AWWA PATH56557

Cryptosporidium is a unicellular parasite that causes cryptosporidiosis in humans, as well as in certain animals, including domestic livestock. The intracellular parasite Cryptosporidium is cosmopolitan and is the third world cause of diarrhea. The life cycle of the protozoan Cryptosporidium is very complex and includes sexual and asexual reproduction. Taxonomically it belongs to phylum Apicomplexa. In the nature Cryptosporidium subsists as oocysts, a resistant form that is viable for months. The transmission root is faecal-oral and involves both animal and water. Cryptosporidiosis is considered a waterborne disease that is contracted by consuming contaminated water. This emergent waterborne pathogen gained attention in the last two decades, mainly due to the increase of AIDS and immunocompromised patients, as there is no chemotherapy available for this organism. Remarkably, Cryptosporidium oocysts are resistant to chlorine disinfections, the treatment pathway of Lisbon water. The water suppliers have the responsibility of performing water quality control and have to follow the Portuguese law 243/2001 transposed from the European Directive 98/83 CE next 2003, in which it is mandatory to test for Cryptosporidium. The Central Laboratory of EPAL started the current year with testing for Cryptosporidium both in treated and untreated water (Castelo do Bode reservoir, Tejo River water and Olhos d.¿gua groundwater). The method used was US Environmental Protection Agency Method 1622: Cryptosporidium in water by filtration/IMS/FA. Natural and artificially contaminated samples with a known number of oocysts have been processed. The mean oocysts recovery was 48.5% (SD 4.9%) in artificially contaminated samples. At present oocysts were detected only in one untreated water (Olhos d.¿gua groundwater). All the treated water samples were negative for Cryptosporidium. Includes 6 references, tables, figures.

Product Details

Edition:

Vol. - No.

Published:

09/22/2002

Number of Pages:

10

File Size:

1 file , 340 KB