Factors Affecting Disease Duration in Patients with Tsutsugamushi Disease

ABSTRACT

BACKGROUND: Tsutsugamushi disease, which is caused by Orientia tsutsugamushi, is an acute febrile illness transmitted by infected mites. Recently, the incidence rate has been increased especially in the Daejeon and Chungcheongnam-do. We analyzed the patients with tsutsugamushi disease, who lived in Daejeon and Chungcheongnam-do, to find out their clinical manifestations and factors affecting the disease duration. METHODS: A total of 102 patients who were diagnosed with tsutsugamushi disease at the department of family medicine in a university hospital from September 2005 to November 2005 were studied. We analyzed their clinical characteristics and investigated the clinical factors associated with disease duration in tsutsugamushi disease by multiple regression analysis. The term "disease duration" was defined as the interval from symptom onset to discharge. RESULTS: Among 102 patients, 33 were males and 69 were female, and the mean age was 57.4 years. The average interval from symptom onset to admission was 6.6 days. The average interval from symptom onset to discharge was 14.5 days. From multiple regression analysis, interval from symptom onset to admission (beta=0.470, P<0.001), serum albumin level (beta=-3.441, P= 0.019), and abnormal findings of chest X-ray (beta=2.925, P=0.021) were shown to independently contribute to disease duration (R(2)= 0.458). CONCLUSION: Disease duration is significantly correlated with clinical factors such as abnormal findings of the chest X-ray, lower serum albumin level, and longer interval from symptom onset to admission. These factors could be used as parameters of the severity of disease in patients with tsutsugamushi disease.