RESUMEN
BACKGROUND: IgE to α-Gal is a cause of mammalian meat allergy and has been linked to tick bites in North America, Australia, and Eurasia. Reports from the developing world indicate that α-Gal sensitization is prevalent but has been little investigated. OBJECTIVE: We sought evidence for the cause(s) of α-Gal sensitization and lack of reported meat allergy among children in less developed settings in Ecuador and Kenya. METHODS: IgE to α-Gal and total IgE were assessed in children from Ecuador (n = 599) and Kenya (n = 254) and compared with children with (n = 42) and without known (n = 63) mammalian meat allergy from the southeastern United States. Information on diet, potential risk factors, and helminth infections was available for children from Ecuador. IgG4 to α-Gal and antibodies to regionally representative parasites were assessed in a subset of children. RESULTS: In Ecuador (32%) and Kenya (54%), α-Gal specific IgE was prevalent, but levels were lower than in children with meat allergy from the United States. Sensitization was associated with rural living, antibody markers of Ascaris exposure, and total IgE, but not active infections with Ascaris or Trichuris species. In Ecuador, 87.5% reported consuming beef at least once per week, including 83.9% of those who had α-Gal specific IgE. Levels of α-Gal specific IgG4 were not high in Ecuador, but were greater than in children from the United States. CONCLUSIONS: These results suggest that in areas of the developing world with endemic parasitism, α-Gal sensitization is (1) common, (2) associated with Ascaris exposure, and (3) distinguished by a low percentage of specific/total IgE compared with individuals with meat allergy in the United States.
Asunto(s)
Disacáridos/inmunología , Hipersensibilidad a los Alimentos/inmunología , Inmunoglobulina E/inmunología , Inmunoglobulina G/inmunología , Adolescente , Adulto , Animales , Ascaris/inmunología , Ascaris/aislamiento & purificación , Niño , Preescolar , Dieta , Ecuador/epidemiología , Heces/parasitología , Femenino , Hipersensibilidad a los Alimentos/sangre , Hipersensibilidad a los Alimentos/epidemiología , Hipersensibilidad a los Alimentos/parasitología , Humanos , Inmunoglobulina E/sangre , Inmunoglobulina G/sangre , Kenia/epidemiología , Masculino , Prevalencia , Carne Roja , Trichuris/aislamiento & purificación , Virginia/epidemiología , Adulto JovenRESUMEN
Ascaris sp. is a soil-transmitted helminth (STH) significantly affecting the health of human and swine populations. Health inequities and poverty, with resulting deficiencies in water, sanitation and hygiene, are directly associated with Ascaris lumbricoides prevalence in humans. Resource constraints also lead to small-scale livestock production under unsanitary conditions. Free-ranging pigs, for instance, are exposed to a number of infectious agents, among which Ascaris suum is one of the most common. Under these conditions, close proximity between people and pigs can result in cross-contamination; that is, pigs harbouring human Ascaris and vice versa. Moreover, the potential interbreeding between these two Ascaris species has been demonstrated. The present study analysed Ascaris worms obtained from children and pigs in Honduras. Adult worms were collected from stool samples of children after pharmacological treatment, and from pigs' intestines after slaughter for commercial purposes at a local abattoir. A nuclear ribosomal internal transcribed spacer (ITS) region was amplified by polymerase chain reaction (PCR) and digested with a restriction enzyme in order to separate putative human- and pig-derived Ascaris isolates. PCR products were also sequenced, and cladograms were constructed. All parasites isolated from children showed the typical human-derived genotype of Ascaris, whereas 91% of parasites from pigs showed the expected pig-derived genotype. Cross-infections between hosts were not demonstrated in this study. Nine per cent of pig-derived worms showed a restriction band pattern highly suggestive of a hybrid human-pig Ascaris genotype. These results contribute to the understanding of ascariasis epidemiology and its zoonotic potential in a highly endemic region.
Asunto(s)
Ascariasis/epidemiología , Ascaris/genética , ADN de Helmintos/genética , Genotipo , Enfermedades de los Porcinos/epidemiología , Animales , Ascariasis/transmisión , Ascariasis/veterinaria , Ascaris/aislamiento & purificación , Ascaris lumbricoides/genética , Ascaris lumbricoides/aislamiento & purificación , Ascaris suum/genética , Ascaris suum/aislamiento & purificación , Niño , ADN Espaciador Ribosómico/genética , Heces/parasitología , Honduras/epidemiología , Humanos , Filogenia , Reacción en Cadena de la Polimerasa , Polimorfismo de Longitud del Fragmento de Restricción , Análisis de Secuencia de ADN , Porcinos/parasitología , Enfermedades de los Porcinos/transmisión , Zoonosis/epidemiología , Zoonosis/parasitología , Zoonosis/transmisiónRESUMEN
This study explored whether the yard environment and child hygiene and play behaviours were associated with presence and intensity of Ascaris and hookworm in preschool children and with eggs and larvae in soil. Data were collected using questionnaires, a visual survey of the yard, soil samples and fecal samples collected at baseline and following re-infection. The presence of eggs/larvae in soil was associated negatively with water storage (eggs) but positively with dogs (eggs) and distance from home to latrine (larvae). Baseline and re-infection prevalences were: hookworm (28.0%, 3.4%); Ascaris (16.9%, 9.5%); Trichuris (0.9%, 0.7%). Zero-inflated negative binomial regression models revealed a higher baseline hookworm infection if yards had eggs or larvae, more vegetation or garbage, and if the child played with soil. Baseline Ascaris was associated with dirt floor, dogs, exposed soil in yard, open defecation and with less time playing outdoors, whereas Ascaris re-infection was associated with water storage, vegetation cover and garbage near the home and not playing with animals. Our results show complex interactions between infection, the yard environment and child behaviours, and indicate that transmission would be reduced if latrines were closer to the home, and if open defecation and water spillage were reduced.
Asunto(s)
Ancylostomatoidea/aislamiento & purificación , Ascariasis/transmisión , Ascaris/aislamiento & purificación , Infecciones por Uncinaria/transmisión , Animales , Ascariasis/epidemiología , Ascariasis/parasitología , Niño , Preescolar , Perros , Ambiente , Heces/parasitología , Femenino , Infecciones por Uncinaria/parasitología , Humanos , Higiene , Larva , Masculino , Panamá/epidemiología , Prevalencia , Población Rural , Suelo/parasitologíaRESUMEN
A alface (Lactuca sativa) é uma das hortaliças mais consumidas no Brasil e no mundo na forma in natura. A ingestão de hortaliças contaminadas com cistos, ovos e/ou larvas de parasitas resultam em enteroparasitoses de importância em saúde pública. Investigar e comparar a contaminação de hortaliças por protozoários e helmintos avaliando a presença destes enteroparasitas em folhas de alface oriundas do cultivo convencional e hidropônico comercializadas em Montes Claros foi o objetivo deste trabalho. Amostras de alface desfolhadas foram tratadas com solução de salina acrescida de 0,1% de detergente. A suspensão foi filtrada e submetida ao método de sedimentação espontânea (HPJ) durante 24 horas. Os sedimentos foram analisados em duplicatas ao microscópio óptico e os achados parasitológicos tabulados e interpretados. Das amostras analisadas 10% apresentaram contaminação parasito lógica, das quais 70% oriundas do cultivo hidropônico. Nossos resultados foram similares aos de Neres e colaboradores (2011), onde amostras de Lactuca sativa de cultivo hidropônico apresentaram um nível maior de contaminação por parasitas intestinais. Dentre as formas parasitárias encontradas, 30% foram ovos de Ascaris lumbricoides, 21% de ovos de Ancilostomídeos, 7% de ovos de Trichuris trichiuria, 7% de larvas de Strongyloides stercoralis, 7% de ovos de Enterobius vermicularis, 14 % de ovos de Taenia spp, 7% de cistos de Endolimax nana e 7% de cistos de Entamoeba histolytica. Embora 10% tenha sido o índice de contaminação encontrado, parasitas patogênicos foram aqui identificados. Entre os possíveis fatores de contaminação estão a falha no processo de higienização em etapas de manipulação das hortaliças (plantio, colheita e distribuição). Além disso, a fonte de água utilizada para o cultivo deverá ser investigada, uma vez que as hortaliças de cultivo hidropônico mostraram maior índice de contaminação. (AU)
Lettuce (Lactuca sativa) is one of the most fresh form vegetables consumed in Brazil and abroad. The ingestion of contaminated vegetables with parasites cysts, eggs or larvae can result in public health importance intestinal diseases. The aim of this study was to investigate and compare parasitological contamination levei of vegetables according to traditional and hydroponics growing processes, commercialized in Montes Claros, collected in November 2011. The lettuce samples were treated with saline solution plus 0.1% detergent. The suspension was filtered and subjected to HPJ sedimentation method. The sediments were duplicated analyzed by optical microscopy and parasitological finding were tabulated and interpreted. 10% of the samples show parasitological contamination, of which 70% originated from hydroponic growing process. Our results were similar to Neres and colleagues (2011) where Lactuca sativa from hydroponics growing showed a higher levei ofparasitological contamination. Among the parasitic forms found 30% were Áscaris lumbricoides, 21% for Hookworm eggs, 7% of the Trichuris trichiuria eggs, 7% for Strongyloides stercoralis larvae, 7% Enterobius vermicularis eggs, 14% Taenia sp eggs, 7% Endolinax nana cysts and 7% Entamoeba histolytica cysts. Although 10% was the contamination level found, pathogenic parasites were here identified. Among the possible contamination cause are the flaws in the process of cleaning steps in handling the vegetables (planting, harvesting and distribution). Furthermore the source of water used for the cultivation should be investigated, since the hydroponic cultivation of vegetables showed higher rate of contamination. (AU)
Asunto(s)
Lactuca/parasitología , Contaminación de Alimentos , Parasitología de Alimentos , Hidroponía , Muestras de Alimentos , Ascaris/aislamiento & purificación , Entamoeba histolytica/aislamiento & purificación , BrasilRESUMEN
Brazilian regulations for nonpotable reuse are being established using World Health Organization guidelines, however, they should be developed based on local monitoring studies. This study intended to analyze enteroviruses, protozoa and viable Ascaris sp. eggs in raw (24) and treated (24) effluents from four Wastewater Treatment Plants of São Paulo State, Brazil. The protozoa were detected with the US Environmental Protection Agency (USEPA) Method 1623 in the treated effluents and by centrifugation/Immunomagnetic Separation in the raw influent samples. Viable Ascaris sp. eggs were analyzed according to a modified USEPA method. Enteroviruses were quantified by using human rhabdomyosarcoma cells after adequate concentration procedures. All wastewater influents were positive for Giardia sp. whereas Cryptosporidium sp. was detected in 58.3% of the samples. Giardia sp. and Cryptosporidium sp. were present in 79.2 and 25.0% respectively, of the treated wastewater samples. Viable Ascaris sp. eggs were detected in 50.0 and 12.5% of influent and treated wastewater samples. Enteroviruses were isolated in the 24 raw influent samples and in 46% of the treated samples. Taking into account the densities of Giardia sp. in some treated wastewaters intended to be used as reclaimed water, Quantitative Microbial Risk Assessment studies should be conducted to establish pathogen quantitative criteria for a future Brazilian regulation for water reuse.
Asunto(s)
Aguas Residuales/parasitología , Aguas Residuales/virología , Microbiología del Agua , Animales , Ascaris/aislamiento & purificación , Brasil , Cryptosporidium/aislamiento & purificación , Enterovirus/aislamiento & purificación , Giardia/aislamiento & purificación , Reciclaje/legislación & jurisprudencia , Medición de RiesgoRESUMEN
Some epidemiologic studies conducted in developing countries demonstrated a high incidence of enteroparasites, Ascaris sp. being the most prevalent. Therefore, the use of sewage sludge in agriculture may pose risks to human health. In order to protect public health, a Brazilian regulation has established standards regarding its use in rural areas. The objective of this study was to quantify Ascaris sp. and other helminth eggs in sewage sludge from five wastewater treatment plants from a dense metropolitan region, and also to check compliance with the law. The analysis was carried according to USEPA 2003 . A rich parasitological fauna was found, with a prevalence of the eggs of Ascaris sp. (9.55%). The samples analyzed presented a large variety of helminth eggs, and Ascaris sp. proved to be the most prevalent which put in evidence that its application poses public health concerns.
Asunto(s)
Ascaris/aislamiento & purificación , Monitoreo del Ambiente , Helmintos/aislamiento & purificación , Aguas del Alcantarillado/parasitología , Agricultura/métodos , Animales , Óvulo , Aguas Residuales/parasitologíaRESUMEN
The objective of this study was to determine the prevalence of parasites in soil and dog feces according to diagnostic tests. We studied soil from 25 public squares in Seropédica, Brazil. Five samples of soil were collected from each square. Eighty-one fresh fecal samples from dogs were analyzed. The technique described by Dunsmore et al. and an adaptation of the Rugai et al. method were used to recover parasites in soil, and the Willis, Hoffman and Centrifugal-Flotation techniques were used to detect parasites in feces. The chi(2) and Fischer's exact tests were used to analyze the statistical significance of the results. Seven squares were found to be contaminated, and the most prevalent parasites were Ancylostoma spp. (13.6%) and Toxocara spp. (4.0%). The Dunsmore et al. technique and the adaptation of the Rugai et al. method did not differ in the detection of Toxocara spp. (p=0.21), Trichuris spp. (p=0.25), Ascaris spp. (p=0.49) and Strongyloides spp. (p=0.49) in soil. However, the two methods differed in the detection of Ancylostoma spp. eggs (p=0.029) and larvae (p=0.001). According to granulometric analysis, the soil samples consisted mainly of sand (from 96.6% to 82.8%). Parasites were detected in 75 fecal samples, the most frequent being Ancylostoma spp. (80.1%), Toxocara spp. (11.1%) and Cryptosporidium spp. (7.4%). There was no difference between the Willis and Centrifugal-Flotation techniques in the detection of Ancylostoma spp., and both techniques were better than the Hoffman technique for detecting this parasite in feces. The Hoffman and Centrifugal-Flotation techniques were different (p=0.03) in Toxocara spp. detection. No difference was observed among these three for Cryptosporidium spp. detection. The prevalences of zoonotic parasites in both dog feces and soil have implications for the spread of human disease in these areas.
Asunto(s)
Perros/parasitología , Heces/parasitología , Suelo/parasitología , Zoonosis/parasitología , Ancylostoma/aislamiento & purificación , Animales , Ascaris/aislamiento & purificación , Prevalencia , Toxocara/aislamiento & purificación , Trichuris/aislamiento & purificaciónRESUMEN
We present the results of a paleoparasitologic, paleogenetic and paleobotanic analysis of coprolites recovered during the excavation of the church La Concepción in Santa Cruz de Tenerife. Coprolites (n = 4) were rehydrated and a multidisciplinary analysis was conducted. The paleobotanic analysis showed numerous silicates, seeds and fruits of the family Moraceae. In the paleoparasitologic study, Ascaris sp. eggs (n = 344) were identified. The paleogenetic results confirmed the Ascaris sp. infection as well as the European origin of human remains. These findings contribute to our knowledge of ancient helminthes infections and are the first paleoparasitological record of Ascaris sp. infection in Spain.
Asunto(s)
Ascaris/aislamiento & purificación , Heces , Fósiles , Moraceae , Paleontología , Silicatos/análisis , Animales , ADN de Helmintos , ADN Mitocondrial , Heces/química , Heces/parasitología , Frutas , Humanos , Reacción en Cadena de la Polimerasa , Semillas , EspañaRESUMEN
The zoonotic potential of Ascaris infecting pigs has stimulated studies of molecular epidemiology with internal transcribed spacer 1 (ITS1) as the target. The aim of this study was to determine the value of Ascaris ITS1 as a molecular marker through assessing the intra-individual genetic diversity of Ascaris isolates from two geographical areas of Brazil. DNA was extracted from single isolated eggs, ITS1 PCR was performed, and the PCR products were cloned and sequenced. Clone analysis showed high ITS1 intra-individual variability revealed by 2-4 ITS1 genotypes/haplotypes per sample (egg). Two genotypes, G1 and G6, and 13 new haplotypes were detected and characterized. The most prevalent in humans, G1 and/or the Brazilian G6, were detected in all samples. Except for genotype G1, no relationship was observed between Brazilian ITS1 genotypes/haplotypes and those previously described in China, Bangladesh, Japan, United Kingdom, Australia, and Denmark, with respect to geographic origin or host affiliation. However, an association between the two geographically separated Brazilian ITS1 isolates was observed. The ITS1 intra-individual variability revealed in this study indicated that the use of this genetic region to discriminate human and pig Ascaris genotypes should be reconsidered.
Asunto(s)
Ascaris , Variación Genética , Animales , Ascariasis/epidemiología , Ascariasis/parasitología , Ascaris/clasificación , Ascaris/genética , Ascaris/aislamiento & purificación , Brasil/epidemiología , ADN de Helmintos/análisis , ADN de Helmintos/genética , ADN de Helmintos/aislamiento & purificación , ADN Espaciador Ribosómico/genética , Genotipo , Humanos , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , Análisis de Secuencia de ADN , Porcinos/parasitología , Enfermedades de los Porcinos/epidemiología , Enfermedades de los Porcinos/parasitologíaRESUMEN
Paleoparasitological studies using microscopy showed that Ascarisand Trichuris trichiura are the human intestinal parasites most found in archaeological sites. However, in pre-Columbian South American archaeological sites, Ascaris is rare. In this work we standardized a molecular methodology for Ascaris diagnosis directly from ancient DNA retrieved from coprolites. Using cythochrome b gene (142 bp) target, ancient DNA sequences were retrieved from South American samples, negative by microscopy. Moreover, the methodology applied was sensitive enough to detect ancient DNA extracted from 30 Ascaris eggs from an European coprolite. These results revealed a new scenery for the paleodistribution of Ascaris in South America.
Asunto(s)
Ascariasis , Ascaris/genética , Citocromos b/genética , ADN de Helmintos/aislamiento & purificación , Heces/parasitología , Paleopatología/métodos , Animales , Ascariasis/diagnóstico , Ascariasis/historia , Ascaris/aislamiento & purificación , Citocromos b/química , ADN de Helmintos/química , ADN de Helmintos/genética , Historia Antigua , Humanos , Reacción en Cadena de la Polimerasa , Sensibilidad y Especificidad , Análisis de Secuencia de ADN , América del SurRESUMEN
Paleoparasitological studies using microscopy showed that Ascarisand Trichuris trichiura are the human intestinal parasites most found in archaeological sites. However, in pre-Columbian South American archaeological sites, Ascaris is rare. In this work we standardized a molecular methodology for Ascaris diagnosis directly from ancient DNA retrieved from coprolites. Using cythochrome b gene (142 bp) target, ancient DNA sequences were retrieved from South American samples, negative by microscopy. Moreover, the methodology applied was sensitive enough to detect ancient DNA extracted from 30 Ascaris eggs from an European coprolite. These results revealed a new scenery for the paleodistribution of Ascaris in South America.
Asunto(s)
Animales , Historia Antigua , Humanos , Ascariasis , Ascaris/genética , Citocromos b/genética , ADN de Helmintos/aislamiento & purificación , Heces/parasitología , Paleopatología/métodos , Ascariasis/diagnóstico , Ascariasis/historia , Ascaris/aislamiento & purificación , Citocromos b/química , ADN de Helmintos/química , ADN de Helmintos/genética , Reacción en Cadena de la Polimerasa , Sensibilidad y Especificidad , Análisis de Secuencia de ADN , América del SurRESUMEN
The presence of helminths and protozoans in public squares and lawns of the city of Maringá, southern Brazil, during winter and summer was assessed in order to evaluate their seasonal fluctuations in relation to edaphic and climatic factors. Samples were collected from January 2003 through June 2004 in 90% (13) of all public squares covered by sand, and in 30% (4) of all lawns used as leisure areas. The samples were analysed quantitatively by modified centrifugal-flotation and sedimentation in water techniques, and qualitatively by a method based on positive larval thermo-hydrotropism. Meteorological data were recorded, and physical, chemical and structural characteristics of the soil were analysed. One hundred and thirty samples of sand from squares, 65 in summer and 65 in winter, and 40 samples of grass from lawns, 20 in each season, were collected. All samples from lawns, 62 (95.38%) from squares in winter and 45 (69.23%) in summer, contained protozoans and/or helminths. Eggs of Toxocara spp. were the most frequently observed parasites in both winter and summer in squares (P < 0.0001) and in lawns (P = 0.6142), being equally distributed among the different locations (P = 0.2038). Species diversity was lower in winter; fewer parasites were found in summer. This region, with a tropical climate and a mild winter dry season, has favourable edaphic and climatic conditions for soil contaminants to persist year-round. In addition, the high frequency of animals such as dogs and cats and the poor sanitary measures in force made it possible for zoonoses to be transmitted in the public spaces.
Asunto(s)
Eucariontes/aislamiento & purificación , Helmintos/aislamiento & purificación , Instalaciones Públicas , Estaciones del Año , Microbiología del Suelo , Clima Tropical , Ancylostomatoidea/aislamiento & purificación , Anquilostomiasis/transmisión , Animales , Ascaris/aislamiento & purificación , Biodiversidad , Brasil , Gatos , Reservorios de Enfermedades , Perros , Eimeria/aislamiento & purificación , Humanos , Isospora/aislamiento & purificación , Recuento de Huevos de Parásitos , Toxascariasis/transmisión , Toxocara/aislamiento & purificación , ZoonosisAsunto(s)
Ascaris/aislamiento & purificación , Heces/parasitología , Inmunoglobulina E/sangre , Hipersensibilidad Respiratoria/parasitología , Infecciones del Sistema Respiratorio/parasitología , Animales , Biomarcadores/sangre , Humanos , Inmunoglobulina E/inmunología , Pruebas de Sensibilidad Parasitaria , Hipersensibilidad Respiratoria/sangre , Infecciones del Sistema Respiratorio/sangreAsunto(s)
Humanos , Animales , Ascaris/aislamiento & purificación , Heces/parasitología , Inmunoglobulina E/sangre , Hipersensibilidad Respiratoria/parasitología , Infecciones del Sistema Respiratorio/parasitología , Biomarcadores/sangre , Inmunoglobulina E/inmunología , Pruebas de Sensibilidad Parasitaria , Hipersensibilidad Respiratoria/sangre , Infecciones del Sistema Respiratorio/sangreRESUMEN
Vitamin A supplementation has consistently reduced infant mortality and the severity of pathogen-induced diarrhea. The mechanism by which vitamin A modulates the mucosal immune response to produce these effects remains poorly defined. To address this issue, stools collected during the summer months from 127 Mexican children 5-15 mo old enrolled in a larger, randomized, double-blind, placebo-controlled, vitamin A supplementation trial were screened for interleukin (IL)-4, IL-6, interferon-gamma (IFN-gamma), and gastrointestinal pathogens. Fecal cytokine values were categorized into 3 levels (undetectable,
Asunto(s)
Diarrea/inmunología , Suplementos Dietéticos , Inmunidad Mucosa/efectos de los fármacos , Vitamina A/farmacología , Animales , Ascariasis/inmunología , Ascaris/aislamiento & purificación , Estatura , Peso Corporal , Control de Enfermedades Transmisibles , Diarrea/parasitología , Heces/parasitología , Femenino , Humanos , Lactante , Masculino , México , Factores Socioeconómicos , Células TH1/microbiología , Células Th2/inmunologíaRESUMEN
A direct relationship exists between the intensity of hookworm infection and blood loss. Other parasites may also contribute to blood loss. Our objective was to assess the relationship between the intensity of soil-transmitted helminth infections and anemia in pregnant women in a highly endemic area of Peru. Recruitment occurred between April and November 2003. Overall, 47.31% of 1,042 women had anemia (hemoglobin < 11 g/dL), 47.22% were infected with hookworm and 82.25% with Trichuris. Prevalences of infections were not associated with anemia. However, those infected with moderate and heavy intensities of hookworm infection (OR = 1.84; 95% CI: 1.06, 3.17) and those with moderate and heavy intensities of both hookworm and Trichuris infections (OR = 2.13; 95% CI: 1.10, 4.13) were more likely to suffer from anemia than women having no or light intensities. These results support routine anthelminthic treatment within prenatal care programs in highly endemic areas.
Asunto(s)
Anemia/epidemiología , Infecciones por Nematodos/complicaciones , Complicaciones Parasitarias del Embarazo/epidemiología , Suelo/parasitología , Adolescente , Adulto , Ancylostomatoidea/aislamiento & purificación , Animales , Ascaris/aislamiento & purificación , Femenino , Hemoglobinas/análisis , Humanos , Infecciones por Nematodos/epidemiología , Infecciones por Nematodos/parasitología , Infecciones por Nematodos/transmisión , Recuento de Huevos de Parásitos , Perú , Embarazo , Complicaciones Parasitarias del Embarazo/parasitología , Segundo Trimestre del Embarazo , Trichuris/aislamiento & purificaciónRESUMEN
To support the development of safe and feasible sludge management strategies, the accumulation rates of sludge and its characteristics were studied in four primary wastewater stabilization ponds (WSPs) in central Mexico (three facultative and one anaerobic). The accumulation rates and distribution of sludge were determined by measuring the thickness of the sludge layer at 8-40 locations throughout each pond. The average, per capita sludge accumulation rates ranged from 0.021 to 0.036m(3)/person/yr. In the anaerobic pond the sludge distribution was uniform throughout the pond, whereas in the three facultative ponds most of the sludge accumulated directly in front of the inlet. To measure the horizontal and vertical variation in the sludge characteristics, sludge cores were collected from 3 to 7 locations in three of the ponds. Each core was divided into 4 sub-samples in which various physical, chemical, and microbiological parameters were measured. In addition, the inactivation of several pathogen indicator organisms was studied in a batch of sludge for 7 months. Based on the microbiological results, it is concluded that reasonable estimates of the inactivation of fecal coliform bacteria, fecal enterococci, F+ coliphage, somatic coliphage, and Ascaris eggs in WSP sludge in central Mexico can be made using first-order rate constants of 0.1, 0.1, 0.01, 0.001, and 0.001d(-1), respectively. From the observed changes in the concentrations of total solids and the volatile to fixed solids ratio, empirical equations were developed to describe anaerobic degradation and compression, which are the two most important processes affecting the volume of sludge after its deposition.
Asunto(s)
Bacterias Anaerobias/fisiología , Reactores Biológicos , Aguas del Alcantarillado/microbiología , Eliminación de Residuos Líquidos/métodos , Microbiología del Agua , Purificación del Agua/métodos , Animales , Ascaris/aislamiento & purificación , Biodegradación Ambiental , Colifagos/aislamiento & purificación , Enterobacteriaceae/aislamiento & purificación , Enterobacteriaceae/patogenicidad , Enterococcus/aislamiento & purificación , Enterococcus/patogenicidad , Monitoreo del Ambiente , México , Óvulo , Aguas del Alcantarillado/químicaRESUMEN
The paper evaluates and models helminth eggs removal in a combined UASB (Upflow Anaerobic Sludge Blanket) reactor-maturation pond system (one baffled and one unbaffled pond in parallel). The system is comprised of demonstration-scale units, treating actual domestic sewage from Itabira city, Brazil. The paper addresses the following points: (i) removal of helminth eggs from the wastewater in the system; (ii) comparison of the observed removal efficiency with the predictions using the Ayres et al. model; (iii) accumulation of helminth eggs in the sludge; (iv) viability of eggs in the sludge; (v) distribution of helminth species in the sludge. The removal efficiency of helminth eggs from the wastewater in both ponds was 100% for most of the time (0 counts in the final effluent). The predictions of helminth eggs removal according to the Ayres et al. model can be considered reasonable. After one year of operation, 88% of the eggs in the sludge remained viable. Helminth eggs counts in the sludge tended to decrease along the baffled pond length (from first to last compartment). The prevailing helminth species found in the sludge from both ponds was Ascaris lumbricoides.
Asunto(s)
Ascaris/aislamiento & purificación , Modelos Teóricos , Eliminación de Residuos Líquidos/métodos , Purificación del Agua/métodos , Animales , Biodegradación Ambiental , Predicción , Óvulo , Clima Tropical , Movimientos del AguaRESUMEN
For the first time, a jar of embalming rejects was studied in search for helminth parasite eggs. This kind of jar was used to put discarded material by Egyptian embalmers during mummification process. Ascaris lumbricoides and Taenia saginata eggs were found in the linen and strip fragment contents of the jar, dated of 2,715-2,656 years ago.