Composition and abundance of anopheline species according to habitat diversity in Mexico / Composición y abundancia de especies de anofelinos según la diversidad de hábitats en México

Abstract: Objective: To determine the abundance and geographic distribution of the main malaria vectors, which are influenced by habitat characteristics and ecological factors that directly impact adult density and the dynamics of malaria transmission in Mexico. Materials and methods: Samples of larvae were collected from 19 states in Mexico. Each larval habitat was characterized in situ determining the following parameters: water depth, turbidity, percentage of vegetation cover, amount of detritus, presence of algae, light intensity, type of vegetation, amount of predators, habitat stability, altitude, and hydrologic type. Results: A total of 21 687 larvae corresponding to 13 anopheline species were obtained from 149 aquatic habitats. The most abundant species were Anopheles pseudopunctipennis (52.91%), An. albimanus (39.14%) and An. franciscanus (5.29%). The multiple logistic regression analysis showed a negative association between An. pseudopunctipennis and water turbidity (ß=-1.342; Wald=6.122; p=0.013) and the amount of detritus (ß=-2.206; Wald=3.642; p=0.050). While in An. albimanus, there was a significant positive association with water turbidity (ß=1.344; Wald=4.256; p=0.039), a negative correlation was found with the altitude (ß=-3.445; Wald=5.407; p=0.020). The highest mosquito species diversity index was found in Chiapas (Fisher's α=1.20) and the lowest diversity in Chihuahua (Fisher's α=0.26). The greatest richness was found in streams (n=11). Conclusions: The two most abundant species were: An. albimanus and An. pseudopunctipennis. Detailed knowledge of the distribution and characteristics of their larval habitats will be useful for the effective implementation of control strategies in Mexico.

Resumen Objetivo: Determinar la abundancia y la distribución geográfica de los principales vectores de la malaria, las cuales están influenciadas por las características del hábitat y los factores ecológicos que afectan directamente la densidad de los adultos y la dinámica de la transmisión de la malaria en México. Material y métodos: Se obtuvieron muestras de larvas de 19 estados de México. Cada hábitat larvario se caracterizó in situ determinando los siguientes parámetros: profundidad del agua, turbidez, porcentaje de cobertura vegetal, cantidad de detritus, presencia de algas, intensidad de luz, tipo de vegetación, cantidad de depredadores, estabilidad del hábitat, altitud y tipo hidrológico. Resultados: Se identificaron un total de 21 687 larvas pertenecientes a 13 especies de anofelinos, de 149 hábitats acuáticos. Las tres especies más abundantes fueron Anopheles pseudopunctipennis (52.91%), An. albimanus (39.14%) y An. franciscanus (5.29%). El análisis de regresión logística múltiple mostró una asociación negativa para An. pseudopunctipennis y la turbidez del agua (ß=-1.342; Wald= 6.122; p=0.013) y la cantidad de detritus (ß=-2.206; Wald= 3.642; p=0.050). Para An. albimanus se encontró una asociación positiva significativa con la turbidez del agua (ß=1.344; Wald= 4.256; p=0.039) y una correlación negativa con la altitud (ß=-3.445; Wald=5.407; p=0.020). El índice de diversidad más alto se encontró en Chiapas (α de Fisher=1.20) y la diversidad más baja en Chihuahua (α de Fisher=0.26). La mayor riqueza se encontró en los arroyos (n=11). Conclusiones: Las dos especies más abundantes fueron An. albimanus y An. pseudopunctipennis. El conocimiento detallado de la distribución y características de sus hábitats larvales será útil para la implementación efectiva de las estrategias de control en México.

Comparison of novaluron, pyriproxyfen, spinosad and temephos as larvicides against Aedes aegypti in Chiapas, Mexico / Comparación de novaluron, piriproxifeno, spinosad y temefos como larvicidas contra Aedes aegypti en Chiapas, México

Abstract: Objective: To compare the efficacy of three modern larvicides with the organophosphate temephos for control of Aedes aegypti in water tanks in Chiapas. Materials and methods: Trials were performed to compare the efficacy of pyriproxyfen, novaluron, two formulations of spinosad (granules and tablets) and temephos in oviposition traps and domestic water tanks. Results: Pyriproxyfen and temephos provided 2-3 weeks of complete control of larvae in oviposition traps, whereas spinosad granules and novaluron provided 7-12 weeks of control. Treatment of water tanks resulted in a significant reduction in oviposition by Ae. aegypt in houses (p<0.001). Higher numbers of larvae were present in temephos and pyriproxyfen-treated water tanks compared to novaluron and spinosad tablet treatments during most of the study. Conclusion: Spinosad formulations and novaluron were effective larvicides in this region. The poor performance of temephos may be indicative of reduced susceptibility in Ae. aegypti populations in Chiapas.

Resumen: Objetivo: Comparar la eficacia de tres larvicidas modernos para el control de Aedes aegypti en tanques de agua doméstica en Chiapas. Material y métodos: Se comparó la eficacia de piriproxifeno, novalurón, dos formulaciones de spinosad (gránulos y tabletas) y temefos en ovitrampas y tanques domésticos de agua. Resultados: El piriproxifeno y el temefos proporcionaron de 2 a 3 semanas de control de larvas en ovitrampas, mientras que los gránulos de spinosad y novaluron proporcionaron de 7 a12 semanas. Los tanques de agua tratados produjeron una reducción significativa en la oviposición por Ae. aegypti en las casas (p<0.001). Se encontró gran cantidad de larvas en los tanques tratados con temefos y piriproxifeno en comparación con los tratados con novaluron y tabletas de spinosad durante la mayor parte del estudio. Conclusión: Las formulaciones de spinosad en tabletas y novaluron fueron larvicidas efectivos en esta región. El bajo desempeño de temefos puede indicar una susceptibilidad reducida en poblaciones de Ae. aegypti en Chiapas.

Utilidad de los registros sanitarios locales para vincular la tasa de incidencia de diarreas con la calidad del agua de consumo / Usefulness of local health reports to link the incidence rate of diarrhea with the quality of drinking water

En este trabajo se realizó un relevamiento de los informes del centro de salud ubicado en Vaqueros (Salta, Argentina) durante un período de 8 meses. Al mismo tiempo se determinó la concentración de Escherichia coli y de quistes de Giardia spp. en muestras procedentes de cuatro fuentes de agua diferentes. No se encontró una relación estadísticamente significativa entre la calidad del agua y los casos de diarrea. Sin embargo, mediante un cálculo de odds ratios, se pudo determinar que uno de los sistemas de potabilización estudiados actúa como factor de protección contra diarreas. El presente trabajo brinda información útil para la planificación de medidas preventivas por parte del sistema de salud local.

In this study, we analyzed the reports of the health care center located in Vaqueros (Salta, Argentina) over an 8-month period. Moreover, we determined the concentration of Escherichia coli and Giardia spp. cysts in samples from four different drinking water sources. A statistical relationship between water quality and cases of diarrhea could not be found. However, using an odds ratio calculation, it was possible to determine that one of the studied drinking water systems acts as a protection factor in cases of diarrhea. The present work provides useful information for planning preventive measures by the local health system.

The effect of water source and soil supplementation on parasite contamination in organic vegetable gardens / O efeito da fonte de água e suplementação de solo na contaminação parasitária em hortas orgânicas

Abstract The objective of this study was to determine factors associated with vegetable contamination with zoonotic protozoan. Samples of water, soil and vegetables were collected from July/2014 to May/2016, totaling 83 samples, 21 properties of Londrina region, Paraná, Brazil. DNA amplification of Toxoplasma gondii, Cryptosporidium spp. and Giardia intestinalis in the samples was conducted using polymerase chain reaction (PCR). The PCR results were positive for T. gondii in 12.9% (8/62), Cryptosporidium spp. in 11.3% (7/62) and G. intestinalis in 25.8% (16/62) of the samples. DNA sequencing identified C. parvum in five samples and G. intestinalis Assemblage E in three. The statistical associations demonstrated greater probability of positive samples for T. gondii and for at least one of the three protozoa when the source of irrigation water was the river; a greater chance of positive samples for Cryptosporidium spp. when deer were present on the property; and a smaller chance of positive samples for at least one of the three etiologic agents when soil was supplemented with limestone. The results expose some critical contamination points, providing support for training farmers on good management practices during the production process.

Resumo O trabalho teve como objetivo determinar os fatores associados à contaminação de vegetais por protozoários zoonóticos. Amostras de água, solo e vegetais foram coletadas de julho/2014 a maio/2016, totalizando 83 amostras de 21 propriedades da região de Londrina, Paraná, Brasil. A amplificação de fragmentos de DNA de T. gondii, Cryptosporidium spp. e Giardia intestinalis foi realizada por meio da reação em cadeia da polimerase (PCR). Os resultados da PCR foram positivos para T. gondii em 12,9% (8/62), Cryptosporidium spp. em 11,3% (7/62) e G. intestinalis. em 25,8% (16/62) das amostras. O sequenciamento de DNA identificou C. parvum em cinco amostras e G. intestinalis, Assemblage E em três amostras. As associações estatísticas evidenciaram maior probabilidade de amostras serem positivas para T. gondii ou para pelo menos um dos três protozoários quando a fonte de água de irrigação era o rio; uma maior chance de amostras positivas para Cryptosporidium spp. quando havia cervos na propriedade; e uma menor chance das amostras serem positivas para pelo menos um dos três agentes etiológicos quando o solo era suplementado com calcário. Os resultados expõem alguns pontos críticos de contaminação, fornecendo suporte para capacitar os agricultores em boas práticas de gestão durante o processo de produção.

Enfermedades infecciosas relacionadas con el agua en el Perú / Infectious diseases related to water in Peru

RESUMEN El crecimiento de la población mundial ha incrementado la demanda de agua, por otro lado, el cambio climático nos muestra que las fuentes de agua que antes eran seguras actualmente ya no lo son. Existen desigualdades entre las zonas urbanas y rurales, así el 96% de la población mundial urbana utiliza fuentes de agua potable frente al 84% de la población rural, mientras que el 82% de la población urbana frente al 51% de la población rural utiliza instalaciones de saneamiento. En el Perú el 80,4% de viviendas se provee de agua por red pública. En el área urbana, este servicio cubre 83,2%; mientras que en el área rural el 71,3% de las viviendas cuenta con servicio higiénico conectado a red pública. Todo lo anterior condiciona la presencia de enfermedades infecciosas relacionadas con el agua como las diarreas, malaria, dengue, leptospirosis, hepatitis virales A y E, cuya clasificación, se muestra en este artículo. En el mundo las diarreas son la tercera causa de muerte entre menores de cinco años y más de 340 000 niños menores de cinco años mueren por enfermedades diarreicas. Una de las metas de los Objetivos de Desarrollo Sostenible (ODS) es la relacionada al acceso universal al agua potable, saneamiento e higiene, lo que no puede lograrse sin prestar la debida atención a las desigualdades en el acceso observadas entre diferentes grupos, evitando las consecuencias de estas deficiencias tanto en nuestro país como en el mundo.

ABSTRACT The growth of the world population has increased the demand for water. On the other hand, climate change shows us that the water sources that were previously safe are not anymore. There are inequalities between urban and rural areas, thus 96% of the urban world population uses drinking water sources compared to 84% of the rural population, while 82% of the urban population versus 51% of the rural population use sanitation facilities. In Peru, 80.4% of homes are supplied with water through a public network. In the urban area, this service covers 83.2%; while in the rural area 71.3% of homes have a toilet service connected to the public network. All the above conditions the presence of water-related infectious diseases, such as diarrhea, malaria, dengue, leptospirosis, viral hepatitis A, and E, whose classification is shown in this article. In the world, diarrhea is the third cause of death among children under five years of age and more than 340,000 children under the age of five die from diarrheal diseases due to poor sanitation. One of the goals of the SDGs is related to universal access drinking water, sanitation and hygiene, which cannot be achieved without due attention to the inequalities in access observed between different groups, avoiding the consequences of these deficiencies both in our country and in the world.

Secondary transmission of cryptosporidiosis associated with well water consumption: two case studies

Abstract: Cryptosporidiosis is a very prominent disease in the field of public health, and usually causes diarrhea. We describe two immunocompetent patients who presented with chronic diarrhea that was ultimately found to be caused by continuous exposure to well water contaminated with the microbial cysts (oocysts) of the Cryptosporidium spp parasite. We describe the patients' histories and possible explanations for their prolonged symptoms.

HUMAN TOXOPLASMOSIS OUTBREAKS AND THE AGENT INFECTING FORM. FINDINGS FROM A SYSTEMATIC REVIEW / Surtos de toxoplasmose humana e a forma infectante do agente. Achados de revisão sistemática

SUMMARY Toxoplasmosis, a worldwide highly prevalent zoonotic infection, is transmitted either by the oocysts, from water and soil, or the tissue cysts, in raw or undercooked infected meat, of Toxoplasma gondii. An ongoing debate is whether there are differences between the clinical and epidemiological characteristics of the outbreaks due to one or the other infective form of the agent. We performed a systematic review, recovering 437 reported outbreaks of which 38 were selected. They were complete reports containing ascribed Toxoplasma infecting form, and clinical and demographic data. There was no gender or age group selection in the outbreaks, which were described more often in the Americas. A large number of individuals were affected when oocysts, associated with soil and water contaminated with cat feces, were considered the transmission source. Onset of symptoms occurred early when the infection was ascribed to meat tissue cysts (11.4 ± 6.7 days) with sharpened temporal distribution of cases, while a broader and prolonged appearance of new cases was observed when oocysts in water were the source of the infection (20 ± 7 days, p < 0.001). Such information may be useful in the design and implementation of control strategies.

RESUMO Toxoplasmose, infecção zoonótica altamente prevalente no mundo, é transmitida pela ingestão de oocistos em água e solo ou cistos teciduais em carne crua ou mal cozida. Um debate em andamento é se há diferenças nas características clínicas e epidemiológicas de surtos devido a uma ou outra forma infectante do agente. Realizamos revisão sistemática a partir de 437 relatos de surtos da doença, selecionando 38 artigos completos que descreveram a forma infectante do Toxoplasmacom dados clínicos e epidemiológicos. Não houve seleção por gênero ou faixa etária nos surtos, descritos mais frequentemente nas Américas. Quantidade maior de indivíduos foi afetada quando oocistos, associados com solo ou água contaminados com fezes de gato, foram considerados a fonte de transmissão. O início dos sintomas ocorreu mais precocemente quando a infecção foi atribuída a cistos na carne (11,4 ± 6,7 dias) com distribuição temporal nítida de casos, embora um aspecto mais amplo e prolongado de novos casos foi observado quando oocistos na água foram a fonte de infecção (20 ± 7 dias, p< 0.001). Essas informações podem ser úteis no desenvolvimento e implantação de estratégias de controle.

Occurrence of Cryptosporidium spp. and Giardia spp. in a public water-treatment system, Paraná, Southern Brazil / Ocorrência de Cryptosporidium spp. e Giardia spp. em uma estação pública de tratamento de água, Paraná, Sul do Brasil

The purpose of this study was to investigate the occurrence of Cryptosporidium spp. and Giardia spp. in a public water-treatment system. Samples of raw and treated water were collected and concentrated using the membrane filtration technique. Direct Immunofluorescence Test was performed on the samples. DNA extraction using a commercial kit was performed and the DNA extracted was submitted to a nested-PCR reaction (n-PCR) and sequencing. In the immunofluorescence, 2/24 (8.33%) samples of raw water were positive for Giardia spp.. In n-PCR and sequencing, 2/24 (8.33%) samples of raw water were positive for Giardia spp., and 2/24 (8.33%) samples were positive for Cryptosporidium spp.. The sequencing showed Cryptosporidium parvum and Giardia duodenalis DNA. In raw water, there was moderate correlation among turbidity, color and Cryptosporidium spp. and between turbidity and Giardia spp.. The presence of these protozoans in the water indicates the need for monitoring for water-treatment companies.

O objetivo deste estudo foi investigar a ocorrência de Cryptosporidium spp. e Giardia spp. em um sistema público de tratamento de água. Amostras de água bruta e tratada foram coletadas e concentradas, utilizando-se a técnica de filtração em membranas. Foi realizada a técnica de Imunofluorescência Direta nas amostras. A extração de DNA foi realizada, utilizando-se um kit comercial, e o DNA extraído foi submetido a uma reação de nested-PCR (n-PCR). Na imunofluorescência, 2/24 (8,33%) amostras de água bruta foram positivas para Giardiaspp.. Na n-PCR, 2/24 (8,33%) amostras de água bruta foram positivas para Giardia spp., e 2/24 (8,33%) amostras foram positivas para Cryptosporidium spp.. O sequenciamento demonstrou DNA de Cryptosporidium parvum e de Giardia duodenalis. Na água bruta, houve correlação moderada entre turbidez, cor e Cryptosporidium spp. e entre a turbidez e Giardia spp.. A presença desses protozoários na água indica a necessidade de monitoramento pelas empresas de tratamento de água.

Water from different sources used for the irrigation of vegetables to be marketed: research on Cryptosporidiumspp, giardiaspp, and Coliforms in Parana, Brazil / Água de diferentes fontes utilizadas na irrigação de hortaliças comercializadas: pesquisa de Cryptosporidiumspp, giardiaspp, e coliformes, Paraná, Brasil

SUMMARYThe aim of this work was to compare, from a parasitological ( Cryptosporidiumspp. and Giardia duodenalis), bacteriological (total and thermotolerants coliforms) and physicochemical perspective, water sources used for drinking and irrigation of vegetables intended to be sold for human consumption. From January 2010 to May 2011, samples of different water sources from vegetable producing properties were collected; 100 liters for parasitological analysis, 200 mL for bacteriological analysis, and five liters for physicochemical analysis. Water samples were filtered under vacuum with a kit containing a cellulose acetate membrane filter, 1.2 µm (Millipore(r), Barueri, SP, Brazil). The material retained on the membrane was mechanically extracted and analyzed by direct immunofluorescence (Merifluor(r)kit). From 20 rural properties investigated, 10 had artesian wells (40 samples), 10 had common wells (40 samples), and one had a mine (four samples), the latter contaminated by Cryptosporidiumspp. In samples from artesian wells, 90 to 130 meters depth, 42.5% were positive for total coliforms and 5.0% were identified to have abnormal coloration. From the samples of common wells, 14 to 37 meters depth, 87.5% were contaminated with total coliforms, 82.5% were positive for thermotolerant coliforms, and 12.5% had color abnormalities. We did not detect the presence of Giardiaspp. or Cryptosporidiumspp. in artesian and common wells. The use of artesian or common wells is an important step in the control of the spreading of zoonoses, particularly Cryptosporidiumspp. and Giardiaspp., as well as artesian wells for coliform control in local production of vegetables to be marketed.

RESUMOO objetivo do estudo foi investigar fontes de água utilizadas para consumo e irrigação de hortaliças a serem comercializadas sob o aspecto parasitológico ( Cryptosporidiumspp. e Giardia duodenalis), bacteriológico (coliformes totais e termotolerantes) e físico-químico. De janeiro de 2010 a maio de 2011 foram coletadas amostras de água de diferentes fontes de abastecimento de propriedades produtoras de hortaliças; 100 litros para análise parasitológica, 200 mL para bacteriológica e cinco litros para análise físico-química. As amostras de água foram filtradas a vácuo com um kit de filtragem contendo uma membrana de acetato de celulose, 1,2 µm, (Millipore(r), Barueri, São Paulo, Brasil). O material retido na membrana foi extraído mecanicamente e analisado por imunofluorescência direta (kit Merifluor(r)). De 20 propriedades rurais, 10 tinham poços artesianos (40 amostras), 10 semi-artesianos (40 amostras) e um possuía uma mina (quatro amostras). Esta última contaminada por Cryptosporidiumspp. Das amostras de poços artesianos com 90 a 130 metros de profundidade, 42,5% foram positivas para coliformes totais e 5,0% apresentavam coloração alterada. Em amostras de poços semi-artesianos com 14 a 37 m de profundidade, 87,5% apresentaram coliformes totais, 82,5% termotolerantes, e 12,5% destas amostras tinham alteração de cor. Não foi detectada a presença de Giardiaspp. e Cryptosporidiumspp. em poços artesianos ou semi-artesianos. A utilização de poços artesianos ou semi artesianos constitui importante medida no controle da disseminação de zoonoses, principalmente Cryptosporidiumspp. e Giardiaspp., assim como de poços artesianos para o controle de coliformes, em locais de produção de hortaliças irrigadas, a serem comercializadas.

Frecuencia y fuentes de Blastocystis sp . en niños de 0 a 5 años de edad atendidos en hogares infantiles públicos de la zona urbana de Calarcá, Colombia / Blastocystis sp . frequency and sources among children from 0 to 5 years of age attending public day care centers in Calarcá, Colombia

Introducción. No se han descrito las fuentes potenciales de infección por Blastocystis sp . en Colombia. Objetivos. Estimar la frecuencia de Blastocystis sp . y explorar posibles asociaciones entre la infección, las manifestaciones clínicas y algunas fuentes ambientales. Materiales y métodos. Se llevó a cabo un estudio descriptivo con una población de 1.993 menores de 5 años (lactantes y preescolares) de estratos socioeconómicos 1 y 2, atendidos en hogares infantiles de Calarcá, Colombia. Se calculó una muestra de 275 y se seleccionó aleatoriamente a los participantes en 10 % de los hogares infantiles. Se practicaron exámenes coprológicos y encuestas y se tomaron muestras para la identificación del parásito en heces, uñas, animales domésticos y algunas fuentes ambientales. Se hicieron preparaciones en fresco con lugol al 1 % y se utilizó una técnica de concentración con formol-éter. Se estimaron prevalencias y razones de momios; para las variables cualitativas se utilizó el test de ji al cuadrado y, para las cuantitativas, la prueba t de Student. Resultados. La prevalencia de infección en los niños fue de 57,5 %. Hubo asociación estadísticamente significativa entre la presencia del parásito en heces y su hallazgo en recipientes de agua de panela (OR=1,70; IC 95% 1,05-2,79), en los pisos de madera o de tierra en la vivienda (OR=3,43; IC 95% 1,12-10,48), y en alimentos diferentes a la leche en el tetero (OR=3,23; IC 95% 1,41-4,41); y se encontró una prevalencia alta sin asociación en muestras de uñas (OR=1,62; IC 95% 0,99-2,67). La diarrea fue más frecuente en niños con Blastocystis sp. (45 %) que en aquellos sin el parásito (33 %) (OR: 1,95; IC 95% 0,99-2,77) (p<0,05). Conclusiones. Blastocystis sp . se asoció significativamente con síntomas de diarrea en los niños menores de 5 años y se encontró distribuido ampliamente en el ambiente y en el agua. Se requeriría determinar si hay huéspedes específicos para genotipos patógenos por medio de técnicas moleculares.

Introduction: There are no reports of the potential sources of Blastocystis sp . in Colombia. Objectives: To estimate the frequency of Blastocystis sp . and explore possible associations among infection, clinical manifestations and environmental sources. Materials and methods: A descriptive study was conducted; a representative sample was calculated from a population of 1,993 children less than 5 years old of the lowest socioeconomic levels (1 and 2) attending day care centers in Calarcá, Colombia. The calculated sample size was 275 children, who were selected randomly in 10 % of the centers. Stool testing, questionnaires and sampling to identify the parasite in feces, nails, pets and environmental sources, were performed. Fresh preparations were made with 1% iodine solution, and a concentration technique with formalin-ether was used. Prevalence and odd ratios were estimated; the chi-square test was utilized for qualitative variables, and Student´s t for the quantitative ones. Results: The prevalence of infection in children was of 57.5%. A statistically significant association was found between the Blastocystis sp . positive stool tests and the presence of the parasite in containers of sugar cane beverage (OR=1.70; 95% CI: 1.05-2.79), wood or ground floors (OR=3.43; 95% CI: 1.12-10.48) and in foods other than bottled milk (OR=3.23; 95% CI: 1.41-4.41) . A non-significant high prevalence was found in nails (OR=1.62; 95% CI: 0.99-2.67), as well as a significantly higher prevalence of diarrhea (OR=1.95; 95% CI: 0.99-2.77) in children with Blastocystis sp . (45%) as compared with those without the parasite (33%; p<0.05). Conclusions: Blastocystis sp . showed a significant association with diarrhea symptoms in children 0 to 5 years old and was widely distributed in the environment and in water. It is necessary to determine if there are specific hosts with pathogenic potential through molecular techniques.

Potentially patoogenic free-living amoebae in sme flood-affected areas during 2011 chiang mai flood / Amebas potencialmente patogenicas de vida livre em algumas areas afetadas durante a inundacao de 2011 em Chiang Mai

SUMMARY The survey was carried out to investigate the presence of potentially pathogenic free-living amoebae (FLA) during flood in Chiang Mai, Thailand in 2011. From different crisis flood areas, seven water samples were collected and tested for the presence of amoebae using culture and molecular methods. By monoxenic culture, FLA were detected from all samples at 37 °C incubation. The FLA growing at 37 °C were morphologically identified as Acanthamoeba spp., Naegleria spp. and some unidentified amoebae. Only three samples (42.8%), defined as thermotolerant FLA, continued to grow at 42 °C. By molecular methods, two non-thermotolerant FlA were shown to have 99% identity to Acanthamoeba sp. and 98% identity to Hartmannella vermiformis while the two thermotolerant FLA were identified as Echinamoeba exundans (100% identity) and Hartmannella sp. (99% identity). This first report of the occurrence of FLA in water during the flood disaster will provide information to the public to be aware of potentially pathogenic FLA. .

RESUMO A pesquisa foi feita para investigar a presença de amebas de vida livre (FLA) durante a inundação em Chiang Mai, Tailândia, ano de 2011. A partir de diferentes áreas de inundação sete amostras de água foram coletadas e testadas para a presença de amebas usando métodos moleculares e de cultura. Através da cultura monoxênica, FLA foi detectada em todas as amostras após incubação a 37 °C. As FLA crescendo a 37 °C foram identificadas morfologicamente como Acanthamoeba spp, Naegleria spp e algumas amebas não determinadas. Somente três amostras (42,8%) definidas como FLA termotolerantes continuaram a crescer a 42 °C. Por métodos moleculares duas FLA termotolerantes tiveram 99% de identidade com a Acanthamoeba sp e 98% de identidade com Hartmannella vermiformis enquanto as duas FLA termotolerantes foram identificadas como Echinamoeba exundans (100% de identidade) e Hartmannella sp (99% de identidade). Este primeiro relato da ocorrência de FLA em águas durante inundações informa ao público que ele deve estar atento de FLA potencialmente patogênica. .

Parasitosis intestinales en Argentina: principales agentes causales encontrados en la población y en el ambiente / Intestinal parasitoses in Argentina: Major causal agents found in the population and in the environment

Las parasitosis intestinales se encuentran ampliamente distribuidas en el mundo, con mayor prevalencia en los países en desarrollo. Principalmente afectan a los niños, en los que además provocan disminución del desarrollo físico y mental, situación que puede potenciarse enormemente cuando se suma a un estado nutricional deficiente. La Organización Mundial de la Salud las considera una de las principales causas de morbilidad, estrechamente ligada a la pobreza y relacionada con inadecuada higiene personal, incorrecta manipulación de los alimentos crudos, falta de servicios sanitarios, falta de provisión de agua potable y contaminación fecal del ambiente. Algunas enfermedades parasitarias se vinculan con condiciones de transmisión que existen universalmente, por lo que son cosmopolitas, mientras que otras tienen distribución geográfica variable. En los últimos años, debido a la globalización, el movimiento de personas de zonas endémicas a regiones no endémicas ha permitido la diseminación de ciertas parasitosis. Y aunque también influyen en la frecuencia de algunas de estas enfermedades las costumbres de los pueblos, las condiciones ambientales son un factor determinante para la supervivencia de los parásitos. En nuestro país, debido a la diversidad de suelos y condiciones climáticas que existen, es posible hallar variedad de agentes causales de estas parasitosis. El objetivo de este trabajo fue realizar una revisión bibliográfica de los agentes parasitarios causantes de enfermedades entéricas encontrados en la República Argentina, tanto en materia fecal de personas como en el ambiente, ya que la contaminación parasitaria de este último constituye un indicador directo del riesgo de infección por parásitos intestinales.

Intestinal parasitic diseases are widely spread in the world, with the highest prevalence in developing countries. Children are mainly affected, showing a decrease in physical and mental development, as well as the expected manifestations of the disease. This situation can be greatly enhanced in children with poor nutritional status. The World Health Organization considers intestinal parasitic diseases a major cause of morbidity, closely linked to poverty and poor personal hygiene, inappropriate handling of raw food, lack of sanitation, lack of potable water supply, and environmental fecal contamination. Some parasitic diseases are cosmopolitan while others have variable geographic distribution, due to different factors such as the presence of exclusive intermediate hosts. In the past few years, globalization allowed the spread of certain parasites from endemic to non-endemic regions. Even though people's customs influence on the frequency of certain parasites, environmental conditions are a determinant factor for parasite survival. In our country, due to the variety of soils and climatic conditions, several causative agents of these parasitoses can be found. The aim of this work was to review the literature on the intestinal parasitic agents found in Argentina in human fecal samples and its environment, as parasitic contamination constitutes a direct indicator of the infection risk by intestinal parasites.

Characterisation of Culex quinquefasciatus (Diptera: Culicidae) larval habitats at ground level and temporal fluctuations of larval abundance in Córdoba, Argentina

The aims of this study were to characterise the ground-level larval habitats of the mosquito Culex quinquefasciatus, to determine the relationships between habitat characteristics and larval abundance and to examine seasonal larval-stage variations in Córdoba city. Every two weeks for two years, 15 larval habitats (natural and artificial water bodies, including shallow wells, drains, retention ponds, canals and ditches) were visited and sampled for larval mosquitoes. Data regarding the water depth, temperature and pH, permanence, the presence of aquatic vegetation and the density of collected mosquito larvae were recorded. Data on the average air temperatures and accumulated precipitation during the 15 days prior to each sampling date were also obtained. Cx. quinquefasciatus larvae were collected throughout the study period and were generally most abundant in the summer season. Generalised linear mixed models indicated the average air temperature and presence of dicotyledonous aquatic vegetation as variables that served as important predictors of larval densities. Additionally, permanent breeding sites supported high larval densities. In Córdoba city and possibly in other highly populated cities at the same latitude with the same environmental conditions, control programs should focus on permanent larval habitats with aquatic vegetation during the early spring, when the Cx. quinquefasciatus population begins to increase.

Presencia de protozoarios intestinales en agua de consumo en la comunidad 18 de Mayo. Estado Aragua-Venezuela, 2011 / Presence of intestinal protozoans in water of consumption in “18 de Mayo Community”. Aragua State-Venezuela. 2011

La transmisión de parásitos intestinales a través del agua representa un problema de salud pública a nivel mundial. Considerando la importancia del agua como uno de los recursos renovables más importantes para el hombre por su utilidad, abundancia y amplia distribución en la naturaleza, la contaminación de ésta con excretas humanas y animales, favorecen la transmisión de infecciones parasitarias. A fin de determinar la presencia de protozoarios intestinales en el agua para consumo humano del pozo profundo en la comunidad 18 de Mayo, municipio Francisco Linares Alcántara y en 10 casas seleccionadas de la misma comunidad, se tomaron muestras de 20 litros en cada punto, por duplicado, y se aplicó la técnica de concentración por floculación, para posteriormente realizar observación directa utilizando solución salina y lugol; y se empleó el método de Kinyoun. Adicionalmente, al agua del pozo se le realizó el análisis fisicoquímico. Se observó presencia de protozoarios patógenos y comensales en 90% de las muestras provenientes de las viviendas. En las muestras del pozo profundo se evidenciaron quistes de Giardia intestinalis, Entamoeba coli y Endolimax nana; no se observó la presencia de coccidios ni microsporidias intestinales. La desinfección del agua del pozo que surte esta comunidad es de suma importancia, además de recomendar a las comunidades el tratamiento del agua de consumo.

The transmission of intestinal parasites through water represents one of the world’s most prominent public health problems. Water is one of the most important renewable resources for the man, for its usefulness, abundance and wide distribution in the nature, but human and animal excretion contamination in potable water favors the transmission of parasitic infections. In order to determinate the presence of intestinal protozoans in drinking water from the deep-wells and in 10 selected houses in the 18 de Mayo community of Francisco Linares Alcantara municipality, Aragua State, two 20 liter water samples were taken and processed through the concentration by flocculation technique for direct observation using physiological saline solution and lugol, and the Kinyoun coloration technique. Additionally, physicochemical analysis was conducted on the well water. Pathogenic and commensal protozoans were observed in 90% of the analyzed samples. Cysts of Giardia intestinalis, Entamoeba coli and Endolimax nana were found in the deep-well sample but not intestinal coccidia and microsporidia. The disinfection of the well water that supplies this community is really important, and it is recommended that the community’s drinking water be routinely treated.

Vigilancia de insectos de importancia en salud pública durante la construcción de los proyectos hidroeléctricos Porce II y Porce III, Antioquia, Colombia, 1990-2009 / Twenty-year surveillance of insects relevant to public health during the construction of hydroelectric facilities in Antioquia, Colombia

Introducción. Los estudios entomológicos en las grandes obras de infraestructura hidroeléctrica constituyen una herramienta para la prevención y el control de enfermedades transmitidas por vectores, debido a que con frecuencia las alteraciones causadas en el medio producen aumento de criaderos naturales y artificiales en el área de influencia y, por ende, incremento de las poblaciones de artrópodos, entre ellos, insectos de interés en salud pública. Objetivo. Realizar estudio y vigilancia de la fauna de Culicidaey Phlebotominae en el área de los proyectos hidroeléctricos Porce II y Porce III, 1990-2009. Materiales y metódos. Se realizaron muestreos entomológicos periódicos para la vigilancia en salud pública de las comunidades ubicadas en el área de influencia y en campamentos y frentes de obra. Los adultos fueron capturados con red para mariposas, trampas de luz Shannon y CDC, y cebo humano protegido. Resultados. Se encontraron larvas de mosquitos de Culex coronator, Cx. nigripalpus, Cx. corniger, Cx. quinquefasciatus y Limatus durhami. Los depósitos más frecuentes fueron: tanques bajos, canecas, llantas y matas sembradas en agua. Aedes aegypti solo fue capturado en dos localidades rurales de dos municipios del área de influencia. En las zonas de bosque se capturaron mosquitos Aedes, Mansonia, Culex, Psorophora, Wyeomyia, Phonyomyia, Uranotaenia, Haemagogus y Sabethes; el principal fue Haemogogus janthinomis, eficiente vector de fiebre amarilla en Colombia. La zona es endémica para leishmaniasis y se identificaron 20 especies de Lutzomyia. Entre los vectores de malaria, las principales especies encontradas fueron Anopheles nuñeztovari y An. pseudopunctipennis. Conclusión. En la zona de Porce II y Porce III existe diversidad de vectores de importancia en salud pública, que es necesario continuar vigilando para minimizar el riesgo de transmisión de enfermedades a los trabajadores de las obras y comunidades aledañas.

Introduction. Entomological studies conducted in large hydroelectric infrastructure projects are a tool for the prevention and control of vector-borne diseases. These diseases emerge as a consequence of changes made to the terrain that often increase the natural and artificial mosquito larval habitats. Many of these insects are of public health importance and population increases result in an increased risk of disease transmission. Objective. The culicine (mosquito) and phlebotomine (sand fly) populations were characterized in the area of the Porce II and Porce III hydroelectric projects of Antioquia between 1990 to 2009. Materials and methods. Periodical entomological samplings were made in the area of impact, in the workers camps, and construction sites. Adult specimens were captured with nets, Shannon light traps, CDC light traps, and protected human bait. Results. Mosquito larvae of the following species were identified: Culex coronator, Culex nigripalpus, Culex corniger, Culex quinquefasciatus and Limatus durhami. The most frequently identifiers of larval habitats were low tanks, waste cans, tires, and aquatic plants. Aedes aegypti specimens were captured in only two rural locations from two municipalities within the area of influence. Specimens from the following mosquito genera were captured in forest areas: Aedes, Mansonia, Culex, Psorophora, Wyeomyia, Phonyomyia, Uranotaenia, Haemagogus and Sabethes. The most important mosquito found was Haemogogus janthinomis, an efficient yellow fever vector in Colombia. The area has been endemic for leishmaniasis and in the current study, 20 species of Lutzomyia sand flies, potential vectors, were identified. Among malaria vectors, the most important species found in the area were Anopheles nuneztovari and Anopheles pseudopunctipennis. Conclusion. A wide variety of vectors were discovered in the area of the Porce II and Porce III hydroelectric projects, and many of these were relevant for public health. Further monitoring will be necessary to minimize disease transmission risks among the workers and the inhabitants of the surrounding areas.

Investigación de blastocystis sp. en agua de consumo humano en una población escolar de la zona rural del estado Mérida, Venezuela / Blastocystis sp. in drinking water at a rural school in Mérida, Venezuela

Para detectar la presencia de Blastocystis sp. en el agua de consumo de una escuela rural del estado Mérida, se recolectaron 36 muestras provenientes de la fuente natural que surte el tanque de distribución, del tanque y de los grifos, durante los meses de Septiembre 2008, Febrero y Diciembre del 2009 y Mayo 2010. El procesamiento de las muestras se realizó siguiendo la técnica propuesta por Suresh y col. (2005). Los resultados sugieren que el agua de consumo estaba exenta de Blastocystis o que la cantidad de quistes viables presentes en las muestras fue muy baja, lo que no permitió lograr la recuperación del parásito en el cultivo. Por ello se requiere el uso de técnicas más sensibles que permitan detectar cantidades bajas del microorganismo en aguas de consumo humano. El estudio de los hábitos de consumo de agua de la población estudiantil de la escuela rural, mostró que más de la mitad de la población consume agua hervida, esto probablemente se deba a que están conscientes que el agua a la cual tienen acceso proviene de una fuente natural no tratada

In order to determine the presence of Blastocystis sp. in drinking water at a rural school in Merida, 36 water samples were collected from natural sources that feed the distribution tank and faucets during the months of September, 2008, February and December, 2009, and May, 2010. Samples were processed using the technique proposed by Suresh et al. (2005). All samples were negative. These results suggest that the water was exempt from Blastocystis or that the quantity of viable cysts present in the samples was very low, not permitting reproduction in the culture. This report suggests the importance of using more sensitive techniques to detect low amounts of the organismin drinking water. The study of student water consumption habits at the rural school showed that more than half the population consume boiled water; probably, they are aware that the water source has not been treated for drinking

Evaluation of water quality of an urban stream in southeastern Brazil using Chironomidae larvae (Insecta: Diptera)

In order to estimate the water quality of São Pedro stream, through distribution and composition of Chironomidae larvae present in the sediment four sampling sites were selected. In each sampling site, three sediment samples were collected within a period of twelve months using the Petersen (0.0189 m²) and the van Veen (0.0518 m²) dredges. Samples were washed through a sieve with a 0.21 mm mesh and the collected organisms were sorted in transparent trays, with a light shine being reflected into the tray. The sites located in the greatest urban mesh showed high densities of the genus Chironomus and lower values for diversity, uniformity and taxa richness, in relation to sites located in a less urbanized area. A significant difference in density of Chironomidae larvae (p = 0.02; H = 5.89) was observed between the sites without domestic sewage effluents (site I) and those with the input of the effluents (sites II, III and IV). The Chironomidae larvae composition and the physical and chemical parameters were effective as indicators of the environmental alterations in São Pedro stream.

Spatial pattern, water use and risk levels associated with the transmission of schistosomiasis on the north coast of Pernambuco, Brazil / Padrão espacial, uso da água e níveis de risco associados à transmissão da esquistossomose no litoral norte de Pernambuco, Brasil

This study aimed to describe epidemiological aspects of schistosomiasis in Carne de Vaca, Goiana, on the coast of Pernambuco State, Brazil and analyze the spatial distribution of households' sanitary conditions and patterns of water contact. A parasitological survey was conducted between 2006 and 2007. An indicator was set to establish risk levels for schistosomiasis based on variables of water contact pattern, household characteristics and proximity to the foci of vector snails. The prevalence was 18.71 in men and 15.96 in women. The age groups most affected were 20-29 years among men and 10-19 among women. The most common parasite load was 1-99 eggs per gram of feces. The prevalence was 17.3 cases per 100 inhabitants and its spatial distribution was not homogeneous. The Bayesian analysis proved unsatisfactory. It is concluded that schistosomiasis is endemic in Carne de Vaca and the risk indicator, based on geoprocessing, proved to be satisfactory, highlighting areas where the problem is more acute.

O estudo objetivou descrever aspectos epidemiológicos da esquistossomose em Carne de Vaca, litoral de Pernambuco, Brasil, e analisar a distribuição espacial das condições de esgotamento sanitário e padrão de contato com a água. Foi realizado um inquérito parasitológico entre 2006 e 2007, e criado indicador de risco para a esquistossomose com base em variáveis do padrão de água de contato, características do agregado familiar e da proximidade com focos de moluscos vetores. A prevalência em homens foi de 18,71, e 15,96 em mulheres. A faixa etária mais acometida em homens e mulheres foi de 20-29 e 10-19, respectivamente. A carga parasitária mais freqüente foi de 1-99 ovos por grama de fezes. A prevalência foi de 17,3 casos por 100 habitantes e sua distribuição espacial não foi homogênea. A estatística Bayesiana não se mostrou satisfatória. Conclui-se que a esquistossomose é endêmica em Carne de Vaca e que o indicador de risco com base em geoprocessamento revelou-se satisfatório, destacando as áreas onde o problema é mais relevante.