Abstract Book of EAVLD2012 - eavld congress 2012

S4 - P - 12
COMPARISON OF THE EFFICIENCY OF DIFFERENT PARASITOLOGICAL DIAGNOSTIC METHODS
USED IN ANALYSIS OF DEHYDRATED SEWAGE SLUDGES
Jolanta Zdybel, Tomasz Cencek, Jacek Karamon
National Veterinary Research Institute, Departament of Parasitology and Invasive Disease, Pulawy, Poland
Ascaris, Toxocara, Trichuris, eggs, sewage sludge, fertilizers
Introduction
The use of sewage sludge as fertilizer is connected with
microbiological and parasitological hazards in terms of public
health safety. Therefore, it is necessary to carry on proper
parasitological investigations of this type of samples. Majority, of
current parasitological diagnostic procedures using in sewage
sludge surveys are derived from soil samples investigation. This
kind of procedure are characterized by low efficiency, due to
occurrence of polyelectrolytes in sewage sludge samples.
Therefore, new method of sewage sludge parasitological
diagnostics was developed. The methods is focused on detection
of parasitic nematodes eggs, belonging to Ascaris, Trichuris and
Toxocara genus. It is combination of floatation and sedimentation
method, preceded by sample prolonged dispersion. The purpose
of this study is to compare the efficiency of the method developed
in Department of Parasitology and Invasive Diseases to other
methods which are used in laboratories worldwide.
References
1. Zdybel J., Karamon J., Cencek C.: The occurrence of eggs of
parasitic roundworms (genera: Ascaris, Trichuris, Toxocara) in
organic and mineral-organic fertilizers and in sewage sludge.
Zycie Wet.2009,84(12),992-996.
2. Simonart T., Roussel S., Gireaudot-Liepman M.F.: desk study
on European standard for the enumeration of diable helminth ova
in sludge, soil and solid waste. HORIZONTAL-WP3-5, France
2003.
Materials & methods
For this study we used randomly chosen 10 dehydrated sewage
sludge samples derived from Polish waste water treatment
plants. Each sample weighed 10 grams (dry weight) and was
examined by our own method, PN-Z-19000-4 method, flotation
method described by Quinn, method according to Environmental
Protection Agency (EPA) and Triple flotation (TF) method
according to ANFOR XP X33-017 . Microscopy (X20) was used
to estimate the number of nematode eggs.
Results
Results concerning percentage of positive samples and numbers
of detected parasite eggs obtained with the use of different
methods were presented in Table 1.
Table. 1. Mean number of parasite eggs and % of positive
samples detected in sewage sludges samples with the use of 5
different methods.
Methods
Mean number of detected eggs
(% of positive samples)
Ascaris Toxocara Trichuris
Quinn
2.2
(70%)
2.1
(90%)
0.3
(30%)
PN-Z-19000-4
0.3
(40%)
0.15
(30%)
0
Triple flotation
0.6
(10%
3.3
(40%)
0
EPA
1.7
(80%)
1.3
(100%)
1.3
(20%)
Own method
16.4
(100%)
11.1
(100%)
1.7
(100%)
Discussion & conclusions
The results of the present study demonstrated that method
developed in Department of Parasitology and Invasive Diseases
is six-fold more efficient than flotation method devised by Quinn,
seven-fold more efficient than TF method and EPA method, 65-
fold more efficient then PN-Z-19000-4 method. The adaptation of
described method in other parasitological laboratories is highly
recommended.