Sporadic and outbreak cases of melioidosis in Southern Taiwan: Clinical features and antimicrobial susceptibility

Background: : Melioidosis has been well known to be endemic in Thailand and Northern Australia, and was reported sporadically in Taiwan before 2005. Methods: : We retrospectively analyzed 58 patients with melioidosis in southern Taiwan from 2000 to 2005, including 40 clustered and 18 sporadic cases, for clinical characteristics and antimicrobial susceptibility. Results: : Fifty-one (88%) cases were found during the rainy season, and there was a significant correlation between the average monthly rainfalls and the case number (r = 0.37; p = 0.001). Diabetes mellitus was the most common underlying disease (35 cases, 60%). The majority (52 cases, 90%) had never traveled abroad before illness, indicating indigenous acquisition of Burkholderia pseudomallei. In comparison, clustered cases were older, less often had underlying diabetes mellitus and had a shorter duration of clinical symptoms before admission than sporadic cases. Acute form of melioidosis predominated, and shock at admission was independently associated with a grave prognosis. Overall, 22% of 58 patients died in hospitals. Ceftazidime, imipenem, meropenem, amoxicillin/clavulanic acid, co-trimoxazole, and doxycycline, as previously recommended, were the potentially therapeutic choices. The role of piperacillin/ tazobactam for melioidosis remains undefined. Conclusions: : Melioidosis can occur sporadically or in a cluster in diabetic patients during rainy seasons in Taiwan.