Abstract
<title>Abstract</title> <p>Objective To investigate the relationship between Pneumocystis colonization and the clinical characteristics of patients with mild to moderate community-acquired pneumonia, as well as its correlation with prognosis (measured by improvement time), and further explore the impact of herpesvirus reactivation on prognosis. Method Patients undergoing bronchoscopy with targeted next-generation sequencing (tNGS) were enrolled. Baseline data, comorbidities, inflammatory markers, length of hospital stay, time to clinical improvement, and prognostic indicators were collected from the enrolled patients. The primary outcome was the time to clinical improvement. Results A total of 350 patients with mild to moderate community-acquired pneumonia were enrolled, among whom 56 cases (15.6%) exhibited Pneumocystis colonization. The median improvement time in the Pneumocystis colonized group was 14 days (IQR: 9.75–17), significantly longer than the 11 days (IQR: 8–15) in the Pneumocystis-negative group (P = 0.004). Kaplan-Meier survival analysis revealed that the cumulative improvement rate in the Pneumocystis colonized group was significantly lower than that in the Pneumocystis-negative group (Log-rank P = 0.020). Multivariate Cox regression showed that, after adjusting for age, gender, admission scores, and underlying diseases, Pneumocystis colonization remained independently associated with improvement time (HR = 0.686,95% CI: 0.512–0.918, P = 0.011). In the overall population, the improvement time in the herpesvirus-positive group was significantly longer than that in the negative group [14 days (10–19) vs. 10 days (8–14), P < 0.001]. Within the Pneumocystis-negative group, herpesvirus-positive patients exhibited a significantly longer median improvement time than negative patients [13 days (10–18) vs. 10 days (7.5–14), P < 0.001]. Similarly, in the Pneumocystis colonized group, patients with herpesvirus reactivation had significantly longer clinical improvement times [15 days (12–22) vs. 11 days (8–14), P = 0.021] compared to those with isolated colonization; moreover, the early improvement rate (< 14 days) was significantly lower in patients with herpesvirus reactivation in both groups. Conclusion Pneumocystis colonization was significantly associated with prolonged recovery time in patients with community-acquired pneumonia, while coexisting herpesvirus reactivation was correlated with poorer clinical outcomes, suggesting that viral reactivation may serve as a critical synergistic factor contributing to adverse prognosis.</p>