Investigation of an infection case of Orientia tsutsugamushi Boryong sub-genotype in Ningbo, Zhejiang, 2022

  Objective  To understand the genotype of Orientia tsutsugamushi by analyzing a suspected tsutsugamushi disease case detected in Ningbo, Zhejiang province, 2022.

  Methods  Epidemiological investigation was conducted. Blood samples of the case in fever phase were collected for the extraction of pathogen DNA. Quantitative real-time fluorescent PCR was performed for the amplification of targeted gene tsa56, and a phylogenetic tree was constructed based on gene sequencing result to determine the genotype of O. tsutsugamushi.

  Results  O. tsutsugamushi was detected in the case's blood samples by quantitative real-time fluorescent PCR. Phylogenetic tree analysis demonstrated it had most closely relationship with Boryong strain.

  Conclusion  An infection case of O. tsutsugamushi was laboratory confirmed in Ningbo, the sub-genotype was Boryong.