Clinical Score System to Differentiate Severe Fever with Thrombocytopenia Syndrome Patients from Patients with Scrub Typhus or Hemorrhagic Fever with Renal Syndrome in Korea

• Published in: Journal of Korean medical science Vol. 35; no. 11; pp. e77 - 10
• Main Authors: Heo, Dae-Hyuk, Kang, Yu Min, Song, Kyoung-Ho, Seo, Jun-Won, Kim, Jeong-Han, Chun, June Young, Jun, Kang Il, Kang, Chang Kyung, Moon, Song Mi, Choe, Pyoeng Gyun, Park, Wan Beom, Bang, Ji Hwan, Kim, Eu Suk, Kim, Hong Bin, Park, Sang-Won, Oh, Won Sup, Kim, Nam Joong, Oh, Myoung-don
• Format: Journal Article
• Language: English
• Published: Korea (South) The Korean Academy of Medical Sciences 23.03.2020; 대한의학회
• Subjects: Adult; Aged; Animals; C-Reactive Protein - analysis; Diagnosis, Differential; Female; Hemorrhagic Fever with Renal Syndrome - diagnosis; Humans; Male; Middle Aged; Original; Phlebotomus Fever - diagnosis; Phlebovirus; Republic of Korea; Retrospective Studies; Scrub Typhus - diagnosis; Zoonoses - diagnosis; 의학일반; Republic of Korea; Hemorrhagic Fever with Renal Syndrome; Scrub Typhus; Differential Diagnosis; Severe Fever with Thrombocytopenia Syndrome; Prediction
• ISSN: 1011-8934; 1598-6357; 1598-6357
• DOI: 10.3346/jkms.2020.35.e77

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease with high mortality in East Asia. This study aimed to develop, for primary care providers, a prediction score using initial symptoms and basic laboratory blood tests to differentiate between SFTS and other endemic zoonoses in Korea. Patients aged ≥ 18 years diagnosed with endemic zoonoses during a 3-year period (between January 2015 and December 2017) were retrospectively enrolled from 4 tertiary university hospitals. A prediction score was built based on multivariate logistic regression analyses. Of 84 patients, 35 with SFTS and 49 with other endemic zoonoses were enrolled. In multivariate logistic regression analysis, independent predictors of SFTS included neurologic symptoms (odds ratio [OR], 12.915; 95% confidence interval [CI], 2.173-76.747), diarrhea (OR, 10.306; 95% CI, 1.588-66.895), leukopenia (< 4,000/mm³) (OR, 19.400; 95% CI, 3.290-114.408), and normal C-reactive protein (< 0.5 mg/dL) (OR, 24.739; 95% CI, 1.812-337.742). We set up a prediction score by assigning one point to each of these four predictors. A score of ≥ 2 had 82.9% sensitivity (95% CI, 71.7%-87.5%) and 95.9% specificity (95% CI, 88.0%-99.2%). The area under the curve of the clinical prediction score was 0.950 (95% CI, 0.903-0.997). This study finding suggests a simple and useful scoring system to predict SFTS in patients with endemic zoonoses. We expect this strategic approach to facilitate early differentiation of SFTS from other endemic zoonoses, especially by primary care providers, and to improve the clinical outcomes.