Epidemiological insights into paratuberculosis in camels in Saudi Arabia: Bayesian estimation of true prevalence and identification of risk factors

Paratuberculosis, caused by Mycobacterium avium subsp. paratuberculosis (MAP), is a significant concern in the camel population of Saudi Arabia. This study aimed to provide epidemiological insights into the disease by estimating the true prevalence in camels in the Eastern Province and Riyadh, using a Bayesian estimation framework, and exploring the associated risk factors through a frequentist approach. A total of 1200 camel blood samples were collected and analyzed using an indirect ELISA method. The true herd-level prevalence was estimated at 0.7 (95% probability interval: 0.57 to 0.81), and the mean expected true animal-level prevalence was 0.17 (0.14 to 0.20). Risk factors associated with Map seropositivity were identified, including sex, breed, raising system, and production type. Females, single breed camels, and nomadic raising systems were found to have lower odds of seropositivity, while camels used for racing and show had significantly higher odds. The study's Bayesian approach, adjusting for the imperfect accuracy of MAP tests, provides a nuanced understanding of the disease's prevalence in the region. The integration of true prevalence estimates with risk factor analysis offers a comprehensive framework that can guide future policies and strategies in the fight against paratuberculosis in Saudi Arabia. The findings emphasize the importance of targeted control measures, underscoring the urgent need for interventions in Saudi Arabia's camel population. By understanding the true disease prevalence and its associated risk factors, we can enhance disease management strategies, offering valuable insights for future control and eradication efforts in the region.

Seroprevalence and risk factors of Q-fever (C. burnetii infection) among ruminants reared in the eastern region of the Kingdom of Saudi Arabia

Q-fever is a worldwide spread zoonotic disease associated with severe illness in humans and abortions and stillbirths in ruminants. Ruminants are major sources of human infection where subclinical carriers shed the bacteria in various secretions and excreta. The goal of the current study was to investigate the prevalence and risk factors of Coxiella burnetii infection among cattle, sheep, and goats in the eastern province of the Kingdom of Saudi Arabia (KSA). A total of 1310 serum samples were collected through a designed cross-sectional study from private farms and slaughterhouses in the study area and examined against antibodies of C. burnetii using ELISA. A multivariate logistic regression analysis was built to detect risk factors of C. burnetii infection among examined species. The prevalence of C. burnetii infection among examined animals was 9.2% (CI, 7.7-10.8)-15.6%, 9.1%, and 5.8% among goats, cattle, and sheep, respectively). The risk of getting C. burnetii infection among old animals (> 1 year old) was 23 times higher than the risk among young animals (< 1 year old) (95% CI, 10.04-53.01; P < 0.01). Goats were 2.27 (95% CI, 1.41-3.66; P < 0.01) and 3 times at higher risk than cattle and sheep, respectively, of getting C. burnetii infection. In conclusion, C. burnetii infection is widespread among different ruminant species of the eastern province of KSA which represents a high risk for environmental contamination and disseminating the infection to humans and animal species in that area. Also, our findings may reflect the disease status in other countries of the Arabian Gulf area.

Detection of Mycobacterium avium subsp. paratuberculosis in an Egyptian mixed breeding farm and comparative molecular characterisation of isolates from cattle, camels and cats – a case report

The present study records and investigates an outbreak of Johne’s Disease in a mixed breeding camel – cattle farm and the possible role of non-domestic non-ruminants animals in the epidemiology of Mycobacterium avium subspecies paratuberculosis in Egypt. For this reason, faecal samples were collected from 24 dairy cattle and from 15 one humped Arabian camels suffering from diarrhoea. Moreover, intestinal tissue samples were provided from 7 cats and 2 rats that were caught from the same farm and were euthanized before necropsy. Samples were examined using traditional culture and IS900 PCR techniques together with the application of BstEII-IS900 RFLP for typing of obtained isolates. Interestingly, MAP was recovered from cattle (n=8) and from camels (n=3) and non-domestic cats (n=3) reared under local conditions in this farm in Egypt. The obtained results highlight the potential role of cats in the epidemiology of MAP, a subject which needs further investigation and might have a public health importance, catsbeing common members of many families.

Bovine ephemeral fever epidemics in Kingdom Saudi Arabia: clinical, epidemiological and molecular investigation

INTRODUCTION

Bovine ephemeral fever virus (BEFV) is an arthropod borne Rhabdovirus affects cattle and water buffalo causes acute febrile disease.

METHODOLOGY

The clinical picture and epidemiological pattern of BEF were described among cattle in epidemics of 2007, 2009 and 2011 in four geographical regions of Kingdom Saudi Arabia (Eastern, Jizan, Qasim, and Riyadh). Serum samples were tested using VNT. Virus isolation and molecular characterization were carried out for the first time in KSA.

RESULTS

The main clinical symptoms were fever, stiffness, lameness, salivation and subcutaneous emphysema. The prevalence and the mortality rate of BEF have decreased from 70% and 4.6% in 2007 to 30% and 0.6% in 2011, respectively in the 4 studied areas. There was no region association with higher prevalence of BEF. The intracluster correlation (ICC) was estimated for the first time in KSA as 0.0034. BEFV had been isolated from 11 out of 20 samples (55%) and isolation was confirmed by VNT. The molecular detection of BEFV by RT-PCR and real- time RT-qPCR were found more sensitive for diagnosis of the disease than virus isolation; 80% and 90% for the former tests and 55% for the latter. Three isolates were sequenced, they showed 84.7% - 100% identities in between and shared 90.4%-96.5% sequence identity with a previously published sequence from Australia (KF679404). The generated sequences belonged to 3rd cluster of BEFV glycoprotein.

CONCLUSIONS

BEF occurrence has cyclic nature and the efficacy of vaccines prepared from local strains has to be evaluated and considered in diseases control.