Background: The contributing role of cytomegalovirus (CMV) in infants treated for Pneumocystis jiroveci pneumonia (PJP) is unknown. High dose steroids used in the treatment of PJP may further immunocompromise these infants contributing to the development of CMV pneumonia.
Aim: The aim of this study was to determine the role of CMV pneumonia in infants being ventilated for suspected PJP.
Methods: In this prospective study HIV infected infants being treated with trimethoprim-sulfamethoxazole (TMP/SMX) and ventilated for suspected PJP were included if they had not responded to treatment. Open lung biopsy was performed if there was no improvement in ventilatory requirements.
Results: Twenty-five HIV positive infants with a mean age of 3.3 months were included. Lung biopsy was performed in 17 (68%) and post-mortem lung tissue was obtained in 8 (32%). After evaluation of the histology, immunohistochemistry, and viral cultures from lung tissue, the most likely causes of pneumonia were: CMV and PJP dual infection 36% (n = 9), CMV pneumonia 36% (n = 9), and PJP 24% (n = 6). The pp65 test for CMV antigen was falsely negative in 24%. The mean blood CD4 count was 287/microl. There was an association between the CD4 lymphocyte status and the final diagnosis, with the CMV and PJP group (CD4 110/microl) having the lowest CD4 status (P = 0.0128). Pediatric Intensive Care Unit (PICU) mortality was 72% (n = 18) and in hospital mortality 88%.
Conclusion: Of the ventilated infants failing to respond to treatment, 72% had histologically confirmed CMV pneumonia, probably accounting for the high mortality in this cohort. The incidence of CMV disease in HIV infected infants being ventilated for severe pneumonia warrants that ganciclovir is used empirically until CMV disease is excluded. The role of lung biopsy in these circumstances needs to be researched.