Abstract

Background: The pathogenic effect of concomitant pulmonary cytomegalovirus (CMV) infection on morbidity and mortality of Pneumocystis jirovecii pneumonia (PCP) has been questioned in the case of non-HIV-infected patients. Methods: We conducted a retrospective cross-sectional study of patients who were diagnosed with PCP by bronchoalveolar lavage. We compared demographics, clinical characteristics, morbidity, and mortality in non-HIV-infected PCP patients with (n = 31) and without (n = 75) pulmonary CMV infection. Morbidity was assessed by length of hospital stay, admission to the intensive care unit, and use of mechanical ventilation. Mortality was defined as 30-day and 90-day all-cause mortality. Results: Morbidity and mortality did not differ between PCP patients with and without pulmonary CMV infection. In multivariate analysis using the Cox proportional hazard model, haematological malignancy (relative risk (RR) 0.20, 95% confidence interval (95% CI) 0.06-0.71), PCP treatment duration (RR 0.81, 95% CI 0.75-0.88), changing to a second-line regimen due to treatment failure (RR 4.51, 95% CI 1.61-12.64), and mechanical ventilation (RR 17.99, 95% CI 4.83-67.04) were independently associated with 30-day all-cause mortality. Being a solid organ transplant recipient (RR 0.17, 95% CI 0.05-0.56) and the use of mechanical ventilation (RR 6.49, 95% CI 2.84-14.83) were independently associated with 90-day all-cause mortality. However, concomitant pulmonary CMV infection was not associated with either 30-day or 90-day mortality. Conclusions: Our results suggest that concomitant pulmonary CMV infection does not significantly affect the prognosis of PCP, as indicated by morbidity and mortality in non-HIV-infected patients with PCP. Based on this result, we propose that it is not essential to administer an anti-CMV regimen when CMV is co-isolated from the bronchoalveolar lavage in patients with PCP.