Albanian j. agric. sci. ISSN: 2218-2020, (2012), (Special Edition) Copyright © Agricultural University of Tirana

THE SEARCH FOR THE PREVALENCE OF ANTIGEN OF BOVINE VIRAL DIARRHEA VIRUS IN KOSOVO. IZEDIN GOGA1*, KRISTAQ BERXHOLI2, BEQE HULAJ1, DRITON SYLEJMANI3 1

Food and Veterinary Laboratory, Food and Veterinary Agency, Pristina, Kosovo

2

Faculty of Veterinary Medicine, Agricultural University, Tirana, Albania

3

Agricultural and Veterinary Faculty, University of Pristina, Kosovo

* Author of correspondence; E-mail: [email protected]

Abstract Bovine viral diarrhea (BVD) is endemic disease of animals in most countries of the world with persistent infections (IP) from 0.1 to 2%. Infection is associated with some economic losses worldwide. In order to find antigen BVD, were examined blood sera of 260 heifers and 221 cows in five municipalities. Samples were tested by antigen ELISA commercial kit (IDEXX BVDV Ag / Serum Plus Test). The presence of BVD antigen (protein Erns) found in four heifers (1.53%) belonging to 3 municipalities of the country (Podujeve, Istog and Ferizaj). Cattle serum samples have not shown the presence of BVD antigen. It recommended advanced control of the spread of the infection in order to prevent economic losses. Key words: Search, BVDV, Erns protein

1. Introduction The bovine viral diarrhoea virus (BVDV) causes a variety of clinical syndromes in cattle, including diarrhea, reproductive failure, respiratory disease, mucosal disease and hemorrhagic syndrome [1, 13]. BVDV affects cattle of all ages including fetuses of susceptible heifers [1]. BVDV belongs to the genus Pestivirus, family Flaviviridae [5]. The length of RNA genome is approximately 12.3 kbp. Based on the presence or absence of visible cytopathic effects in infected cell cultures, BVDV were classified in cytopathic (CP) and noncytopathic (NCP) biotypes. In other hand, BVDV genotypes (I and II) are detected by polymerase chain reaction (PCR) for nucleotide and antigenic differences [14]. Type I BVDV strains include the classic BVDV isolates which are often used as a laboratory reference and vaccine strain. Type II comprises the BVDV strains associated with high mortality, acute and peracute infections [15, 16]. Intrauterine BVDV infections cause high rates of abortion, foetal resorption, mummification, congenital malformations, weak calf births, and growth retardation [7, 11]. Bovine viral diarrhea (BVD) is endemic in animals of most countries, with level of 0.1 to 2% of persistent infections (PI) [2, 6, 8, 10]. The key to control BVDV is to prevent the early fetal infections that are associated with the process which caused International Conference 31 October 2012, Tirana

persistent infections. Another important issue, during BVD control is to detect and eliminate all the young animals with the PI, in order to reduce the risk of transmitting the virus to other animals. The aim of this study was to estimate the prevalence of antigen of BVD in animals. 2. Material and Methods As material for research, are taken randomly blood serum samples of heifers and cattle during the late of 2011 in 5 municipalities of Kosovo. Total are taken 260 blood samples heifers aged 6-24 months and 221 cattle blood samples. Blood samples were taken into tubes without anticoagulant and stored up to 5 days at a temperature of 4 ° C. Samples are centrifuged at 3500 rpm for 20 minutes in order to obtain sera samples. The sera were refrigerated and tested within 2 days with antigen ELISA commercial kit (IDEXX BVDV Ag / Serum Plus Test). All samples were tested for BVDV antigen using the Erns ELISA according to the manufacturer's instructions. Detection antibodies were added to all wells of a microtitre plate wells, coated with Erns MAbs. Positive and negative control sera were added to appropriate duplicate wells. Serum samples (50 μl) then added to the remaining wells. The plate was incubated for 2 hours at 37°C. After incubation, is done washing, adding the conjugate and

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incubation at room temperature (18-25 ° C) for 30 min. After washing the conjugate is added substrate which is incubated for 10 minutes at room temperature in dark conditions. After this incubation, reaction was stopped. Optical density values (OD) were measured at 450 nm. Optical density averages of positive and negative controls were calculated. Calculation of tested samples was done according to the formula (S-N = OD sample A450- OD average of negative control A450) by subtracting the optical density value of the sample with mean optical density value of the negative control.

Samples with S-N values greater than 0.300 were classified as positive for BVDV antigen. 3. Results and Discussion Analysis of blood serum samples of 260 heifers from five municipalities has shown that 4 animal from 3 municipalities (1.53%) has given the presence of Ag of BVDV (Table 1), whereas analysis of blood serum samples of 221 cattle has not show the presence of Ag of BVDV. (Table 2)

Table 1: Results of serological analysis of blood serum samples of 260 heifers Municipality

Number of samples

Ag Negative results

ELISA Positive results

Podujeve

42

41

1

Istog

70

68

2

Prizren

41

41

0

Ferizaj

77

76

1

Prishtina

30

30

0

Total

260

256

4

%

100

98.46

1.53

Table 2: Results of serological analysis of blood serum samples of 221cattle Municipality

Number of samples

Ag

ELISA

Negative results

Positive results

Podujeve

55

55

Istog

40

40

Prizren

50

50

Ferizaj

56

56

Prishtina

20

20

Total

221

221

%

100%

The virus has a worldwide distribution with serum antibody prevalence’s ranging from 19% to 90% and with level of 0.1 to 2% of persistent infections (PI) [2, 3, 6, 8, 9, 10]. PI animals are considered the principal source of infection in a farm and direct contact between these animals and susceptible animals is the most important infection route [3, 9]. It is believed that infected animals in the acute form spread virus, a few days or weeks, depending on the strain of virus [4, 12]. However, identification of animals with viremia is an essential element of BVD control program, and depends on accurate diagnostic tests. Antigen prevalence in this study (1.53%) is International Conference 31 October 2012, Tirana

100%

0 0 0 0 0 0 0%

similar to the prevalence of persistent infections in other countries 0.1 to 2%. Program associated with the control and eradication of BVD in Kosovo currently does not exist. Due to the high economic importance of this disease, the aim of this study was to estimate the prevalence of antigen of BVD in animals. 4. Conclusions From the results obtained by serological analysis of blood serum, we present the following conclusions:

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The search for the prevalence of antibody against Bovine viral diarrhea virus in Kosovo

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Analysis of blood serum samples of 260 heifers from five municipalities has shown that 4 animal (1.53%) has given the presence of Ag of BVDV. Positive samples of heifers where from 3 municipalities (Podujeve, Istog and Ferizaj). Analysis of blood serum samples of 221 cattle from five municipalities has not shown the presence of Ag of BVDV. Recommended advancing control the spread of infection in order to prevent economic losses.

7. Houe H: Epidemiological features and economical importance of bovine viral diarrhea virus (BVDV) infections. Vet. Microbiol., 1999, 64: 89-107. 8. Howard CJ, Brownlie J, Thomas LH: Prevalence of bovine virus diarrhoea virus viremia in cattle in the UK. Vet. Rec.,1986, 119:628-629. 9. Lindberg A, Houe H: Characteristics in the epidemiology of bovine viral diarrhea virus (BVDV) of relevance to control. Prev. Vet. Med., 2005, 72:55–73

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5. Heinz FX, Collett MS, Purcell RH, Gould EA, Howard CR, Houghton M, Moormann RJM, Rice CM, Thiel HJ: Genus pestivirus. In Virus Taxonomy. Edited by Van Regenmortel MHV, Fauquet CM, Bishop DHL, Carsrens E, Estes MK, Lemon S, Maniloff J, Mayo MA, Mcgeogh D, Pringle CR, Wickner RB. New York: Academic press; 2000, 867-872.

14. Ridpath JF, Bolin SR: Differentiation of types 1a, 1b and 2 bovine viral diarrhea virus (BVDV) by PCR. Mol. Cell Probes., 1998, 12:101–106.

5. References

6. Houe H, Meyling A: Surveillance of cattle herds for bovine virus diarrhoea virus (BVDV)infection using data on reproduction and calf mortality. Arch. Virol. Suppl., 1991, 3:157-164.

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15. Saliki JT, Dubovi EJ: Laboratory diagnosis of bovine viral diarrhea virus infections. Vet. Clin. North Am. Food Anim. Pract., 2004, 20: 69-83. 16. Sandvik T: Laboratory diagnostic investigations for bovine viral diarrhea virus infections in cattle. Vet. Microbiol., 1999, 64:123-134

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