Nosocomial infections and antimicrobial resistance pattern in a tertiary referral hospital in Hamedan, Iran.

Sir,

Nosocomial infections are defined as infections occurring during a patient's stay at hospital (those happen after 48 h of being admitted).[1] Nosocomial infections occur in 30% of patients in intensive care units (ICUs) with variation from 9% to 37% according to different populations and definitions.[2] Nosocomial infections are an important cause of mortality and morbidity in multiple trauma patients bedridden in ICUs.[3]

Since there are few studies about nosocomial infections in trauma patients in Hamedan, we conducted a study to determine the prevalence of nosocomial infections, the responsible microorganisms, and to identify the patients at high risk.

In a prospective study, 225 multiple trauma patients referred to ICU in Hamedan (mid west of Iran) were chosen sequentially, over a period of 2 years (2005-2007).

Upon ICU admission, an investigator-administered questionnaire was completed for each patient. After completing the questionnaire, all patients were under observation. If a patient experienced fever during the first 48 h of admission, different samples were collected for culture. These samples included blood, tracheal tube aspirate, urine collected from urinary catheter, and wound secretions in the case of bedsore. All samples were transferred to the laboratory by expert technicians according to a standard protocol. The samples were studied for detection of infection followed by antibiotic susceptibility.

We compared patient with and without nosocomial groups using the chi-square test for dichotomous variables or the Student t-test for continuous variables. A P value of <0.05 was considered statistically significant. All results were analyzed using Statistical Package for the Social Sciences (SPSS Inc. Chicago, Illinois) for Windows version 16.

The results showed during ICU hospitalization, 63 patients (28%) experienced fever after 48 h of admission and following further evaluations 36 patients were reported as culture positives. Hence, the frequency of nosocomial infection was 16%. The most common nosocomial infection was pneumonia (32%), while the second one was urinary tract infection (UTI) (22%) and septicemia (14%). Ventilator-associated pneumonia (VAP) was found in 58% of patients. Tracheal tube aspirates cultures showed Klebsiella and Pseudomonas aeruginosa were the most prevalent bacteria; 38.09% and 23.8% respectively. Klebsiella was most susceptible to amikacin and co-trimoxazole and resistant to nalidixic acid and chloramphenicol.

A comparison of the two groups with and without nosocomial infection revealed that age, gender, and underlying disease were not significantly different among two groups. However, the length of in-hospital stay (14.1± 10 vs. 5.27 ± 4 respectively, P=0.001), Glasgow Coma Scale (GCS) on admission (7.0 ± 3 vs. 9.4 ± 4 respectively, P=0.001), and having tracheal tube (91.6% vs. 52.9%, P=0.001), or nasogastric tube inserted (63.8% vs. 39.7%, P=0.006) had a significant association with nosocomial infections.

The comparison of our study with similar ones in the world shows a similarity in the prevalence and risk factors.[45] Considering the importance of nosocomial infection, we recommend establishment of a committee to control nosocomial infections in hospitals to study the nosocomial infections, epidemiology of the prevalent microorganisms, and to control the administration of prophylactic antibiotics according to the susceptibility of the microorganisms.