Invasive aspergillosis in immunocompetent patients.

To the Editor: We read with interest the case report by Garcia and colleagues regarding an apparently immunocompetent individual. (1) As the authors state, invasive aspergillosis is mainly encountered in patients suffering from severe immunodeficiency, such as hematologic malignancy, or in patients receiving chemotherapy or immunosuppressive therapy following solid organ transplantation. However, we disagree with the authors' statement that invasive aspergillosis occurs almost exclusively in patients with severely impaired immune function. Evidence that invasive aspergillosis is an emerging opportunistic infection in nonimmunocompromised patients is accumulating. (2) Especially in critically ill patients, it appears that invasive aspergillosis might be an underestimated problem, but yet, with a very high associated and attributable mortality rate. (3) In a series of 38 intensive care unit (ICU) patients with invasive aspergillosis, we found that only 17 had specific risk factors for the development of the disease. (4) In a larger series of 127 medical ICU patients, Meersseman et al found 70% of patients to have no malignancy. (5) Because the definitions of probable aspergillosis include an immunocompromised state, this diagnosis may be easily missed or delayed in patients with a nonspecific risk profile, resulting in higher fatality rates. (4,6) Furthermore, diagnostic examination by tissue biopsy in ICU patients is often impossible due to coagulation disorders, and medical imaging of the lungs is frequently nonspecific due to mechanical ventilation. To overcome these problems, Vandewoude et al proposed a diagnostic algorithm, partially derived from the European Organisation for the Research and Treatment of Cancer (EORTC) criteria, but designed to deal with the specific conditions of ICU patients. (7) Although this algorithm can be a guideline toward a more timely diagnosis of invasive aspergillosis, further validation is necessary.

Stijn I. Blot, PhD

Koenraad H. Vandewoude, PhD

Intensive Care Department

Ghent University Hospital

Ghent, Belgium

References

1. Garcia RJ, Troya P, Edwards C. Invasive aspergillosis with central nervous system dissemination in a presumably immunocompetent, non-neutropenic patient: case report and review. South Med J 2006;99:607-610.

2. Vandewoude K, Vogelaers D, Blot S. Aspergillosis in the ICU--The new 21st century problem? Med Mycol 2006;44 (Suppl):607-610.

3. Vandewoude KH, Blot SI, Benoit D, et al. Invasive aspergillosis in critically ill patients: attributable mortality and excesses in length of ICU stay and ventilator dependence. J Hosp Infect 2004;56:269-276.

4. Vandewoude K, Blot S, Benoit D, et al. Invasive aspergillosis in critically ill patients: analysis of risk factors for acquisition and mortality. Acta Clin Belg 2004;59:251-257.

5. Meersseman W, Vandecasteele SJ, Wilmer A, et al. Invasive aspergillosis in critically ill patients without malignancy. Am J Respir Crit Care Med 2004;170:621-625.

6. Blot S, Vandewoude K. Early detection of systemic infections. Acta Clin Belg 2004;59:20-23.

7. Vandewoude KH, Blot SI, Depuydt P, et al. Clinical relevance of Aspergillus isolation from respiratory tract samples in critically ill patients. Crit Care 2006;10:R31

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