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- Saturday, January 31, 2009
- AN OUTBREAK OF TOXOPLASMOSIS IN ADULT GOATS
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AN OUTBREAK OF TOXOPLASMOSIS IN ADULT GOATS
(1)-SALAMEH BARHOOM, (2)-ABD EL-HAFEED DALA'B
(3)- ZAIN ALA'BEDEIN ABU ALWAFA
Clinical studies, Faculty of Vet. Med., An- Najah National University P.o. Box 7, Nablus-Palestine
E-mail :(1)-[email protected],(2)[email protected], ( 3)- [email protected]
Abstract:
Clinical, pathological, and serological studies were conducted in a flock of 30 goats, between the ages of 2-3 years old, (cross breed), suffering from Toxoplasmosis in Palestine. The clinical findings of the disease were: Pyrexia, lethargy, repeated abortion, Stillbirth or death of weak Kids and some accompanied by a mummified fetus. Morbidity rate was 100%. Gross lesion of the fetal membranes showed odema of the intercotyledonary chorioallantois and white foci of necrosis approximately 2-3 mm in diameter visible in cotyledon. Histopathology showed that the cotyledonary lesions are distinctive and consist of multiple foci of necrosis and brain showed focal microgliosis . The clinico-pathological diagnosis was supported serologically by Enzyme linked immunosorbent assay (ELISA) using a reference "Toxoplasma gondii , IgG Kit ELISA" . The results showed four folds rising in the titer of antibodies during the course of acute stage and convalescent one after abortion.
KEYWORDS:
Goat, Toxoplasma gondii , Toxoplasmosis , abortion , cotyledon , ELISA .
تفشي داء المقوسات في قطيع من الماعز البالغ
(1)- سلامة برهوم (2)- عبد الحفيظ دلعب ( 3)- زين العابدين ابو الوفا
الدراسات الاكلينيكية كلية الطب البيطري جامعة النجاح الوطنية ص ب 7 نابلس فلسطين
الملخص :
لقد اجريت دراسات سريرية ، مرضية ومصلية على قطيع من الماعزعدده 30 راساويتراوح عمره بين 2-3 سنوات ( خليط السلالة) والذي يعاني من داء المقوسات في فلسطين ، لقد تميزت العلامات السريرية بحمى ، الخمول ، اجهاض متكرر او نفوق الجديان الضعيفة والمرافقة تكون متحنطة ، نسبة الاصابة 100% . الافات المرضية الظاهرة على السخد اظهرت وجود خزب بين الفلقات والغشاء اللقانقي المشيمي ، وجود حبيبات متعدد بيضاء صغيرة قطرها 2-3 ملم تقريبا على سطح الفلقات ، الفحص النسيجي لافات الفلقات كان مميزا ويتكون من عدة بؤر تنخرية ، اما نسيج المخ اظهر وجود microgliosis ،لقد عزز التشخيص السريري المرضي بالاستعانة باختيار الاليزا ELISA" Toxoplasma gondii , IgG Kit" والذي اظهر وجود ارتفاع اربع اضعاف من مستوى الاجسام المضادة خلال فترة النقاهية مقارنة مع الفترة الحادة من الاجهاض .
الكلمات الدالة : ماعز ، داء المقوسات ، اجهاض ، الفلقات ، الاليزا .
Introduction
Toxoplasmosis is a zoonotic infection of animals caused by the protozoan parasite Toxoplasma gondii. The parasite is an obligate intracellular parasite occurring worldwide in domestic cats and occasionally other members of cat family (Felidae ) as final host while man and other animals are intermediate host .The final host is responsible for widespread transmission of this parasite through fecal contamination of pasture , soil , feed concentrate and occasionally water . In sheep and goats toxoplasmosis causes abortion or the birth of weak lambs and kids which may accompanied by a mummified fetus , while aborted ewe or doe remains clinically normal(2) , Diagnosis is based on clinical signs and pathological finding and isolation of T. gondii from placental and fetal tissues. However, if the placenta is not available or is decomposed , diagnosis can be confirmed by testing for the presence of antibody against T.gondii in the fetal fluid or sera using various serological tests such as indirect Haemagglutination , indirect Immunofluorescent (IFAT) or Enzyme linked Immunosorbant Assay (ELISA) (3) . This study investigates an outbreak of Toxoplasmosis in adult goats recently encountered in Palestine where clinical, pathological and serological studies were conducted.
Materials and methods
An outbreak of Toxoplasmosis occurring in a private farm with 30 goats ( cross – breed ) , between the ages of 2 -3 years old was investigated , the disease appeared in Tulkarem Governorate , Northern Palestine .
Complete clinical examination was performed on the flock in March of 2007, the aborted does and their fetuses were both subjected to examination.
Specimen from placenta, cotyledons and brain of the fetuses were collected and fixed in a 10% neutral buffered formalin for routine histopathology, Hematoxylin – Eosin stain (4) , Two blood samples were collected from aborted does , the first one after abortion and the second four weeks later . Sera were separated and tested using original ELISA( 5) for estimation the level of antibodies using a soluble antigen preparation made from Toxoplasma RH strain tachygoites , layered into wells in microtiter plate . Test sera are added, followed by an anti-species enzyme labeled conjugate such as horseradish peroxidase - labelled anti - ovine IgG . Any attached conjugated causes a colour change in the substrate that is directly related to the amount of the bound antibody which can be read with spectrophotometer at absorbance specific to the substrate used. The defined anti species conjugate, substrate, whole Kit used was toxoplasma gondii " IgG Kit ELISA"
Results
This study was conducted on flock of 30 adult goats (cross-breed) that were housed in close pen, main ration consisted of concentrate and straw, the supplied water was tap water. All animals were treated with Ivermectin and vaccinated annually against the following enzootic infectious diseases: Brucellosis, Sheep pox, Pest Des Petit Ruminant and Foot and Mouth disease.
Clinical finding: All animals appeared clinically normal before abortion, the prominent clinical sign in the flock was repeated abortion in successive pregnancies and occurs in the last trimester of pregnancy , stillbirth , mummification of fetuses , congenital anomalies and weak kids were observed . Table ( I ) illustrates the number of aborted animals and average of their gestation periods . Aborted doe showed pyrexia and lethargy. Morbidity rate was 100%.
Table (1): Number of aborted animals and average of their gestation period in days
Total kidding
Abortion number
%
Stillbirth number %
Mummified fetus %
Gestation period (days)
14
8 (5.7 % )
4 (2.9% )
2 (1, 4%)
130-136
16
10 (7.8 % )
6 (4.3%)
0
120-140
Gross pathology: There was edema of the intercotyledonary chorinoallantois and numerous white foci of necrosis approximately 2 – 3 mm in diameter visible in cotyledons as seen in fig .1
Fig .1. Placenta of aborted doe showed numerous white foci of necrosis on cotyledons
Histopathology: the cotyledonary lesions were distinctive and consist of multiple foci of necrosis and the brain showed focal microgliosis .
Estimation level of antibodies: Enzyme Linked Immunosorbent Assay showed the level of antibodies in acute (first sera after abortion) and convalescent stage (second sera four weeks after abortion) in the table number (II)
Table (II): Illustrate the level of antibodies (optical demity ) in the tested sera by ELISA in both acute and convalescent stage .
Number
1
2
3
4
5
6
7
8
9
10
Mean
Average age (years)
2.1
1.8
1.7
2.7
3
1.4
2.6
3.4
2.3
0.7
2.1
Abortion within last 2 years
1
0
0
1
2
1
0
2
2
1
1
Acute
.338
.344
.346
.386
.405
.425
.608
.345
.315
.338
.351
convalescent
2,584
2,457
2,531
2,345
2,258
2,583
2,585
2,354
1,853
2,765
2,178
Discussion
Toxoplasmosis is a disease that causes abortions, weak Kids, stillbirth, birth defects and fetal mummification in pregnant does (9) as we encountered in our clinical findings. Cats are the carriers of this protozoan known as Toxoplasma gondii , Cats especially kitten less than six months of age pass the oocysts through their feces when they eat infected rodents , raw meat , or placenta of Toxoplasmosis – infected animals (10 ) . Goats become infected with the parasite when they eat grains, or hay that has been contaminated by cat feces containing T.gondii oocyste ( 11) as we saw in this study. The disease is the second common cause of abortion in goats in Palestine (12) and the rise in the level of antibodies in paired serum sample of aborted doe and four folds is considered as diagnostic method for the disease as reported by (2) and we found it in the present study by using Enzyme Linked Immunosorbent Assay .
In this study the clinical findings in aborted does were abortion in the late gestation period, mummified fetuses, stillbirth with gross lesions foci of fetal membranes and presence of necrotic foci of necrosis in cotyledon were previously reported by (1, 2, 4). The existence of necrotic foci in cotyledons and detection in the rise of antibody titer and four fold in convalescent phase of aborted animal than acute phase all were diagnostic for the disease and they were in agreement with the findings of (11, 7, 8). We strongly recommend to isolating all aborted animals from the flock. Also, The pregnant females should not exposed to infected cat feces Finally, cats should not be allowed to enter goat farms and fetal membranes should not be fed to cats .
Reference
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