ANNALS OF IBADAN POSTGRADUATE MEDICINE
O.B. Makanjuola1,2, S.A. Fayemiwo1,2, A.O. Okesola1,2, A. Gbaja2 , V.A. Ogunleye2 , A.O. Kehinde1, 2 and R.A. Bakare1,2
Background: Patients admitted into the intensive care unit (ICU) usually have impaired immunity and are therefore at high risk of acquiring hospital associated infections. Infections caused by multidrug resistant organisms now constitute a major problem, limiting the choice of antimicrobial therapy.
Objectives: This study was aimed at determining the antimicrobial resistance pattern of pathogens causing ICU infections in University College Hospital (UCH), Ibadan, Nigeria. The aetiological agents, prevalence and types ICU infections were also determined.
Methods: One year hospital associated infections surveillance was conducted in the ICU of UCH, Ibadan. Blood, urine, tracheal aspirate and wound biopsies specimens were collected under strict asepsis and sent to the Medical Microbiology laboratory of the same institution for immediate processing. All pathogens were isolated and identified by standard microbiological methods. Disk diffusion antibiotic susceptibility testing was performed and interpreted according to Clinical and Laboratory Standards Institute (CLSI) guidelines.
Results: The overall prevalence of ICU infections was 30.9% out of which 12.9% were bloodstream infections, 31.5% urinary tract infections, 38.9% pneumonia, and 16.7% skin and soft tissue infections. Klebsiella species and Escherichia coli were the predominant pathogens. Multidrug resistant organisms constituted 59.3% of the pathogens, MDR Klebsiella spp and MDR E. coli were 70.8% and 71.4% respectively. Resistance to Cefuroxime was the highest (92.9%) while Meropenem had the least resistance (21.4%).
Conclusion: There is a high prevalence of multidrug resistant bacteria causing ICU infections. Application of more stringent infection control procedures and institution of functional antimicrobial stewardship are recommended to combat this problem.
Keywords: Healthcare associated infections, Infection control, Antibiotic resistance, Intensive care unit.
Dr. S.A. Fayemiwo
Dept. of Medical Microbiology & Parasitology,
University College Hospital,
Nosocomial infections, which are now known as hospital-acquired or healthcare-associated infections rank high among important public health problems globally, and developing countries in particular.1,2 Patients who are admitted into the intensive care unit (ICU) usually have impaired immunity either due to their underlying disease conditions or exposure to invasive procedures which adversely affect their immune mechanisms. They are therefore at high risk of acquiring nosocomial infections. In addition, they are susceptible to secondary infections such as candidiasis and pseudomembranous colitis arising from destruction of protective microbiota by administration of broad spectrum antimicrobials.3,4,5
Hospital-associated infection, a serious problem for patients admitted into the ICU, is associated with appreciable cost of care, length of hospital stay, morbidity and mortality.6,7 It has been documented that acquiring ICU infection is an independent factor associated with hospital mortality and that ICU patients with infections have two times the death rate of those not infected.7,8 About 40% of the total expenditure in the ICU is related to infections.7 ICU infections and indeed all healthcare associated infections have also been noted to be much higher in low and middle income countries compared with high income countries.9 Bloodstream infections, pneumonia, surgical site infections, and other nosocomial infections affect ICU patients more than patients in other areas of the health care setting.10 Globally, 12 - 49% ICU infection rate has been reported with a median time to infection being 4 days and most patients develop an infection within 6 days of admission.11,12,13
Nosocomial infections are often due to resistant organisms which exhibit intrinsic and/or acquired resistance to antimicrobial agents.14 Multidrug resistant (MDR) organisms are those with acquired nonsusceptibility to one or more agents in at least three antimicrobial categories.15 This antimicrobial resistance is on the rise and multidrug drug resistant organisms are now widespread. However, therapeutic options for these resistant infections are limited thus threatening optimal antibiotic coverage of patients with such infections.16,17 In addition to therapeutic challenges, multidrug resistant pathogens also have a high potential for acquiring additional resistance and being widely disseminated within the hospital, posing a higher threat to the control of infection.18 Antibiotic resistance has been reported to be higher among those on prolonged hospitalization which is a frequent finding in ICU patients.19 There are also reports that patients with MDR pathogens have a higher ICU-mortality than those with non-MDR.20
One study reported an overall almost 4-fold increase in MDR gram negative bacteria over their study period with the highest individual increases of 73-fold seen in Enterococci and 14.6-fold in Klebsiella pneumoniae.21 The resistance rates for Gram negative bacteria was 36% while for Gram positive cocci was 51.7%.21
The causes of antibiotic resistance and MDR organisms though multifactorial are related to selective pressure that result from inappropriate antibiotic use. 17 Although a general increase in the number of resistant microorganisms is being reported worldwide, there is considerable variation in the specific patterns and rates of MDR across the countries and geographical regions.17,21 This reiterates the need for locally relevant data which can be used to predict the resistance type and also guide choice of antibiotics when infections occur.17 The development of proper strategies for combating multidrug resistant pathogens require adequate knowledge of the prevalent pathogens, types of infections and the antimicrobial susceptibility pattern.22 This study was conducted to determine the resistance pattern of ICU pathogens to antibiotics. We also determined the prevalence of ICU infections, types and pathogens associated with such infections.