Key Points Question What is the risk of developing cardiomyopathy among patients with the acute phase of Chagas infection or the indeterminate chronic form of Chagas disease? Findings In this systematic review and meta-analysis of 32 studies of patients with Chagas disease, the pooled estimated annual rate of cardiomyopathy was 4.6% among patients with acute Chagas infection and 1.9% among patients with indeterminate chronic Chagas disease. Meaning The findings indicate that asymptomatic individuals with indeterminate chronic Chagas disease without cardiac injury and individuals with acute Chagas infection may have a significant risk of developing chronic cardiomyopathy.

Circadian rhythms of parasites and their hosts can influence processes such as transmission, pathology and life cycle evolution. For trematode parasites that depend on free-living infectious stages (i.e. cercariae) to move among host species, the timing of parasite release is hypothesized to increase the likelihood of contacting a host. Yet, a persistent challenge in studying such biorhythms involves selection of appropriate analytical techniques. Here, we extend a generalized linear mixed modelling (GLMM) framework to cosinor analyses, thereby allowing flexibility in the statistical distribution of the response variable, incorporation of multiple covariates and inclusion of hierarchical grouping effects. By applying this approach to 93 snails infected with trematode parasites from freshwater pond ecosystems, we detected non-random rhythms in six of eight species, with variation in both the timing of peak cercariae release (between 5:10 and 21:46 h) and its magnitude (between 13 and 386). The use of GLMM yielded more accurate and precise estimates of the cosinor parameters compared with classical least-squares (LS) based on a simulation-based sensitivity analysis. The sensitivity analysis revealed that the amplitude and rhythm-adjusted mean values from the LS models diverged from the true values at some limits. We highlight the importance of novel analytical approaches for evaluating parasite circadian rhythms and investigating their underlying mechanisms.

Aims This study aimed to estimate the annual mortality risk and its determinants in chronic Chagas cardiomyopathy. Methods and results We conducted a systematic search in MEDLINE, Web of Science Core Collection, Embase, Cochrane Library, and LILACS. Longitudinal studies published between 1 January 1946 and 24 October 2018 were included. A random‐effects meta‐analysis using the death rate over the mean follow‐up period in years was used to obtain pooled estimated annual mortality rates. Main outcomes were defined as all‐cause mortality, including cardiovascular, non‐cardiovascular, heart failure, stroke, and sudden cardiac deaths. A total of 5005 studies were screened for eligibility. A total of 52 longitudinal studies for chronic Chagas cardiomyopathy including 9569 patients and 2250 deaths were selected. The meta‐analysis revealed an annual all‐cause mortality rate of 7.9% [95% confidence interval (CI): 6.3–10.1; I2 = 97.74%; T2 = 0.70] among patients with chronic Chagas cardiomyopathy. The pooled estimated annual cardiovascular death rate was 6.3% (95% CI: 4.9–8.0; I2 = 96.32%; T2 = 0.52). The annual mortality rates for heart failure, sudden death, and stroke were 3.5%, 2.6%, and 0.4%, respectively. Meta‐regression showed that low left ventricular ejection fraction (coefficient = −0.04; 95% CI: −0.07, −0.02; P = 0.001) was associated with an increased mortality risk. Subgroup analysis based on American Heart Association (AHA) classification revealed pooled estimate rates of 4.8%, 8.7%, 13.9%, and 22.4% (P < 0.001) for B1/B2, B2/C, C, and C/D stages of cardiomyopathy, respectively. Conclusions The annual mortality risk in chronic Chagas cardiomyopathy is substantial and primarily attributable to cardiovascular causes. This risk significantly increases in patients with low left ventricular ejection fraction and those classified as AHA stages C and C/D.

Background Pneumocystis jirovecii pneumonia (PJP) remains a cause of mortality in HIV-negative patients. The clinical benefit of adjuvant corticosteroids in these patients is uncertain. This study aimed to determine if corticosteroids reduced mortality in a cohort of HIV-negative PJP patients. Methods We examined a retrospective case series of patients diagnosed with PJP at the University of Colorado Hospital between 1995-2019. Data were collected in 71 PJP-infected patients. Twenty-eight patients were HIV-negative, and 43 were infected with HIV. We performed bivariate and forward, stepwise multivariable logistic regressions to identify mortality predictors. Results Common underlying conditions in HIV-negative patients were hematologic malignancies (28.6%), autoimmune disorders (25.9%), or solid organ transplantation (10.7%). HIV-negative patients had higher rates and duration of mechanical ventilation and ICU stay. Survival was significantly increased in HIV-negative patients receiving adjuvant corticosteroids, with 100% mortality in patients not receiving corticosteroids vs 60% mortality in patients receiving corticosteroids (p=0.034). In an adjusted multivariable model, no adjuvant corticosteroids use was associated with higher mortality (OR 13.5, 95% CI: 1.1-158.5, p= 0.039) regardless of HIV status. Conclusions We found substantial mortality among HIV-negative patients with PJP and adjuvant corticosteroid use was associated with decreased mortality. Response to corticosteroids is best established in HIV infected patients, but emerging reports suggest a similar beneficial response in PJP patients without HIV infection. Further prospective studies may establish a more definitive role of corticosteroid addition among HIV-negative patients with PJP.