Enumeration of Giardia cysts in Wastewater as an indicator of Giardiasis in the Community

Transcription

1 Enumeration of Giardia cysts in Wastewater as an indicator of Giardiasis in the Community Abidelfatah M. Nasser, Beitberl academic college and Ministry of Health, IL COST is supported by the EU Framework Programme Horizon 2020 ESF provides the COST Office through an EC contract

2 Microbiological Risks Waterborne Diseases

3 GIARDIA LAMBLIA Protozoan parasites causing Giardiasis Symptoms: diarrhea, abdominal cramps, fever, weight loss and vomiting Fecal-oral route through drinking water, reclaimed water, swimming pools, food industry

4 Very resistent (oo)cysts to chlorination. Small to pass through the WWTP High concentration in wastewater. Karanis et al. (2007), responsable for 40,6% (Giardia) from the 325 wateborne diseases outbreaks reported.. Giardia

5 OUTSIDE HOST: CYSTS Small size Oval/Round Thick-walled Environmentally stable High infectivity 10 µm International Journal for Parasitology 38, (2008) Courtesy of Dr Stan Erlandsen; CDC Public Health Image Library (PHIL) Courtesy of H.D.A Lindquist; U.S. EPA

6 IMMUNOFLUORESCENCE ASSAY (IFA) MICROSCOPY (a) (b) (c) (a)(c) Journal of medical microbiology 61, (2012) (b) Applied Microbiology and Biotechnology 1, 3-14 (2010)

7 GIARDIA SPECIES 6 Giardia species G. duodenalis infects humans and other mammals G. duodenalis assemblage A and assemblage B are zoonotic Unclear host specificity

8 WASTEWATER TREATMENT 1. Prevent the transmission of pathogens 2. Protection of fresh water sources 3. Production of water to increase the water budget to be used for irrigation of food and industrial crops

9 Water Reuse

10 Wastewater reclamation Treatment barriers for unrestricted irrigation 1.Secondary treatment + SAT 2. Secondary treatment + high rate filtration + Chlorine disinfection

11 AIMS AND OBJECTIVES To determine Giardia prevalence in wastewaters and wastewater effluents in Israel, comparing detection techniques IFA and PCR. To estimate the removal efficacy of Giardia by wastewater treatment technologies, and their correlation to indicator microorganisms To identify Giardia species that are present in sewage and effluents from wastewaters in Israel

12 ertiary treatment Activated sludge

13 GIARDIA ENUMERATION AND GENOTYPE 50 L 10 L 200 ml TE SE RWW filter elution Centrifugation IMS filter elution Centrifugation DNA IMS 800µl 200µl 800µl 200µl DNA RT- PCR Nested PCR, RFLP, IF Microscope RT- PCR Nested PCR, RFLP, IF Microscope 800µl Centrifugation DNA IMS RT-PCR Nested PCR, RFLP, IF 200µl Microscope

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16 Concentration and prevalence of Cryptosporidium oocysts and Giardia cysts compared to fecal coliform and turbidity in raw wastewater, secondary and tertiary effluents. sample RWW* (n=43) SE** (n=43) TE*** (n=25) paramete r Giar/L Crypt/L Fecal coliform (cfu/100 ml) turbidity min E max E avg E % positive min max E avg E % positive min max avg % positive

17 Reported cases of Giardiasis in Israel Year Avrg Reported cases

18 Estimated number of Giardiasis infected individuals # served individuals = 400,000 Volume of wastewater generated 39,000 m 3 /day Avg. Giardia concentration 3690 cysts/l Total # of detected cysts 1.4x10 11 day Estimated # of cysts shed by infected individual cysts/day Estimated # Giardiasis infected individuals is individuals out of 400,000 are infected The number of Giardiasis infected individuals annually in Israel is 100,800 and not compared to 20 per 100,000

19 Seasonal prevalence of Giardia cysts in raw wastewater

20 Comparative reduction of turbidity, fecal coliform, Giardia and Cryptosporidium by secondary and tertiary wastewater treatment. Parameter Average Reduction log 10 (Ct/C0)±STDEV ST* TT** Giardia -3.28± ±1.0 Cryptosporidium -0.94± ±1.4 Fecal coliform -1.68± ±1.2 Turbidity -1.72± ±0.5

21 PCR-RFLP for genotyping of Giardia cysts Three patterns were observed 150,126,70,34,4 -A 176,150,34,24 -B -MIX,176,150,126,70.34,24,4

22 RAW WASTEWATER SAMPLES % n= # of samples Assembly A B MIX

23 Giardia assembly in stool samples # OF SAMPLES % n= Assembly A B MIX

24 CONCLUSIONS Giardia Cysts are prevalent at higher concentrations in wastewater samples Wastewater treatment (secondary and tertiary) was found efficient for removal of Giardia Giardia lamblia was more prevalent than assembly B in wastewater, whereas in Giardia positive stool samples assembly B was more prevalent. It is known that assembly B is more virulent than assembly A. The results indicate that mostly analyzed clinical samples are from sever giardiasis. Giardiasis is under reported to the health authorities and wastewater can be used as a reliable indicator for the prevalence of the infection.

25 ACKNOWLEDGEMENT Mekorot Co, Israel Marina Taran Noami Ofer Neta le Baror Avi Aharaoni Dalit Visel-Ohaion Minachem Rebhon