A Study of Patients with Community Acquired Abscesses at Khartoum North Teaching Hospital

Abstract

Background: Abscess incision and drainage (I&D) operation represents the bulk of surgical procedures in the emergency department (ED).  Nevertheless, epidemiological, clinical, and bacteriology data are lacking or non-existent on patients with abscesses. Information is also lacking on the magnitude of the problem of community acquired methicillin-resistant Staphylococcus aureus (CA-MRSA), and their susceptibility to the most commonly used antibiotics.
Objectives: To identify and document epidemiological and clinical variables of patients with superficial abscesses, and isolate the causative  organism(s) in the pus and determine their antibiotic susceptibility. Also, to determine the prevalence of CA-MRSA and their antibiotic susceptibility
and ao audit our practice of I&D of abscess.
Patients and 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) emergency department (ED), was done during the period 2009-2010. A pro-forma was designed to record the  personal, epidemiological, and clinical data of each patient. The I&D of the abscesses was performed as a day case. Swabs of pus drained from the abscess were sent to the laboratory for culture. Micro-organisms isolates
underwent susceptibility testing against a group of the most commonly used antibiotics.
Results: A total of 248 patients were included in the study. The majority (84%) were below the age of 40 years. Males (69%) were twice as many as females (31%). The majority of patients did not have a known predisposing factor, but 13% had a previous history of an abscess. A  history of trauma was found in 27% of the patients, whereas diabetes  mellitus history was obtained in only 6%. The most common site of the abscess was the upper limb (46%) followed by the lower limb (20%). The study showed that 85% of the abscesses were drained under local  anaesthesia. Susceptibility tests were performed on 151 pus specimens using a group of commonly used antibiotics. 123 (81.5%) specimens grew micro-organisms. Of those, Staphylococcus aureus was the commonest organism grown (90%), followed by Klebsiella spp (6.5%). The proportion  of CAMRSA was 24%. High proportions of S. aureus were resistant to other antibiotics too. Lists of antibiotics and their efficacy in the treatment of S. aureus and Klebsiella were constructed.
Conclusion: This study documents some epidemiological and  bacteriological data on one of the most common surgical problems. The study showed the presence of a significant proportion of CAMRSA. This reflects the abuse of antibiotics in the community and stresses the importance of health education. Standardized surgical and anaesthetic guidelines on I&D of abscess should be followed to avoid recurrences. Further studies are urgently needed.

Keywords: Antibiotics, Community Acquired Methicillin Resistant  Staphylococcus aureus (CAMRSA), surgical drainage.