Background Mycobacterium avium subspecies paratuberculosis (MAP) causes chronic, wasting, and progressive enteritis in cattle, bringing significant economic losses in livestock industries. MAP has spread worldwide mainly due to movement of animals. The objective of this study was to determine the MAP seroprevalence in cattle in the Xinjiang Uygur Autonomous Region, Northwest China, and evaluate the difference between intensive farming herds (cattle number in a herd is more than 200, and the cattle cannot have access to pasture) and free-range herds (the cattle are bred by individual households, a herd is defined as the cattle are bred in a village or town in this study).ResultsA total of 3157 serum specimens were collected from 42 herds in nine different regions. This included 1481 specimens from 18 intensive farming herds in four regions and 1676 specimens from 24 free-range herds in six regions. Antibody against MAP was tested with commercial ELISA test kits. The results showed that the overall apparent prevalence was 4.8% (95% CI, 4.1 to 5.6%) at animal level, and 50.0% (21/42) at herd level. The apparent prevalence in intensive farming herds and free-range herds were 9.5% (141/1481) and 0.7% (11/1676) at the animal-level, 88.9%(16/18) and 20.8% (5/24) at herd level, respectively, with a significant statistical difference between these two farming modes (p < 0.01). Cattle in intensive farming herds had a relatively higher risk to be infected with MAP than those in free-range herds (RR = 14.4).ConclusionThis study demonstrates that apparent prevalence of MAP infection in dairy cattle differs with farming modes at the animal level and herd level, and farming density could be an important risk factor associated with the presence of MAP infected cattle. This study provides important epidemiological data for bovine MAP control in Xinjiang, Northwest China.

We conducted a serological survey to detect antibodies against avian influenza virus (AIV) in Gazella subgutturosa, Canis lupus, Capreolus pygargus, Sus scrofa, Cervus elaphus, Capra ibex, Ovis ammon, Bos grunniens and Pseudois nayaur in Xinjiang, China. Two hundred forty-six sera collected from 2009 to 2013 were assayed for antibodies against H5, H7 and H9 AIVs using hemagglutination inhibition (HI) tests and a pan-influenza competitive ELISA. Across all tested wildlife species, 4.47 % harbored anti-AIV antibodies that were detected by the HI assay. The seroprevalence for each AIV subtype across all species evaluated was 0 % for H5 AIV, 0.81 % for H7 AIV, and 3.66 % for H9 AIV. H7-reactive antibodies were found in Canis lupus (9.09 %) and Ovis ammon (4.55 %). H9-reactive antibodies were found in Gazella subgutturosa (4.55 %), Canis lupus (27.27 %), Pseudois nayaur (23.08 %), and Ovis ammon (4.55 %). The pan-influenza competitive ELISA results closely corresponded to the cumulative prevalence of AIV exposure as measured by subtype-specific HI assays, suggesting that H7 and H9 AIV subtypes predominate in the wildlife species evaluated. These data provide evidence of prior infection with H7 and H9 AIVs in non-avian wildlife in Xinjiang, China.

Wild ruminants are at risk for zoonotic pathogen infection as a result of interactions with domestic animals and humans. One way to assess the level of a wild ruminant disease in a population is to determine the seroprevalence of the pathogen of interest. The objective of this study was to determine the seroprevalence of five zoonotic pathogens in wild ruminants in Xinjiang, Northwest China. In 2009 and 2011-2015, 258 wild ruminant sera samples were collected from various species. Samples were obtained from 30 Siberian ibexes, 94 goitered gazelles, 6 Tibetan antelopes, 32 argali sheep, 16 roe deer, 20 blue sheep, 56 red deer, and 4 wild yaks, in 10 regions of Xinjiang. Samples were tested using antibodies against Brucella spp., Chlamydophila abortus, Coxiella burnetii, Toxoplasma gondii, and West Nile virus. Seropositivity was detected for all five pathogens, with detection rates of Brucella spp., C. abortus, C. burnetii, T. gondii, and West Nile virus of 2.3% (95% confidence interval [CI], 0.5-4.2%), 6.2% (95% CI, 3.3-9.1%), 7.8% (95% CI, 4.5-11.0%), 2.3% (95% CI, 0.5-4.2%), and 0.8% (95% CI, 0-1.8%), respectively. The level of pathogens differed for different species and different regions. The results indicate that seropositivity to zoonotic pathogens is common among wild ruminants in Xinjiang, Northwest China, with C. burnetii and C. abortus detected at the highest levels. This study provides a baseline for future assessment of spillover events.

No abstract

Porcine reproductive and respiratory syndrome (PRRS) is a swine disease of major economic importance that causes reproductive and respiratory problems in pigs. In the present study, one strain of porcine reproductive and respiratory syndrome virus (PRRSV) was isolated in Xinjiang province, Northwest China, designated XJu-1. The full-length genome of XJu-1 was found to be 14,987 nucleotides in length, including the poly(A) tail. Comparative analysis with the genomic sequences of type 2 isolates revealed that XJu-1 shared 87.2-99.2 % identity with these isolates, but only 60.4 % with the type 1 virus-Lelystad Virus, indicating that this new Chinese isolate was closely related to the North American PRRSV genotype. XJu-1 was a novel strain with unique deletions in NSP2 region, namely that 150-amino acid deletion in NSP2. The genomic variations of XJu-1 strain provided the basis for further studies of virulence determinants and evolution for PRRSVs.