Seroprevalence of, and risk factors for, peste des petits ruminants in sheep and goats in Northern Jordan

Abstract

Peste des petits ruminants (PPR) is an economically important disease that affect sheep and goat industry in Asia and Africa. In this study, we investigated the seroprevalence, and risk factors, of PPR in sheep and goat flocks from five different governorates (Irbid, Jarash, Ajloun, Mafraq and Zarka) located in Northern Jordan. Serum samples from 929 and 400 sheep and goats, respectively, corresponding to 122 sheep flock and 60 goats flock were collected. Seroprevalence was determined using PPR competitive ELISA. Health status and management information were collected using a semi-structured pre-tested questionnaire. The individual true prevalence of PPR in sheep and goats was 29 and 49%, respectively. The flock level true prevalence of PPR was 60 and 74% in sheep and goats, respectively. In both sheep and goat flocks, large flock size, visiting live animals market and inadequate veterinary services were identified as risk factors for PPR seropositivity. Mixed (sheep and goats) raising was identified as a risk factor for PPR seropositivity in sheep flocks only.

Introduction

Peste des petits ruminants (PPR) is an acute and highly contagious viral disease of small ruminants that is characterized by high fever, ocular and nasal discharge, pneumonia, necrosis, ulceration of the mucous membranes and inflammation of the gastro-intestinal tract leading to severe diarrhea (Radostits et al., 2000). This disease is of high economical importance because of the high mortality rate, especially among young animals, and the restriction on livestock trading. Goats are severely affected but sheep undergo a mild form of the disease (Lefèvre et al., 1991). Morbidity and mortality rates in small ruminants vary but can be as high as 100% (Lefèvre et al., 1991, Anderson and McKay, 1994). Infection with PPR virus is usually magnified if complicated with other concurrent respiratory and/or gastro-intestinal infections.

The PPR virus (a member of the Morbillivirus genus) is antigenically related to rinderpest virus which infects cattle and other large ruminants (Anderson and McKay, 1994). As of today, PPR-virus isolates were grouped into four distinct lineages on the basis of partial sequence analysis of the fusion (F) protein genes; lineage III is the lineage found in Eastern Africa (Ethiopia) (Shaila et al., 1996). However, lineage IV was reported in Asia (Ozkul et al., 2002). In Jordan, lineage IV was isolated form one single outbreak in 1993 (Al domy, 1993).

PPR was first reported from West Africa in the early 1940s and later recognized as an endemic disease in West and Central Africa (Anderson and McKay, 1994). It has been reported in Sudan, Kenya, Uganda and in Ethiopia (El Hag and Taylor, 1984, Wosu, 1994). In addition, the disease was reported in most of the countries of the Arabian Peninsula and the Middle East (Taylor, 1997, Lefèvre et al., 1991, AL-Afaleq et al., 2004). Many outbreaks were reported in the Indian sub-continent (Singh et al., 2004).

The objectives of this study were to determine the seroprevalence of antibodies against PPR in sheep and goats from five different governorates located in the northern part of Jordan and to elucidate risk factors associated with sheep and goat flocks seropositivity to PPRV.