Participatory Surveillance for COVID-19 Trend Detection in Brazil: Cross-sectional Study.

BACKGROUND: The ongoing COVID-19 pandemic has emphasized the necessity of a well-functioning surveillance system to detect and mitigate disease outbreaks. Traditional surveillance (TS) usually relies on health care providers and generally suffers from reporting lags that prevent immediate response plans. Participatory surveillance (PS), an innovative digital approach whereby individuals voluntarily monitor and report on their own health status via web-based surveys, has emerged in the past decade to complement traditional data collection approaches. OBJECTIVE: This study compared novel PS data on COVID-19 infection rates across 9 Brazilian cities with official TS data to examine the opportunities and challenges of using PS data, and the potential advantages of combining the 2 approaches. METHODS: The TS data for Brazil are publicly accessible on GitHub. The PS data were collected through the Brazil Sem Corona platform, a Colab platform. To gather information on an individual's health status, each participant was asked to fill out a daily questionnaire on symptoms and exposure in the Colab app. RESULTS: We found that high participation rates are key for PS data to adequately mirror TS infection rates. Where participation was high, we documented a significant trend correlation between lagged PS data and TS infection rates, suggesting that PS data could be used for early detection. In our data, forecasting models integrating both approaches increased accuracy up to 3% relative to a 14-day forecast model based exclusively on TS data. Furthermore, we showed that PS data captured a population that significantly differed from a traditional observation. CONCLUSIONS: In the traditional system, the new recorded COVID-19 cases per day are aggregated based on positive laboratory-confirmed tests. In contrast, PS data show a significant share of reports categorized as potential COVID-19 cases that are not laboratory confirmed. Quantifying the economic value of PS system implementation remains difficult. However, scarce public funds and persisting constraints to the TS system provide motivation for a PS system, making it an important avenue for future research. The decision to set up a PS system requires careful evaluation of its expected benefits, relative to the costs of setting up platforms and incentivizing engagement to increase both coverage and consistent reporting over time. The ability to compute such economic tradeoffs might be key to have PS become a more integral part of policy toolkits moving forward. These results corroborate previous studies when it comes to the benefits of an integrated and comprehensive surveillance system, and shed light on its limitations and on the need for additional research to improve future implementations of PS platforms.

Association of COVID-19 Incidence and Mortality Rates With School Reopening in Brazil During the COVID-19 Pandemic.

Importance: School closures because of COVID-19 have left 1.6 billion students around the world without in-person classes for a prolonged period. To our knowledge, no study has documented whether reopening schools in low- and middle-income countries during the pandemic was associated with increased aggregate COVID-19 incidence and mortality with appropriate counterfactuals. Objective: To test whether reopening schools under appropriate protocols during the COVID-19 pandemic was associated with increased municipal-level COVID-19 cases and deaths in São Paulo State, Brazil. Design Setting and Participants: This observational study of municipalities in São Paulo State, Brazil, uses a difference-in-differences analysis to examine the association between municipal decisions to reopen schools during the COVID-19 pandemic and municipal-level COVID-19 case and death rates between October and December 2020. The study compared 129 municipalities that reopened schools in 2020 with 514 that did not and excluded data for 2 municipalities that reopened schools and closed then again. Main Outcomes and Measures: New COVID-19 cases and deaths per 10 000 inhabitants up to 12 weeks after school reopenings and municipal-level aggregate mobility for a subset of municipalities. Results: There were 8764 schools in the 129 municipalities that reopened schools compared with 9997 in the control group of 514 municipalities that did not reopen schools. The municipalities that reopened schools had a cumulative COVID-19 incidence of 20 cases per 1000 inhabitants and mortality of 0.5 deaths per 1000 inhabitants in September 2020 (the baseline period) compared with an incidence of 18 cases per 1000 inhabitants and mortality of 0.45 deaths per 1000 inhabitants during the baseline period in the comparison group. The findings indicated that there were no statistically significant differences between municipalities that authorized schools to reopen and those that did not for (1) weekly new cases (difference-in-differences, -0.03; 95% CI, -0.09 to 0.03) and (2) weekly new deaths (difference-in-differences, -0.003; 95% CI, -0.011 to 0.004) before and after October 2020. Reopening schools was not associated with higher disease activity, even in relatively vulnerable municipalities, nor aggregate mobility. Conclusions and Relevance: The findings from this study suggest that keeping schools open during the COVID-19 pandemic did not contribute to the aggregate disease activity.

The impacts of remote learning in secondary education during the pandemic in Brazil.

The transition to remote learning in the context of coronavirus disease 2019 (COVID-19) might have led to dramatic setbacks in education. Taking advantage of the fact that São Paulo State featured in-person classes for most of the first school quarter of 2020 but not thereafter, we estimate the effects of remote learning in secondary education using a differences-in-differences strategy that contrasts variation in students' outcomes across different school quarters, before and during the pandemic. We also estimate intention-to-treat effects of reopening schools in the pandemic through a triple-differences strategy, contrasting changes in educational outcomes across municipalities and grades that resumed in-person classes or not over the last school quarter in 2020. We find that, under remote learning, dropout risk increased by 365% while test scores decreased by 0.32 s.d., as if students had only learned 27.5% of the in-person equivalent. Partially resuming in-person classes increased test scores by 20% relative to the control group.

Participatory Surveillance Based on Crowdsourcing During the Rio 2016 Olympic Games Using the Guardians of Health Platform: Descriptive Study.

BACKGROUND: With the evolution of digital media, areas such as public health are adding new platforms to complement traditional systems of epidemiological surveillance. Participatory surveillance and digital epidemiology have become innovative tools for the construction of epidemiological landscapes with citizens' participation, improving traditional sources of information. Strategies such as these promote the timely detection of warning signs for outbreaks and epidemics in the region. OBJECTIVE: This study aims to describe the participatory surveillance platform Guardians of Health, which was used in a project conducted during the 2016 Olympic and Paralympic Games in Rio de Janeiro, Brazil, and officially used by the Brazilian Ministry of Health for the monitoring of outbreaks and epidemics. METHODS: This is a descriptive study carried out using secondary data from Guardians of Health available in a public digital repository. Based on syndromic signals, the information subsidy for decision making by policy makers and health managers becomes more dynamic and assertive. This type of information source can be used as an early route to understand the epidemiological scenario. RESULTS: The main result of this research was demonstrating the use of the participatory surveillance platform as an additional source of information for the epidemiological surveillance performed in Brazil during a mass gathering. The platform Guardians of Health had 7848 users who generated 12,746 reports about their health status. Among these reports, the following were identified: 161 users with diarrheal syndrome, 68 users with respiratory syndrome, and 145 users with rash syndrome. CONCLUSIONS: It is hoped that epidemiological surveillance professionals, researchers, managers, and workers become aware of, and allow themselves to use, new tools that improve information management for decision making and knowledge production. This way, we may follow the path for a more intelligent, efficient, and pragmatic disease control system.

Saúde na Copa: The World's First Application of Participatory Surveillance for a Mass Gathering at FIFA World Cup 2014, Brazil.

BACKGROUND: The 2005 International Health Regulations (IHRs) established parameters for event assessments and notifications that may constitute public health emergencies of international concern. These requirements and parameters opened up space for the use of nonofficial mechanisms (such as websites, blogs, and social networks) and technological improvements of communication that can streamline the detection, monitoring, and response to health problems, and thus reduce damage caused by these problems. Specifically, the revised IHR created space for participatory surveillance to function, in addition to the traditional surveillance mechanisms of detection, monitoring, and response. Participatory surveillance is based on crowdsourcing methods that collect information from society and then return the collective knowledge gained from that information back to society. The spread of digital social networks and wiki-style knowledge platforms has created a very favorable environment for this model of production and social control of information. OBJECTIVE: The aim of this study was to describe the use of a participatory surveillance app, Healthy Cup, for the early detection of acute disease outbreaks during the Fédération Internationale de Football Association (FIFA) World Cup 2014. Our focus was on three specific syndromes (respiratory, diarrheal, and rash) related to six diseases that were considered important in a mass gathering context (influenza, measles, rubella, cholera, acute diarrhea, and dengue fever). METHODS: From May 12 to July 13, 2014, users from anywhere in the world were able to download the Healthy Cup app and record their health condition, reporting whether they were good, very good, ill, or very ill. For users that reported being ill or very ill, a screen with a list of 10 symptoms was displayed. Participatory surveillance allows for the real-time identification of aggregates of symptoms that indicate possible cases of infectious diseases. RESULTS: From May 12 through July 13, 2014, there were 9434 downloads of the Healthy Cup app and 7155 (75.84%) registered users. Among the registered users, 4706 (4706/7155, 65.77%) were active users who posted a total of 47,879 times during the study period. The maximum number of users that signed up in one day occurred on May 30, 2014, the day that the app was officially launched by the Minister of Health during a press conference. During this event, the Minister of Health announced the special government program Health in the World Cup on national television media. On that date, 3633 logins were recorded, which accounted for more than half of all sign-ups across the entire duration of the study (50.78%, 3633/7155). CONCLUSIONS: Participatory surveillance through community engagement is an innovative way to conduct epidemiological surveillance. Compared to traditional epidemiological surveillance, advantages include lower costs of data acquisition, timeliness of information collected and shared, platform scalability, and capacity for integration between the population being served and public health services.

Digital disease detection and participatory surveillance: overview and perspectives for Brazil.

This study aimed to describe the digital disease detection and participatory surveillance in different countries. The systems or platforms consolidated in the scientific field were analyzed by describing the strategy, type of data source, main objectives, and manner of interaction with users. Eleven systems or platforms, developed from 1996 to 2016, were analyzed. There was a higher frequency of data mining on the web and active crowdsourcing as well as a trend in the use of mobile applications. It is important to provoke debate in the academia and health services for the evolution of methods and insights into participatory surveillance in the digital age.

Using mobile technology to conduct epidemiological investigations.

INTRODUCTION: The aim of this study was to report the experience of an epidemiological field survey for which data were collected and analyzed using tablets. METHODS: The devices used Epi Info 7 (Android version), which has been modeled a database with variables of the traditional form. RESULTS: Twenty-one households were randomly selected in the study area; 75 residents were registered and completed household interviews with socioeconomic and environmental risk variables. CONCLUSIONS: This new technology is a valuable tool for collecting and analyzing data from the field, with advantageous benefits to epidemiological surveys.

The schisto track: a system for gathering and monitoring epidemiological surveys by connecting geographical information systems in real time.

BACKGROUND: Using the Android platform as a notification instrument for diseases and disorders forms a new alternative for computerization of epidemiological studies. OBJECTIVE: The objective of our study was to construct a tool for gathering epidemiological data on schistosomiasis using the Android platform. METHODS: The developed application (app), named the Schisto Track, is a tool for data capture and analysis that was designed to meet the needs of a traditional epidemiological survey. An initial version of the app was finished and tested in both real situations and simulations for epidemiological surveys. RESULTS: The app proved to be a tool capable of automation of activities, with data organization and standardization, easy data recovery (to enable interfacing with other systems), and totally modular architecture. CONCLUSIONS: The proposed Schisto Track is in line with worldwide trends toward use of smartphones with the Android platform for modeling epidemiological scenarios.

Risk analysis for occurrences of schistosomiasis in the coastal area of Porto de Galinhas, Pernambuco, Brazil.

BACKGROUND: Manson's schistosomiasis continues to be a severe public health problem in Brazil, where thousands of people live under the risk of contracting this parasitosis. In the Northeast of Brazil, schistosomiasis has expanded from rural areas to the coast of Pernambuco State, where the intermediate host is Biomphalaria glabrata snails. This study aims at presenting situational analyses on schistosomiasis at the coastal locality of Porto de Galinhas, Pernambuco, Brazil, by determining the risk factors relating to its occurrence from the epidemiological and spatial perspectives. METHODS: In order to gather prevalence data, a parasitological census surveys were conducted in 2010 in the light of the Kato-Katz technique. Furthermore, malacological surveys were also conducted in the same years so as to define the density and infection rates of the intermediate host. Lastly, socioeconomic-behavioral survey was also conducted to determine the odds ratio for infection by Schistosoma mansoni. Based on these data, spatial analyses were done, resulting in maps of the risk of disease transmission. To predict the risk of schistosomiasis occurrence, a multivariate logistic regression was performed using R 2.13 software. RESULTS: Based on prevalence, malacological and socioeconomic-behavioural surveys, it was identified a prevalence of 15.7% in the investigated population (2,757 individuals). Due to the malacological survey, 36 breeding sites were identified, of which 11 were classified as foci of schistosomiasis transmission since they pointed out snails which were infected by Schistosoma mansoni. Overall, 11,012 snails (Biomphalaria glabrata) were collected. The multivariate regression model identified six explanatory variables of environmental, socioeconomic and demographic nature. Spatial sweep analysis by means of the Bernoulli method identified one statistically significant cluster in Salinas (RR = 2.2; p-value < 0.000), the district with the highest occurrence of cases. CONCLUSIONS: Based on the resulting information from this study, the epidemiological dimensions of this disease are significant and severe, within the scenario of schistosomiasis in Pernambuco state. The risk factors which were identified in the predictive model made it clear that the environmental and social conditions influence on the schistosomiasis occurrences.

Epidemiologia da esquistossomose no litoral de Pernambuco / Epidemiology of schistosomiasis in coastal areas of Pernambuco State, Brazil

A expansão da esquistossomose para o litoral de Pernambuco vem sendo registrada desde 1992 coma detecção de casos agudos da doença em indivíduos de classe média/alta. Para diagnosticar estenovo cenário de transmissão da endemia em localidades turísticas na orla marítima do estado é defundamental importância o conhecimento prévio da distribuição georreferenciada das espécies demoluscos vetores, por meio de mapas que apontem sua exata localização, assim como é necessárioespacializar as situações de risco biológico e as condições ambientais insalubres. Nos períodos de 15a 18 de setembro de 2008 e 10 a 13 de setembro de 2013 foram realizadas caravanas expedicionárias,por epidemiologistas e parasitologistas por 11 municípios do litoral do estado, percorrendo todasas coleções de água doce distantes até 2 km da beira-mar. Os dados foram georreferenciados paraposterior condução de análises espaciais. Para identificação da positividade dos exemplares deBiomphalaria glabrata, foi utilizada a técnica de exposição à luz. Os espécimes de B. stramineaque permaneceram negativos até o 15º dia foram submetidos à técnica de diagnóstico molecular(PCR-single tube). Nas coletas de 2008 foram capturados 3.392 caramujos B. glabrata e 725 B.straminea, cujas taxas de infecção variaram entre 0,9 por cento a 22,2 por cento. Em 2013, foram coletados 948B. glabrata e 504 B. straminea e somente foram encontrados caramujos eliminando cercarias nalocalidade Porto de Galinhas com taxa de infectividade de 81,4 por cento, permanecendo como localidadede maior risco para transmissão da esquistossomose.

The expansion of schistosomiasis to the coast of Pernambuco has been registered since 1992 withthe detection of acute cases of the disease in individuals of middle/upper class. To diagnose thisnew scenario of transmission of schistosomiasis in tourist areas on the waterfront of the state,knowledge of georeferenced species distribution of vector snails through maps that show theirexact location seems essential, as it is necessary to localize situations with biohazard and unhealthyenvironmental conditions. From 15 to 18 September 2008 and 10 to 13 September 2013, expeditionswere conducted by groups of epidemiologists and parasitologists for 11 coastal municipalities ofthe state, checking all the collections of fresh water up to 2 km away from the seaside. Data weregeoreferenced for a later conduction of spatial analysis. For positive identification of Biomphalariaglabrata, the technique of light exposure was used. Specimens of B. straminea that remainednegative until the 15th day underwent the technique of molecular diagnosis (PCR-single tube). Inthe 2008 expedition, 3,392 B. glabrata snails and 725 B. straminea snails were captured, whose infection rates ranged from 0.9 percent to 22.2 percent. In the 2013 expedition, 948 B. glabrata and 504 B. straminea snails were collected and only in Porto de Galinhas city were B. glabrata snails found releasing S. mansoni cercariae, with an infectivity rate of 81.4 percent, confirming that in this locality the risk of schistosomiasis transmission is still present.

Schisto Track: um sistema para coleta e monitoramento de inquéritos epidemiológicos conectando sistemas de informações geográficas em tempo real / Schisto Track: a system for gathering and monitoring epidemiological surveys by connecting geographical information systems in real time

A evolução da epidemiologia abrange também instrumentos que são utilizados para a condução de rotinas nos serviços de saúde. Com o desenvolvimento dos recursos tecnológicos aplicáveis à saúde, é possível incorporar nos estudos epidemiológicos plataformas como os sistemas móveis Android para sua adaptação e utilização nos serviços de vigilância epidemiológica e ambiental. A modernização dos processos de coleta de dados, além de diminuir substancialmente o número de erros de transcrição, favorece uma maior velocidade na consolidação dos dados e promove aprimoramento da qualidade de informação gerada. O objetivo deste trabalho é apresentar uma solução para a modernização da condução de inquéritos epidemiológicos em esquistossomose baseado em tecnologia móvel. A aplicação desenvolvida chamada de Schisto Track, é uma ferramenta para captura e análise em tempo real de dados baseados em inquéritos epidemiológicos tradicionais. Para sua implementação foram seguidas as tendências globais no desenvolvimento de instrumentos de coleta de dados, tendo seu arcabouço tecnológico modulado em app nativa e servidor web. A app nativa foi desenvolvida em linguagem Java e otimizada para uso em smartphones e tablets com Android 4.0 ou superior, com sua transmissão de dados feita por rede 3G, via http. O servidor conta com arquitetura backend em linguagem php com banco de dados My SQL. O Frontend foi baseado em linguagem HTML 5, com estruturas de bootstrap e janelas modais atendendo a melhor usabilidade do sistema por parte de técnicos do serviço...

The evolution of epidemiology also includes instruments that are used for improvementroutines in the public health services. With the development of technological resourcesapplicable to health, it is possible to incorporate epidemiological studies on platforms likeAndroid mobile systems for adaptation and utilization in health surveillance services. Themodernization of the processes of data collection, in addition to substantially reduce thenumber of transcription errors, favors a higher speed in data consolidation and consequentimprovement in the quality of information generated. The objective of this work is to presenta solution for the modernization of conducting surveys in schistosomiasis based on mobiletechnology. The developed application called Schisto Track, is a tool for capturing andanalyzing in real-time data based on traditional epidemiological investigations. To implementglobal trends in the development of instruments for data collection were followed, taking theirtechnological framework modulated native app and web server. The native application isoptimized for use on smartphones and tablets with Android 4.0 (or superior) and itstransmission data taken by the 3G network via http. The server architecture includes backendin php language with database My SQL database. The frontend is based on HTML 5 languagewith structures and bootstrap modal windows serving better usability of the system by servicetechnicians...

Autochthonous cases of schistosomiasis in children in Recife, Northeastern Brazil.

OBJECTIVE: Investigate breeding sites with host snails and autochthonous human cases of schistosomiasis. METHODS: Between July 2010 and September 2012 were performed: (1) malacological survey searching for breeding sites, collection and identification of Biomphalaria snails positive for Schistosoma mansoni in Recife, PE, Northeastern Brazil; (2) prevalence survey in 2,718 schoolchildren aged from seven to 14 years old to identify cases of schistosomiasis, clinical examination and ultrasound in positive cases of S. mansoni. The autochthony of the cases was investigated and the case were clinically evaluated. The cases and breeding sites were georeferenced and spatially described. RESULTS: The results identified 30 breeding with B. straminea, four of which were potential foci of transmission, as molecular testing identified snails with S. mansoni DNA. There were 14 children diagnosed with schistosomiasis, of which five were considered to be autochthonous cases of the disease. CONCLUSIONS: Urgent measures are required in order to avoid schistosomiasis becoming endemic to Recife, as has happened in other coastal areas of the state of Pernambuco.

Casos autoctones de esquistossomose mansonica em criancas de Recife, PE / Casos autoctonos de esquistosomiasis mansonica en ninos de Recife, PE, Brasil / Autochthonous cases of schistosomiasis in children in Recife, Northeastern Brazil

OBJETIVO : Investigar criadouros com moluscos hospedeiros e casos humanos autóctones para esquistossomose. MÉTODOS : Entre julho de 2010 e setembro de 2012 foram realizados: (1) levantamento malacológico para busca ativa de criadouros, coleta e identificação de caramujos Biomphalaria positivos para Schistosoma mansoni em Recife, PE; (2) inquérito de prevalência com 2.718 escolares, de sete a 14 anos, para diagnóstico de casos de esquistossomose; (3) exame clínico e ultrassonografia nos casos positivos para S. mansoni. Os casos foram investigados quanto à sua autoctonia e avaliados clinicamente. Os casos e criadouros foram georreferenciados e espacializados. RESULTADOS : Foram identificados 30 criadouros de B. straminea , quatro deles potenciais focos de transmissão, uma vez que os testes moleculares identificaram DNA de S. mansoni nos caramujos coletados. Foram diagnosticadas 14 crianças com esquistossomose; entre elas, cinco foram consideradas casos autóctones da doença. CONCLUSÕES : Ações emergenciais pela vigilância em saúde são necessárias para evitar que a esquistossomose se endemize em Recife, como acontece em localidades litorâneas do estado de Pernambuco. .

OBJETIVO Investigar criaderos con moluscos hospedadores y casos humanos autóctonos para esquistosomiasis. MÉTODOS Se ejecutaron: estudio malacológico para búsqueda activa de criaderos, colecta e identificación de caracoles Biomphalaria positivos para S. mansoni en Recife, PE, entre julio de 2010 y septiembre de 2012, pesquisa de prevalencia con 2.718 escolares, de siete a 14 años, para diagnóstico de casos de esquistosomiasis, examen clínico y de ultrason en los casos positivos para S. mansoni. Los casos fueron investigados con respecto a su autoctonía y evaluados clínicamente. Los casos y criaderos fueron geo-referenciados y espacializados. RESULTADOS Se identificaron 30 criaderos de B. straminea, cuatro de ellos potenciales focos de transmisión, luego que las pruebas moleculares identificaron DNA de S. mansoni en los caracoles colectados. Se diagnosticaron 14 niños con esquistosomiasis, entre ellas cinco fueron considerados casos autóctonos de la enfermedad. CONCLUSIONES Acciones de emergencia para vigilancia de salud son necesarias para evitar que la esquistosomiasis se vuelva endémica en Recife como sucede en localidades del litoral de Pernambuco. .

OBJECTIVE : Investigate breeding sites with host snails and autochthonous human cases of schistosomiasis. METHODS : Between July 2010 and September 2012 were performed: (1) malacological survey searching for breeding sites, collection and identification of Biomphalaria snails positive for Schistosoma mansoni in Recife, PE, Northeastern Brazil; (2) prevalence survey in 2,718 schoolchildren aged from seven to 14 years old to identify cases of schistosomiasis, clinical examination and ultrasound in positive cases of S. mansoni. The autochthony of the cases was investigated and the case were clinically evaluated. The cases and breeding sites were georeferenced and spatially described. RESULTS : The results identified 30 breeding with B. straminea, four of which were potential foci of transmission, as molecular testing identified snails with S. mansoni DNA. There were 14 children diagnosed with schistosomiasis, of which five were considered to be autochthonous cases of the disease. CONCLUSIONS : Urgent measures are required in order to avoid schistosomiasis becoming endemic to Recife, as has happened in other coastal areas of the state of Pernambuco. .

Biological and environmental factors associated with risk of schistosomiasis mansoni transmission in Porto de Galinhas, Pernambuco State, Brazil.

Schistosomiasis has expanded to the coast of Pernambuco State, Brazil, where there are frequent reports of Biomphalaria glabrata snails and human cases of the disease. This study analyzes factors related to schistosomiasis transmission risk in Porto de Galinhas. A one-year malacological survey was conducted to identify biological, abiotic, and environmental factors related to the host snail breeding sites. Data analysis used Excel 2010, GTM Pro, and ArcGis 10. A total of 11,012 B. glabrata snails were captured in 36 breeding sites, and 11 schistosomiasis transmission foci were identified. A negative correlation was found between breeding site temperature and snail density and infection rate, and a positive correlation with pH and salinity. The rainy season showed a positive correlation with snail density and infection rate. The study emphasizes the factors involved in the maintenance of schistosomiasis breeding sites, in light of persistence of this disease in Porto de Galinhas for more than 10 years.

Biological and environmental factors associated with risk of schistosomiasis mansoni transmission in Porto de Galinhas, Pernambuco State, Brazil / Fatores biológicos e ambientais associados ao risco de transmissão da esquistossomose mansoni na localidade de Porto de Galinhas, Pernambuco, Brasil / Factores biológicos y ambientales asociados al riesgo de transmisión de la esquistosomiasis mansoni en la localidad de Porto de Galinhas, Pernambuco, Brasil

Schistosomiasis has expanded to the coast of Pernambuco State, Brazil, where there are frequent reports of Biomphalaria glabrata snails and human cases of the disease. This study analyzes factors related to schistosomiasis transmission risk in Porto de Galinhas. A one-year malacological survey was conducted to identify biological, abiotic, and environmental factors related to the host snail breeding sites. Data analysis used Excel 2010, GTM Pro, and ArcGis 10. A total of 11,012 B. glabrata snails were captured in 36 breeding sites, and 11 schistosomiasis transmission foci were identified. A negative correlation was found between breeding site temperature and snail density and infection rate, and a positive correlation with pH and salinity. The rainy season showed a positive correlation with snail density and infection rate. The study emphasizes the factors involved in the maintenance of schistosomiasis breeding sites, in light of persistence of this disease in Porto de Galinhas for more than 10 years.

A esquistossomose se expande para o litoral de Pernambuco, Brasil, onde têm sido frequente os registros de caramujos Biomphalaria glabrata e de casos humanos da doença. Este estudo apresenta fatores relacionados ao risco de transmissão da esquistossomose na localidade de Porto de Galinhas. Durante um ano, foi conduzido um inquérito malacológico para identificar fatores biológicos, abióticos e ambientais relacionados aos criadouros dos moluscos hospedeiros. Para análise dos dados, foram utilizados os softwares Excel 2010, GTM Pro e ArcGis 10. Foram coletados 11.012 caramujos B. glabrata nos 36 criadouros identificados, sendo diagnosticados 11 focos de transmissão da esquistossomose. Foi verificada correlação negativa entre a temperatura dos criadouros, densidade e taxa de infecção dos caramujos e correlação positiva para pH e salinidade. O período de chuva apresentou correlação positiva com a densidade e taxa de infecção dos moluscos. O estudo enfatiza os fatores envolvidos na manutenção dos criadouros da esquistossomose visto à persistência dessa doença na localidade de Porto de Galinhas há mais de 10 anos.

La esquistosomiasis se expande hacia el litoral de Pernambuco, Brasil, donde han sido frecuentes los registros de caracoles Biomphalaria glabrata y casos humanos de la enfermedad. Este estudio presenta factores relacionados con el riesgo de transmisión de la esquistosomiasis en la localidad Porto de Galinhas. Durante un año se llevó a cabo una investigación malacológica para identificar factores biológicos, abióticos y ambientales, relacionados con los criaderos de los moluscos huéspedes. Para el análisis de los datos se utilizaron los softwares Excel 2010, GTM Pro y ArcGis 10. Se recogieron 11.012 caracoles B. glabrata en los 36 criaderos identificados, siendo diagnosticados 11 focos de transmisión de la esquistosomiasis. Se verificó la correlación negativa entre la temperatura de los criaderos, densidad y tasa de infección de los caracoles, y la correlación positiva entre el pH y salinidad. El período de lluvia presentó una correlación positiva con la densidad y tasa de infección de los moluscos. El estudio enfatiza los factores involucrados en el mantenimiento de los criaderos de la esquistosomiasis, vista la persistencia de esta enfermedad en la localidad de Porto de Galinhas hace más de 10 años.

Análise espacial dos casos humanos de esquistossomose em uma comunidade horticultora da Zona da Mata de Pernambuco, Brasil / Spatial analysis of schistosomiasis human cases in the horticultural community of Zona da Mata of Pernambuco state, Brazil

O objetivo deste trabalho foi descrever a distribuição espacial da esquistossomose na comunidade horticultora de Natuba, Vitória de Santo Antão, Pernambuco. Foi conduzido um inquérito parasitológico, onde foi examinado o material fecal de 310 moradores da comunidade. Os casos positivos para Schistosoma mansoni foram georreferenciados e incluídos no croqui da localidade, gerando os mapas de distribuição espacial com estimadores de kernel. Os resultados apresentaram uma alta prevalência para esquistossomose, com 28,4% da população parasitada. Outros parasitos foram encontrados em 25,8% da população. O uso das ferramentas de geoprocessamento permitiu mapear e compreender a distribuição dos casos de esquistossomose no espaço ocupado pela comunidade, destacando e relacionando locais de menor altitude (passíveis de alagamento), com uma maior frequência de casos humanos. Estudos como este fornecem informações para que os serviços de saúde local possam intervir e promover mudanças para que indivíduos residentes em áreas com baixas condições habitacionais minimizem sua exposição ao risco de contrair a esquistossomose.

The objective of this study was to describe the spatial distribution of schistosomiasis in horticultural community of Natuba, district of Vitória de Santo Antão, Pernambuco state. It was conducted a parasitological survey, examined the fecal material of 310 community residents. The cases positive for Schistosoma mansoni were geocoded and included in the computerized template of the community, generating maps of spatial distribution with kernel estimators. The results showed a high prevalence of schistosomiasis, with 28.4% of the parasites. Other parasites were found in 25.8% of the population. The use of GIS tools to map and understand the possible distribution of cases of schistosomiasis in the space occupied by the community highlighting and listing locations of lower elevation (able to flooding), with a higher frequency of human cases. Studies like this provide information to the local health services, may intervene and bring about change for individuals living in areas with low housing conditions to minimize their exposure to risk of contracting schistosomiasis.

Spatial distribution of schistosomiasis and geohelminthiasis cases in the rural areas of Pernambuco, Brazil.

INTRODUCTION: The prevalence and intensity of geohelminth infections and schistosomiasis remain high in the rural areas of Zona da Mata, Pernambuco (ZMP), Brazil, where these parasites still represent a significant public health problem. The present study aimed to spatially assess the occurrences of schistosomiasis and geohelminthiasis in the ZMP. METHODS: The ZMP has a population of 1,132,544 inhabitants, formed by 43 municipalities. An ecological study was conducted, using secondary data relating to positive human cases and parasite loads of schistosomiasis and positive human cases of geohelminthiasis that were worked up in Excel 2007. We used the coordinates of the municipal headquarters to represent the cities which served as the unit of analysis of this study. The Kernel estimator was used to spatially analyze the data and identify distribution patterns and case densities, with analysis done in ArcGIS software. RESULTS: Spatial analysis from the Kernel intensity estimator made it possible to construct density maps showing that the northern ZMP was the region with the greatest number of children infected with parasites and the populations most intensely infected by Schistosoma mansoni. In relation to geohelminths, there was higher spatial distribution of cases of Ascaris lumbricoides and Trichuris trichiura in the southern ZMP, and greater occurrence of hookworms in the northern/central ZMP. CONCLUSIONS: Despite several surveys and studies showing occurrences of schistosomiasis and geohelminthiasis in the ZMP, no preventive measures that are known to have been effective in decreasing these health hazards have yet been implemented in the endemic area.

Schistosomiasis transmission and environmental change: a spatio-temporal analysis in Porto de Galinhas, Pernambuco--Brazil.

BACKGROUND: In Brazil, schistosomiasis mansoni infection is an endemic disease that mainly affects the country's rural populations who carry out domestic and social activities in rivers and water accumulations that provide shelter for the snails of the disease. The process of rural migration to urban centers and the disorderly occupation of natural environments by these populations from endemic areas have favored expansion of schistosomiasis to locations that had been considered to be disease-free. Based on environmental changes that have occurred in consequent to an occupation and urbanization process in the locality of Porto de Galinhas, the present study sought to identify the relationship between those chances, measure by remote-sensing techniques, and establish a new endemic area for schistosomiasis on the coast of Pernambuco State--Brazil. METHODS: To gather prevalence data, two parasitological census surveys were conducted (2000 and 2010) using the Kato-Katz technique. Two malacological surveys were also conducted in the same years in order to define the density and infection rate of the intermediate host. Based on these data, spatial analyses were done, resulting in maps of the risk of disease transmission. To ascertain the environmental changes that have occurred at the locality, images from the QuickBird satellite were analyzed, thus resulting in land use maps. RESULTS: Over this 10-year period, the foci of schistosomiasis became more concentrated in the Salinas district. This area was considered to be at the greatest risk of schistosomiasis transmission and had the highest prevalence rates over this period. The study illustrated that this was the area most affected by the environmental changes resulting from the disorderly urbanization process, which gave rise to unsanitary environments that favored the establishment and maintenance of foci of schistosomiasis transmission, thereby consolidating the process of expansion and endemization of this parasitosis.

Spatial distribution of schistosomiasis and geohelminthiasis cases in the rural areas of Pernambuco, Brazil / Distribuição espacial dos casos de esquistossomose e geohelmintoses em áreas rurais de Pernambuco, Brasil

INTRODUCTION: The prevalence and intensity of geohelminth infections and schistosomiasis remain high in the rural areas of Zona da Mata, Pernambuco (ZMP), Brazil, where these parasites still represent a significant public health problem. The present study aimed to spatially assess the occurrences of schistosomiasis and geohelminthiasis in the ZMP. METHODS: The ZMP has a population of 1,132,544 inhabitants, formed by 43 municipalities. An ecological study was conducted, using secondary data relating to positive human cases and parasite loads of schistosomiasis and positive human cases of geohelminthiasis that were worked up in Excel 2007. We used the coordinates of the municipal headquarters to represent the cities which served as the unit of analysis of this study. The Kernel estimator was used to spatially analyze the data and identify distribution patterns and case densities, with analysis done in ArcGIS software. RESULTS: Spatial analysis from the Kernel intensity estimator made it possible to construct density maps showing that the northern ZMP was the region with the greatest number of children infected with parasites and the populations most intensely infected by Schistosoma mansoni. In relation to geohelminths, there was higher spatial distribution of cases of Ascaris lumbricoides and Trichuris trichiura in the southern ZMP, and greater occurrence of hookworms in the northern/central ZMP. CONCLUSIONS: Despite several surveys and studies showing occurrences of schistosomiasis and geohelminthiasis in the ZMP, no preventive measures that are known to have been effective in decreasing these health hazards have yet been implemented in the endemic area.

INTRODUÇÃO: A prevalência e intensidade das infecções produzidas por geohelmintos e esquistossomose continuam elevadas na Zona da Mata de Pernambuco (ZMP), onde essas parasitoses se apresentam como relevante problema de saúde pública. O presente estudo objetivou espacializar a ocorrência da esquistossomose e geohelmintoses na ZMP. MÉTODOS: A ZMP apresenta uma população de 1.132.544 habitantes, composta por 43 municípios. Um estudo ecológico foi desenvolvido, utilizando dados secundários referentes aos casos humanos positivos e cargas parasitárias para esquistossomose e casos humanos positivos para geohelmintoses que foram trabalhados no Excel 2007. Foram utilizadas as coordenadas das sedes municipais para representar o município o qual serviu de unidade de análise deste estudo. Para análise espacial dos dados e identificação de padrões de distribuição e densidade dos casos, foi adotado o estimador de Kernel, sendo as análises feitas no software ArcGIS. RESULTADOS: A análise espacial, a partir do estimador de intensidade de Kernel, permitiu a construção de mapas de densidade mostrando a Mata Norte como a região onde se concentra o maior número de crianças parasitadas e as populações mais intensamente infectadas pelo Schistosoma mansoni. Com relação aos geohelmintos, há uma maior distribuição espacial dos casos de Ascaris lumbricoides e Trichuris trichiura na Mata Sul, destacando a maior ocorrência de ancilostomídeos entre as Matas Norte e Centro de Pernambuco. CONCLUSÕES: Apesar dos inquéritos e dos vários estudos mostrando a ocorrência de esquistossomose e geohelmintoses na ZMP ainda se desconhecem medidas preventivas que tenham sido implementadas na área endêmica mostrando efetividade na redução destes agravos.