An outbreak of Pichia anomala fungaemia

Abstract number: 1134_01_191

Pasqualotto A.C., Sukiennik T.C.T., Rocha I.G., Martins L.R., Colares S.M., Colombo A.L., Severo L.C.

Objectives:  

To report an outbreak of Pichia anomala fungaemia (formerly Hansenula anomala the perfect state of Candida pelicullosa).

Methods:  

Report of an outbreak of fungaemia caused by a rare yeast. Clinical investigation was supported by a case-control study and by molecular studies.

Results:  

In the period comprising October 2002 to November 2003, 16 cases of fungaemia due to P. anomala occurred in a pediatric intensive care unit (ICU) at Porto Alegre, Brazil. We performed a case-control study to determine the potential risk factors for P. anomala fungaemia, defining cases (n = 16) as those patients in whom P. anomala was isolated from at least one blood culture, in association with signs and symptoms of sepsis. Controls (n = 48) were randomized among all patients hospitalized for at least 2 days in pediatric ICU during the outbreak period. During these studies, multiple environmental cultures were also obtained, as well as hand cultures of all health care workers. Weekly surveillance swabs (mouth, rectum, umbilicus, and groin) were done in all children admitted to ICU. Compared to controls, cases had higher duration of stay in intensive care (mean 16.9 versus 9.3 days, p < 0.01), and more days of mechanical ventilation (13.4 versus 5.8, p < 0.01); they also used more H2 blockers (93.8% versus 56.3%, p < 0.01), central venous catheters (93.8% versus 56.3%, p < 0.01), and antibiotics (mean 4.2 for 19.2 days, versus 3.1 for 13.4 days, p < 0.05), and they were more frequently submitted to neurosurgery (25.0% versus 6.3%, p < 0.05). Mortality rate was higher in cases then in controls (43.8% versus 6.3%, p < 0.01). At multivariate analysis, however, only the presence of central venous catheter was associated with P. anomala fungaemia (p = 0.009, OR 17.1, CI 2.0–145.7). Despite the high rate of yeast colonization among pediatric patients during surveillance study (>80%), P. anomala was not found in these patients, in health care workers or from environmental. Molecular studies showed that only one strain of P. anomala was responsible for the outbreak, and the outbreak was controlled after institution of oral nystatin prophylaxis and improvement of care of central venous catheters.

Conclusion:  

In accordance to previous studies, we reinforce that P. anomala can be exogenously acquired.