Objective—To determine the prevalence of Mycoplasma suis infection in swine, swine-farm workers, and swine veterinarians in Shanghai, China.
Sample Population—172 swine and 65 workers and veterinarians from 19 commercial swine farms.
Procedures—Blood samples were collected from all study subjects. Blood samples were examined for the presence of M suis by means of compound and scanning electron microscopy. A species-specific PCR assay was developed for detection of M suis DNA extracted from blood samples. Relationships between infection status of swine and sex, age, geographic location, and clinical signs of disease were evaluated by use of a C2 test. The phylogenetic relationship between partial 16S ribosomal RNA (rRNA) sequences from swine and human isolates of M suis was determined.
Results—86% (148/172) of swine and 49% (32/65) of humans had positive PCR assay results for M suis infection. Swine infection status was not associated with any variable, with the exception of pyrexia and subcutaneous bleeding. The partial 16S rRNA sequences from human and swine isolates of M suis were 98% homologous and in the same phylogenetic cluster as a previously identified swine isolate of M suis.
Conclusions and Clinical Relevance—A large proportion of swine and humans in close contact with those swine were infected with M suis in Shanghai, China. The close phylogenetic relationship between swine and human isolates of M suis suggested possible interspecies transmission; however, additional research is required to better assess that possibility.