Prospective cohort study showing changes in the monthly incidence of Pneumocystis carinii pneumonia

Abstract

Pneumocystis carinii pneumonia (PCP) remains a serious opportunistic infection in HIV infected individuals. Seasonal changes in climate are associated with changes within individual susceptibility to infection. The possibility of monthly variability in the incidence of PCP was therefore examined by means of a cohort study of a database of 8640 HIV infected individuals attending the Chelsea and Westminster Hospital. There were 792 cases of PCP diagnosed since 1985. A marked decline was observed in the incidence of PCP in mid-1992 coincident with the introduction of PCP prophylaxis. There was a further decline in 1996 after the introduction of highly active antiretroviral therapy. Despite no significant monthly variation in the mean attendance to clinic and CD4 count, both new and all cases of PCP were higher in January than in other months (15.9% and 14.5% of all cases, respectively). A correlation with low rainfall in January and new cases of PCP was observed. These data are consistent with an influence of climatic conditions on the presentation of PCP. The diagnosis of PCP is more common in winter months suggesting that this is a transmissible infection.

Highly active anti-retroviral therapy (HAART)-induced maintenance of adaptive but not innate immune parameters is associated with protection from HIV-induced mortality

“…The multivariate analysis (Table 2) demonstrated the following: (i) age at entry to cohort remained significantly associated with mortality, ages >39 having an increase in rate per year of increase in age (RR 1·03, 95% CI 1·02-1·03, P < 0·001); (ii) being female is associated with an increased mortality (RR 1·19, 95% CI 1·02-1·38, P = 0·028); (iii) T lymphocyte CD4 counts of <144 cells/mm 3 ( P = 0·001) and CD8 counts of less than 595 cells/mm 3 ( P = 0·001) were associated with an increased risk of death; (iv) nadir B cell CD19 counts <39 cells/mm 3 were associated with an increased risk of death (RR 1·41, 95% CI 1·18-1·67); and (v) decreased maximal HIV-1 viral loads, below the 75th centile of measured viraemia, was associated with protection from death (RR 0·85, 95% CI 0·73-0·98). When the parameters that approached significance were entered in a multivariate analysis, we found that low natural killer counts were not associated with death.…”

“…In those for whom it is available, highly active anti-retroviral therapy (HAART), consisting of at least three drugs, has decreased the morbidity and mortality associated with HIV, mainly by reducing the incidence of opportunistic infections such as Pneumocystis carinii pneumonia [1][2][3][4][5]. The protective effect of HAART has also been shown to result in a decreased incidence of HIV-associated cancers, including an increased time to disease progression [6,7].…”

Pneumocystis jiroveciicolonization in chronic pulmonary disease

“…However, they could also be due to differences in population density, and in HIV infection or PcP incidence (Gal et al , 2010). On the other hand, several studies have shown seasonal changes of PcP incidence that seem to be associated with climate factors (Lubis et al , 2003; Varela et al , 2004; Sing et al , 2009). In this sense, the higher P. jirovecii colonization rates observed in patients with CF from Southern Europe than in patients from Northern Europe could be related with climate factors (Sing et al , 2001; Respaldiza et al , 2005; Gal et al , 2010).…”

Influence of Climatic Factors on Pneumocys Carriage within a Socially Organized Group of Immunocompetent Macaques (Macaca fascicularis)

“…Similar observations were made according to the climate of cities in the USA [6]. Only one study reported a correlation between low rainfall and new cases of pneumocystosis [8]. Navin et al 2000 indicated that outdoor activities such as gardening, camping or hiking were significantly associated with pneumocystosis in adults with human immunodeficiency virus [11].…”