Epidemiological Survey, Molecular Detection and Risk Factors of Camel ORF Virus in Arero District, Ethiopia

Abstract

Background: While camels (dromedaries) were traditionally believed to be resistant to mostlivestock diseases, research has demonstrated that they are susceptible to a large number ofinfectious agents. Based on the clinical appearance of typical lesions, Camel contagiousecthyma (CCE), caused by a Orf virus, is thought to be one of the most common viraldiseases of camelids in Ethiopia. However, the epidemiology of the disease has not beenformally described and the causative agent has never been molecularly confirmed.Methods: a cross-sectional study was conducted from November 2013 to April 2014 inArero district of Borena Zone, to assess morbidity and mortality rates of the of diseaseconsistent with CCE, isolate and molecularly identify the causative agents and to find out thepotential risk factors. Molecular technique, namely, PCR based on B2L gene-specific primers ofORFV was used for the confirmatory diagnosis of CCE virus from the skin lesions.Results: Majority (86.8%) of the respondents indicated occurrence of CCE outbreaks in theirherds in the past one year (a year preceding the start of the study). The overall morbidity andmortality rates attributed to CCE was 43.6% (95 % CI: 41.2%–46%) and 6.3% (95 % CI: 5.2–7.6%) respectively. Confirmatory diagnosis of the suspected Orf virus isolates usingconventional PCR techniques generated the expected amplification product of 1200bp for oneof the samples. No product was amplified from the DNA samples of the negative control.This study showed that young camels (calves) had higher odds of becoming affected by CCEthan adults [OR=3.44 (95 % CI: 2.29 –4.09); (p<0.05)]. The disease had marked seasonalitywith most of the cases occurring during rainy season. Acacia trees significantly contribute tovirus dissemination through damaging the lips of browsing camels.Conclusions: This study confirms the presence and importance of CCE in Ethiopia andestablishes the basis for further research.