Plesiomonas shigelloides infection in Hong Kong: retrospective study of 167 laboratory-confirmed cases

TY Wong, HY Tsui, MK So, JY Lai, ST Lai, CWS Tse, TK Ng
Department of Medicine and Geriatrics, Princess Margaret Hospital, Laichikok, Kowloon, Hong Kong

OBJECTIVE. To study the epidemiological, clinical, and microbiological features of Plesiomonas shigelloides infection in Hong Kong.

DESIGN. Retrospective study.

SETTING. Infectious Disease Unit of a district hospital, Hong Kong.

PATIENTS. Patients with laboratory-confirmed cases of Plesiomonas shigelloides infection between 1 January 1995 and 31 December 1998.

MAIN OUTCOME MEASURES. Epidemiological and clinical data, antibiotic sensitivity, and clinical outcome.

RESULTS. There was an increasing trend in the number of isolates of Plesiomonas shigelloides obtained and the prevalence of the bacterium. A total of 197 isolates were obtained from 188 patients, and most isolates (172; 87.3%) were obtained during the summer. Clinical and epidemiological data were available for 167 patients (85 males, 82 females). Patient age ranged from 1 month to 95 years; the mean and median ages of the patients older than 15 years were 51.0 and 40.5 years, respectively (n=132). Only 35 (21.0%) of the 167 patients had a history of travel outside Hong Kong, whereas 21 (12.6%) had a history of consuming seafood or uncooked food; 39 (23.4%) had underlying medical conditions. Most patients (165; 98.8%) had symptoms of Plesiomonas shigelloides infection. Nine (5.4%) patients had had chronic diarrhoea for more than 2 weeks; watery and bloody diarrhoea was discharged by 122 (73.1%) and 42 (25.1%) of the patients, respectively. All 197 Plesiomonas shigelloides isolates were sensitive to ofloxacin, or levofloxacin and ceftriaxone. Resistance or partial resistance was recorded for ampicillin (72%), tetracycline (67%), co-trimoxazole (12%), and chloramphenicol (5%). The majority of patients (142/167; 85.0%) had self-limiting cases of infection, but 25 patients were given antibiotics for more severe symptoms at the time of presentation; there were two deaths.

CONCLUSIONS. The occurrence of Plesiomonas shigelloides infection in Hong Kong is increasing, although most cases of are self-limiting.

Hong Kong Med J 2000;6:375-80

Key words: Diarrhea/microbiology; Gastroenteritis; Gram-negative bacterial infections; Plesiomonas/drug effects