Abstract: Objective: To explore the clinical characteristics and laboratory characteristics of 73 cases of tsutsugamushi disease in
Anning area, as well as the risk factors of severe tsutsugamushi disease. Methods: The clinical characteristics, laboratory characteristics,
and treatment of 73 cases of tsutsugamushi disease hospitalized in Yunnan Kungang Hospital from January 2015 to December 2018
were retrospectively analyzed. According to the criteria of severe diagnosis, the patients were divided into 18 cases in the severe
group and 55 cases in the non-severe group. The clinical characteristics and laboratory results of the two groups were compared to
explore the risk factors associated with the occurrence of severe tsutsugamushi disease. Results: The incidence of 73 cases of tsutsugamushi
disease was mainly in summer and autumn, and the onset time was concentrated in July to October every year. Clinical features: all
patients had fever, and 87.7% of patients has eschar. Other atypical clinical manifestations: sick, abdominal pain, and diarrhea. Positive
laboratory indicators associated with the incidence of tsutsugamushi disease have elevated ALT, AST, LDH, PCT and CRP, decreased
eosinophils, and abnormal lymphocytes. PLT reduction, CRP, PCT, AST, and LDH elevation were statistically significant between the
severe tsutsugamushi disease group and the non-severe tsutsugamushi disease group (P<0.01). Conclusion: In addition to high fever,
tsutsugamushi disease has a variety of clinical manifestations, and there are a variety of laboratory abnormalities. Clinicians need to
carefully ask about the medical history, do comprehensive analyses of various laboratory data during the high seasons of tsutsugamushi
disease and find the eschar of the hidden parts of the body to avoid missed diagnosis and misdiagnosis of tsutsugamushi disease; patients
with severe tsutsugamushi disease are prone to PLT reduction and increased CRP, PCT, AST and LDH. Active early treatment should
be carried out to reduce the mortality of severe tsutsugamushi disease.

Key words: tsutsugamushi disease, eschar, lymphocyte subsets, abnormal lymphocytes