Seroprevalence of Mycobacterium avium subspecies paratuberculosis (MAP) and evaluation of risk factors in camels of the Sultanate of Oman.

Johne's disease (JD) is a World Animal Health Organization (OIE)-listed disease of ruminants including camels with serious economic impacts worldwide. A cross-sectional serological survey involving multistage simple random sampling was conducted to investigate the prevalence of JD in camels of Oman. In total, 2255 camels (254 males and 2001 females) and different ages from 553 geographically marked holdings were bled for serum. The samples were analyzed by a commercial indirect enzyme-linked immunosorbent assay (ELISA) with protein 'G' as conjugate (LSI VET Ruminant Serum Paratuberculosis Advanced, France). Results indicated a widespread herd and individual level seroprevalence, respectively of 9.2 % (95 % CI = 0.7-50) and 2.6 % (95 % CI = 2.0-3.4) in Oman. Differences (p < 0.01) were observed regarding the prevalence of JD in sampled governorates, and the highest prevalence was recorded in Dhofar (13.5 %). Higher (p > 0.05) seroprevalence was observed in females (2.8 %), and their odds for testing positive were 3.69 (95 % confidence interval (CI) = 0.90-15.23) times higher as compared to males (0.8 %). Seropositivity increased with the age of camels, and the highest prevalence (4.4 %) was observed in camels of more than 10 years of age (p = 0.03). Large and medium size herds (odds ratio (OR) = 1.77, 95 % CI = 0.96-3.24) where camels were kept as single species (OR = 1.54, 95 % CI = 0.84-2.84) and confined (OR = 1.93, 95 % CI = 1.05-3.54) were found more likely to test positive. This is the first record of seroprevalence of JD among the camels in the country which highlights their potential as an important host of the disease. The results advocate that a comprehensive control program based upon further risk analysis and molecular study should be devised in Oman.

Seroepidemiology of foot and mouth disease (FMD) virus non-structural protein (NSP) antibodies in the livestock of Oman.

Foot and mouth disease (FMD) is a highly contagious acute viral disease that causes severe economic losses to the affected countries. To estimate the serological prevalence of the local livestock to the natural infection with FMD virus, a cross-sectional study was conducted from 2015 to 2017 in Oman. Sera from 5807 randomly selected animals (1792 cattle, 2119 goats and 1896 sheep) belonging to 884 herds were tested for the presence of antibodies against 3ABC non-structural protein (NSP) of the FMD virus by a Competition ELISA. Prevalence along with confidence intervals (CI) and odds ratio (OR) was calculated, and the data were further analysed through univariable and multivariable techniques. The herd-level seroprevalence of NSP (41.4%) varied significantly among 11 governorates of Oman. At herd-level seroprevalence varied significantly among cattle (55.2%), goats (38.2%) and sheep (37.7%). At animal-level, the significantly higher prevalence was recorded in cattle (26.8%) followed by sheep (17.9%) and goats (17.3%). Binary logistic regression analysis at the individual level indicated that cattle (OR: 1.88), livestock above one year of age (OR: 3.47), imported breeds (OR: 1.82) and females (OR: 1.27) were the risk factors associated with higher prevalence. Whereas, sedentary (OR: 2.63) farming system, vaccination against FMD (OR: 5.98) and previous history of FMD (OR: 5.55) were the variables found associated with higher seroprevalence at the herd-level. We conclude that natural infection of FMDV is widespread in Oman and in future molecular typing of FMD virus outbreaks strains and vaccine matching studies should be employed to develop an effective control program in Oman.

African Lineage Brucella melitensis Isolates from Omani Livestock.

Brucellosis is a common livestock disease in the Middle East and North Africa, but remains poorly described in the region both genetically and epidemiologically. Traditionally found in goats and sheep, Brucella melitensis is increasingly recognized as infecting camels. Most studies of brucellosis in camels to date have focused on serological surveys, providing only limited understanding of the molecular epidemiology of circulating strains. We genotyped B. melitensis isolates from Omani camels using whole genome SNP assays and VNTRs to provide context for regional brucellosis cases. We identified a lineage of B. melitensis circulating in camels as well as in goats, sheep, and cattle in Oman. This lineage is genetically distinct from most genotypes from the Arabian Peninsula and from isolates from much of the rest of the Middle East. We then developed diagnostic assays that rapidly identify strains from this lineage. In analyses of genotypes from throughout the region, Omani isolates were genetically most closely related to strains from brucellosis cases in humans and livestock in North Africa. Our findings suggest an African origin for B. melitensis in Oman that has likely occurred through the trade of infected livestock. Moreover, African lineages of B. melitensis appear to be undersampled and consequently are underrepresented in genetic databases for Brucella. As we begin to more fully understand global genomic diversity of B. melitensis, finding and characterizing these unique but widespread lineages is essential. We predict that increased sampling of humans and livestock in Africa will reveal little known diversity in this important zoonotic pathogen.

Sero-epidemiology of cystic echinococcosis (Echinococcus granulosus) in the livestock of Oman.

A cross-sectional serological survey of cystic echinocossis was carried out on 2802 randomly collected sera of camels (n=706), cattle (n=687), goats (n=701) and sheep (n=708) from all governorates of Oman. The samples were analysed by in house indirect ELISA (iELISA) using Echinococcus granulosus antigen B (EgAgB) of naturally infected camels. The overall percentage of antibodies against EgAgB was found to be 14.6%. The highest percentage of positive was observed in sera from camels (22.4%) followed by cattle (12.9%), sheep (12.2%) and goats (10.9%). The highest percentage of seropositivity was observed in females (15.4%) as compared to male animals (10.6%). The imported livestock were found more seropositive (15.2%) as compared to local (14.7%) and crossbred livestock (14.1%). The highest exposure was observed in animals with the age group of above 5years (18.3%) followed by the age group of up to 2years (15.1%,) and those between 2 and 5years (12.4%). The univariate analysis has indicated that camels (OR:2.33, CI 1.74, 3.14), cattle (OR:1.21, CI 0.87, 1.67), sheep (OR:1.12, CI 0.81, 1.55) were more likely to test positive than goats. Furthermore, females (OR: 1.53, CI 1.11, 2.11) were more likely to test seropositive. Sera from animals above 5years of age (OR:1.58, CI 1.25, 2.01) and between 2 and 5years old (OR:1.30, CI 0.98, 1.71) were found more likely to test seropositive than those up to 2years of age. The multivariable analysis at individual level indicated that camels (OR: 2.07, CI 1.66, 2.56, p<0.001) and female (OR: 1.43, CI 1.04, 1.98, p=0.030) were more likely to acquire CE. At herd level, the final multivariable model indicated that herds located in Dofar and Musandam (OR: 4.48, CI 2.69, 7.45, p<0.001), in areas receiving seasonal rains (OR: 2.54, CI 1.09, 5.90, p<0.001) and practicing transhumance (OR: 4.22, CI 1.84, 9.65, p<0.001) and sedentary (OR: 2.07, CI 1.38, 3.12, p=0.001) farming system were more likely to acquire CE in Oman. The study documents the serological evidence of CE in livestock of Oman and a carefully planned control program should be devised after further epidemiological and molecular investigations in the intermediate and final hosts.

Genetic characterisation of Taenia multiceps cysts from ruminants in Greece.

This study was designed to genetically characterise the larval stage (coenurus) of Taenia multiceps from ruminants in Greece, utilising DNA regions within the cytochrome c oxidase subunit 1 (partial cox1) and NADH dehydrogenase 1 (pnad1) mitochondrial (mt) genes, respectively. A molecular-phylogenetic approach was used to analyse the pcox1 and pnad1 amplicons derived from genomic DNA samples from individual cysts (n=105) from cattle (n=3), goats (n=5) and sheep (n=97). Results revealed five and six distinct electrophoretic profiles for pcox1 and pnad1, respectively, using single-strand conformation polymorphism. Direct sequencing of selected amplicons representing each of these profiles defined five haplotypes each for pcox1 and pnad1, among all 105 isolates. Phylogenetic analysis of individual sequence data for each locus, including a range of well-defined reference sequences, inferred that all isolates of T. multiceps cysts from ruminants in Greece clustered with previously published sequences from different continents. The present study provides a foundation for future large-scale studies on the epidemiology of T. multiceps in ruminants as well as dogs in Greece.

Abattoir based surveillance of cystic echinococcosis (CE) in the Sultanate of Oman during 2010-2013.

A passive surveillance was conducted in 8 selected abattoirs belonging to 8 governorates of Oman. Routine slaughtering of 282.020 animals was observed during 2010-2013 by duty veterinarians and suspected samples (n=1440) for cystic echinococcosis (CE) from camels (n=292), cattle (n=303), goats (n=682) and sheep (n=163) were collected. In total, 587 (40.8%) samples were found positive for CE and the highest percentage (64.2%) of positive samples belonged to Dhofar (Salalah) as compared to other governorates, p<0.01. The infection rate of CE was calculated as 5.3, 0.6, 0.07 and 0.03 in camel, cattle, sheep and goats respectively. Fertile cysts were found in 30.7% of positive samples and camels (52%) were found as major source of these followed by cattle (14.1%) and goats (9.7%). Percentage of positive to submitted samples was higher in females (67.9%) than males (29.8%). The fertility of cyst increased with age and the highest percentage of fertile cysts were collected from animals above 5 years of age (54.4%) followed by between 3 and 5 years (36.7%) and below 3 years of age (8.9%). For different breeds, 478 (62.7%) samples from local breeds of livestock were positive for CE as compared to 108 (15.9%) from imported animals (OR 8.92), p<0.01. The highest percent of positive samples was observed in cysts from lungs (54.4%) followed by those from liver (25.7%), liver and lungs (14.1%) and others (3.8%). Molecular investigations indicated that G1 and G6/7 were the two strains of CE circulating in camels and cattle while G1 was the only strain found in samples from small ruminants. Results indicated that CE is endemic in the livestock of Oman and further molecular epidemiological work in different host species is required for the conceptualization of a comprehensive control program.

Spatio-temporal pattern of sylvatic rabies in the Sultanate of Oman, 2006-2010.

Rabies was first reported in the Sultanate of Oman is 1990. We analysed passive surveillance data (444 samples) collected and reported between 2006 and 2010. During this period, between 45 and 75% of samples submitted from suspect animals were subsequently confirmed (fluorescent antibody test, histopathology and reverse transcription PCR) as rabies cases. Overall, 63% of submitted samples were confirmed as rabies cases. The spatial distribution of species-specific cases were similar (centred in north-central Oman with a northeast-southwest distribution), although fox cases had a wider distribution and an east-west orientation. Clustering of cases was detected using interpolation, local spatial autocorrelation and scan statistical analysis. Several local government areas (wilayats) in north-central Oman were identified where higher than expected numbers of laboratory-confirmed rabies cases were reported. For fox rabies, more clusters (local spatial autocorrelation analysis) and a larger clustered area (scan statistical analysis) were detected. In Oman, monthly reports of fox rabies cases were highly correlated (rSP>0.5) with reports of camel, cattle, sheep and goat rabies. The best-fitting ARIMA model included a seasonality component. Fox rabies cases reported 6 months previously best explained rabies reported cases in other animal species. Despite likely reporting bias, results suggest that rabies exists as a sylvatic cycle of transmission in Oman and an opportunity still exists to prevent establishment of dog-mediated rabies.