Pseudo-outbreak of Stenotrophomonas Maltophilia in an Intensive Care Unit in São Paulo – Brazil

Abstract

<h3>Background</h3> In April 2020, a group of identical isolates of Stenotrophomonas maltophilia was observed in adult intensive care units (ICU), Covid - 19 units and surgical ICU in a large general hospital in greater São Paulo. The hospital infection control service team (SCIH) of the institution, in agreement with the care team of the intensive care units, started to investigate a possible outbreak, as well as all the processes related to the care of these patients. <h3>Methods</h3> This is a prospective study in which we followed all patients with results of tracheal secretion samples admitted to the ICUs; and we evidenced a significant in-crease in S. maltophilia isolates, which, for the most part, met epidemiological criteria for tracheobronchitis associated with mechanical ventilation, at the time it was not possible to perform typing using pulse field gel electrophoresis (PFGE). <h3>Results</h3> 100% of the cases of tracheobronchitis associated with mechanical ventilation were hospitalized in the ICU and using mechanical ventilation for more than 5 days, all cases remained with the closed suction system during the entire period of mechanical ventilation, this system was only changed if dirt or malfunction. In August 2020, after reviewing the entire process, we changed the closed suction system before collecting tracheal secretions. After this intervention, no other sample of tracheal secretions was isolated from S. maltophilia for three consecutive months. <h3>Conclusions</h3> We cannot exclude the potential for colonization of respiratory rats, but after changing the process, it became evident that this was the most effective measure to control the increase in S. maltophilia cases in ICUs.