Identifizierung von Cryptosporidium und Giardia und Überwachung deren Persitenz in einer Hamburger Kläranlage mittels molekularbiologischer Methoden

Sewage treatment plants are environments where protozoa species are likely to exist, and despite the importance of these potential reservoirs in the transmission of protozoan diseases, relatively little research or resources have been directed on their occurrence in sewage, compared to similar issues concerned with water. Giardia lamblia and Cryptosporidium purvum, are the most common human parasitic protozoa transmitted by water in industrialised nations. The infective forms, cysts and oocyts, are known to be highly resistant to wastewater treatment procedures and to represent a potential hazard to human populations through contaminated raw or treated water. 
There is little information documenting the occurrence of cysts and oocysts in sewage and treated effluents in Germany. Similarly, the effect if sewage sludge treatment processes on cysts and oocysts survival has not been investigated. In Hamburg, most or all of the drinking water is obtained from ground water which cannot be easily contaminated with parasitic protozoa. However, the release of contaminated effluents into the environment couldincrease the risk of human infection through cross-contamination of drinking water, contamination of swimming pools and the consumption of vegetables. There is limited awareness among the population, including the medical community, on the potential risks of these infections. At the Hamburg wastewater treatment plant, primary effluent is periodically released into the environment each time there is sewage in excess of the biological capacity (1.2 m3/s) of the of plant. This represents a potential source of transmission and subsequent outbreak. 
These problems highlight the need to apply rigorous scientific methods to determine the occurrence of these pathogens in wastewater and sludge as well as estimate the removal efficiencies in the different treatment regimes. In this study, immunofluorescence antibody and Polymerase chain reaction (PCR) methods will be employed to determine the occurrence and reduction of Giardia cysts and Cryptosporidium oocysts during the different processes of wastewater and sludge treatment. 
This study shall produce data which will serve as a building block upon which models, essential to justify good wastewater management could be designed to predict the inactivation of parasites. Furthermore, findings of this study could be applied in a variety of studies to further elucidate aspects of the epidemiology, both conventional and molecular, of these parasites in particular populations or geographic regions. Additionally, such analysis can be used as an indirect method of assessing the occurrence of these infections in human populations.

Stichworte

• Abwasser
• Hygiene

Publikationen

• Ajonina, C.; Buzie, Ch.; Ajonina, I.; Basner, A.; Reinhardt, H.; Guyas, H.; Liebau, E.; Otterpohl, R.: Occurrence of Cryptosporidium in a wastewater treatment plant in North Germany Journal of Toxicology and Environmental Health A, Vol. 75 (22-23) 1351-1358, 2012.