Coexistence of Anti-NP-PPRV, VP7-BTV, and NS-FMDV Antibodies among Non-Vaccinated Domestic Ruminants in Hail Saudi Arabia

| des Petits ruminants (PPR), Blue tongue (BT), and Foot and mouth disease (FMD) are infectious viruses of livestock. The present work aimed to screen for anti-NP-PPRV, VP7-BTV, and NS-FMDV antibodies among non-vaccinated domestic ruminants (n=841) in Hail. Saudi Arabia. Sera were collected randomly from sheep (n=270), goats (n=270), cattle (n=31), and camels (n=270) of different ages and sex and tested at once by NP-PPR, VP7- BTV, and 3ABC-FMD competitive ELISA. The overall prevalence was 51.8% for PPR, 48.9% for BT, and 17.5% for FMD. Higher positivity for PPR (79.3%), BT (74.1%), and FMD (23.3%) was found in sheep. Co-occurrence of antibodies was 32.9% for PPR/BT and 11.2% for PPR/FMD and BT, PPRV/ BTV and FMDV antibodies was detected in sheep (6.5%), goats (4.4%) and camels (0.2%), PPRV and BTV in sheep (17.4%), goats (15.5%) and camels (0.1%), PPRV and FMDV in goats (0.7%) and cattle (0.2%) and FMDV and BTV was detected in goats (0.5%) and camels (0.1%). Significant correlations between seroprevalence and animal species, PPRV and BTV, PPRV and FMDV, BTV and FMDV were estimated. Novel rapid, sensitive, and specific multiplex immunoassays are essential for the detection of co-infection to improve the management of these devastating viruses.


P este des Petits Ruminants (PPR), Blue tongue (BT) and
Foot and mouth disease (FMD) are among the most important viruses in ruminants. PPRV infects domestic and wild ruminants causing significant economic losses in Africa, Middle East, Asia, and new regions (Banyard et al., 2010(Banyard et al., , 2014. The virus belongs to morbillivirus genus of the Paramyxoviridae (Zahur et al., 2009), it was reported in Saudi Arabia for the first time in 1990 (EME et al., 1990), later it spread to eastern, central, and northern regions (Adel et al., 2004;Boshra et al., 2015;Mahmoud et al., 2016. BTV is an arbovirus that is transmitted by certain species of Culicoides biting midges, affecting domestic and wild ruminants, it is one of the 22 serogroups in the Orbivirus genus of the Reoviridae (Mertens et al., 2005). It is characterized by high morbidity and mortality in sheep, while the infection is sub-clinical in some domestic and wild ruminants (Ratinier et al., 2011), it was described in different parts of the country (Hafez et al., 1984;Abu Elzein et al., 1998;Housawi et al., 2004a;Yousef et al., 2012b). FMDV is a member of the Apthovirus of the Picornaviridae, it causes direct production losses and indirect losses due to the implementation of control measures (Knight-Jones and Rushton, 2013). Introduction of subclinical animals acts as a source of new serotypes (Hafez et al., 1994;El-Rahim et al., 2016;Mahmoud and Galbat, 2017).
Co-infection may change the clinical picture, epidemiology and hamper diagnosis and preventive measures against these devastating viruses. The present survey was undertaken to

Vp7-btV elisA
Competitive enzyme immunoassay for the detection of antibodies against BT-VP7 protein was used (IDEXX Blue tongue Competition Ab test, 34090 Montpellier, France) according to the recommended procedure. Samples with S/N ≥80% were considered negative, >70% and ˂ 80% were doubtful and ≤70% were positive.

3Abc-fmd elisA
The 3ABC-FMD ELISA (IDEXX FMD 3ABC Ab test. IDEXX Laboratories, Inc. Westbrook, Maine 04092, USA) was used for the detection of non-structural Polyprotein (NSP), it was performed according to the manufacturer's instructions. Samples with percentage values >30% were considered positive, >20% were negative and samples between 20 and 30% were suspicious.

stAtisticAl AnAlYsis
Spearman correlation was adopted to estimate the significant correlation of PPRV, FMDV, BTV antibodies and animal species if any (r = 0.7, P-value = 0.01). The analysis was performed using SPSS-22 (Statistical Package for Social Sciences 22).

RESULTS AND DISCUSSION
This work aimed to investigate the coexistence of PPRV, BTV, and FMDV antibodies among domestic ruminants in Hail, Saudi Arabia. The prevalence of NP-PPRVantibodies was 51.8%, sheep exhibited the highest percentage (79.3%) ( Figure 1). The incidence of PPRV antibodies was significantly higher in sheep and goats compared to cattle and camels, as a matter of fact, goats and sheep are the natural hosts of the virus (Lefèvre and Diallo, 1990;Salih et al., 2014). The prevalence of PPRV was higher than the reports from Tchad (34%) (Bidjeh et al., 1995), Sudan (51%) (Osman et al., 2009) (Mahmoud et al., 2016. However, exposure of 2.97% dromedary camels from eastern and south regions of the country to PPR was published by Hemida and Al-Ghadeer (2019). Low percentage may be due to the fatal picture of PPR or to the nature of camel sera (Intisar et al., 2017;Omani et al., 2019), Since, unique classes and antibody binding of camel immunoglobulins was described by Li et al. (2012). Daley et al. (2010) reported divergences in the regulation and function among camelid heavy-chain isotypes on testing immunized alpacas for West Nile virus antibodies. Furthermore, inconsistency of the results obtained by ELISA and virus neutralization in testing camel sera for camel pox virus antibodies was described by Mentaberre et al. (2013), may indicate the need of standardization of ELISA when screening camel sera.

CONCLUSION
The results provided evidence of concurrent PPRV, BTV, and FMDV infections among farm animals in Hail, Saudi Arabia. Attention should be paid to explore the effects of virus interaction on the pathogenesis, clinical and/or epidemiological features that may hinder the diagnosis and execution of prevention and control policies. Development of rapid, sensitive, and specific multiplex immunoassays is necessary to improve the management against these infectious viruses.

AUTHOR'S CONTRIBUTION
Mahmoud AZE participated in the design of the study, collect samples and perform ELISA tests. Abdellatif MM design the study, participated in the lab work, analysed the results and wrote the manuscript. Ali YH participated in the design of the study, participated in the lab work and revised the manuscript.

CONFLICTS OF INTEREST
The authors have declared no conflict of interest.