[Epidemiological investigation of two leptospirosis death cases in Guizhou Province]

Objective: To conduct an epidemiological investigation of two leptospirosis death cases reported in Guizhou Province in 2014. Methods: The information of the patients were investigated and analyzed. The serological detection, samples of the two patients was detected using ELISA and microscopic agglutination test (MAT). Leptospira carrier status of murine host animal in the living environment of the two patients was investigated in October and November of 2014. Leptospires in the kidney were cultured and isolated, the isolates were identified using Leptospira specific PCR and further identified with serogroup specific PCR and the conventional MAT. The relativity between the carrier status of murine and the death cases of human leptospirosis was analyzed. Results: The two death cases of human leptospirosis came from Liping County and the clinical symptoms were consistent with the diagnosis criteria for Leptospirosis. The results of ELISA detection showed that the anti-Leptospira antibody was positive for one of the death cases, MAT identified the serum reacted with sera-group icterohaemorrhagiae Leptospira, while the serum sample of the other case was failed to perform antibody detection due to hemolysis. 1 600 traps were placed in the living environment of the two death cases and 183 murine rodents were trapped. The murine density was 11.44% (183/1 600); 40 leptospirea suspected strains were isolated and all of them were isolated from Apodemus agrarius. The positive rate was 21.86% (40/183); 95 Apodemus agrarius were trapped and the murine density was 5.93% (95/1 600). Species specific PCR identified all the 40 strains as Leptospire. Serogroup specific PCR further identification showed that they were iterohaemorrahgiae serogroup Leptospria. interrogans. Conclusion: Anti-iterohaemorrahgiae Leptospira antibody was detected from one of the two patients. 40 strains of iterohaemorrahgiae serogroup Leptospira interrogans were isolated and all of them were isolated from Apodemus agrarius in the living environment and the serogroup of the Leptospira matched with the serological detection results from patients, which indicated that the two death cases were caused by the infection of iterohaemorrahgiae serogroup Leptospira interrogans, and Apodemus agrarius were the potential source of infection.