Molecular detection of Clostridium difficile on inert surfaces from a Costa Rican hospital during and after an...

Hospital transmission of Clostridium difficile is fostered by contamination of surfaces and medical equipment with spores highly resistant to disinfectants and regular cleaning procedures. Despite the outbreaks and fatalities that C difficile causes, its epidemiology has not been studied in hospitals from middle- and low-income countries. To tackle this knowledge gap, the detection frequency of C difficile DNA on inert surfaces of a major Costa Rican hospital during and after an outbreak was compared.

We used a presence-absence real-time polymerase chain reaction to detect a fragment of the tpi gene of C difficile on 21 surface samples collected during an outbreak and 54 surface samples taken 2 years later at the same hospital.

C difficile DNA was detected in 40% of the 75 environmental samples analyzed. Whereas 71% of the samples collected during the outbreak were positive, only 28% of the samples obtained 2 years after the outbreak gave the same result. This 2.5× ratio was maintained when the comparison was restricted to the wards that were sampled both during and after the outbreak (72% vs 35%, P = .016).

Our results show that environmental surfaces in the hospital analyzed are continuously being contaminated with C difficile DNA and that their level of contamination is higher during an outbreak than after it.