Serological diagnosis of tsutsugamushi disease and gene sequence analysis of Orientia tsutsugamushi in northern area of Anhui

  Objective  To analyze the serotype and gene sequence of Orientia tsutsugamushi detected and understand the genotype characteristics of Orientia tsutsugamushi infection in northern area of Anhui province.

  Methods  A total of 92 blood samples were collected from patients with clinically diagnosed tsutsugamushi disease in Fuyang, Bengbu, Suzhou of Anhui in 2018. The IgM antibodies and partial tsa56 genes of Orientia tsutsugamushi were tested respectively with indirect immunofluorescence assay (IFA) and nested-polymerase chain reaction (nPCR). The sequences of tsa56 genes were analyzed.

  Results  In 92 serum samples, 61 were IgM positive, Gilliam was the main serotype of Orientia tsutsugamushi detected, and 48 were nucleic acid positive in PCR, the genotypes of all the strains belonged to Kawasaki-related.

  Conclusion  The genotypes of Orientia tsutsugamushi detected in Fuyang, Bengbu, and Suzhou were Kawasaki-related, it is necessary to strengthen the surveillance for Orientia tsutsugamushi to prevent the outbreak of tsutsugamushi disease in Anhui.