In order to prevent the transmission of cryptosporidium to the public via public drinking water systems, various surveillance systems and regulations have been implemented hitherto, in order to increase the treatment of surface water supplies. Among these techniques is the molecular surveillance for the presences of cryptosporidium in water using PCR which resulted following the cryptosporidium outbreak in Milwaukee Wisconsin in 1993 (Johnson, et al., 1995). The outbreak resulted in effective systems being implemented to improve the quality of water treatment globally as Mac Kenzie, et al., (1994) observes.
Guerrant, (1997) documents the onset of validation studies in Milwaukee health labs post 1993 of the EPA method 1622 AND 1623 which are employed in detecting and identifying cryptosporidium in water as well as the presence of other parasites. The presence of cryptosporidium oocysts in water following processing by EPA 1623 method are then detected by immunoflorescent microscopy or PCR-RFLP genotyping method as Krometis, (2009) documents. Following successful extraction of DNA, samples are then be analyzed using SSU-rRNA based nested PCR. Establishing the number of cryptosporidium species and genotypes that are present in every water sample is then achieved by restriction fragment analysis of the secondary PCR products, which also allows for the provisional identification of cryptosporidium genotypes in water samples. (Hsu, et al., 2001,pp. 419-424) Such a stringent surveillance system exceeds the standard requirement set by the EPA and the Wisconsin department of natural resources by testing for the presence of more than 500 contaminants other than cryptosporidium. The EPA methods are now novel and are studied globally as a template for water surveillance following the outbreak in Milwaukee Wisconsin. The qPCR analysis can be done in 24-48 hours and the surveillance method offers promise of protecting the public against contamination. With such implemented techniques, Milwaukee is a global leader in water quality- a positive outcome of the 1993 outbreak.
References
Guerrant, R. L. (1997). Cryptosporidiosis: an emerging, highly infectious threat. Emerging infectious diseases, 3(1), 51.
Hsu, B. M., Huang, C., Hsu, Y. F., & Jiang, G. Y. (2001). Evaluation of two concentration methods for detecting Giardia and Cryptosporidium in water. Water Research, 35(2), 419-424.
Johnson, D. W., Pieniazek, N. J., Griffin, D. W., Misener, L., & Rose, J. B. (1995). Development of a PCR protocol for sensitive detection of Cryptosporidium oocysts in water samples. Applied and Environmental Microbiology, 61(11), 3849-3855.
Krometis, L. A. H., Characklis, G. W., & Sobsey, M. D. (2009). Identification of particle size classes inhibiting protozoan recovery from surface water samples via US Environmental Protection Agency Method 1623. Applied and environmental microbiology, 75(20), 6619-6621.
Mac Kenzie, W. R., Hoxie, N. J., Proctor, M. E., Gradus, M. S., Blair, K. A., Peterson, D. E., & Davis, J. P. (1994). A massive outbreak in Milwaukee of Cryptosporidium infection transmitted through the public water supply. New England journal of medicine, 331(3), 161-167.
