Severe fever with thrombocytopenia syndrome (SFTS), caused by the SFTS
virus (SFTSV), is a new acute infectious disease transmitted by ticks.
Rickettsiosis is caused by Rickettsia spp. carried by ticks. Here, we
conducted case analyses and molecular biological diagnosis of some
patients with suspected SFTS in Liaoning Province in 2019 to identify
rates of SFTSV and Rickettsia coinfection. Molecular diagnostic results
confirmed SFTSV infection in 5 out of 17 suspected SFTS patients. Two
strains of genotype A SFTSV were successfully isolated from patient
blood. Ticks collected from the patient’s locations had high positivity
rates for SFTSV, which was highly similar to SFTSV from patients.
Antibody testing of 7 patient serum samples revealed all samples to be
positive for Rickettsia antibodies. These results indicate coinfection
of SFTSV with Rickettsia that may complicate disease presentation and
diagnosis. Therefore, coinfection of tick-borne disease should be
considered for correct diagnosis and treatment.