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

Abstract

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.