Diego Averaldo Guiguet Leal

Transmission of toxoplasmosis (Toxoplasma gondii) by foods.

Protozoan foodborne diseases are generally underrecognized. Toxoplasma gondii is the causative agent of toxoplasmosis, one of the most prevalent parasitic infections to humans and domestic animals. The most likely source of T. gondii occurring through food is the consumption of raw or undercooked meat contaminated with tissue cysts. Sporulated T. gondii oocysts, from the feces of infected cats, present in the environment are a potential source of infection. The ingestion of water contaminated with oocysts and the eating of unwashed raw vegetables or fruits were identified as an important risk factor in most epidemiological studies. This review presents information and data to show the importance of T. gondii transmission by foods.

Evaluation of tropical water sources and mollusks in southern Brazil using microbiological, biochemical, and chemical parameters

Florianópolis, a city located in the Santa Catarina State in southern Brazil, is the national leading producer of bivalve mollusks. The quality of bivalve mollusks is closely related to the sanitary conditions of surrounding waters where they are cultivated. Presently, cultivation areas receive large amounts of effluents derived mainly from treated and non-treated domestic, rural, and urban sewage. This contributes to the contamination of mollusks with trace metals, pesticides, other organic compounds, and human pathogens such as viruses, bacteria, and protozoan. The aim of this study was to perform a thorough diagnosis of the shellfish growing areas in Florianópolis, on the coast of Santa Catarina. The contamination levels of seawater, sediments, and oysters were evaluated for their microbiological, biochemical, and chemical parameters at five sea sites in Florianópolis, namely three regular oyster cultivation areas (Sites 1, 2, and oyster supplier), a polluted site (Site 3), and a heavily polluted site (Site 4). Samples were evaluated at day zero and after 14 days. Seawater and sediment samples were collected just once, at the end of the experiment. Antioxidant defenses, which may occur in contaminated environments in response to the increased production of reactive oxygen species (ROS) by organisms, were analyzed in oysters, as well as organic compounds (in oysters and sediment samples) and microbiological contamination (in oysters and seawater samples). The results showed the presence of the following contaminants: fecal coliforms in seawater samples (four sites), human adenovirus (all sites), human noroviruses GI and GII (two sites), Hepatitis A viruses (one site), JC Polyomavirus in an oyster sample from the oyster supplier, Giardia duodenalis cysts, and Cryptosporidium sp oocysts (one site). Among organochlorine pesticides, only DDT (dichlorodiphenyltrichloroethane) and HCH (hexachlorocyclohexane) were detected in some sediment and oysters samples in very low levels; site 4 had the highest concentrations of total aliphatic hydrocarbons, PAHs, and linear alkylbenzenes (LABs) found either in oysters or in sediment samples. The major concentration of fecal sterol coprostanol was found at site 4, followed by site 3. After 14 days of allocation in the four selected sites, there was a significant difference in the enzymes analyzed at the monitored spots. The detection of different contaminants in oysters, seawater, and sediment samples in the present study shows the impact untreated or inadequately treated effluents have on coastal areas. These results highlight the need for public investment in adequate wastewater treatment and adequate treatment of oysters, ensuring safe areas for shellfish production as well as healthier bivalve mollusks for consumption.

First report of Cryptosporidium spp. oocysts in oysters (Crassostrea rhizophorae) and cockles (Tivela mactroides) in Brazil.

The consumption of oysters and cockles, which are usually eaten raw or lightly-cooked, can cause outbreaks of human diseases, especially if these shellfish are harvested from polluted areas. In Brazil data about the occurrence of pathogens, like hepatitis A virus, in shellfish have been reported but research on natural contamination for pathogenic protozoa is still non-existent. Cryptosporidium oocyst contamination of oysters (Crassostrea rhizophorae) and cockles (Tivela mactroides) was evaluated during two different periods in a coastal area from São Paulo, Brazil. From June to November 2005, and from July to December 2006, 180 mollusks were harvested for tissue examination. The gills and gastrointestinal tract (n = 36 pools) were carefully extracted from the animals and homogenized in a tissue homogenizer by adding surfactant Tween 80 (0.1%). Immunofluorescence assays were performed and Cryptosporidium oocysts were detected in 50.0% of gill pools of cockles and 10.0% of gill pools of oysters. In order to evaluate seawater quality in shellfish growing areas, total levels of thermotolerant coliforms, Escherichia coli and enterococci were determined. This is the first time that Cryptosporidium oocysts were found in shellfish from the coastal region of Brazil, and to the best of our knowledge it is also the first report in Latin America and the case might be of public health importance, reflecting the extension of the contamination on seafood, requiring a need for quality control standards.

A Parasitological Survey of Natural Water Springs and Inhabitants of a Tourist City in Southeastern Brazil

The goals of this study were to investigate the occurrence of Cryptosporidium oocysts and Giardia cysts in main springs of Campos do Jordão, an important tourist city, in Brazil and to gather the largest amount of parasitological data from autochthonous population that live in rural areas of this city. The membrane filtration technique followed by direct immunofluorescence assay was employed for concentration and visualization of waterborne protozoa. In the period between June 2003 and May 2004, the presence of at least one pathogenic protozoa was detected in 25.0% (3/12) of the springs studied, with mean concentrations ranging from 0.2 to 0.3 Cryptosporidium sp. oocysts and 0.07 to 0.1 Giardia sp. cysts/L. The coproparasitological investigation conducted in dwellers from two rural communities from this city revealed that 49.2% (91/185) of people had intestinal parasites. Among pathogenic protozoa, Cryptosporidium was the most prevalent species (8.1%) followed by Giardia duodenalis (5.9%), Entamoeba histolytica/Entamoeba dispar (2.7%), and Blastocystis hominis (2.2%). The most prevalent geohelminths were Ascaris lumbricoides (14.9%) and Trichuris trichiura (9.7%). This study demonstrated the contamination and the distribution of intestinal parasites, especially Cryptosporidium and Giardia species, in different springs of an important tourist city in Brazil, highlighting the need of monitoring natural water sources. The high prevalence of intestinal parasitosis detected in some specific populations of this city may function as a link of transmission of different intestinal parasitosis due to soil and water contamination, contributing to the maintenance of parasite life cycles. Therefore, the inclusion of consistent public health interventions with measures that include the protection of springs, the installation of minimum health infrastructure, and primary education of the population are widely necessary, aiming the control and prevention of parasite infections.

Avaliação da performance de metodologias de detecção de Cryptosporidium spp. e Giardia spp. em água destinada ao consumo humano, para o atendimento às demandas da Vigilância em Saúde Ambiental no Brasil

Objective: this study aimed to evaluate three different concentration protocols of cysts and oocysts in raw water samples in Brazilian rivers. Methods: the protocols studied were chemical precipitation, filtration in membranes of 47mm of diameter versus nominal porosity of 3μm and filtration using Filta-Max® system. The raw water samples collected from rivers in the states of Sao Paulo and Minas Gerais were analyzed after being seeded with Color-Seed®. The results of initial precision using filtration in membranes and recovery of Color-Seed® organisms were compared to the acceptance criteria established by the United States Environmental Protection Agency (USEPA). Results: the study of initial precision to Giardia using filtration in membranes and recovery of Color-Seed® met the USEPA criteria; for Cryptosporidium only the Filta-Max® achieved the established criteria. Conclusion: Filta-Max® system showed to be the only method that achieved all the performance criteria for identification of Giardia and Cryptosporidium in water.

Acute Schistosomiasis in Brazilian Traveler: The Importance of Tourism in The Epidemiology of Neglected Parasitic Diseases

Parasitic infectious diseases acquired in tourist areas may pose a challenge to physicians and to travel medicine practitioners. Acute schistosomiasis may be seen in returning travelers and migrants after primary infection. This form of schistosomiasis is frequently misdiagnosed due to its temporal delay and its nonspecific presentation and might occur even in countries where the disease is endemic, such as in Brazil. The patient developed the acute phase of schistosomiasis with severe clinical manifestations. The quantitative analysis revealed the presence of 240 eggs per gram of stool. The treatment was administered with oxamniquine, and the control of cure of the patient was monitored and was favorable. The present paper aims to emphasize the importance of a detailed clinical history including information regarding travel history.