Melioidosis from Thailand and Risk Classification and Precautionary Measures for Laboratory Staff who were Exposed

Melioidosis is an infectious disease caused by Burkholderia pseudomallei, a Gram-negative bacillus, with a fatality rate of 14-49%. They are mainly exposed to contaminated soil or water through wounds, mucosa, inhalation, and ingestion. In addition, the exposure of healthcare workers (HCWs) participating in sample handling in the laboratory may occur. Herein, we report a case of melioidosis and introduce infection control guidelines for laboratory exposure. A 45-year-old male patient, a travel agent who resided in Chiang Mai, Thailand, and had uncontrolled diabetes, visited the hospital with a fever for 1 month. Initial laboratory study suggested systemic infection (C-reactive protein 259.8 mg/L, white blood cell 16,500/mm3), and liver abscess was identified in abdominal computed tomography (CT). Blood cultures identified Gram-negative bacilli, and B. pseudomallei was confirmed using 16s rRNA sequencing. Ceftazidime and doxycycline were administered, and the symptoms improved. The patient was discharged with trimethoprim-sulfamethoxazole treatment for 3 months. Ten laboratory staff handled the contaminated samples without proper protective personal equipment. Through risk classification, they were classified into the low-risk group and were monitored without post-exposure prophylaxis for 21 days, and none of the patients developed any symptoms. Therefore, it is recommended to classify laboratory exposures to B. pseudomallei according to risk classification, monitor symptoms, and provide appropriate post-exposure prophylaxis.ope