Circulation of Trypanosoma evansi antibodies and risk variables among dromedary camels in Al Batinah governorates, Sultanate of Oman.

Trypanosoma evansi is a blood protozoan infects camels with Surra disease and causes high economic losses. The current study was focused on estimating the seroprevalence and associated risk factors of Surra disease among camels, using 425 blood samples collected from 45 farms in nine Wilayats of Al Batinah governorates in the Sultanate of Oman. Host and environmental risk factors associated with T. evansi seroprevalence were analyzed by questionnaire arranged during sample collection. The overall seroprevalence by the serological CATT/T. evansi was 19.5% (83/425, CI: 16.0-23.6%). The seroconversion rate between the two governorates of north and south Al Batinah was not statistically significant (p > 0.05). However, the highest frequency was in Al Musannah at 41.7% (10/24, CI: 22.1-63.4%), and the lowest was in Al Khaburah at 10.5% (6/57, CI: 4.0-21.5%). Most of the owners in Al Khaburah (82.5%) were aware of T. evansi importance, and therefore they kept camels separate from ruminants. The ticks-free camels, racing camels and camels less than five years old showed higher T. evansi seroprevalence than other camels. The mean total protein was significantly (t = 2.817, p = 0.006) higher in seropositive camels (6.49 ± 0.75) compared to seronegative ones (6.25 ± 0.55), whereas PCV was not statistically different between the positive (28.96 ± 4.33) and negative camels (29.83 ± 3.63). Further studies are highly recommended to determine the prevalence and type of T. evansi in camels and ruminants in different governorates in Oman, especially in the Dhofar region, where the highest camel density is reported in the country.

Seroprevalence and Risk Factors of Brucellosis in Ruminants in Dhofar Province in Southern Oman.

Objective: The aim of the present work was to raise awareness of Brucella infection and emphasize the use of serological tests for screening and confirmation of the presence of the infection in different localities in the Dhofar region in the Sultanate of Oman. Methods: A seroprevalence of Brucella infection in naturally infected livestock was undertaken in 50 farms (a total of 434 sera, 207 goats, 84 sheep, 54 cattle, and 89 camels) from different wilayat of the Dhofar region in the southern part of Oman. Rose Bengal (RBT), complement fixation (CFT), and indirect enzyme-linked immunosorbent assay (I-ELISA) tests were used to determine the presence of Brucella antibodies. Statistical analysis (Pearson chi-square, binary logistic regression, and univariate logistic regression) was used to investigate the significance between the prevalence and the categorical risk factors individually, with two or more levels (animal species, animal condition, and or location). Results: Our results show that the overall seroprevalence based on CFT, RBT, and I-ELISA was 3% (13/424, CI: 1.8-5.1%), 4.8% (21/434, CI: 3.1-7.3%), and 8% (35/434, CI: 5.8-10.9%), respectively. The highest seroprevalence was reported in goats (13% (27/207)) and animals from East Jabal (13% (21/161)), whereas the lowest was recorded in camels (3.4% (3/89)) and animals from deserts (1.4% (1/69)). Parameters such as the positive predictive value (PPV) and the negative predictive value (NPV) showed that the sensitivity of I-ELISA and CFT based on the RBT test was 61.9% and 57.1%, respectively, whereas the specificity of I-ELISA (94.6%) was less than that of CFT (97.33%). Conclusion: We concluded that three tests are confirmatory for the presence of Brucella infection.

Concurrent vaccination of goats with foot and mouth disease (FMD) and peste des petits ruminants (PPR) booster vaccines.

Foot and mouth disease (FMD) remains subclinical and self-limiting in small ruminants, but risk of spread of infection to susceptible cohorts is of great epidemiological significance; therefore, small ruminants must be included in vaccination campaigns in FMD endemic regions. Three groups of goats already immunized against peste des petits ruminants (PPR) were vaccinated with FMD and PPR vaccines alone or concurrently. The specific antibody response against three FMD virus strains and PPR virus were evaluated by competitive enzyme-linked immunosorbent assay (cELISA). Goats concurrently vaccinated with PPR + FMD vaccines had significantly (p < 0.05) higher antibody titers to two serotypes of FMD virus at 28, 45, and 60 days post-immunization compared to goats vaccinated with FMD vaccine alone, while goats vaccinated with PPR vaccines alone or PPR + FMD vaccines concurrently showed similar antibody kinetics against PPR virus up till 60 days post-vaccination. Overall, antibody kinetic curves for all three tested strains of FMD virus and PPR virus were similar in vaccinated groups during the course of experiment.