Ocorrência de Cryptosporidium sp em amostras fecais de crianças, menores de 10 anos de idade, com indicação clínica de Rotavírus

New insights into the detection and molecular characterization of Cryptosporidium with emphasis in Brazilian studies: a review

Cryptosporidium spp. is a pathogenic protozoan present in the gastrointestinal tract of several hosts. This protozoan was originally classified as within the Coccidia Class and has recently been reclassified to gregarine based on studies that observed the evolutionary phases from the process of excision and sequencing of the 18S rRNA gene. Molecular biology techniques have become diagnostic tools and have also been used to understand the epidemiology of Cryptosporidium spp., since several species of this genus are very similar morphologically and morphometrically. Molecular techniques have been used in the identification of parasites, at the species and subtypes levels and to study disease transmission. The laboratory diagnosis of human cryptosporidiosis can be made by parasite detection methods, such as optical microscopy, antigens or genetic material detection, as well as serum antibodies raised to Cryptosporidium spp. Molecular methods were developed and allowed, not only an extensive revision of the taxonomy, but also an improvement in the laboratory diagnosis. In Brazil, there are few reports of Cryptosporidium spp. outbreaks in humans and all of them took place in nurseries. A few epidemiological studies developed in Brazil have used molecular methods for the detection of Cryptosporidium spp., as well as genotyping studies of their species and subtypes. The use of real-time PCR, together with microscopy and immunochromatography techniques, would result in a more precise diagnosis of cryptosporidiosis. The analysis of genotypes, subtypes and clonality of Cryptosporidium could be useful to understand and define the prognosis and severity of infections.

[Presence of Cryptosporidium spp in children with acute diarrhea in a public daycare center in Recife, State of Pernambuco]

The objective of the present study was to analyze the frequency of oocysts of Cryptosporidium spp in fecal samples from children aged one to fourteen years at a public daycare center located in a needy community in the city of Recife, Pernambuco. The investigation was carried out between June 28, 2006, and April 3, 2007, and involved 182 children. Among the samples analyzed, 59 (32.4%) were positive regarding the presence of oocysts of Cryptosporidium spp, and the age group most affected was between three and five years (54.2%). The high frequency of samples positive for Cryptosporidium spp obtained in this study confirms that daycare centers are an environment that favors such occurrences, because of the direct contact between children or between children and staff. The most important infection route for Cryptosporidium spp is person-to-person transmission, which is well illustrated in daycare centers. Immaturity, deficiencies of the immune system and inadequate hygiene habits are factors that also contribute towards this type of infection.

Detection of Cryptosporidium sp. in non diarrheal faeces from children, in a day care center in the city of São Paulo, Brazil

The protozoan Cryptosporidium sp. has been frequently detected in faeces from children with persistent diarrhoea. This work achieved to investigate an outbreak of cryptosporidiosis, in a day care center, attending children of high socio-economic level, between 0 and six years old. The outbreak was detected through the network of public health, when stool samples, not diarrhoeic, were examined at the Parasitology Service of the Adolfo Lutz Institute. Among the 64 examined children, 13 (20.3%) showed oocysts of Cryptosporidium sp. in the faeces examined by Kinyoun technique: seven children one year old, three, two years old and three, three years old. Among the 23 examined adults, only a 22 years old woman, possibly having an immunocomprometiment, was positive. Clinical and epidemiological aspects were investigated by questionnaires, highlighting the occurrence of the outbreak in a very dry period.