Sero-surveillance and immunization in sheep and goats against peste des petits ruminants in Bangladesh

Abstract

The sero-surveillance and immunization studies on Peste des Petits Ruminants (PPR) in non-descriptive indigenous sheep and Black Bengal goats aged between 5 to 12 months were carried out in the district of Mymensingh during the period from June to November 2003. Sero-prevalence of PPR by using competitive enzyme linked immunosorbent assay (C-ELISA) was conducted on 100 sheep and 100 goats which were selected randomly from 10 different areas in the district of Mymensingh. Of the 100 sheep and 100 goats tested, 27% sheep and 25% goats had positive (≥ 50) antibody titre. This indicates that 27% sheep and 25% goats might have the capability to resist natural PPR infection and accordingly, sero-monitoring could be required to give a better indication of nation herd immunity. The immunization study against PPR with a commercial PPR VAC® was conducted on 10 sheep and 10 goats by inoculating @ 1.0 ml vaccine / animal subcutaneously. The clinical, haematological, biochemical and antibody levels were determined at pre-immunization and at 7th, 14th and 21st day of postimmunization. The mean antibody titre at 7th, 14th and 21st day of post-immunization in sheep (38.28 ± 4.34, 58.63 ± 3.60 & 68.27 ± 3.09) and goats (49.84 ± 4.37, 63.23 ± 3.64 & 76.60 ± 4.07) were significantly (p < 0.01) increased in comparison to the respective pre-immunization mean titre of sheep (20.0 ± 6.78) and goats (14.00 ± 6.96). Results of haematological examination showed that the PPR VAC® has no effects on haemoglobin (Hb), erythrocyte sedimentation rate (ESR), packed celled volume (PCV) and total erythrocyte count (TEC). The TLC was markedly increased at all the stages of postimmunization in both sheep and goats but significantly (p < 0.05) increased at 21st day (10.08 ± 1.55 103 / mm3) in sheep and at 14th day (14.76 ± 0.84 103 / mm3) in goats in comparison to pre-immunization values of sheep (7.95 ± 0.97 103 / mm3) and goats (9.00 ± 1.28 103 / mm3). No distinct difference was observed on rectal temperature, pulse and respiratory rate between the pre- and post-immunization values which indicates PPR-VAC® has no clinical effects in vaccinated animals. No significant differences on calcium, albumin, total serum protein (TSP) and glucose levels were observed between the pre- and post-immunization values in both the sheep and goats. But the TSP in both the sheep 8.43 ± 0.69 g/dl) and goats (8.26 ± 0.50 g / dl) at 21st day of post-immunization increased insignificantly (p > 0.05) in comparison to the pre-immunization values of sheep (7.66 ± 0.79 g / dl) and goats (7.89 ± 0.92 g / dl). The results of humoral immune response produced by PPR-VAC® indicates the activity of the inoculated vaccine but challenge studies with virulent PPR virus would be required to confirm its efficacy. Key words: PPR, sheep, goats, sero-surveillance, C-ELISA, PPR-VAC®, haematology, biochemistry   doi: 10.3329/bjvm.v6i2.2334 Bangl. J. Vet. Med. (2008). 6 (2): 185-190