Comparison of bacteria isolated from surface swabs to bacteria isolated from core tonsilar tissue of patients undergoing tonsillectomy at Mulago Hospital

Abstract

Introduction and background; Tonsillitis is a common condition among ENT patients, with raw data showing up to 10 patients with tonsillitis seen daily in the Mulago hospital ENT OPD. The throat swab has been the main diagnostic tool in identifying bacteria that cause tonsillitis. Studies have however shown that the throat swab is not always representative of the bacteria within core tonsilar tissue, which is thought to be the source of recurrent and chronic infections. This study therefore aims at comparing the bacteriology on the surface and within the core of the tonsil. Problem statement; Tonsillitis is a common condition seen among patients in MNRH, with tonsillectomy waiting lists up to 1 year in advance. Acute tonsillitis is traditionally managed with antibiotics basing on the clinical picture and occasionally throat swabs while chronic and recurrent tonsillitis are managed by tonsillectomy. If a difference is found to exist in the surface and core bacteriology among patients undergoing tonsillectomies in MNRH as in prior studies, antibiotic therapy may be altered and this may reduce the need for tonsillectomies among patients. Justification; the cost of management of tonsillitis is high in terms of time and finances yet if tonsillitis could be treated by administration of the right antibiotic many patients would probably not need tonsillectomy. Information is therefore needed to document any difference in bacteriology on the surface and core of tonsilar tissue in order to effect treatment transformation. Objectives; The objective of the study was to compare bacteria from surface swabs to that from tonsilar core in patients undergoing tonsillectomy at MNRH and describe the susceptibility of the bacteria involved to commonly used antimicrobial agents. Methodology; the study was a descriptive cross sectional study on surface swabs and core tissue of patients scheduled for tonsillectomy. Questionnaires were administered to 34 consecutively selected patients scheduled for tonsillectomy. All patients underwent tonsillectomy under general anesthesia in a standard operating room. Bacteria from orally collected surface tonsilar swabs and core tissue were compared. Results & conclusion; Of the 34 respondents 18(52.9%) were female and 16(47.1%) were male. Streptococcus pyogenes was the most frequent isolate occurring in 17(50%) of swabs and 10(29.4%) of core. Of the 27 S. pyogenes only 78 %( 21/27) were susceptible to penicillin G. and 56% susceptible to erythromycin. The viridan streptococci and Streptococci spps showed high rates of resistance to penicillin G with only 29% susceptible. 2/4(50%) staphylococcus aureus were methicillin resistant. There was a poor co-relation between surface swabs and core bacterial isolates with Streptococcus pyogenes and Viridan Streptococci which were the commonest isolates matching in only 50% and 18.7% respectively of respondents from whom they were isolated. S.pyogenes was 44% resistance and there were possible resistant strains to Penicillin G although MICs were not performed