Evidence of mixed infection of peste des petits ruminants virus and bluetongue virus in a flock of goats as confirmed by detection of antigen, antibody and nucleic acid of both the viruses B. Mondal & A. Sen & K. Chand & S. K. Biswas & A. De & K. K. Rajak & S. Chakravarti Accepted: 1 May 2009 # Springer Science + Business Media B.V. 2009 Abstract A mixed infection with peste des petits ruminants virus (PPRV) and bluetongue virus (BTV) occurred in goats which exhibited symptoms charac- teristic of PPR. A number of samples were collected from ailing or dead goats for labrotory diagnosis. Antibody to BTV and PPRV was detected in sera samples by competitive ELISA. No PPRV antigen was detected in tissue samples like lung and spleen, however, presence of PPRV antigen in some sera samples was confirmed by sandwich ELISA. All the blood samples collected from the ailing animals were found positive for BTV antigen by a sandwich ELISA. BTV- and PPRV nucleic acids were amplified from the pooled blood and tissue samples respectively by RT-PCR assays. The identity of the amplicons was confirmed by cloning and sequencing. All these tests confirm that the goats were infected with PPRV and BTV simultaneously. Isolation of viruses from the clinical samples is underway. Keywords Peste des petits ruminants virus . Bluetongue virus . Mixed infection . ELISA . RT-PCR Introduction Peste des petits ruminants (PPR) is a highly conta- gious viral disease of sheep and goats which is caused by the peste des petits ruminants virus (PPRV). The virus has been classified in the genus Morbillivirus within the family Paramyxoviridae (Van Regenmortel et al. 2000). PPR is endemic in India (Shaila et al. 1996; Dhar et al. 2002) and regular outbreaks in small ruminants occur throughout the country (Aruni et al. 1998; Kulkarni et al. 1996) since its first report from the Southern peninsula in late 1980s (Shaila et al. 1989). Bluetongue (BT) is an arthropod-borne viral disease primarily of sheep caused by the bluetongue virus (BTV), which is the prototype species of the genus Orbivirus in the Reoviridae family (Mertens et al. 2004). BT is endemic in India. The first outbreak of BT in India was reported in the early 1960s and thereafter regular outbreaks have been recorded in different parts of the country (Jain et al. 1986; Mehrotra et al. 1996; Sreenivasulu et al. 1999; Aruni et al. 2006; Ilango 2006). The virus can infect most species of domestic and wild ruminants such as goat, cattle, buffalo, camel, deer and other artiodactyls (McLachalan 1994). BTV infection in goat is asymp- tomatic and infected goats serve as reservoir of virus. Trop Anim Health Prod DOI 10.1007/s11250-009-9362-3 B. Mondal (*) : A. Sen : K. Chand : S. K. Biswas : K. K. Rajak : S. Chakravarti Division of Virology, Indian Veterinary Research Institute, Mukteswar Campus, Dist. Nainital, 263 138 Uttarakhand, India e-mail: bimalendu.m@email.com A. De Department of Veterinary Biochemistry, West Bengal University of Animal and Fishery Sciences, 37, Khudiram Bose Sarani, Belgachia, Kolkata 700 037, India