Epidemiological and Bacteriological profile of Hospital Acquired Pneumonia with special reference to Klebsiella Pneumoniae and its characterization by Antibiogram and Klebocin typing.

INTRODUCTION : Hospital acquired infections continue to be an important cause of morbidity and mortality among hospitalized patients. The critically ill patient is at particular risk of developing ICU acquired infection, with the lungs being especially vulnerable. Hospital acquired pneumonia (HAP) is currently the second most common hospital infection accounting for 13 to 18 percent of all nosocomial infections, with estimates of associated mortality ranging from 20 to 50 percent. The majority of cases of HAP occur outside of ICUs. However the highest risk is in patients on mechanical ventilation. Estimates of incidence range from 4 to 7 episodes per 1000 hospitalizations. Intubated patients may have rates of pneumonia 7 to 21- fold higher than patients without a respiratory therapy device. Infection rates are twice as high in large teaching hospitals as compared with smaller institutions. Though HAP is widely analyzed by many researchers, not much is known about the incidence and bacteriological profile i.e., only few studies are being published by them. This study is conducted prospectively to evaluate the clinical and bacteriological profile of HAP in ICU patients. It may increase the awareness of clinicians about the need to reduce the morbidity and mortality by coming to know about the various pathogens causing HAP and its sensitivity and/or resistance to various antibiotics. The clinicians need to establish a suitable antibiotic policy by working out local ICU antibiogram charts. This study is also done to find out the prevalence of ESBL producers in HAP. Klebocin typing in association with antibiogram may help to find out the source of Hospital Acquired Infections. AIMS AND OBJECTIVES : To analyze the incidence, epidemiology, antimicrobial susceptibility pattern of isolates from HAP patients in IMCU and klebocin typing of Klebsiella pneumoniae isolated in HAP. OBJECTIVES: 1. To study the incidence of Hospital Acquired Pneumonia (HAP) among patients admitted in IMCU. 2. To evaluate the Clinical and Bacteriological profile of HAP. 3. To determine the antibiotic susceptibility pattern of the all bacteria isolated. 4. To find out the prevalence of ESBL producers in HAP. 5. To evaluate the role of Klebocin typing in epidemiological typing of K.pneumoniae strains. 6. To detect the source of infection in IMCU using antibiogram and klebocin typing. MATERIALS AND METHODS : This prospective study was conducted over a period of one year among patients admitted in Intensive Medical Care Unit (IMCU) of Coimbatore Medical College & Hospital, Tamil Nadu. The study population comprised all patients admitted to the IMCU from May 1, 2007 to April 30, 2008. Approval was obtained from the Ethical Committee prior to conducting the study and informed consent from all patients under study was also obtained. HAP was diagnosed based on standard diagnostic criteria adapted by the Centers for Disease Control and Prevention for the diagnosis of pneumonia if signs of pneumonia occurred after 48 hours following IMCU admission. HAP was considered when new or progressive chest radiographical infiltrates occurred ≥48 hours after hospital admission in conjunction with the following clinical criteria: At least one of the following: 1. Fever (> 38° C/ 100.4° F) with no other recognized cause 2. Leukocytosis (≥ 12,000 WBC/mm3) or leucopenia (< 4,000 WBC/mm3) 3. For adults ≥ 70 years old, altered mental status with no other recognized cause. RESULTS : During the one-year study period, among 2658 patients admitted to the IMCU, only 2454 cases were followed and included in this study. The remaining 204 cases were excluded. (118 died within 48hrs of admission, 86 were discharged or went home against advice). Among 2454 patients, 64% of patients (n=1570) were males and 36% (n=884) were females. The mean age was 59.96 with the range of 15 to 89 yrs old. 35% of the patients were more than 60yrs of age. Out of 2454 cases, 253(10.3%) patients developed HAP. The highest incidence of HAP (55.73%) was observed in the age group more than 60 years. CONCLUSION : The incidence of HAP was 10.3% with the occurrence being most in the age group more than 60 years. Mechanical ventilation was a important risk factor for the development of HAP. Klebsiella pneumoniae, Pseudomonas aeruginosa, E.coli, Acinetobacter, Proteus spp, and MRSA were the most common bacterial isolates. The most effective antibiotics against the GNB isolated from HAP patients were Imipenem followed by Cefepime and Gatifloxacin. The antibiotic susceptibility pattern of the isolates will help the clinicians to choose the appropriate antimicrobial agents for prophylactic as well as treatment purposes. When klebocin typing was used in association with antibiogram, in 86.84% cases of nosocomial Klebsiella infection probable source of infection could be detected. Thus a combination of these two typing methods poses a contribution in epidemiological studies