Microbiological contamination profile of open tibia fractures at the university teaching hospitals, Lusaka, Zambia.

Abstract

Open tibia fractures are common injuries which are a major cause of morbidity and of great public health concern in Zambia and globally. They are considered contaminated and therefore are at greater risk of soft tissue and bone infection. In an environment of high infection and morbidity rates, this study is of great importance as it investigated factors that influence infection of open tibia fractures and provided a scientific basis for the choice of prophylactic antimicrobial chemotherapy for judicious use in the management of these injuries. This cross-sectional study was conducted in the Accident and Emergency Department of the University Teaching Hospitals (UTHs), Adult Hospital, in Lusaka, Zambia, over a period of nine (9) months. The study received prior ethical approval from ERES Converge IRB. Children and adults meeting the eligibility criteria were recruited. The patient’s sociodemographics were noted and recorded in a tailor-made data collection tool. Thereafter, swabs for microbiological evaluation were collected in the emergency theatre prior to surgical debridement. A total of 78 patients with open tibia fractures assessed for the study, of which 52 met the eligibility criteria. All analyses were performed using STATA software, version 13. The study outcome variables were pattern of injuries (GA) presenting to the Hospital, positivity rate of the different injury types and sensitivity pattern to specific antimicrobial agents. The study concluded that mean age was 32(IQR 21 – 43) and sex ratio of males to females was 71.11% to 28.89%. Only 28.7% of patients presenting with open tibia fractures received appropriate treatment prior to referral. In addition, study showed that the majority (80.7%) of patients also presented late (mean 9.375 hours). It was further observed that there was a positive correlation between delayed time of presentation and positivity rate of wound swabs (p =0.04). The vast majority (43.7%) of injuries were of GA IIIA type, with positivity rate of 77%. The most common (45.4%) isolated organism was Proteus mirabilis. It was also found that the incidence of MRSA from isolated organisms was 6.06%. Lasly, it found ciprofloxacin to be the most effective drug for prophylaxis in the management of open tibia fractures The study recommended mentorship of personnel in peripheral health facilities in management of open tibia fractures.. Lastly, it recommended for increased awareness, detection and appropriate treatment of MRSA cases.

Keywords: Open tibial fracture, soft tissue, Gustilo-Anderson classification, microbiological profile, sensitivity profile