. A tal efecto, son fundamentales ciertos elementos como el diseño del protocolo, la selección de los grupos pobla- cionales y las enfermedades objetivo, la capacidad de los laboratorios, y la previsión de las capacidades de análisis e interpretación de datos complejos y la forma de utilizarlos.
[RESUMO]. Objetivo. Sistematizar a experiência e identificar desafios e lições aprendidas na implementação de uma iniciativa de vigilância sorológica integrada de doenças transmissíveis, usando ensaio de micro-esferas multiplex em países das Américas. Métodos. Os documentos produzidos na iniciativa foram compilados e examinados, e incluíram notas con- ceituais, documentos internos de trabalho, relatórios de reuniões regionais e protocolos de pesquisa dos três países participantes (México, Paraguai e Brasil) e de dois países adicionais (Guiana e Guatemala), onde a vigilância sorológica de várias doenças transmissíveis foi incluída em pesquisas sobre doenças tropicais negligenciadas. As informações foram extraídas e resumidas para descrever a experiência e os desafios e as lições aprendidas mais relevantes. Resultados. A implementação de inquéritos sorológicos integrados requer equipes de trabalho interpro- gramáticas e interdisciplinares para o delineamento de protocolos que respondam a questões programáticas chave, alinhadas com as necessidades dos países. Resultados laboratoriais válidos são essenciais, e depen- dem da instalação e implantação padronizadas de técnicas laboratoriais. As equipes de campo precisam de treinamento e supervisão apropriados para implementar adequadamente os procedimentos de pesquisa. A análise e a interpretação dos resultados dos inquéritos sorológicos devem ser antígeno-específicas, con- textualizando as respostas para cada doença, e trianguladas com dados programáticos e epidemiológicos para a tomada de decisões adaptadas aos contextos socioeconômicos e ecológicos específicos de cada população. Conclusões. A vigilância sorológica integrada como ferramenta complementar para sistemas de vigilância epidemiológica funcionais é viável. Os componentes-chave a seguir devem ser considerados: engajamento político, engajamento técnico e planejamento integrado. Aspectos como o delineamento do protocolo, a seleção de populações-alvo e doenças-alvo, a capacidade laboratorial, a previsão das capacidades para análise e interpretação de dados complexos e como usá-los são fundamentais.
Assuntos
Sorologia , Sistema de Vigilância em Saúde , Doenças Transmissíveis , América , Sorologia , Vigilância Sanitária , Doenças Transmissíveis , América , Vigilância Sanitária , Doenças Transmissíveis , AméricaRESUMO
ABSTRACT Objective. Systematize the experience and identify challenges and lessons learned in the implementation of an initiative for integrated serosurveillance of communicable diseases using a multiplex bead assay in countries of the Americas. Methods. Documents produced in the initiative were compiled and reviewed. These included concept notes, internal working papers, regional meetings reports, and survey protocols from the three participating countries (Mexico, Paraguay, and Brazil) and two additional countries (Guyana and Guatemala) where serology for several communicable diseases was included in neglected tropical diseases surveys. Information was extracted and summarized to describe the experience and the most relevant challenges and lessons learned. Results. Implementing integrated serosurveys requires interprogrammatic and interdisciplinary work teams for the design of survey protocols to respond to key programmatic questions aligned to the needs of the countries. Valid laboratory results are critical and rely on the standardized installment and roll-out of laboratory techniques. Field teams require adequate training and supervision to properly implement survey procedures. The analysis and interpretation of serosurveys results should be antigen-specific, contextualizing the responses for each disease, and triangulated with programmatic and epidemiological data for making decisions tailored to specific population socioeconomic and ecologic contexts. Conclusions. Integrated serosurveillance as a complementary tool for functional epidemiological surveillance systems is feasible to use and key components should be considered: political engagement, technical engagement, and integrated planning. Aspects such as designing the protocol, selecting target populations and diseases, laboratory capacities, anticipating the capacities to analyze and interpret complex data, and how to use it are key.
Resumen Objetivo. Sistematizar la experiencia y determinar los desafíos y las enseñanzas obtenidas durante la aplicación de una iniciativa de serovigilancia integrada de enfermedades transmisibles mediante un ensayo de perlas múltiples en países de la Región de las Américas. Métodos. Se recopilaron y revisaron los documentos generados en el marco de la iniciativa. Estos incluían notas conceptuales, documentos de trabajo internos, informes de reuniones regionales y protocolos de encuesta de los tres países participantes (Brasil, México y Paraguay) y otros dos países (Guatemala y Guyana) donde en las encuestas sobre enfermedades tropicales desatendidas también se incluía la serología para varias enfermedades transmisibles. Se recabó y resumió la información para describir tanto la experiencia como los desafíos y las enseñanzas de mayor relevancia. Resultados. La realización de encuestas serológicas integradas requiere equipos de trabajo interprogramáticos e interdisciplinarios para la elaboración de protocolos de encuesta que permitan responder a cuestiones programáticas fundamentales y ajustadas a las necesidades de los países. Es imprescindible contar con resultados de laboratorio válidos, para lo que es preciso que sus técnicas e instalaciones estén estandarizadas. Para que los equipos de campo puedan ejecutar correctamente los procedimientos de la encuesta, deben contar con una formación y supervisión adecuadas. El análisis y la interpretación de los resultados de las encuestas serológicas deben ser específicos para cada antígeno, situar las respuestas en el contexto de cada enfermedad y triangularse con los datos programáticos y epidemiológicos para tomar decisiones adaptadas a los contextos socioeconómicos y ecológicos específicos de la población. Conclusiones. Es uso de la vigilancia serológica integrada como una herramienta complementaria en los sistemas funcionales de vigilancia epidemiológica es algo posible; para esto deben tenerse en cuenta ciertos elementos fundamentales: el compromiso político, el compromiso técnico y la planificación integrada. A tal efecto, son fundamentales ciertos elementos como el diseño del protocolo, la selección de los grupos poblacionales y las enfermedades objetivo, la capacidad de los laboratorios, y la previsión de las capacidades de análisis e interpretación de datos complejos y la forma de utilizarlos.
RESUMO Objetivo. Sistematizar a experiência e identificar desafios e lições aprendidas na implementação de uma iniciativa de vigilância sorológica integrada de doenças transmissíveis, usando ensaio de micro-esferas multiplex em países das Américas. Métodos. Os documentos produzidos na iniciativa foram compilados e examinados, e incluíram notas conceituais, documentos internos de trabalho, relatórios de reuniões regionais e protocolos de pesquisa dos três países participantes (México, Paraguai e Brasil) e de dois países adicionais (Guiana e Guatemala), onde a vigilância sorológica de várias doenças transmissíveis foi incluída em pesquisas sobre doenças tropicais negligenciadas. As informações foram extraídas e resumidas para descrever a experiência e os desafios e as lições aprendidas mais relevantes. Resultados. A implementação de inquéritos sorológicos integrados requer equipes de trabalho interprogramáticas e interdisciplinares para o delineamento de protocolos que respondam a questões programáticas chave, alinhadas com as necessidades dos países. Resultados laboratoriais válidos são essenciais, e dependem da instalação e implantação padronizadas de técnicas laboratoriais. As equipes de campo precisam de treinamento e supervisão apropriados para implementar adequadamente os procedimentos de pesquisa. A análise e a interpretação dos resultados dos inquéritos sorológicos devem ser antígeno-específicas, contextualizando as respostas para cada doença, e trianguladas com dados programáticos e epidemiológicos para a tomada de decisões adaptadas aos contextos socioeconômicos e ecológicos específicos de cada população. Conclusões. A vigilância sorológica integrada como ferramenta complementar para sistemas de vigilância epidemiológica funcionais é viável. Os componentes-chave a seguir devem ser considerados: engajamento político, engajamento técnico e planejamento integrado. Aspectos como o delineamento do protocolo, a seleção de populações-alvo e doenças-alvo, a capacidade laboratorial, a previsão das capacidades para análise e interpretação de dados complexos e como usá-los são fundamentais.
Assuntos
Humanos , Pré-Escolar , Criança , Adolescente , Adulto , Controle de Doenças Transmissíveis/métodos , Monitoramento Epidemiológico , América/epidemiologia , Estudos Soroepidemiológicos , Estudos RetrospectivosRESUMO
BACKGROUND: Lymphatic filariasis (LF) has been targeted for global elimination as a public health problem since 1997. The primary strategy to interrupt transmission is annual mass drug administration (MDA) for ≥5 years. The transmission assessment survey (TAS) was developed as a decision-making tool to measure LF antigenemia in children to determine when MDA in a region can be stopped. The objective of this study was to investigate potential sampling strategies for follow-up of LF-positive children identified in TAS to detect evidence of ongoing transmission. METHODOLOGY/PRINCIPLE FINDINGS: Nippes Department in Haiti passed TAS 1 with 2 positive cases and stopped MDA in 2015; however, 8 positive children were found during TAS 2 in 2017, which prompted a more thorough assessment of ongoing transmission. Purposive sampling was used to select the closest 50 households to each index case household, and systematic random sampling was used to select 20 households from each index case census enumeration area. All consenting household members aged ≥2 years were surveyed and tested for circulating filarial antigen (CFA) using the rapid filarial test strip and for Wb123-specific antibodies using the Filaria Detect IgG4 ELISA. Among 1,927 participants, 1.5% were CFA-positive and 4.5% were seropositive. CFA-positive individuals were identified for 6 of 8 index cases. Positivity ranged from 0.4-2.4%, with highest positivity in the urban commune Miragoane. Purposive sampling found the highest number of CFA-positives (17 vs. 9), and random sampling found a higher percent positive (2.4% vs. 1.4%). CONCLUSIONS/SIGNIFICANCE: Overall, both purposive and random sampling methods were reasonable and achievable methods of TAS follow-up in resource-limited settings. Both methods identified additional CFA-positives in close geographic proximity to LF-positive children found by TAS, and both identified strong signs of ongoing transmission in the large urban commune of Miragoane. These findings will help inform standardized guidelines for post-TAS surveillance.
Assuntos
Filariose Linfática , Filaricidas , Animais , Antígenos de Helmintos/uso terapêutico , Criança , Filariose Linfática/tratamento farmacológico , Filariose Linfática/epidemiologia , Filariose Linfática/prevenção & controle , Filaricidas/uso terapêutico , Seguimentos , Haiti/epidemiologia , Humanos , Administração Massiva de Medicamentos/métodos , Prevalência , Wuchereria bancroftiRESUMO
In Haiti, 22 communes still require mass drug administration (MDA) to eliminate lymphatic filariasis (LF) as a public health problem. Several clinical trials have shown that a single oral dose of ivermectin (IVM), diethylcarbamazine (DEC) and albendazole (ALB) (IDA) is more effective than DEC plus ALB (DA) for clearing Wuchereria bancrofti microfilariae (Mf). We performed a cluster-randomized community study to compare the safety and efficacy of IDA and DA in an LF-endemic area in northern Haiti. Ten localities were randomized to receive either DA or IDA. Participants were monitored for adverse events (AE), parasite antigenemia, and microfilaremia. Antigen-positive participants were retested one year after MDA to assess treatment efficacy. Fewer participants (11.0%, 321/2917) experienced at least one AE after IDA compared to DA (17.3%, 491/2844, P<0.001). Most AEs were mild, and the three most common AEs reported were headaches, dizziness and abdominal pain. Serious AEs developed in three participants who received DA. Baseline prevalence for filarial antigenemia was 8.0% (239/3004) in IDA localities and 11.5% (344/2994) in DA localities (<0.001). Of those with positive antigenemia, 17.6% (42/239) in IDA localities and 20.9% (72/344, P = 0.25) in DA localities were microfilaremic. One year after treatment, 84% percent of persons with positive filarial antigen tests at baseline could be retested. Clearance rates for filarial antigenemia were 20.5% (41/200) after IDA versus 25.4% (74/289) after DA (P = 0.3). However, 94.4% (34/36) of IDA recipients and 75.9% (44/58) of DA recipients with baseline microfilaremia were Mf negative at the time of retest (P = 0.02). Thus, MDA with IDA was at least as well tolerated and significantly more effective for clearing Mf compared to the standard DA regimen in this study. Effective MDA coverage with IDA could accelerate the elimination of LF as a public health problem in the 22 communes that still require MDA in Haiti.
Assuntos
Albendazol/administração & dosagem , Antiparasitários/administração & dosagem , Dietilcarbamazina/administração & dosagem , Ivermectina/administração & dosagem , Adolescente , Adulto , Albendazol/efeitos adversos , Animais , Antiparasitários/efeitos adversos , Criança , Pré-Escolar , Dietilcarbamazina/efeitos adversos , Quimioterapia Combinada , Filariose Linfática/tratamento farmacológico , Feminino , Haiti , Humanos , Ivermectina/efeitos adversos , Modelos Logísticos , Masculino , Administração Massiva de Medicamentos/efeitos adversos , Pessoa de Meia-Idade , Prevalência , Resultado do Tratamento , Adulto JovemRESUMO
BACKGROUND: Insecticide-treated bednets (ITNs) are effective in preventing malaria where vectors primarily bite indoors and late at night, but their effectiveness is uncertain where vectors bite outdoors and earlier in the evening. We studied the effectiveness of ITNs following a mass distribution in Haiti from May to September, 2012, where the Anopheles albimanus vector bites primarily outdoors and often when people are awake. METHODS: In this case-control study, we enrolled febrile patients presenting to outpatient departments at 17 health facilities throughout Haiti from Sept 4, 2012, to Feb 27, 2014, who were tested with malaria rapid diagnostic tests (RDTs), and administered questionnaires on ITN use and other risk factors. Cases were defined by positive RDT and controls were febrile patients from the same clinic with a negative RDT. Our primary analysis retrospectively matched cases and controls by age, sex, location, and date, and used conditional logistic regression on the matched sample. A sensitivity analysis used propensity scores to match patients on ITN use propensity and analyse malaria among ITN users and non-users. Additional ITN bioefficacy and entomological data were collected. FINDINGS: We enrolled 9317 patients, including 378 (4%) RDT-positive cases. 1202 (13%) patients reported ITN use. Post-hoc matching of cases and controls yielded 362 cases and 1201 matched controls, 19% (333) of whom reported consistent campaign net use. After using propensity scores to match on consistent campaign ITN use, 2298 patients, including 138 (7%) RDT-positive cases, were included: 1149 consistent campaign ITN users and 1149 non-consistent campaign ITN users. Both analyses revealed that ITNs did not significantly protect against clinical malaria (odds ratio [OR]=0·95, 95% CI 0·68-1·32, p=0·745 for case-control analysis; OR=0·95, 95% CI 0·45-1·97, p=0·884 for propensity score analysis). ITN and entomological data indicated good ITN physical integrity and bioefficacy, and no permethrin resistance among local mosquitoes. INTERPRETATION: We found no evidence that mass ITN campaigns reduce clinical malaria in this observational study in Haiti; alternative malaria control strategies should be prioritised. FUNDING: The Global Fund to Fight AIDS, Tuberculosis, and Malaria, and the US-based Centers for Disease Control and Prevention (CDC).
Assuntos
Mosquiteiros Tratados com Inseticida , Malária/prevenção & controle , Controle de Mosquitos/métodos , Adolescente , Animais , Estudos de Casos e Controles , Feminino , Haiti , Humanos , Malária/transmissão , Masculino , Fatores de Risco , Inquéritos e QuestionáriosRESUMO
BACKGROUND: As a nation reduces the burden of falciparum malaria, identifying areas of transmission becomes increasingly difficult. Over the past decade, the field of utilizing malaria serological assays to measure exposure has grown rapidly, and a variety of serological methods for data acquisition and analysis of human IgG against falciparum antigens are available. Here, different immunoassays and statistical methods are utilized to analyse samples from a low transmission setting and directly compare the estimates generated. METHODS: A subset of samples (n = 580) from a 2012 Haitian nationwide malaria survey was employed as sample population of low falciparum endemicity. In addition to the Haitian samples, samples from 247 US residents were used as a reference population of 'true seronegatives'. Data acquisition was performed through standard ELISA and bead-based multiplex assays assaying for IgG antibodies to the Plasmodium falciparum antigens MSP-1p19, MSP-1p42(D), MSP-1p42(F), and AMA-1. Appropriate parametric distributions and seropositivity cutoff values were determined by statistical measures. RESULTS: Data from both assays showed a strong positive skew, and the lognormal distribution was found to be an appropriate statistical fit to the Haitian and American populations. The American samples served as a good serological true negative population for the multiplex assay, but not for ELISA-based data. Mixture model approaches to determine seronegative and seropositive populations from the Haitian data showed a high degree of distribution overlap-likely due to the historical low falciparum transmission in this nation. Different fittings to the reversible catalytic model resulted depending upon the immunoassay utilized and seropositivity cutoff method employed. Data were also analysed through fitting to penalized B-splines, presenting another possible analytical tool for the analysis of malaria serological data. CONCLUSIONS: Standardization of serological techniques and analyses may prove difficult as some tools can prove to be more useful depending on the area and parasite in question, making clear interpretation a vital pursuit. The presented analysis in the low-endemic nation of Haiti found malaria-naive US residents to be an appropriate seronegative reference population for the multiplex assay, and this assay providing consistent estimates between MSP-1 and AMA-1 antigens of percent seropositives for this low-endemic population.
Assuntos
Anticorpos Antiprotozoários/sangue , Imunoensaio/métodos , Malária Falciparum/epidemiologia , Malária Falciparum/imunologia , Plasmodium falciparum/imunologia , Antígenos de Protozoários/imunologia , Estudos Transversais , Haiti/epidemiologia , Humanos , Imunoglobulina G/sangueRESUMO
BACKGROUND: Chagas disease control campaigns relying upon residual insecticide spraying have been successful in many Southern American countries. However, in some areas, rapid reinfestation and recrudescence of transmission have occurred. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a cross-sectional survey in the Bolivian Chaco to evaluate prevalence of and risk factors for T. cruzi infection 11 years after two rounds of blanket insecticide application. We used a cubic B-spline model to estimate change in force of infection over time based on age-specific seroprevalence data. Overall T. cruzi seroprevalence was 51.7%. The prevalence was 19.8% among children 2-15, 72.7% among those 15-30 and 97.1% among participants older than 30 years. Based on the model, the estimated annual force of infection was 4.3% over the two years before the first blanket spray in 2000 and fell to 0.4% for 2001-2002. The estimated annual force of infection for 2004-2005, the 2 year period following the second blanket spray, was 4.6%. However, the 95% bootstrap confidence intervals overlap for all of these estimates. In a multivariable model, only sleeping in a structure with cracks in the walls (aOR = 2.35; 95% CI = 1.15-4.78), age and village of residence were associated with infection. CONCLUSIONS/SIGNIFICANCE: As in other areas in the Chaco, we found an extremely high prevalence of Chagas disease. Despite evidence that blanket insecticide application in 2000 may have decreased the force of infection, active transmission is ongoing. Continued spraying vigilance, infestation surveillance, and systematic household improvements are necessary to disrupt and sustain interruption of infection transmission.