Evaluation of dedicated stethoscopes' contamination and their cleaning strategy in neonatal care units

الملخص EN

Background : Nosocomial infection is considered as an important health threat to hospitalized patients.

Many reports have documented the presence of bacteria implicated in serious hospital-acquired infections on stethoscopes in various hospital settings.

Aims : The aim of this study was to determine the frequency and type of microorganisms contaminating dedicated stethoscopes used in neonatal units.

Also, verifying the efficacy of two different cleaning strategies in disinfecting stethoscopes.

Methods : We have conducted a prospective study on 24 dedicated stethoscopes at neonatal care unit.

Cultures from the surface of diaphragm of dedicated stethoscopes were immediately placed in transport media and subsequently inoculated onto blood agar plate.

The culture results of various microorganisms were expressed as the number of colony forming units for each bacterium at the end of the inculcation period.

Bacteria were identified by standard microbiological tests.

Surveillance skin cultures of patients to whom the stethoscopes were dedicated, obtained at the time of stethoscopes' cultures.

Antibiotic resistance profile was considered to determining relatedness of isolates.

After initial evaluation of bacterial load, dedicated stethoscopes were classified into two groups for disinfection with propyl alcohol 70 %.

: once a day or at the beginning at every shift-(every 8 hours)-.- Results : There were 11 / 24 (45.

8 %) stethoscopes found to be colonized with a significant number of bacteria where Staphylococci were the predominant microorganisms found in 8/11 (72.

7 %) of the contaminated stethoscopes.

One methicillin resistant coagulase negative staphylococci was identified.

Gram negative bacilli were found in 3/11 (27.

3 %) of contaminated stethoscopes.

The surveillance skin cultures of 126 patients came in contact with the dedicated stethoscopes, 34 / 126 (26.

9 %) grew single species of micro-organisms that were similar to microorganisms colonized on their dedicated stethoscopes and of the same antibiotic resistance profile.

Nevertheless 11/126 (8.

7 %) patients grew mixed microorganisms.

The cleaning of the dedicated stethoscopes regularly every 8 hours with propyal alcohol 70% have markedly reduced the incidence of bacterial colonization on such stethoscopes when compared to regular daily cleaning (RR = 0.

28, CI = 0.

4-2.

32, P = 0.02).

Conclusion : The heath professional in neonatal care units have to regularly clean dedicated stethoscopes on 8 hours bases as be part of neonatal care infection control policy.