[Cyclospora cayetanensis infection. Laboratory diagnosis]. / Infección por Cyclospora cayetanensis. Diagnóstico de laboratorio.

Cyclospora cayetanensis is an Apicomplexa protozoa which was found to cause gastroenteritis in humans in 1979. This paper reviews the laboratory diagnosis of the disease. The usefulness of direct examination of fresh fecal matter with special acid-fast stains is emphasized as well as the morphometric differentiation between this organism and other similar coccidia. The paper reviews the sporulation technique of Cyclospora cayetanensis for the recognition and differentiation of artifacts and green-blue algae. Another aspect discussed is the morphology of the parasite in histological sections and with electromicroscopic examination whereby tissue morphology changes caused by the microorganism can be identified. The experience of the Service and Laboratory of Parasitology of the Instituto Nacional de Pediatría of Mexico in the laboratory diagnosis of this protozoosis is described. The paper is oriented towards the inclussion of Cyclospora cayetanensis in the diagnostic protocols for the study of diarrheas in our health Institutions.

[Vegetables for human consumption as probable source of Toxocara sp. infection in man]. / Verduras de consumo humano como probable fuente de infección de Toxocara sp. para el hombre.

Although Toxocara canis life cycle is known, other possible mechanisms dynamically involved in its transmission to man are still ignored. The object of the present investigation was to search the occurrence of Toxocara sp. eggs in vegetables which humans consume. Five hundred and thirty six vegetables from a supply distribution center in Mexico City (Distrito Federal) were examined. Those included 212 carrots, 76 potatoes, 31 radishes, 22 mushrooms, 27 lettuces, 20 sweet potatoes and 66 bundles of spinaches, 32 bundles of salt-worts, 29 bundles of coriander, and 21 bundles of purslane. Each unit or bundle was washed with 50 ml of sterilized water, allowing sedimentation at room temperature for 8 hours. Five ml of sediment were centrifugated at 3,000 r.p.m. for 5 minutes. Sediment was examined in lugol stained fresh plates through light microscopy, which turned to be Toxocara sp. eggs were found only in two vegetables: 1.9% of carrots and 6.5% of radishes. Toxocara sp. eggs were: 66.7% recently emitted and 33.3% embryonated. Other parasite elements were: Ascaris lumbricoides eggs 1.9% in carrots, 2.6% in potatoes, 9.1% in mushrooms, 6.9% in corianders, 20.0% in sweet potatoes and 6.1% in spinachs. Entamoeba histolytica cyts were found in 0.9% of carrots. Soil contamination with Toxocara sp. eggs from parasitized dogs or cats, or with either sewage systems or contaminated water where vegetables for human consumption are grown, play a role as a transmission mechanism must be deeperly studied since 33.3% of Toxocara sp. eggs found contained larvae, potentially infective to man.

[Frequency of Toxocara cati eggs in domestic cats in Mexico City and the State of Mexico]. / Frecuencia de hallazgo de huevos de Toxocara cati en gatos domésticos de la Ciudad de México y el Estado de México.

Toxocariosis is a zoonosis which has been widely studied in dogs. However, not much is known about this parasitosis in cats. The aim of the present work was to determine the frequency of Toxocara cati in domestic cats in Mexico City and the State of Mexico. Feces of 660 domestic cats were studied by the Faust concentration-floating test; 401 samples were from cats living in Mexico City of which 308 lived in houses and 93 in apartments; 231 were from urban areas of the State of Mexico and 28 from a rural area of the same state. The total frequency of T. cati eggs obtained from domestic cats in Mexico City was 42.9%; in cats living in apartments it was 18.3% and in cats living in houses it was 50.3%. In domestic cats from the State of Mexico, T. cati frequency was 36.4% in the urban and 21.4% in the rural areas. We consider that toxocariosis frequency observed at the two studied sites is high and that the need to prevent dissemination of the infectious forms of T. cati is urgent, as is the necessity of informing the population of the risk of living with T. cati parasited animals and of the anatomopathological alterations caused by T. cati in man.

[Infection by Toxoplasma gondii in children with infantile cerebral palsy]. / Infección por Toxoplasma gondii en niños con parálisis cerebral infantil.

An analytic relationship between positivity of the indirect immunofluorescent test (IIFT) for toxoplasmosis and clinical findings in a population of 328 children with cerebral infantile palsy (CIP) was performed. Children were distributed by age in one of four groups: I (0-2 years); II (3-6 years); III (7-12 years) and IV (13-18 years). One control group of 168 children with no PCI clinical findings was included. 125 sera were positive at 1:64 dilutions. The study of the binomial mother-child of 40 cases rendered 26 mothers with significant titer values. The majority of positive mothers to IIFT correlated with the youngest children (Groups I, II and III), mainly with group I (70.0%), which showed the highest titer ranges. Correlation between positive IIFT and clinical features was as high as 100.0%.

[Soil contamination with Toxocara sp. eggs in public parks and home gardens from Mexico City]. / Contaminación de suelos por huevos de Toxocara sp. en parques públicos y jardines de casas-habitación de la ciudad de México.

Due to de high number of stray dogs and cats which defecate in public places in Mexico City (3 millions approximately), in addition to domestic dogs and cats, exists the potential risk to man of infection by Toxocara sp. eggs. A study to determine the contamination frequency by Toxocara sp. eggs in public parks, public flower beds, and home gardens in Mexico City, Distrito Federal, was carried out in the 1995 first semester. Fourteen hundred and five soil samples were collected from 156 public parks, 83 public flower beds and 42 home gardens across the 16 delegations in Mexico City, Distrito Federal. Samples were processed by the zinc sulfate centrifugal flotation method, and supernatants read by microscopy. Out of the whole 281 sampled sites, 12.5% were found contaminated with Toxocara sp. eggs. Positivity found was: 10.9% in public parks, 13.3% in public flower beds and 16.7% in home gardens. Ninety percent of the eggs were embryonated or larvaeted measuring 60 to 90 micrometers. The high contamination frequencies found make necessary to prompt for Public Health measures granted the risk of infection acquisition spread on the most exposed population (children) provided that it is acquired via geophagia.