“…The case fatality rate among HIV-negative patients with PCP has remained approximately 50% over the last three decades (Walzer et al, 1974;Sepkowitz et al, 1992;Sepkowitz, 2002), despite identification of risk factors, including malignancy (Sepkowitz et al, 1992;Zahar et al, 2002), haematologic disorders (Sepkowitz et al, 1992), radiation therapy (Mathew and Grossman, 2003), chemotherapy (Hughes et al, 1975;Sepkowitz et al, 1992), organ transplantation (Hardy et al, 1984;Sepkowitz et al, 1995) and CD4 þ lymphopenia (Mansharamani et al, 2000). In patients with solid tumours or haematologic malignancy, corticosteroid therapy is the most common predisposing risk factor for developing PCP (Sepkowitz et al, 1992;Sepkowitz, 1993;Yale and Limper, 1996).…”