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High Seroprevalence of PPRV-Antibodies among Sheep and Goats in Hail, Saudi Arabia

VSRR_3_1_1-5

High Seroprevalence of PPRV-Antibodies among Sheep and Goats in Hail, Saudi Arabia

Ahmed Zein Mahmoud1, Muaz Abdellatif2* and Ahmed Abdalla3

1Veterinary Laboratories, Ministry of Environment, Water and Agriculture, Saudi Arabia; 2Department of Biology (Microbiology), Faculty of Arts and Science, Northern Borders University, Saudi Arabia; 3Sudan University of Sciences and Technology, Veterinary Medicine and Surgery, Sudan.

Abstract | Peste des petits ruminant’s virus (PPRV) causes a highly contagious disease in both domestic, wild ruminants and camels. Sera from non-vaccinated sheep (n=683), goats (n=624) and camels (n=155) of all ages and sexes were collected in a cross-sectional study in Hail, Bagaa, Shenan and Ghazalah. Saudi Arabia. The seroprevalece was determined by NP-epitopes based competitive ELISA. The overall prevalence was 59.9%, goats had a significantly higher sero-prevalence of 75.3% compared to 59.4% obtained from sheep, whereas camels were seronegative. The prevalence of PPR was increasing from 27.9% in 2011 to 77.3% in 2016. Seropositivity was higher in wet seasons (60.9 to 61.4%) to 56.7% in dry hot season. Species, year and location appeared to be having significant effect (p<0.01) on the frequency of circulating antibodies in the study. The results highlight that PPR in Hail is alarming and warrants mass vaccination along with appropriate control measures.


Editor | Muhammad Abubakar, National Veterinary Laboratories, Park Road, Islamabad, Pakistan.

Received | January 01, 2017; Accepted | February 01, 2017; Published | February 08, 2017

*Correspondence | Muaz Abdellatif, Department of Biology (Microbiology), Faculty of Arts and Science, Northern Borders University, Saudi Arabia; Email: muazm20@gmail.com

Citation | Mahmoud, A.Z., M. Abdellatif and A. Abdalla. 2017. High seroprevalence of PPRV-antibodies among sheep and goats in Hail, Saudi Arabia. Veterinary Sciences: Research and Reviews, 3(1): 1-5.

DOI | http://dx.doi.org/10.17582/journal.vsrr/2017.3.1.1.5


Introduction

Peste des petits ruminants (PPR) is a highly infectious and often fatal viral disease of sheep, goats and wild small ruminants. The disease is caused by PPR virus (PPRV), classified under genus Morbillivirus in the family Paramyxoviridae (Gibbs and Taylor, 1979; Shaila et al., 1996). Its transmitted by direct contact with infectious animals shedding the virus in both ocular-nasal discharges and in fecal matter (Munir et al., 2013; Albina et al., 2013). After first identification, the virus spread to sub- Saharan Africa, the Middle East, Turkey and the Indian subcontinent. During the last decade, the disease has been reported for the first time in China, Kenya, Uganda, Tanzania, Morocco and Tunisia (Abu Elzein et al., 1990; Banyard et al., 2010). The first report in Saudi Arabia was in 1990 (Abu Elzein et al., 1990), later it was reported in eastern and central region (Housawi et al., 2004; Al-Afaleq et al., 2004; Boshra et al., 2015). We recorded evidence of spreading PPR in smaller population of non-vaccinated sheep and goats in Hail during 2012–2013 (Mahmoud et al., 2016), the present study was proposed to evaluate the status of the disease in larger population during 2011-2016 surveys.

Materials and Methods

Sera Collection

Sera (n=1462) were collected from non-vaccinated sheep (n=683), goats (n=624) and camels (n=155) of all ages and sexes in Hail district, Saudi Arabia (Figure 1) during 2011–2016 surveys and outbreaks investigation (Table 1). Samples were stored at –20ºC until further analysis.


 

ELISA

The NP-epitopes based competitive ELISA kit (310 rue Louis Pasteur, 34790 Grabels, FRANCE, http://www.id-vet.com/produit/id-screen-PPR-competition) was used for detection of PPRV-antibodies according to the manufacturer’s protocol (Libeau et al., 1995).

Statistical Analysis

The prevalence of PPR and the associations between variables and seropositivity were estimated. Pearson correlation was performed to assess statistical significance of seroprevalence with discrete variables. Statistical analysis was performed using SPSS-22 (Statistical Package for Social Sciences 22).

Table 1: Cross tabulations of the results* species, year, season and location

Result Species Sheep   Goat   Camel   Total
Positive Count 406   470   0   876
% within Result 46.3%   53.7%   0.0%   100.0%
Negative Count 277   154   155   586
% within Result 47.3%   26.3%   26.5%   100.0%
Total Count 683   624   155   1462
% within Result 46.7%   42.7%   10.6%   100.0%
  Year 2011 2012 2013 2014 2015 2016  
Positive Count 36 77 33 185 283 262 876
% within Result 4.1% 8.8% 3.8% 21.1% 32.3% 29.9% 100.0%
Negative Count 93 94 45 88 189 77 586
% within Result 15.9% 16.0% 7.7% 15.0% 32.3% 13.1% 100.0%
Total Count 129 171 78 273 472 339 1462
% within Result 8.8% 11.7% 5.3% 18.7% 32.3% 23.2%

100.0%

  Season Wet cold   wet moderate   Dry hot    
Positive Count 420   239   217   876
% within Result 47.9%   27.3%   24.8%   100.0%
Negative Count 270   150   166   586
% within Result 46.1%   25.6%   28.3%   100.0%
Total Count 690   389   383   1462
% within Result 47.2%   26.6%   26.2%   100.0%
  Location Hail   Bagaa   Shenan Ghazalah  
Positive Count 603   158   60 55 876
% within Result 68.8%   18.0%   6.8% 6.3%

100.0%

Negative Count 289   153   73 71 586
% within Result 49.3%   26.1%   12.5% 12.1% 100.0%
Total Count 892   311   133 126 1462
% within Result 61.0%   21.3%   9.1% 8.6%

100.0%

 

Table 2: Significant difference between the prevalence and species, season, year and location

  Result Species Season Year Location
Result Pearson Correlation 1

-.188**

-.032

.270**

-.187**

Sig. (2-tailed)   .000 .221 .000 .000
N 1462 1462 1462 1462 1462
Species Pearson Correlation

-.188**

1

-.108**

.033

.064*

Sig. (2-tailed) .000   .000 .207 .014
N 1462 1462 1462 1462

1462

Season Pearson Correlation -.032

-.108**

1

-.355**

-.090**

Sig. (2-tailed) .221 .000   .000 .001
N 1462 1462 1462 1462 1462
Year Pearson Correlation

.270**

.033

-.355**

1

-.094**

Sig. (2-tailed) .000 .207 .000   .000
N 1462 1462 1462 1462 1462
Location Pearson Correlation

-.187**

.064*

-.090**

-.094**

1
Sig. (2-tailed) .000 .014 .001 .000  
N 1462 1462 1462 1462

1462

*: Correlation is significant at the 0.05 level (2-tailed); **: Correlation is significant at the 0.01 level (2-tailed)

Results

Out of tested sera eight hundred and seventy-six (59.9%) were found positive for PPRV-antibodies, 470 (75.3%) from goats, compared to 406 (59.4%) obtained from sheep. However, all camel samples were seronegative (Figure 2 and 3).

The prevalence of PPR was found to be higher in 2016 (77.3%) compared to 27.9% in 2011 (Figure 4). The positivity was higher in wet moderate season (61.4%) followed by 60.9% in wet cold and 56.7% in dry hot season (Table 1). Species, year and location appeared to be having significant effect (p< 0.01) on the frequency of circulating antibodies in the study (Table 2).




Discussion

Seroprevalence of antibodies clarifies the status of the PPR especially in non-vaccinated flocks. The present investigation provided data about infection in Hail district in goats, sheep and camels during 2011-2016 where vaccination is not practiced. We reported evidence of spreading PPR in the region in relatively small population (Mahmoud et al., 2016).

The study showed overall prevalence of 59.9%, high sero-prevalence rates in goats (75.3%) and sheep (59.4%), whereas camels were seronegative. Our results further suggest that the incidence was increasing from 27.9% in 2011 onwards to 77.3% in 2016. Species, year and location are significant variables associated with PPRV. Seropositivity was higher in wet seasons (60.9 to 61.4%) to 56.7% in dry hot season. Ameen and Ajayi (2013) reported that clinical conditions of small ruminants was influenced by seasonality, with high percentage of PPR (9.59%) on dry season. Obi (1983) and Okoli (2003) who recorded 25.1% of PPR in dry season. The results obtained varied from previously recorded data (Al-Afaleq et al., 2004; Al-Dubaib, 2009; Boshra et al., 2015), which may be due to seasonal effects, host population density, age, prevailing management practices and the social environment that can influence the contact rates (Abu Elzein et al., 1990; Singh et al., 2004; Bhanuprakash et al., 2006; Bowden et al., 2008). Field and laboratory observations indicate that PPR is less severe in sheep than in goats (Taylor, 1984; Lefèvre and Diallo, 1990). Seronegative camel sera may be related to sample size and/or the circulating virus strain.

Saudi Arabia serves as a major center for international trade, where hundreds of thousands of ruminants are imported every year changing prevalence in a short period of time. Increasing prevalence of PPR in Hail district is alarming and necessitate systematic and intensive serological surveillance programme along with measurement of clinical prevalence, implementing intensive vaccination campaigns and effective control measures/strategies for PPR.

Acknowledgments

The authors gratefully acknowledge the outstanding staff of the Veterinary Laboratory. Hail, Ministry of Environment, Water and Agriculture, Saudi Arabia

Conflict of Interests

The authors declare that they have no conflict of interest.

Author’s Contribution

Mahmoud, A.Z., M. Abdellatif collected and tested sera, performed statistical analysis and wrote the manuscript. A. Abdalla supervised the study and corrected the manuscript, all read and approved it for submission.

References

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Veterinary Sciences: Research and Reviews

June

Vol. 9, Iss. 1, Pages 1-86

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