20
Isolation and Identification of the Waterborne
Protozoan Parasites Cryptosporidium spp. and
Giardia spp., and Their Presence on Restricted
and Unrestricted Irrigated Vegetables in Israel
R. Annonr, G. Oron 2 , D. Gold 3 , R. Sheinman 4 , U. Zuckerman 5
IFaculty of Civil Engineering, Environmental & Water Resources Eng.,
Technion-Israel Institute of Technology, Haifa 32000, Israel,
e-mail: cvrrobi@tx.technion.ac.il, Tel: +972-4-8292377, Fax: +972-4-822876
2Environment Water Resources, The Institute for Desert Research, Ben-Gurion
University of the Negev, Kiryat Sde-Boker 84990, Israel.
e-mail: gidiCa)bgumail.bgu.ac.il, Tel: +972-8-659-6900; Fax: +972-8-659-6909
3Department of Human Microbiology, Sackler School of Medicine, Tel-Aviv
University, Tel-Aviv 69978, Israel. e-mail: goldy(w.posUau.ac.i1
Tel: +972-3-6409530, Fax: +972-3-6409160
4Laboratory of Public Health, Ministry of Health, Haifa, Israel.
e-mail: lbhrivca@health.gov.il, Tel: +972-4-8619724, Fax: 972-4-8510172
5Mekorot Water Co. Ltd, Jordan District, Nazareth Illit 17105, Israel.
e-mail: ezukerman@mekorot.co.il, Tel.lFax: +972-9-9503960
Abstract
Cryptosporidium parvum and Giardia lamblia are protozoan parasites that cause
major human infections through waterborne transmission. The presence of these
two parasites is closely linked with effluent reuse. Since most of the effluent,
primarily in arid and semi-arid regions is reused for agricultural irrigation, extra
work was conducted in order to detect these parasites in wastewater, the applied
effluent, soil and crops. Unrestricted irrigation of a variety of vegetables with lowquality effluents could lead to crop contamination with large amounts of
Cryptosporidium oocysts and Giardia cysts. A special occurrence was observed
with zucchini that will be discussed further. Sprinkle, surface and subsurface
dripping irrigation revealed that the last two methods are much safer for
unrestricted irrigation, using the soil as an efficient filter matrix. Nevertheless,
from the obtained results (using a new method for parasite recovery from soil)
both protozoan parasites were isolated from soil, revealing their migration to a
depth of 60 and 90 cm below surface when subsurface dripping irrigation was
applied. These results will be further discussed as linked to optimization of
secondary wastewater reuse in order to minimize environmental risk.
H. Rubin / P. Nachtnebel / J. Fuerst! U. Shamir
Preserving the Quality of Our Water Resources
© Springer-Verlag Berlin Heidelberg 2002
Isolation and Identification of the Waterborne
Protozoan Parasites Cryptosporidium spp. and
Giardia spp., and Their Presence on Restricted
and Unrestricted Irrigated Vegetables in Israel
R. Annonr, G. Oron 2 , D. Gold 3 , R. Sheinman 4 , U. Zuckerman 5
IFaculty of Civil Engineering, Environmental & Water Resources Eng.,
Technion-Israel Institute of Technology, Haifa 32000, Israel,
e-mail: cvrrobi@tx.technion.ac.il, Tel: +972-4-8292377, Fax: +972-4-822876
2Environment Water Resources, The Institute for Desert Research, Ben-Gurion
University of the Negev, Kiryat Sde-Boker 84990, Israel.
e-mail: gidiCa)bgumail.bgu.ac.il, Tel: +972-8-659-6900; Fax: +972-8-659-6909
3Department of Human Microbiology, Sackler School of Medicine, Tel-Aviv
University, Tel-Aviv 69978, Israel. e-mail: goldy(w.posUau.ac.i1
Tel: +972-3-6409530, Fax: +972-3-6409160
4Laboratory of Public Health, Ministry of Health, Haifa, Israel.
e-mail: lbhrivca@health.gov.il, Tel: +972-4-8619724, Fax: 972-4-8510172
5Mekorot Water Co. Ltd, Jordan District, Nazareth Illit 17105, Israel.
e-mail: ezukerman@mekorot.co.il, Tel.lFax: +972-9-9503960
Abstract
Cryptosporidium parvum and Giardia lamblia are protozoan parasites that cause
major human infections through waterborne transmission. The presence of these
two parasites is closely linked with effluent reuse. Since most of the effluent,
primarily in arid and semi-arid regions is reused for agricultural irrigation, extra
work was conducted in order to detect these parasites in wastewater, the applied
effluent, soil and crops. Unrestricted irrigation of a variety of vegetables with lowquality effluents could lead to crop contamination with large amounts of
Cryptosporidium oocysts and Giardia cysts. A special occurrence was observed
with zucchini that will be discussed further. Sprinkle, surface and subsurface
dripping irrigation revealed that the last two methods are much safer for
unrestricted irrigation, using the soil as an efficient filter matrix. Nevertheless,
from the obtained results (using a new method for parasite recovery from soil)
both protozoan parasites were isolated from soil, revealing their migration to a
depth of 60 and 90 cm below surface when subsurface dripping irrigation was
applied. These results will be further discussed as linked to optimization of
secondary wastewater reuse in order to minimize environmental risk.
H. Rubin / P. Nachtnebel / J. Fuerst! U. Shamir
Preserving the Quality of Our Water Resources
© Springer-Verlag Berlin Heidelberg 2002