Aerosol and bioaerosol particle size and dynamics from defective sanitary plumbing systems.

Aerosols are readily transported on airstreams through building sanitary plumbing and sewer systems, and those containing microbial pathogens (known as bioaerosols) are recognized as contributors to infection spread within buildings. When a defect occurs in the sanitary plumbing system that affects the system integrity, a cross-transmission route is created that can enable the emission of bioaerosols from the system into the building. These emission occurrences are characterized as short-burst events (typically <1 min in duration) which make them difficult to detect and predict. The characterization of these emission events is the focus of this research. Two methods were used to characterize bioaerosol emission events in a full-scale test rig: (a) an Aerodynamic Particle Sizer (APS) for particle size distribution and concentrations; and (b) a slit-to-agar sampler to enumerate the ingress of a viable tracer microorganism (Pseudomonas putida). The APS data confirmed that most particles (>99.5%) were <5 µm and were therefore considered aerosols. Particles generated within the sanitary plumbing system as a result of a toilet flush leads to emissions into the building during system defect conditions with an equivalence of someone talking loudly for over 6 and a half minutes. There were no particles detected of a size >11 µm anywhere in the system. Particle count was influenced by toilet flush volume, but it was not possible to determine if there was any direct influence from airflow rate since both particle and biological data showed no correlation with upward airflow rates and velocities. Typical emissions resulting from a 6 L toilet flush were in the range of 280-400 particles per second at a concentration of typically 9-12 number per cm3 and a total particle count in the region of 3000 to 4000 particles, whereas the peak emissions from a 1.2 L toilet flush were 60-80 particles per second at a concentration of 2.4-3 number per cm3 and a total particle count in the region of 886 to 1045 particles. The reduction in particles is in direct proportion to the reduction in toilet flush volume. The slit-to-agar sampler was able to provide viable time course CFU data and confirmed the origin of the particles to be the tracer microorganism flushed into the system. The time course data also have characteristics consistent with the unsteady nature of a toilet flush.

Types and factors affecting injury rates of mechanical contractors.

BACKGROUND: In the United States, about 38,000 cases of nonfatal workplace injuries were reported in 2015, in the category of 'mechanical work' (plumbing, heating, and air conditioning); this is nearly identical to the number of cases reported under 'building construction'. OBJECTIVE: This paper analyzes the types and rates of injuries and illnesses of mechanical contractors of southern Nevada, including the nature of the injuries and illnesses, body parts affected by injuries, causes of injuries, and factors affecting the injury rates. METHODS: To obtain data, a survey consisting of questions regarding the number of injuries and types of injuries was conducted with 31 mechanical contractors of southern Nevada involved in plumbing, piping, heating, refrigeration, and air conditioning. RESULTS: The injury rate for larger mechanical contractors (n = 16), in terms of number of employees and annual revenue, was significantly lower than for smaller mechanical contractors (n = 15). Mechanical contractors who worked on residential buildings (n = 13) had significantly higher rates of injuries than those involved with industrial (n = 7) or commercial buildings (n = 10). Results showed that sprains and strains (31%) were dominant injuries, and the major causes were from parts and materials (39%), hand tools (16%), contact with objects (14%), and falls (7%). CONCLUSIONS: The study concluded that the injury rate for these mechanical contractors was found to be higher than that reported by the Occupational Safety and Health Administration for specialty trade contractors.

[Infrastructure and adherence to hand hygiene: challenges to patient safety]. / Infraestrutura e adesão à higienização das mãos: desafios à segurança do paciente.

Considering the importance of hands in the chain of transmission of microorganisms, this observational research investigated the material infrastructure and compliance of hand hygiene in an intensive care unit in the south of Brazil in 2010. The data was collected by direct non-participant observation and through the use of self-administered questionnaires to be completed by the 39 participants, which was analyzed with the assistance of the chi2 Test, descriptive statistics and quantitative discourse analysis. Although health professionals overestimate compliance rates, recognize the practice as relevant to the prevention of infection and refer there are no impeding factors, of the 1,277 opportunities observed, compliance was 26% and significantly lower before patient contact and the use of aseptic procedures than after patient contact: infrastructure was shown to be deficient. The results indicate risk to patient safety, and thus, the planning of corrective actions to promote hand washing is relevant.

Infraestrutura e adesão à higienização das mãos: desafios à segurança do paciente / Infrastructure and adherence to hand hygiene: challenges to patient safety / Infraestructura y adhesión a la higienización de las manos: desafíos a la seguridad del paciente

Considerando a importância das mãos na cadeia de transmissão de microrganismos, esta pesquisa observacional investigou a infraestrutura material e a adesão à higienização das mãos em unidade de terapia intensiva do sul do Brasil, em 2010. Os dados foram coletados por observação direta não participante e emprego de instrumento autoaplicável a 39 profissionais, analisados com auxílio de Teste do χ², estatística descritiva e análise de discurso quantitativa. Embora os profissionais superestimem a adesão, reconheçam a prática como relevante para a prevenção de infecções e refiram não haver fatores de impedimento, entre 1277 oportunidades observadas, a adesão foi de 28,6%, e significativamente menor antes do contato e dos procedimentos assépticos do que após o contato com o paciente. A infraestrutura apresentou-se deficiente em funcionalidade. Os resultados implicam risco para a segurança dos pacientes, sendo relevante o planejamento de ações corretivas e que promovam essa prática.

Considering the importance of hands in the chain of transmission of microorganisms, this observational research investigated the material infrastructure and compliance of hand hygiene in an intensive care unit in the south of Brazil, in 2010. The data was collected by direct non-participant observation and through the use of self-administered questionnaires to be completed by the 39 participants, which was analyzed with the assistance of the χ² Test, descriptive statistics and quantitative discourse analysis. Although health professionals overestimate compliance rates, recognize the practice as relevant to the prevention of infection and refer there are no impeding factors, of the 1,277 opportunities observed, compliance was 26% and significantly lower before patient contact and the use of aseptic procedures than after patient contact: infrastructure was shown to be deficient. The results indicate risk to patient safety, and, thus, the planning of corrective actions to promote hand washing is relevant.

Con base en la importancia de las manos en la cadena de transmisión de microorganismos, esta investigación observacional tuvo el objetivo de observar la infraestructura material y la adhesión a la higienización de las manos en unidad de terapia intensiva del sur de Brasil, en 2010. Los datos fueron recogidos por la observación directa no participante y empleo de instrumento autoaplicable a 39 participantes, analizados con ayuda del Test de χ², estadística descriptiva y análisis de discurso cuantitativo. A pesar de que los profesionales sobrestimen la adhesión, reconocen la práctica como relevante para la prevención de infecciones y refieren no haber factores de impedimento. Entre 1277 oportunidades observadas, la adhesión fue del 28,6% y significativamente menor antes del contacto y procedimientos asépticos que después del contacto con el paciente; la infraestructura se ha presentado deficiente en funcionalidad. Los resultados revelan riesgo para la seguridad de los pacientes siendo relevante el planeamiento de acciones correctivas y que promuevan esa práctica.

Comparison of the burden of diarrhoeal illness among individuals with and without household cisterns in northeast Brazil.

BACKGROUND: Lack of access to safe and secure water is an international issue recognized by the United Nations. To address this problem, the One Million Cisterns Project was initiated in 2001 in Brazil's semi-arid region to provide a sustainable source of water to households. The objectives of this study were to determine the 30-day period prevalence of diarrhoea in individuals with and without cisterns and determine symptomology, duration of illness and type of health care sought among those with diarrhoea. A subgroup analysis was also conducted among children less than five years old. METHODS: A face-to-face survey was conducted between August 20th and September 20th, 2007 in the Agreste Central Region of Pernambuco State, Brazil. Households with and without a cistern that had at least one child under the age of five years were selected using systematic convenient sampling. Differences in health outcomes between groups were assessed using Pearson's Chi-squared and two-way t-tests. Demographic variables were tested for univariable associations with diarrhoea using logistic regression with random effects. P-values of 0.05 or less were considered statistically significant. RESULTS: A total of 3679 people from 774 households were included in the analysis (1863 people from 377 households with cisterns and 1816 people from 397 households without cisterns). People from households with a cistern had a significantly lower 30-day period prevalence of diarrhoea (prevalence = 11.0%; 95% CI 9.5-12.4) than people from households without a cistern (prevalence = 18.2%; 95% CI 16.4-20.0). This significant difference was also found in a subgroup analysis of children under five years old; those children with a cistern had a 30-day period prevalence of 15.6% (95% CI 12.3-18.9) versus 26.7% (95% CI 22.8-30.6) in children without a cistern. There were no significant differences between those people with and without cisterns in terms of the types of symptoms, duration of illness and health care sought for diarrhoea. CONCLUSIONS: Our results indicate that the use of cisterns for drinking water is associated with a decreased occurrence of diarrhoea in this study population. Further research accounting for additional risk factors and preventative factors should be conducted.

[Energy audit: a management tool in health centers]. / La auditoría energética: una herramienta de gestión en atención primaria.

OBJECTIVE: The aim of this study was to evaluate the viability of energy audit as a management tool in primary care to improve the energy efficiency and environmental performance of a health center by reducing its operating costs. METHOD: We conducted 55 energy audits in health centers from 2005-2010. The health centers were sized between 500 and 3,500 m(2), were located in health areas with 3,500 to 25,000 users, and were built between 1985 and 2007. RESULTS: With an average investment of 11,601 € per site, energy consumption can be reduced by 10,801 kWh per year, saving 2,961 € with a mean payback period of 3.92 years, and preventing emission of 7,010 kg of CO(2). CONCLUSIONS: Energy auditing is a practical tool to reduce the operating and maintenance costs of health centers and of improving the comfort of the facilities.

[Residential typologies in Chilean irregular settlements with precarious housing conditions]. / Tipologías residenciales en comunidades chilenas en condiciones de precariedad habitacional.

OBJECTIVE: To identify residential parameters that characterize the physical and social environment in Chile's irregular settlements, and to construct typologies that will allow to develop profiles with those distinctive residential attributes. METHODS: The study examined the universe of irregular settlements (n = 122) in Chile's Metropolitan Region, based on the 2007 national inventory of irregular settlements conducted by the "Un Techo para Chile" foundation. Information about the communities and their locations was obtained from key informants, and these variables were modeled using factor analysis to identify residential parameters, which were then refined by k-means clustering. RESULTS: The factor analysis pointed to three underlying parameters: local social response, the environment beyond the community, and basic services. The key variables shaping these categories were the existence of housing projects, the urban area involved, and access to electricity. The cluster analysis generated four profiles that combined the three parameters: an urban profile with relatively reliable basic services (n = 30), an urban-rural profile with high potential for local social response (n = 32), an urban profile with a high level of environmental threat (n = 43), and a rural profile with low potential for local social response (n = 17). CONCLUSIONS: The residential parameters formed are consistent with the revised theoretical model and suggest relevant indicators for monitoring these communities. Definition of the profiles facilitates assessment of the heterogeneity of residential situations, which helps in the prioritization of areas with deficits or risks that may be present in each cluster. This, in turn, opens the door to further investigation and to exploring opportunities for action.

Tipologías residenciales en comunidades chilenas en condiciones de precariedad habitacional / Residential typologies in Chilean irregular settlements with precarious housing conditions

OBJETIVO: Identificar dimensiones residenciales que caractericen el ambiente físico y social en los campamentos de Chile y construir tipologías que permitan elaborar perfiles con esos atributos residenciales distintivos. MÉTODOS: Se estudió el universo de campamentos (n = 122) de la Región Metropolitana (Chile) a partir del Catastro Nacional de Campamentos realizado por la fundación "Un Techo para Chile" en 2007. Se recolectó información proveniente de informantes clave sobre las comunidades y los lugares de emplazamiento, variables que fueron modeladas empleando un análisis factorial para identificar dimensiones residenciales, las que a su vez fueron refinadas con la técnica de agrupamientos de k-medias. RESULTADOS: El análisis factorial destacó tres dimensiones subyacentes: respuesta social local, ambiente extracomunitario y servicios básicos. Las variables centrales en la formación de esas categorías fueron la existencia de proyectos habitacionales, el área urbana y el acceso a electricidad, respectivamente. El análisis de agrupamientos generó cuatro perfiles que combinaron las tres dimensiones: perfil urbano con baja precariedad de servicios básicos (n = 30), perfil urbano-rural con alto potencial de respuesta social local (n = 32), perfil urbano con alta amenaza ambiental (n = 43) y perfil rural con bajo potencial de respuesta social local (n = 17). CONCLUSIONES: Las dimensiones residenciales formadas son consistentes con el modelo teórico revisado y sugieren indicadores relevantes para el seguimiento de estas comunidades. La identificación de perfiles permite dimensionar la heterogeneidad de realidades residenciales contribuyendo a la priorización de dominios de déficit o riesgos que pueden estar presentes en cada grupo, para con ello profundizar en su investigación y oportunidades de acción.

OBJECTIVE: To identify residential parameters that characterize the physical and social environment in Chile's irregular settlements, and to construct typologies that will allow to develop profiles with those distinctive residential attributes. METHODS: The study examined the universe of irregular settlements (n = 122) in Chile's Metropolitan Region, based on the 2007 national inventory of irregular settlements conducted by the "Un Techo para Chile" foundation. Information about the communities and their locations was obtained from key informants, and these variables were modeled using factor analysis to identify residential parameters, which were then refined by k-means clustering. RESULTS: The factor analysis pointed to three underlying parameters: local social response, the environment beyond the community, and basic services. The key variables shaping these categories were the existence of housing projects, the urban area involved, and access to electricity. The cluster analysis generated four profiles that combined the three parameters: an urban profile with relatively reliable basic services (n = 30), an urban-rural profile with high potential for local social response (n = 32), an urban profile with a high level of environmental threat (n = 43), and a rural profile with low potential for local social response (n = 17). CONCLUSIONS: The residential parameters formed are consistent with the revised theoretical model and suggest relevant indicators for monitoring these communities. Definition of the profiles facilitates assessment of the heterogeneity of residential situations, which helps in the prioritization of areas with deficits or risks that may be present in each cluster. This, in turn, opens the door to further investigation and to exploring opportunities for action.

[Environmental sanitation and mortality associated with waterborne diseases in children under 5 years of age in Brazil]. / Saneamiento ambiental y mortalidad en niños menores de 5 años por enfermedades de transmisión hídrica en Brasil.

OBJECTIVE: Determine and evaluate the relationship between the variables for water conditions, environmental sanitation, and mortality in children under 5 years of age associated with a group of waterborne diseases. METHODS: An exploratory ecological study was conducted based on data obtained from the 2000 national demographic census and the Unified Health System for the 558 microregions of Brazil. The model used multiple linear regression analysis. Mortality associated with waterborne diseases in children under 5 years of age was considered to be the response variable. Water conditions, sanitation, and level of education were considered to be explanatory variables. RESULTS: A direct relationship was observed between inadequate sanitation in the dwelling (e.g., sewage disposal via rudimentary gutters and pits, the disposal of waste in uncultivated land or public areas) and mortality in children under 5 years of age associated with waterborne diseases. An inverse relationship was found between level of education and mortality associated with waterborne diseases in these children. CONCLUSIONS: The greatest health hazards related to poor sanitation were found in the microregions with a high concentration of low-income population with limited education. The general sanitation conditions and other factors related to dwelling quality and infrastructure are major determinants of mortality. Coverage of the water services, which reach 90% of households in Brazil, was not in itself found to be an important factor in the reduction of the mortality studied.

Saneamiento ambiental y mortalidad en niños menores de 5 años por enfermedades de transmisión hídrica en Brasil / Environmental sanitation and mortality associated with waterborne diseases in children under 5 years of age in Brazil

OBJETIVO: Determinar y evaluar las asociaciones entre las variables que reflejan las condiciones del agua y el saneamiento ambiental y la mortalidad en niños menores de 5 años por un grupo de enfermedades de transmisión hídrica. MÉTODOS: Se realizó un estudio ecológico y exploratorio a partir de datos obtenidos del Censo Demográfico Nacional de 2000 y del Sistema Único de Salud para las 558 micro-regiones de Brasil. El modelo aplicó la técnica de regresión lineal múltiple y consideró como variable de respuesta la mortalidad por enfermedades de transmisión hídrica en menores de 5 años y, como variables explicativas, las condiciones del agua y el saneamiento y el nivel de escolaridad. RESULTADOS: Se observó una relación directa entre saneamiento inadecuado en la vivienda -incluidos desagües por canaletas y fosas rudimentarias, y disposición de la basura en terrenos baldíos o áreas públicas- y mortalidad en menores de 5 años por enfermedades de transmisión hídrica. También se encontró una relación inversa entre el nivel de escolaridad y la mortalidad de esos menores por dichas causas. CONCLUSIONES: Los mayores riesgos para la salud derivados del saneamiento inapropiado se registraron en las micro-regiones con gran concentración de poblaciones que, además de su condición económica humilde, tenían bajo nivel de escolaridad. Se destacan, como determinantes de la mortalidad, las condiciones generales de saneamiento y también otros factores asociados a la calidad y la infraestructura de las viviendas. La cobertura de abastecimiento de agua -que en Brasil alcanza a 90 por ciento de los hogares- no se mostró por sí sola como factor importante en la reducción de la mortalidad estudiada.

ABSTRACT OBJECTIVE: Determine and evaluate the relationship between the variables for water conditions, environmental sanitation, and mortality in children under 5 years of age associated with a group of waterborne diseases. METHODS: An exploratory ecological study was conducted based on data obtained from the 2000 national demographic census and the Unified Health System for the 558 microregions of Brazil. The model used multiple linear regression analysis. Mortality associated with waterborne diseases in children under 5 years of age was considered to be the response variable. Water conditions, sanitation, and level of education were considered to be explanatory variables. RESULTS: A direct relationship was observed between inadequate sanitation in the dwelling (e.g., sewerage disposal via rudimentary gutters and pits, the disposal of waste in uncultivated land or public areas) and mortality in children under 5 years of age associated with waterborne diseases. An inverse relationship was found between level of education and mortality associated with waterborne diseases in these children. CONCLUSIONS: The greatest health hazards related to poor sanitation were found in the microregions with a high concentration of low-income population with limited education. The general sanitation conditions and other factors related to dwelling quality and infrastructure are major determinants of mortality. Coverage of the water services, which reach 90 percent of households in Brazil, was not in itself found to be an important factor in the reduction of the mortality studied.

[Hansen's disease, social conditions, and deforestation in the Brazilian Amazon]. / Hanseníase, condições sociais e desmatamento na Amazônia brasileira.

OBJECTIVE: To analyze the association between social and environmental indicators and the Hansen's disease new case detection rate (HNCDR) in the Brazilian Amazon. METHODS: This ecological study was based on the new cases of Hansen's disease reported to the Brazilian Disease Surveillance System SINAN in 2006. Analyses were performed considering 105 micro-regions formed by adjacent municipalities with economic and social similarities. HNCDRs per 10 000 people were calculated. Independent variables were total area deforested (km(2)) in each micro-region until 2006; proportion of people living in households with rudimentary septic tanks; proportion of people living in households with water supply from wells; and human development index (HDI) in 2000. Local empirical Bayes smoothing was applied to HNCDR. Analyses were carried out to determined correlations and differences between means (analysis of variance) for a significance level of 5%. The Kernel technique was used to investigate the geographic distribution of events of interest for all the study indicators. RESULTS: A positive correlation was observed between HNCDR and total deforested area (r = 0.50; P < 0.000) and percent of households with rudimentary septic tanks (r = 0.49; P < 0.000). HDI was inversely correlated with HNCDR: the higher the HDI, the lower the HNCDR (r = -0.36; P < 0.000). Considering the entire region, proportion of households with water from wells was not associated with NCDR. CONCLUSIONS: The Hansen's disease new case detection rate, which reflects the magnitude of disease, is associated with social conditions and land settlement practices in the Brazilian Amazon.

Hanseníase, condições sociais e desmatamento na Amazônia brasileira / Hansen's disease, social conditions, and deforestation in the Brazilian Amazon

Objetivo: Analisar a associação entre indicadores sociais e ambientais e o coeficiente de detecção de hanseníase (CDH) na Amazônia brasileira. Métodos: Neste estudo ecológico, foram selecionados os registros de casos novos de hanseníase no ano de 2006 da base de dados do Sistema de Informação de Agravos de Notificação (SINAN) e calculados os CDHs por 10 000 habitantes. As análises foram realizadas considerando-se 105 microrregiões formadas por municípios adjacentes com semelhanças econômicas e sociais. As variáveis independentes foram área total (km²) desmatada nas microrregiões até 2006; proporção de residentes em domicílios com fossa rudimentar; proporção de residentes em domicílios abastecidos com água de poço; e índice de desenvolvimento humano (IDH) do ano de 2000. O coeficiente CDH foi suavizado pelo método Bayesiano empírico local. As análises foram conduzidas por meio de correlação e diferenças de médias (ANOVA) com nível de significância de 5 por cento. A técnica de Kernel foi utilizada para investigar a distribuição geográfica dos eventos de interesse para todos os indicadores analisados. Resultados: Verificou-se correlação positiva dos CDHs com o total de área desmatada (r = 0,50; P < 0,000) e a proporção de domicílios com fossa rudimentar (r = 0,49; P < 0,000). O IDH apresentou comportamento inverso ao CDH - quanto maior o IDH, menor o CDH (r = -0,36; P < 0,000). A variável proporção de domicílios com abastecimento de água de poço não apresentou associação com o CDH quando analisada toda a região. conclusões: O coeficiente de detecção de hanseníase, que representa a magnitude da doença, está associado aos indicadores de condições de vida e ao modo de ocupação territorial da Amazônia.

Objective: To analyze the association between social and environmental indicators and the Hansen's disease new case detection rate (HNCDR) in the Brazilian Amazon. Methods: This ecological study was based on the new cases of Hansen's disease reported to the Brazilian Disease Surveillance System SINAN in 2006. Analyses were performed considering 105 micro-regions formed by adjacent municipalities with economic and social similarities. HNCDRs per 10 000 people were calculated. Independent variables were total area deforested (km²) in each micro-region until 2006; proportion of people living in households with rudimentary septic tanks; proportion of people living in households with water supply from wells; and human development index (HDI) in 2000. Local empirical Bayes smoothing was applied to HNCDR. Analyses were carried out to determined correlations and differences between means (analysis of variance) for a significance level of 5 percent. The Kernel technique was used to investigate the geographic distribution of events of interest for all the study indicators. Results: A positive correlation was observed between HNCDR and total deforested area (r = 0.50; P < 0.000) and percent of households with rudimentary septic tanks (r = 0.49; P < 0.000). HDI was inversely correlated with HNCDR: the higher the HDI, the lower the HNCDR (r = -0.36; P < 0.000). Considering the entire region, proportion of households with water from wells was not associated with NCDR. Conclusions: The Hansen's disease new case detection rate, which reflects the magnitude of disease, is associated with social conditions and land settlement practices in the Brazilian Amazon.

Household characteristics associated with home water treatment: an analysis of the Egyptian Demographic and Health Survey.

OBJECTIVES: The objective of this study is to understand the characteristics of households who treat their water in the home. In promoting home water treatment, there may be valuable lessons to be learnt from countries with many home water treatment users. METHODS: Responses to the new Demographic and Health Survey question on water treatment were analysed for 21,972 Egyptian households interviewed during 2005. Logistic regression was used to assess the relationship between home water treatment and household characteristics. RESULTS: 5.9% (CI 5.2-6.7%) of households used home water treatment, mostly either home filtration or letting water stand to settle. Filtration use was significantly related to educational attainment and wealth, whilst letting water stand to settle was related to use of stoneware water vessels, groundwater sources, and water supply disruptions. DISCUSSION: The Egyptian data suggest that 4.5 million people use home water treatment and confirm some water handling behaviours reported elsewhere. Because of limited detail in the DHS data about the technologies used and their effectiveness, it is unclear whether this behaviour reduces waterborne disease. Further research should consider how such data can be augmented with additional information to address this question.

Related factors to human toxocariasis in a rural community of Argentina.

The objective of this study was to evaluate the relationship between toxocariasis frequency and demographic, environmental, sanitary variables, eosinophylia, and other intestinal parasites in a rural population of Argentina. Serological examination of 100 individuals was carried out by using ELISA technique for the detection of anti-toxocara antibodies. Eosinophiles in peripheral blood, presence of intestinal parasites, and demographic, environmental, and socio-cultural data were evaluated. Eighty-one feces samples of dogs belonging to the studied people were analyzed to detect eggs of Toxocara canis. Thirty of them were from 30 dogs and 51 were pools from dog feces. Samples of dirt from around the homes (n: 47) and from public park (n: 4) were taken. To determine the associations, the c(2) and Fisher tests were used. The seroprevalence was 23%. Eosinophilia in peripheral blood was detected in 86.95% seropositive individuals and in 37.66% seronegative individuals (p < 0.001, OR = 11.03). Of the 23 people with positive serology, 69.56% had at least one intestinal parasite. All individuals with positive serology had dogs in their homes. Among the dog owners there was a significant association between the presence of anti-toxocara antibodies and home flooding. Eggs of T. canis were detected in the feces of 5/81 dogs and three of these dogs belonged to individuals with positive serology. Eggs of Toxocara spp. were found in 41.17% of the dirt samples, eight of which came from the area surrounding the homes of individuals with positive serology (p = 0.032; OR = 4.36). Taking into account all the variables influencing the frequency of toxocariasis in this population, the implementation of Public Health programs specifically focused on anti-parasitic treatment of dogs is recommended.

Related factors to human toxocariasis in a rural community of Argentina

The objective of this study was to evaluate the relationship between toxocariasis frequency and demographic, environmental, sanitary variables, eosinophylia, and other intestinal parasites in a rural population of Argentina. Serological examination of 100 individuals was carried out by using ELISA technique for the detection of anti-toxocara antibodies. Eosinophiles in peripheral blood, presence of intestinal parasites, and demographic, environmental, and socio-cultural data were evaluated. Eighty-one feces samples of dogs belonging to the studied people were analyzed to detect eggs of Toxocara canis. Thirty of them were from 30 dogs and 51 were pools from dog feces. Samples of dirt from around the homes (n: 47) and from public park (n: 4) were taken. To determine the associations, the c² and Fisher tests were used. The seroprevalence was 23 percent. Eosinophilia in peripheral blood was detected in 86.95 percent seropositive individuals and in 37.66 percent seronegative individuals (p < 0.001, OR = 11.03). Of the 23 people with positive serology, 69.56 percent had at least one intestinal parasite. All individuals with positive serology had dogs in their homes. Among the dog owners there was a significant association between the presence of anti-toxocara antibodies and home flooding. Eggs of T. canis were detected in the feces of 5/81 dogs and three of these dogs belonged to individuals with positive serology. Eggs of Toxocara spp. were found in 41.17 percent of the dirt samples, eight of which came from the area surrounding the homes of individuals with positive serology (p = 0.032; OR = 4.36). Taking into account all the variables influencing the frequency of toxocariasis in this population, the implementation of Public Health programs specifically focused on anti-parasitic treatment of dogs is recommended.

Optimal reconstruction of historical water supply to a distribution system: A. Methodology.

The New Jersey Department of Health and Senior Services (NJDHSS), with support from the Agency for Toxic Substances and Disease Registry (ATSDR) conducted an epidemiological study of childhood leukaemia and nervous system cancers that occurred in the period 1979 through 1996 in Dover Township, Ocean County, New Jersey. The epidemiological study explored a wide variety of possible risk factors, including environmental exposures. ATSDR and NJDHSS determined that completed human exposure pathways to groundwater contaminants occurred in the past through private and community water supplies (i.e. the water distribution system serving the area). To investigate this exposure, a model of the water distribution system was developed and calibrated through an extensive field investigation. The components of this water distribution system, such as number of pipes, number of tanks, and number of supply wells in the network, changed significantly over a 35-year period (1962--1996), the time frame established for the epidemiological study. Data on the historical management of this system was limited. Thus, it was necessary to investigate alternative ways to reconstruct the operation of the system and test the sensitivity of the system to various alternative operations. Manual reconstruction of the historical water supply to the system in order to provide this sensitivity analysis was time-consuming and labour intensive, given the complexity of the system and the time constraints imposed on the study. To address these issues, the problem was formulated as an optimization problem, where it was assumed that the water distribution system was operated in an optimum manner at all times to satisfy the constraints in the system. The solution to the optimization problem provided the historical water supply strategy in a consistent manner for each month of the study period. The non-uniqueness of the selected historical water supply strategy was addressed by the formulation of a second model, which was based on the first solution. Numerous other sensitivity analyses were also conducted using these two models. Both models are solved using a two-stage progressive optimality algorithm along with genetic algorithms (GAs) and the EPANET2 water distribution network solver. This process reduced the required solution time and generated a historically consistent water supply strategy for the water distribution system.

Inequities in access to and use of drinking water services in Latin America and the Caribbean.

OBJECTIVE: To identify and evaluate inequities in access to drinking water services as reflected in household per capita expenditure on water, and to determine what proportion of household expenditures is spent on water in 11 countries of Latin America and the Caribbean. METHODS: Using data from multi-purpose household surveys (such as the Living Standards Measurement Survey Study) conducted in 11 countries from 1995 to 1999, the availability of drinking water as well as total and per capita household expenditures on drinking water were analyzed in light of socioeconomic parameters, such as urban vs. rural setting, household income, type and regularity of water supply service, time spent obtaining water in homes not served by running water, and type of water-purifying treatment, if any. RESULTS: Access to drinking water as well as total and per capita household expenditures on drinking water show an association with household income, economic conditions of the household, and location. The access of the rural population to drinking water services is much more restricted than that of the urban population for groups having similar income. The proportion of families having a household water supply system is comparable in the higher-income rural population and the lower-income urban population. Families without a household water supply system spend a considerable amount of time getting water. For poorer families, this implies additional costs. Low-income families that lack a household water supply spend as much money on water as do families with better income. Access to household water disinfection methods is very limited among poor families due to its relatively high cost, which results in poorer drinking water quality in the lower-income population. CONCLUSIONS: Multi-purpose household surveys conducted from the consumer's point of view are important tools for research on equity and health, especially when studying unequal access to, use of, and expenditures on drinking water. It is recommended that countries improve their portion of the surveys that deals with water and sanitation in order to facilitate national health assessments and the establishment of more equitable subsidy programs.

Bacteriological qualities of indoor and out-door drinking water in Kibera sub-location of Nairobi, Kenya.

OBJECTIVES: To compare the bacteriological quality of out-house (tank or standpipe) water and in-house drinking water (storage containers) and determine the risk factors influencing it. DESIGN: A cross-sectional study. SETTING: The study was carried out in Kibera slums located 7 km southwest from the Nairobi City centre. SUBJECTS: Water samples from twenty outside tanks/standpipes and sixty from in-house water storage containers. MAIN OUTCOME MEASURES: Pour plate method was used to enumerate total bacterial counts in water, while the multiple tube technique was used to determine faecal coliform (FC) and faecal streptococci (FS) numbers. A questionnaire and environmental observation were used to determine the risk factors influencing bacteriological quality of water. RESULTS: The mean total bacterial counts (TBC) for out-house water was 46.6 per 100 ml while that for in-house water was 818.2 per 100 ml. Faecal coliforms were isolated from 7 (35%) standpipes and 57 (95%) in-house storage containers. The mean faecal coliform count was 93 and 103.4 per 100 ml for out-house and in-house water, respectively. The counts were significantly higher in the latter. Faecal streptococci were isolated from 2 (10%) standpipes and 37 (61.7%) in-house storage containers. The mean faecal streptococci counts were 35 and 65 per 100 ml for out-house and in-house water sources, respectively. Escherichia coli was isolated in 2 (10%) of out-house water and 30 (50%) of in-house. Of these, four were enteropathogenic, serotype 011 from one out-house water source and serotypes 011, 011, 0112ac from in-house water sources. CONCLUSIONS: Bacteriological contamination of water at the source with a further deterioration between the collection points and homes was observed. A defective water delivery system and inadequate environmental sanitation were a potential source of contamination for out-house water. Scoops were a major source of contamination for stored water.

[An epidemiological study of a group of workers employed in the maintenance of a sewer network and of urban waste water treatment plants]. / Studio epidemiologico su un gruppo di operatori addetti alla manutenzione della rete fognaria e degli impianti di depurazione delle acque reflue urbane.

The paper reports the results of a study on occupational risks of a group of sewage workers of the city of Genoa vs. a control group of nonexposed subjects; the first group was divided into three subgroups according to the job characteristics. After bibliographical research on the topic, a specific questionnaire was used to analyse individual symptoms. Clinical examinations, blood and respiratory tests were also performed. The statistical analysis was performed by evaluating F test for differences between parametric measures and the relative risk for non-parametric findings. The relative risk of alterations in respiratory function (both instrumental and clinical findings) was increased among the water treatment workers. The average platelets count in the exposed workers appeared to be significantly reduced compared to non-exposed subjects although both were within the normal limits. There was non evidence of an increased prevalence of positive A hepatitis markers in the exposed workers.