Surto por Pseudomonas aeruginosa resistente ao imipenem em duas Unidades de Terapia Intensiva/Adulto de dois hospitais de Uberlândia-MG

Abstract

One outbreak by imipenem-resistant Pseudomonas aeruginosa, were investigated in regard to classics and molecular epidemiology aspects in two adult mixed intensive care unit (ICU) in two hospitals of Uberlandia. As a whole, 68 patients were involved: 47 from the Hospital de Clinicas (A) of the Universidade Federal de Uberlandia and 21 from the Hospital Santa Catarina (B), admitted in the period November/03 to october/05 and September/o4, respectively. A control-case study was carried out: including 47 cases (patients infected by P. aeruginosa) and 122 controls (patients admitted and not infected by P. aeruginosa in ICU) only in the hospital (A), the epidemiologic, clinical and demographic data have been considerate. The antibiotics susceptibility in vitro was analyzed by diffusion in gel technique, and phenotypes presence: metallo-P-lactamase (MBL), inducible AmpC and outer membrane protein. Research of environment contamination and health staff s hands in hospital (A) ICU were carried out, additionally. The index-case was detected in November/03, the surgical patient had been transferred to the hospital (B), who had been subjected to mechanical ventilation and developed ventilator-associated pneumonia (VAP) by imipenem-resistant Pseudomonas aeruginosa in the hospital (A). A temporal/special relationship was detected in most (94.0%) patients in hospital (A). The pneumonia was the predominant infection (77.0%) both units. The majority of the samples imipenem-resistant Pseudomonas aeruginosa (94.0%) were resistants others antimicrobials, except polimixin. The imipenem-resistant and others P-lactamics took place by means enzymatic inactivation MBL (66.0%), the hyperproduction inducible AmpC (31.0%) added to the loss of porina D. The mechanical ventilation, tracheostomy and the imipenem prescription were significant risk factors in multivariate analysis. A policlonality in the hospital (A) with prevailing the clone A in the first year of the research as well as in the hospital (B) was identified. The happening of the outbreak related to the predominant clone, suggests a horizontal transmission intra and interhospital induced by controls practices and prevention measures of nosocomial infections inadequate. Although the questions related to the policies of the used of antimicrobials may produced a selective pressure as well as in the presence of policlonality as confirmed by epidemic infections, these ones can not be forgotten in situations of outbreaks.