Epidemiology of acute q Fever, scrub typhus, and murine typhus, and identification of their clinical characteristics compared to patients with acute febrile illness in southern taiwan.
OBJECTIVE
In Taiwan, acute Q fever, scrub typhus, and murine typhus (QSM diseases) are the most common rickettsioses, but their epidemiology and clinical characteristics have not been clarified. Diagnosis of these three diseases based on clinical manifestations is difficult, and most of their reported characteristics are identified by describing the predominant manifestations, without being compared with other diseases.


METHODS
Serological tests for QSM diseases were examined simultaneously in patients suspected of the three diseases, regardless of which one was suspected. Clinical manifestations were recorded retrospectively from their charts. The characteristics of QSM diseases were identified by comparison with patients who had non-QSM diseases.


RESULTS
From April 2004 to April 2007, a total of 226 cases of suspected QSM diseases were included. One hundred (44.2%) cases were serologically confirmed as QSM diseases (68 acute Q fever, 23 scrub typhus, and 9 murine typhus), and 126 (55.8%) cases were non-QSM diseases. Only 33 cases (33.0%) of QSM diseases were initially suspected at the time of hospital visit, whereas 54 cases (42.9%) of non-QSM diseases were incorrectly suspected as QSM diseases. Cases of Q fever and scrub typhus were distributed over plain and mountain areas, respectively. By multivariate analysis, relative bradycardia (OR [95% CI], 2.885 [1.3-6.4]; p = 0.009), radiographic hepatomegaly (OR [95% CI], 4.454 [1.6-12.3]; p = 0.004), and elevated serum aminotransferases (OR [95% CI], 5.218 [1.2-23.1]; p = 0.029) were independent characteristics for QSM diseases, and leukocytosis (OR [95% CI], 0.167 [0.052-0.534]; p = 0.003) was negative for the diagnosis of QSM diseases.


CONCLUSIONS
In southern Taiwan, acute Q fever is the most common rickettsiosis. QSM diseases should be suspected in febrile patients who present with relative bradycardia, hepatomegaly, and elevated serum aminotransferases, but without leukocytosis.
Lai
Chung-Hsu
CH
Division of Infectious Diseases, Department of Internal Medicine, E-Da Hospital/I-Shou University, Taiwan.
Huang
Chun-Kai
CK
Chen
Yen-Hsu
YH
Chang
Lin-Li
LL
Weng
Hui-Ching
HC
Lin
Jiun-Nong
JN
Chung
Hsing-Chun
HC
Liang
Shiou-Haur
SH
Lin
Hsi-Hsun
HH
D000208:Acute Disease; D000328:Adult; D005260:Female; D005334:Fever / Q000453:epidemiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011778:Q Fever / Q000453:epidemiology*; D012612:Scrub Typhus / Q000453:epidemiology*; D013624:Taiwan / Q000453:epidemiology; D014437:Typhus, Endemic Flea-Borne / Q000453:epidemiology*