Epidemiology and problematic of invasive fungal infections

Prevalence of invasive fungal infections has increased over the past twenty years. One of the major difficulties encountered in caring for these patients is to obtain a definitive diagnosis, particularly in patients with Candida or Aspergillus infections, which account for the majority of fungal infections. Autopsy reports have demonstrated that the diagnosis is not achieved in 50% of the patients before death. Recent progress should contribute to improving the rate of early diagnosis, an important prognosis factor, and/or provide information supporting suspected invasive fungal infection. Early, repeated, chest scans in neutropenic patients with fever with a risk of Aspergillus infection can detect lung infiltration before signs appear on the pain chest X-ray. In these circumstances, highly suggestive signs include the halo sign during a period of aplasia or air crescent. Although some false positive results are reported, detection of aspergillus galactomannan can support or suggest the diagnosis of aspergillosis, sometimes a few days before signs appear on the scan. PCR detection of fungal genetic material is still in the research stage; standard methods remain to be established. PCR should provide arguments further supporting early diagnosis, particularly for candidosis when blood cultures are negative and biopsy is contraindicated. Careful examination of risk factors (neutropenia, nature of the underlying hematology disease, corticosteroid therapy, GVHD, colonization) helps define patients with the highest risk, and may further support the suspected diagnosis or contribute to more adapted therapeutic strategies.