Aspergillus endocarditis after open heart surgery: an epidemiological investigation.

The occurrence of aspergillus endocarditis in four patients after open heart surgery, within a period of 10 months, in a centre where no case had been encountered in the previous 7 years, led us to investigate the possible source and factors contributing to this 'outbreak'. The ventilation system, air conditioning plant, air and inanimate sources in the operating theatre were investigated. With the exception of the operating room which was fitted with laminar air flow, it was possible to isolate Aspergillus spp. from all rooms in the operating suite. Air conditioner cooling coils and pigeon droppings on the ledges outside the suite were found to harbour aspergillus spores in large amounts. The ubiquitous presence of Aspergillus spp. in the operating suite indicated that the existing ventilation system was ineffective in eliminating aspergillus spores from the operating environment. The use of a newly introduced broad spectrum antibiotic protocol seemed to be a major contributory factor according to incidental evidence (although no case control studies were done). Improvements in the ventilation system and the restriction of newly introduced antibiotics was recommended. No further case of fungal endocarditis was observed up to the time of reporting (6 months after the last case).