Laboratory-based surveillance of Pneumocystis jirovecii pneumonia in South Africa, 2006–2010i

Abstract

Background: We aimed to establish the characteristics of patients with confirmed Pneumocystis jirovecii pneumonia recruited by passive, sentinel laboratory-based surveillance.

Method: The study design was prospective, observational, cross-sectional, laboratory-based sentinel surveillance. Laboratorybased surveillance of Pneumocystis jirovecii pneumonia (PJP), formerly known as Pneumocystis carinii pneumonia (PCP), was conducted in six South African provinces at 61 hospitals, of which 17 were sentinel sites, where surveillance officers collected clinical and demographic data from cases. A case was defined as a patient with a respiratory tract specimen that was confirmed positive for P. jirovecii by immunofluorescent microscopy or PCR test, either as a first diagnosis or ≥ 30 days after the last confirmed laboratory diagnosis of PJP. The chi-square test or Fisher’s exact test were used to compare the categorical variables.

Results: From 2006–2010, 1 537 cases of PJP were recorded. Eighty-nine per cent (460/518) were found to be human immunodeficiency virus (HIV)-infected. This was a first diagnosis of HIV infection in 57% of the cases. The case fatality ratio was 34% (177/525). Recurrent infection was significantly more common in the 26- to 45-year age group, compared to children aged ≤ 5 years (odds ratio 1.7, 95% confidence interval: 1.1–2.8) (p 0.040). Treatment for tuberculosis was common in cases aged ≥ 5 years (37%, 85/229).

Conclusion: PJP was the acquired immune deficiency syndrome-defining illness in more than half of the patients detected through laboratory-based surveillance. The high mortality rate and number of recurrent cases is noteworthy. This study may not have reflected the full spectrum of clinical presentation of the disease as case report forms were only completed for hospitalised patients at sentinel surveillance sites.