Risk factors and outcomes of Pneumocystis jiroveciii pneumonia in Christchurch, New Zealand: a retrospective clinical study.

Pneumocystis jirovecii pneumonia (PJP) is an opportunistic fungal infection historically associated with advanced HIV infection but now seen more commonly in recipients of immunomodulatory medications used for the treatment of malignancies and autoimmune conditions. Evidence-based guidance on prophylaxis has not kept pace with the rapidly expanding use of immunomodulatory therapy.

Methods

This was a retrospective clinical study of all patients with a positive Pneumocystis jirovecii immunofluorescence or PCR result from a respiratory specimen who were subsequently treated for PJP at Christchurch Hospital, New Zealand, between 18/04/2013 and 12/10/2023. Analysis was undertaken to determine the distribution of risk factors for acquisition of PJP and the outcomes of treatment.

Results

After exclusion of patients who did not receive treatment for PJP and children <18 years, 190 patients were analysed. The most prevalent underlying comorbidities associated with acquisition of PJP were chronic respiratory conditions (58 patients, 30.5%), rheumatological conditions (54 patients, 28.4%) and haematological malignancies (53 patients, 27.9%). 114 patients (60.0%) were receiving corticosteroids in the week leading up to diagnosis, 41.2% (n = 47) of whom were receiving additionalimmunomodulatory treatments. The 30-day mortality in patients with PJP was 23.7%, with case fatality highest amongst those with ANCA-associated vasculitis (42.9%), an underlying respiratory condition (32.8%) or solid organ malignancy (30.3%). Seven (3.7%) patients were receiving chemoprophylaxis at the time of PJP diagnosis.

Conclusion

Corticosteroid use is the most common identifiable risk factor for PJP at Christchurch Hospital. Expanded use of chemoprophylaxis in steroid recipients could substantially reduce the incidence of this dangerous disease.