Performance of sewage treatment technologies for the removal of Cryptosporidium sp. and Giardia sp.: Toward water circularity.

Cryptosporidium sp. and Giardia sp. are parasites that cause diseases in the population. Most of parasite diseases regarding the consumption of drinking water polluted with sewage are caused by Cryptosporidium sp. or Giardia sp. it is because of the incomplete disinfection of the wastewater treatment. Therefore, in this work the removal or inactivation efficiency of different treatment technologies presented by around 40 scientific studies was evaluated, with a view to water circularity. For Cryptosporidium sp., we conclude that the most efficient secondary technologies are aerobic technologies, which remove between 0.00 and 2.17 log units (Ulog), with activated sludge presenting the greatest efficiency, and that the tertiary technologies with the greatest removal are those that use ultrasound, which reach removal values of 3.17 Ulog. In the case of Giardia sp., the secondary technologies with the greatest removal are anaerobic technologies, with values between 0.00 and 3.80 Ulog, and the tertiary technologies with the greatest removal are those that combine filtration with UV or a chemical disinfection agent. Despite the removal values obtained, the greatest concern remains detecting and quantifying the infectious forms of both parasites in effluents; therefore, although the technologies perform adequately, discharge effluents must be monitored with more sensitive techniques, above all aiming for circularity of the treated water in a context of the water scarcity that affects some parts of the world.

High occurrence of viable forms of Cryptosporidium and Giardia in domestic sewage from an agricultural region of Brazil.

Cryptosporidium and Giardia are the main etiologies of waterborne outbreaks caused by protozoa. These parasites are commonly detected in wastewater; however, there is little knowledge about the concentration of viable forms in treated sewage, mainly in small communities. To understand more about the presence of viable oocysts and cysts in domestic sewage, we monitored the affluent and effluent of a wastewater treatment plant (WWTP) in inner-city Brazil. Ten samplings and seven follow-ups were performed in 2020. Samples were concentrated by centrifugation, filtration and purified by fluctuation. Viability was accessed by propidium-monoazide (PMA) associated with nPCR and qPCR. Both viable protozoa were detected in all raw sewage samples (average: 438.5 viable oocysts/L). Regarding treated sewage, Cryptosporidium was detected in all of the samples (average: 92.8 viable oocysts/L) and Giardia was detected in 70% with viable cysts in 30%. Considering the follow-ups, 31.17% of Cryptosporidium viable oocysts remained in the effluent after the treatment. High amounts of Cryptosporidium and a high frequency of Giardia were detected, therefore both arrived at WWTP and were discharged into the river. These alert the presence of agro-industrial effluents into domestic sewage and demonstrated the effectiveness of the concentration technique for monitoring protozoa in wastewater.

Human health risk assessment for (re)emerging protozoan parasites in surface water used for public supply and recreational activities.

Gastrointestinal diseases caused by protozoan parasites remain a major challenge in developing countries and ingestion of contaminated surface water represents one of the main sources by which these diseases are contracted. This study assessed the risk of infection and diseases caused by Cryptosporidium spp. and Giardia sp. due to ingestion of surface water used for public supply and recreational activities, focusing on the southeastern Brazilian Pardo River and applying the USEPA 1623 method to quantify (oo)cyst concentrations. Infection and disease probabilities due to ingestion of drinking water or during recreational activities were estimated using the Quantitative Microbial Risk Assessment (QMRA) approach. Mean concentrations of Cryptosporidium spp. and Giardia sp. in surface water ranged from 0.2 to 0.4 oocysts L-1 and 0.2 to 4.4 cysts L-1, respectively. Considering public water supply, annual infection probabilities were higher for adults than children and exceeded the USEPA limit; also, disease probabilities were higher for adults than children. For recreational activities, annual infection and disease probabilities were higher for children, followed by men and women. The occurrence of both parasites likely reflects raw sewage discharge, effluent from sewage treatment plants, and diffuse sources of pollution, such as runoff from pasture lands and deforested riparian forest corridors. Our results highlight substantial infection risks by both parasite types after conventional treatment of water used for public supply and also call for careful monitoring of water bodies used for recreational purposes.

Surveillance of Giardia and Cryptosporidium in sewage from an urban area in Brazil.

Cryptosporidium and Giardia are protozoan parasites that cause diarrhea in humans and animals. Molecular characterization of these pathogens in sewage may provide insight on their occurrence and prevalence in Brazil. This study aimed to investigate the presence of Giardia and Cryptosporidium in raw and treated sewage from Londrina, Paraná, Brazil. Samples were collected every two weeks during a year. Samples were concentrated, then DNA was extracted and subjected to a nested PCR targeting the Giardia 18S rRNA gene and the Cryptosporidium 18S rRNA gene. Species of Cryptosporidium were characterized by restriction fragment length polymorphism (RFLP). All raw sewage and 76% of the treated sewage were positive for Giardia; 84% of raw sewage samples and 8% of treated sewage were positive for Cryptosporidium. C. muris, C. hominis, C. baileyi, C. parvum and C. suis were detected in 100%, 19%, 9%, 9% and 4% of raw sewage, respectively. C. muris was the only species found in treated sewage. Multiple species of Cryptosporidium were present in 19.04% of the raw sewage. Treated sewage water can pose a threat to human health. The speciation of Cryptosporidium revealed the presence of non-common zoonotic species as C. suis and C. muris.

Giardia spp. and Cryptosporidium spp. removal efficiency of a combined fixed-film system treating domestic wastewater receiving hospital effluent.

Giardia and Cryptosporidium have caused numerous outbreaks of diarrhea as a result of the ingestion of water contaminated with sewage. In Brazil, the efficiency of Giardia and Cryptosporidium removal by combined fixed-film systems has rarely been studied. The aims of the present study were therefore to verify the removal efficiency of Giardia and Cryptosporidium by a combined system (anaerobic/anoxic filter and aerated submerged biofilter) and to perform the genetic characterization of these parasites. The (oo)cysts were detected by centrifuge concentration and membrane filtration from raw sewage, effluents, adhered biomass, and sludge samples. Immunofluorescence assay and differential interference contrast microscopy were used for the visualization of the (oo)cysts. Nested PCR was applied to confirm Giardia and Cryptosporidium. Giardia and Cryptosporidium were detected in 27% and 5.5% of the 144 analyzed samples of raw sewage and effluents, respectively. A total of 33,000 cysts/L were recovered in the adhered biomass samples (n = 25) from different points of the aerated submerged biofilter, while 6000 oocysts/L were registered in a single point. An average of 11,800 cysts/L were found in the sludge samples (n = 5). The combined system exhibited a removal efficiency of Giardia cysts of 1.8 ± 1.0 log removal. The C and BIV assemblages of Giardia were identified in the raw sewage while AII was found in the treated effluent sample. It was not possible to calculate the removal efficiency of Cryptosporidium oocysts by the combined system. The combined system exhibited some potential as a suitable treatment for the removal of parasites from sewage.

Surveillance of Giardia and Cryptosporidium in sewage from an urban area in Brazil / Monitoramento de Giardia e Cryptosporidium em esgoto de uma área urbana no Brasil

Abstract Cryptosporidium and Giardia are protozoan parasites that cause diarrhea in humans and animals. Molecular characterization of these pathogens in sewage may provide insight on their occurrence and prevalence in Brazil. This study aimed to investigate the presence of Giardia and Cryptosporidium in raw and treated sewage from Londrina, Paraná, Brazil. Samples were collected every two weeks during a year. Samples were concentrated, then DNA was extracted and subjected to a nested PCR targeting the Giardia 18S rRNA gene and the Cryptosporidium 18S rRNA gene. Species of Cryptosporidium were characterized by restriction fragment length polymorphism (RFLP). All raw sewage and 76% of the treated sewage were positive for Giardia; 84% of raw sewage samples and 8% of treated sewage were positive for Cryptosporidium. C. muris, C. hominis, C. baileyi, C. parvum and C. suis were detected in 100%, 19%, 9%, 9% and 4% of raw sewage, respectively. C. muris was the only species found in treated sewage. Multiple species of Cryptosporidium were present in 19.04% of the raw sewage. Treated sewage water can pose a threat to human health. The speciation of Cryptosporidium revealed the presence of non-common zoonotic species as C. suis and C. muris.

Resumo Cryptosporidium e Giardia são protozoários causadores de diarreia em animais e humanos. A caracterização molecular destes protozoários em esgoto pode prover dados ainda desconhecidos da ocorrência de espécies. O objetivo do presente estudo foi monitorar a ocorrência de Giardia e espécies de Cryptosporidium em esgoto bruto e tratado em uma estação de tratamento de esgoto (ETE) de Londrina, Paraná. Amostras de esgoto bruto e tratado foram coletadas no período de um ano, com periodicidade quinzenal. A ocorrência destes protozoários foi caracterizada por meio de concentração das amostras e posterior extração de DNA seguida de nested-PCR para amplificação de fragmentos dos genes 18S rRNA de Giardia e 18S rRNA de Cryptosporidium. A caracterização das espécies de Cryptosporidium foi realizada por meio de análise por polimorfismo de comprimento do fragmento de restrição (RFLP) dos produtos obtidos. Foram coletadas no total 25 amostras de cada, esgoto bruto e esgoto tratado. Para Giardia, todas as amostras de esgoto bruto e 76% das de esgoto tratado foram positivas. Cryptosporidium esteve presente em 84% das amostras de esgoto bruto e em 8% do tratado. No esgoto tratado foi encontrado apenas C. muris, já nas amostras de esgoto bruto foram encontradas cinco espécies: C. muris, C. hominis, C. baileyi, C. suis e C. parvum em 100%, 19%, 9%, 9% e 4%, respectivamente. A presença de espécies mistas foi observada em 19,04% das amostras. A presença de Giardia e Cryptosporidium em esgoto tratado pode pôr em risco a saúde humana. A discriminação de espécies de Cryptosporidium revelou a presença de espécies zoonóticas incomuns como C. suis e C. muris.

Molecular surveillance of Cryptosporidium and Giardia duodenalis in sludge and spent filter backwash water of a water treatment plant.

The purpose of this study was to monitor the presence of Cryptosporidium spp. and Giardia duodenalis in a water treatment plant (WTP) using settling sludge and backwash water (BW) samples in previous and post the deflocculation of polyaluminium chloride (PAC) flacks. Eleven collections were performed. BW and settling sludge (SSF) were concentrated by calcium carbonate flocculation, and another aliquot of settling sludge (SSC) by centrifugation. The samples were divided as follows: Group A, containing 33 samples without degradation of PAC flakes, and Group B, with degradation by alkalinization with 10 M NaOH. Sample DNA was extracted with a commercial kit, and nested polymerase chain reaction (PCR) was used to detect Cryptosporidium and G. duodenalis. All samples from Group A were negative for Cryptosporidium spp., and 6.1% (2/33) were positive for G. duodenalis in SSC samples. While the absence of Cryptosporidium may be due to a low contamination level of the water resource, the presence of G. duodenalis indicates contamination of the raw water. The detection of G. duodenalis in SSC samples indicates that this detection method was the most effective. The 33 samples from Group B were negative for both protozoa, probably due to the presence of aluminium and humic substances.

Performance comparison of three methods for detection of Giardia spp. cysts and Cryptosporidium spp. oocysts in drinking-water treatment sludge.

Detecting pathogenic protozoa in drinking-water treatment sludge is a challenge as existing methods are complex, and unfortunately, there are no specific technical standards to follow. Selecting an efficient analytical method is imperative in developing countries, such as Brazil, in order to evaluate the risk of parasite infection. In this context, three methods to detect Giardia spp. cysts and Cryptosporidium spp. oocysts were tested in sludge generated when water with protozoa and high turbidity was treated. Jar testing was carried out using polyaluminium chloride as a coagulant to generate the residue to be analyzed. The results showed that calcium carbonate flocculation with reduced centrifugation and immunomagnetic separation obtained the highest recoveries in the tested matrix showing 60.2% ± 26.2 for oocysts and 46.1% ± 5 for cysts. The other two methods, the first using the ICN 7× cleaning solution and the second considering the acidification of the sample, both followed by the immunomagnetic separation step, also presented high recoveries showing 41.2% ± 43.3 and 37.9% ± 52.9 for oocysts and 11.5% ± 85.5 and 26% ± 16.3 for cysts, respectively. Evidently, these methods and others should be studied in order to make it possible to detect protozoa in settled residue.

Does the use of tubular digesters to treat livestock waste lower the risk of infection from Cryptosporidium parvum and Giardia lamblia?

Worldwide, high incidences of cryptosporidiosis and giardiasis are attributed to livestock waste. Quantitative microbial risk assessment can be used to estimate the risk of livestock related infections from Cryptosporidium parvum and Giardia lamblia. The objective of this paper was to assess the occupational and public health risks associated with management of raw and anaerobically digested livestock waste in two rural communities in Costa Rica based on fomite, soil and crop contamination and livestock waste management exposure pathways. Risks related to cattle waste were greater than swine waste due to cattle shedding more (oo)cysts. Cryptosporidium parvum also posed a greater risk than Giardia lamblia in all exposure pathways due to livestock shedding high loads of Cryptosporidium parvum oocysts and oocysts' lower inactivation rates during anaerobic digestion compared with Giardia lamblia cysts. The risk of infection from exposure to contaminated soil and crops was significantly lower for a community using tubular anaerobic digesters to treat livestock waste compared to a community where the untreated waste was applied to soil. The results indicate that treatment of livestock waste in small-scale tubular anaerobic digesters has the potential to significantly decrease the risk of infection below the World Health Organization's acceptable individual annual risk of infection (10-4).

Ciliated protozoa community of a combined UASB-activated sludge system in southeastern Brazil.

The aims of the present study were (1) to evaluate the abundance and taxonomic composition of ciliated protozoa in the activated sludge of a full-scale combined anaerobic-aerobic system operating in a tropical country and (2) to study the relationship between the effluent quality, the physicochemical variables, and the ciliates present in the operating system. The total ciliate fauna of the activated sludge of the Piçarrão Wastewater Treatment Plant (Piçarrão WWTP) was composed of 36 morphospecies belonging to 33 genera. These included 21 species observed in the activated sludge samples on the day of collection and 15 species found in cultures. The activated sludge of the Piçarrão WWTP contained a diversified ciliate community composed mainly of indicator organisms. The most frequently occurring morphospecies were Aspidisca cicada, Vorticella spp., Gastronauta aloisi, Acineria uncinata, and Epistylis plicatilis complex. These results showed that satisfactory operating conditions prevailed at the Piçarrão WWTP. In the combined UASB-activated sludge system, the presence of Aspidisca cicada suggests the occurrence of denitrification in the process while the presence of Acineria uncinata and G. alosi indicates the removal of carbonaceous organic matter.

Raw sewage as breeding site to Aedes (Stegomyia) aegypti (Diptera, culicidae).

The selection of oviposition sites by females of Aedes (Stegomyia) aegypti is a key factor for the larval survival and egg dispersion and has a direct influence in vector control programs. In this study, we evaluated the aspects of reproductive physiology of Ae. aegypti mosquitoes tested in the presence of raw sewage. Ae. aegypti females were used in oviposition bioassays according to two methodologies: (i) choice assay, in which three oviposition substrates were offered in the same cage: treatment (raw sewage), positive control (distilled water) and negative control (1% sodium hypochlorite) and; (ii) no choice assay, in which only one substrate was available. The physicochemical and microbiological analysis of the raw sewage used in this study indicated virtually no levels of chlorine, low levels of dissolved oxygen and high levels of nitrogenous compounds as well as the presence of Escherichia coli and total fecal coliforms. After 72h of oviposition, the eggs were counted and there was no statistically significant difference (p>0.05) in the oviposition rate between raw sewage and positive control in both methodologies. In addition, females were dissected to evaluate egg-retention and also there were no appreciable differences in egg retention even when raw sewage was the only substrate offered. The data also showed that egg hatching and larvae development occurred normally in the raw sewage. Therefore, the present study suggests that Ae. aegypti can adapt to new sites and lay eggs in polluted water, such as the raw sewage. These findings are of particular importance for the control and surveillance programs against Ae. aegypti in countries where the conditions of poor infrastructure and lack of basic sanitation are still an issue.

First report of predation of Giardia sp. cysts by ciliated protozoa and confirmation of predation of Cryptosporidium spp. oocysts by ciliate species.

Ciliated protozoa are important components of the microbial food web in various habitats, especially aquatic environments. These organisms are useful bioindicators for both environmental quality assessment and the wastewater purification process. The pathogenic parasitic protozoan species Giardia and Cryptosporidium represent a significant concern for human health, being responsible for numerous disease outbreaks worldwide. The predation of cysts and oocysts in 15 ciliate species from water and sewage samples collected in Campinas, São Paulo, Brazil were verified under laboratory conditions. The ciliated protozoan species were selected based on their mode of nutrition, and only bacterivorous and suspension-feeders were considered for the experiments. The species Blepharisma sinuosum, Euplotes aediculatus, Sterkiella cavicola, Oxytricha granulifera, Vorticella infusionum, Spirostomum minus, and Stentor coeruleus ingested cysts and oocysts, the resistance forms of Giardia spp. and Cryptosporidium spp., respectively. This is the first time that the ingestion of Giardia cysts by ciliated protozoa has been reported. These findings may contribute to a better understanding of the biological removal of these pathogens from aquatic environments.

Identificação de helmintos encontrados em uma estação de tratamento de esgoto de Feira De Santana, Bahia, Brasil / Identification of helminths found in a sewage treatment plant in Feira De Santana, Bahia, Brazil / Identificación de helmintos encontrados en una estación de tratamiento de alcantarilla De Feira De Santana, Bahía, Brasil

O objetivo desse trabalho foi fazer a descrição morfológica e a identificação de Nematoda encontrados em uma estação de tratamento de esgoto de Feira de Santana, BA, Brasil. Foram coletadas 56 amostras de 500 mL em todos os pontos das etapas aeróbias do tratamento. As amostras foram processadas para estudo em microscopia óptica de campo claro (MO) e microscopia eletrônica de varredura (MEV). Foram encontradas larvas L1e L4, classificadas de acordo com o tamanho. As larvas L1 apresentaram as seguintes medidas de comprimento Md = 255,0?m; diâmetro Md = 15,0?m; vestíbulo bucal Md = 10,0?m; esôfago Md = 82,5?m; e cauda Md = 26,2?m. As larvas L4 apresentaram as seguintes medidas de comprimento Md = 740,0?m; diâmetro Md = 42,0?m; vestíbulo bucal Md = 22,5?m; esôfago Md = 200,0?m; e cauda Md = 47,5?m. Fêmeas adultas também foram encontradas, caracterizando-se por apresentam esôfago rabditoide, maturação sexual com presença de ovos na tuba uterina em diferentes fases de formação embrionária. Alguns ovos foram vistos larvados, sugerindo um padrão de larviparidade. Os vermes foram considerados de vida livre e classificadas como da Ordem Rhabditida, Família Strongyloidae e Gênero Strongyloides.

The objective of this work was to morphologically describe and identify Nematoda found in a sewage treatment plant in Feira de Santana, BA, Brazil. A total of 56 samples with 500-mL each were collected at all points in the aerobic treatment stages. The samples were processed for bright light microscopy (LM) and scanning electron microscopy (SEM). L1 and L4 larvae were found, classified according to size. L1 larvae presented the following measurements: Md=255.0-?m length; Md=15.0-?m diameter; Md=10.0-?m oral vestibule; Md=82.5-?m esophagus; and Md=26.2 ?m tail. L4 larvae presented the following measurements: Md=740.0-?m length; Md=42.0-?m diameter; Md=22.5-?m oral vestibule; Md=200.0-?m esophagus; and Md=47.5-?m tail. Adult females have also been found, characterized by rhabditoid esophagus, sexual maturation with presence of eggs in the uterine tube at different stages of embryo formation. Some eggs were seen at larvae stage, suggesting a pattern of larvae parity. The worms were considered as free-living and classified in the Rhabditida order, Strongyloidae Family and Strongyloides genus.

El objetivo de ese trabajo fue realizar la descripción morfológica y la identificación de Nematodo encontrados en una estación de tratamiento de alcantarilla de Feira de Santana, BAHIA, Brasil. Fueron recogidas 56 muestras de 500 mL en todos los puntos de las etapas aerobias del tratamiento. Las muestras fueron procesadas para estudio en microscopía óptica de campo claro (MO) y microscopia electrónica de barrido (MEB). Se encontraron larvas L1 y L4, clasificados según el tamaño. Las larvas L1 presentaron las siguientes medidas de longitud Md=255.0?m; diámetro Md=15.0?m; vestíbulo oral Md=10.0 µm; esófago Md=82,5?m; y cola Md=26.2?m. Las larvas L4 presentaron las siguientes medidas de longitud Md=740.0?m; diámetro Md=42.0?m; vestíbulo oral Md=22,5?m; esófago Md=200.0?m; y cola Md=47.5?m. También se han encontrado hembras adultas, caracterizándose por presentar esófago rabditoide, maduración sexual con presencia de huevos en las trompas uterina en diferentes etapas de la formación del embrión. Algunos huevos fueron vistos larvados, sugiriendo un estándar de larviparidad. Los gusanos fueron considerados de vida libre y clasificados como de Orden Rhabditida, Familia Strongyloidae y género Strongyloides.

Identificação de helmintos encontrados em uma estação de tratamento de esgoto de Feira De Santana, Bahia, Brasil / Identification of helminths found in a sewage treatment plant in Feira De Santana, Bahia, Brazil / Identificación de helmintos encontrados en una estación de tratamiento de alcantarilla De Feira De Santana, Bahía, Brasil

O objetivo desse trabalho foi fazer a descrição morfológica e a identificação de Nematoda encontrados em uma estação de tratamento de esgoto de Feira de Santana, BA, Brasil. Foram coletadas 56 amostras de 500 mL em todos os pontos das etapas aeróbias do tratamento. As amostras foram processadas para estudo em microscopia óptica de campo claro (MO) e microscopia eletrônica de varredura (MEV). Foram encontradas larvas L1e L4, classificadas de acordo com o tamanho. As larvas L1 apresentaram as seguintes medidas de comprimento Md = 255,0?m; diâmetro Md = 15,0?m; vestíbulo bucal Md = 10,0?m; esôfago Md = 82,5?m; e cauda Md = 26,2?m. As larvas L4 apresentaram as seguintes medidas de comprimento Md = 740,0?m; diâmetro Md = 42,0?m; vestíbulo bucal Md = 22,5?m; esôfago Md = 200,0?m; e cauda Md = 47,5?m. Fêmeas adultas também foram encontradas, caracterizando-se por apresentam esôfago rabditoide, maturação sexual com presença de ovos na tuba uterina em diferentes fases de formação embrionária. Alguns ovos foram vistos larvados, sugerindo um padrão de larviparidade. Os vermes foram considerados de vida livre e classificadas como da Ordem Rhabditida, Família Strongyloidae e Gênero Strongyloides.(AU)

The objective of this work was to morphologically describe and identify Nematoda found in a sewage treatment plant in Feira de Santana, BA, Brazil. A total of 56 samples with 500-mL each were collected at all points in the aerobic treatment stages. The samples were processed for bright light microscopy (LM) and scanning electron microscopy (SEM). L1 and L4 larvae were found, classified according to size. L1 larvae presented the following measurements: Md=255.0-?m length; Md=15.0-?m diameter; Md=10.0-?m oral vestibule; Md=82.5-?m esophagus; and Md=26.2 ?m tail. L4 larvae presented the following measurements: Md=740.0-?m length; Md=42.0-?m diameter; Md=22.5-?m oral vestibule; Md=200.0-?m esophagus; and Md=47.5-?m tail. Adult females have also been found, characterized by rhabditoid esophagus, sexual maturation with presence of eggs in the uterine tube at different stages of embryo formation. Some eggs were seen at larvae stage, suggesting a pattern of larvae parity. The worms were considered as free-living and classified in the Rhabditida order, Strongyloidae Family and Strongyloides genus.(AU)

El objetivo de ese trabajo fue realizar la descripción morfológica y la identificación de Nematodo encontrados en una estación de tratamiento de alcantarilla de Feira de Santana, BAHIA, Brasil. Fueron recogidas 56 muestras de 500 mL en todos los puntos de las etapas aerobias del tratamiento. Las muestras fueron procesadas para estudio en microscopía óptica de campo claro (MO) y microscopia electrónica de barrido (MEB). Se encontraron larvas L1 y L4, clasificados según el tamaño. Las larvas L1 presentaron las siguientes medidas de longitud Md=255.0?m; diámetro Md=15.0?m; vestíbulo oral Md=10.0 µm; esófago Md=82,5?m; y cola Md=26.2?m. Las larvas L4 presentaron las siguientes medidas de longitud Md=740.0?m; diámetro Md=42.0?m; vestíbulo oral Md=22,5?m; esófago Md=200.0?m; y cola Md=47.5?m. También se han encontrado hembras adultas, caracterizándose por presentar esófago rabditoide, maduración sexual con presencia de huevos en las trompas uterina en diferentes etapas de la formación del embrión. Algunos huevos fueron vistos larvados, sugiriendo un estándar de larviparidad. Los gusanos fueron considerados de vida libre y clasificados como de Orden Rhabditida, Familia Strongyloidae y género Strongyloides.(AU)

Impact of tilling on biosolids drying and indicator microorganisms survival during solar drying process.

As biosolids application to croplands becomes a common practice, potential harm from pathogenic microbes needs to be mitigated for its safe reuse. The objective of this study was to investigate the impacts of tilling treatment on biosolids drying and microbial inactivation during the solar drying process in a semi-arid and temperate region. Solar drying experiments were conducted in sand and gravel dying beds open-to-the-air and under covering structures with biosolids to 20 cm depth from 2004 to 2006. Anaerobically- and Aerobically-digested biosolids received different tilling treatments throughout the drying process, while a series of biosolids samples were collected to determine the impact on total solids and microbial concentrations (Salmonella spp and heminth ova). Tilling treatments appeared to enhance the biosolids drying and microbial inactivation. Tilling was more effective during the cold season compared with the summer season and tilling treatments were also helpful in elevating biosolids temperature by expediting biosolids drying. The combined effect of temperature increase and moisture decrease by tilling may have resulted in faster microbial inactivation, particularly for persistent helminth ova. It was concluded that incorporation of tilling into biosolids solar drying can expedite biosolids drying as well as microbial inactivation, and thus can be an effective measure for shortening the biosolids conversion to Class A biosolids in which pathogens are reduced to below detectable levels.

Employment of anaerobic reactors in real scale and polishing ponds for removal of eggs Ascaris suum of swine effluent / Emprego de reatores anaeróbios em escala real e lagoas de polimento para remoção de ovos de Ascaris suum de efluente de suinocultura

The swine confinement farms and the improper disposal of their wastes carry result in contamination of water and soil. On many farms is common slurry application to soil as a means of fertilization, but without any control over the quality of the effluent being released. What is a parasite Ascaris suum from pigs can infect humans, but is not given due importance to the presence of this contaminant as soil and water. In this work the effluent of a pig was treated in a system composed of anaerobic baffled reactor (ABR) and a UASB followed by polishing ponds for removal of helminthes eggs. The experiment was conducted at the Hélio Barbosa Experimental Farm pig in the city of Igarapé / MG. Values found in the influent of helminthes eggs in the range from 2891 to 88,848 eggs L-1, while the effluent showed absence of eggs, showing the high efficiency of the treatment system. While the sludge ponds, it showed high concentration of viable eggs ranged from 10.1% to 59.8%, not being in conformity with the requirements for reuse in agriculture.(AU)

Os confinamentos suínos e a disposição inadequada desses dejetos trazem como consequência a contaminação de águas e do solo. Em muitas granjas é comum a aplicação dos dejetos ao solo como forma de fertilização, porém, sem nenhum controle sobre a qualidade do efluente que está sendo lançado. O Ascaris suum é um parasita de suínos que pode infectar humanos, porém não é dada a devida importância à presença deste como contaminante do solo e água. Neste trabalho o efluente de uma suinocultura foi tratado em um sistema composto por reator anaeróbio compartimentado (RAC) e um reator anaeróbio de manta de lodo UASB seguido de lagoas de polimento para remoção de ovos de helmintos. O experimento foi realizado na suinocultura da Fazenda Experimental hélio Barbosa em Igarapé/MG. No afluente foi encontrado valores de ovos de helmintos na faixa de 2.891 a 88.848 ovos L-1, enquanto o efluente apresentou ausência de ovos, mostrando a alta eficiência do sistema de tratamento. Quanto ao lodo das lagoas, este apresentou elevada concentração de ovos viáveis variando entre 10,1% a 59,8%, fora dos padrões preconizados para a sua utilização na agricultura.(AU)

Employment of anaerobic reactors in real scale and polishing ponds for removal of eggs Ascaris suum of swine effluent / Emprego de reatores anaeróbios em escala real e lagoas de polimento para remoção de ovos de Ascaris suum de efluente de suinocultura

The swine confinement farms and the improper disposal of their wastes carry result in contamination of water and soil. On many farms is common slurry application to soil as a means of fertilization, but without any control over the quality of the effluent being released. What is a parasite Ascaris suum from pigs can infect humans, but is not given due importance to the presence of this contaminant as soil and water. In this work the effluent of a pig was treated in a system composed of anaerobic baffled reactor (ABR) and a UASB followed by polishing ponds for removal of helminthes eggs. The experiment was conducted at the Hélio Barbosa Experimental Farm pig in the city of Igarapé / MG. Values found in the influent of helminthes eggs in the range from 2891 to 88,848 eggs L-1, while the effluent showed absence of eggs, showing the high efficiency of the treatment system. While the sludge ponds, it showed high concentration of viable eggs ranged from 10.1% to 59.8%, not being in conformity with the requirements for reuse in agriculture.

Os confinamentos suínos e a disposição inadequada desses dejetos trazem como consequência a contaminação de águas e do solo. Em muitas granjas é comum a aplicação dos dejetos ao solo como forma de fertilização, porém, sem nenhum controle sobre a qualidade do efluente que está sendo lançado. O Ascaris suum é um parasita de suínos que pode infectar humanos, porém não é dada a devida importância à presença deste como contaminante do solo e água. Neste trabalho o efluente de uma suinocultura foi tratado em um sistema composto por reator anaeróbio compartimentado (RAC) e um reator anaeróbio de manta de lodo UASB seguido de lagoas de polimento para remoção de ovos de helmintos. O experimento foi realizado na suinocultura da Fazenda Experimental hélio Barbosa em Igarapé/MG. No afluente foi encontrado valores de ovos de helmintos na faixa de 2.891 a 88.848 ovos L-1, enquanto o efluente apresentou ausência de ovos, mostrando a alta eficiência do sistema de tratamento. Quanto ao lodo das lagoas, este apresentou elevada concentração de ovos viáveis variando entre 10,1% a 59,8%, fora dos padrões preconizados para a sua utilização na agricultura.

Polymerase chain reaction and nested-PCR approaches for detecting Cryptosporidium in water catchments of water treatment plants in Curitiba, State of Paraná, Brazil.

INTRODUCTION: Cryptosporidium is an important protozoan cause of waterborne disease worldwide of concern to public health authorities. To prevent outbreaks of cryptosporidiosis, the monitoring of this parasite in drinking water is necessary. In the present work, the polymerase chain reaction (PCR) and nested-PCR techniques were used to detect Cryptosporidium in raw water from catchment points of four water treatment plants (WTP) in Curitiba, Paraná, Brazil. METHODS: First, DNA extraction techniques were tested in samples containing decreasing amount of oocysts in reagent water, and PCR and nested-PCR with specific primers for 18SSU rDNA of Cryptosporidium were conducted to determine their sensitivity. In reagent water, a commercial extraction kit provided the best analytical sensitivity, and PCR and nested-PCR allowed the detection of five and two oocysts, respectively, with the primers XIAOR/XIAOF and XIAO1F/XIAO2R. RESULTS: In the spiking experiments, only the PCR with the primers AWA995F/AWA1206R was successful at detecting concentrations of 0.1 oocysts/mL. Two catchments samples of raw water and/or water sludge from four WTPs were contaminated with Cryptosporidium. CONCLUSIONS: The application of the techniques to monitor Cryptosporidium in water and detect contamination in water catchments of WTPs in Curitiba are discussed in the present work.

Polymerase chain reaction and nested-PCR approaches for detecting Cryptosporidium in water catchments of water treatment plants in Curitiba, State of Paraná, Brazil

Introduction Cryptosporidium is an important protozoan cause of waterborne disease worldwide of concern to public health authorities. To prevent outbreaks of cryptosporidiosis, the monitoring of this parasite in drinking water is necessary. In the present work, the polymerase chain reaction (PCR) and nested-PCR techniques were used to detect Cryptosporidium in raw water from catchment points of four water treatment plants (WTP) in Curitiba, Paraná, Brazil. Methods First, DNA extraction techniques were tested in samples containing decreasing amount of oocysts in reagent water, and PCR and nested-PCR with specific primers for 18SSU rDNA of Cryptosporidium were conducted to determine their sensitivity. In reagent water, a commercial extraction kit provided the best analytical sensitivity, and PCR and nested-PCR allowed the detection of five and two oocysts, respectively, with the primers XIAOR/XIAOF and XIAO1F/XIAO2R. Results In the spiking experiments, only the PCR with the primers AWA995F/AWA1206R was successful at detecting concentrations of 0.1 oocysts/mL. Two catchments samples of raw water and/or water sludge from four WTPs were contaminated with Cryptosporidium. Conclusions The application of the techniques to monitor Cryptosporidium in water and detect contamination in water catchments of WTPs in Curitiba are discussed in the present work. .

Persistence of Giardia, Cryptosporidium, Rotavirus, and Adenovirus in treated sewage in São Paulo state, Brazil.

Abstract : The persistence of Giardia, Cryptosporidium, Rotavirus, and Adenovirus in samples of raw and treated sewage collected monthly in 2010 at the Biological Wastewater Treatment Plant of Ribeirão Preto, SP, Brazil, was analyzed. The USEPA Method 1623 was used to detect and quantify Giardia and Cryptosporidium. An enzyme immunoassay was carried out to test Rotavirus and Adenovirus antigen optical density (Rotascreen® and Adenoscreen®). The results show a significant decrease in the concentrations of Giardia, Rotavirus and Adenovirus (P < 0.05) and a trend of decreasing Cryptosporidium densities, without statistical significance. Giardia concentrations ranged from 120 to 2,200 cysts/L in raw sewage and from 0.45 to 3.5 cysts/L in treated sewage. Cryptosporidium concentration ranged from undetectable to 28.9 oocysts/L in raw sewage and undetectable to 1.05 oocysts/L in treated sewage. Rotavirus presented absorbance values that ranged from 1.17 ± 0.81 in raw sewage to 0.46 ± 0.32 in treated sewage. Adenovirus, in turn, presented absorbance values of 0.64 ± 0.20 in raw sewage and of 0.45 ± 0.04 in treated sewage. There was no significant seasonal tendency observed in the distribution of protozoa (oo)cysts and in the viral antigen density in the monthly sewage samples during 2010 (P > 0.05). Even though these pathogenic agents decreased after treatment, the remaining loads observed in treated sewage can reach the watercourses receiving it. Giardia, Cryptosporidium, Rotavirus, and Adenovirus are pathogens with very low infectious doses, representing a public health risk especially for vulnerable groups, such as children living near these watercourses and homeless people using this water for various purposes. Studies addressing the environmental persistence of opportunistic pathogens in watercourses are hugely important in the public health sphere, especially in developing countries, where economic, social, cultural, and environmental factors still persist that are favorable to population's exposure to diarrhea-causing agents.