Study of patients with community-acquired abscesses.

BACKGROUND

Abscess incision and drainage (I&D) operations form the bulk of surgical procedures in the emergency department (ED). Nevertheless, epidemiologic, clinical, and bacteriology data are lacking for patients with abscesses presenting at Sudanese hospitals. Information also is unavailable on the magnitude of the problem of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) and its susceptibility to the most commonly used antibiotics. Our objectives were (1) to identify and document the epidemiologic and clinical variables of patients with superficial abscesses; (2) to isolate the causative organism(s) from the pus and determine their antibiotic sensitivity; (3) to determine the prevalence of CA-MRSA and its antibiotic susceptibility; and (4) to audit our practice of I&D of abscesses.

METHODS

A prospective observational study, involving a convenience sample of patients who presented with community-acquired skin and soft tissue (superficial) abscesses to a single unit at Khartoum North Teaching Hospital (KNTH) ED, was done for the years 2009-2010. A pro-forma was designed to record the personal, epidemiologic, and clinical data of each patient. All I&D operations were performed as day cases. Swabs of pus drained from the abscess were sent to the laboratory for culture. Isolates underwent sensitivity testing against the most commonly used antibiotics.

RESULTS

A total of 248 patients were included. The majority (84%) were younger than 40 years of age. There were twice as many male as female patients (69% vs. 31%, respectively). The majority of patients did not have a known predisposing factor, but 13% had a history of an abscess. A history of trauma was found in 27% of the patients, whereas diabetes mellitus was found in only 6%. The most common site of the abscess was the upper limb (46%) followed by the lower limb (20%). Most (85%) of the abscesses were drained under local anesthesia. Sensitivity tests were performed on 151 pus isolates. No growth was obtained in 28 (18.5%) of the specimens. Of the 123 specimens yielding growth, S. aureus was the most common organism (90%), followed by Klebsiella spp. (6.5%). The proportion of CA-MRSA was 24%. Many of these S. aureus isolates were resistant to other antibiotics also.

CONCLUSION

This study documents some epidemiologic and bacteriological data on one of the most common surgical problems. We found a substantial proportion of the infecting organisms to be CA-MRSA. This reflects the abuse of antibiotics in the community and stresses the importance of health education. Standardized surgical and anesthetic guidelines should be followed for I&D of abscesses to avoid recurrence. Further studies are needed urgently.