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.

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.

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.