Epidemiological and clinical characteristics of psittacosis among cases with complicated or atypical pulmonary infection using metagenomic next-generation sequencing: a multi-center observational study in China.

BACKGROUND: Chlamydia psittaci (C. psittaci) causes parrot fever in humans. Development of metagenomic next-generation sequencing (mNGS) enables the identification of C. psittaci. METHODS: This study aimed to determine the epidemiological and clinical characteristics of parrot fever cases in China. A multi-center observational study was conducted in 44 tertiary and secondary hospitals across 14 provinces and municipalities between April 2019 and October 2021. RESULTS: A total of 4545 patients with complicated or atypical pulmonary infection were included in the study, among which the prevalence of C. psittaci was determined to be 2.1% using mNGS. The prevalence of C. psittaci was further determined across demographic groups and types of specimens. It was significantly higher in patients with senior age (2.6% in those > 50 years), winter-spring (3.6%; particularly in December, January, and February), and southwestern (3.4%) and central and southern China (2.7%) (each P < 0.001). Moreover, the prevalence was the highest in bronchoalveolar lavage fluid (BALF) (2.9%), compared with sputum (1.1%) and peripheral blood specimens (0.9%). Additionally, co-infection of principal microorganisms was compared. Certain microorganisms were more likely to co-infect in parrot fever cases, such as Candida albicans in BALF (26.7%) and peripheral blood (6.3%), compared with non-parrot fever cases (19.7% and 1.3%); however, they did not significantly differ (each P > 0.05). CONCLUSION: Parrot fever remains low in patients with complicated or atypical pulmonary infection. It is likely to occur in winter-spring and southwestern region in China. BALF may be the optimal specimen in the application of mNGS. Co-infection of multiple microorganisms should be further considered.

Cytokeratin 7 and thyroid transcription factor - 1 levels in patients with lung cancer complicated with superior vena cava syndrome and their correlation with clinicopathological characteristics.

PURPOSE: This study aimed to detect the levels of cytokeratin 7 (CK7) and thyroid transcription factor -1(TTF-1) in serum of patients with non-small cell lung cancer (NSCLC) complicated with superior vena cava syndrome (SVCS), and to explore their prognosis and relationship and correlation with pathological characteristics. METHODS: 68 patients with non-small cell lung cancer (NSCLC) complicated with SVCS treated in Shaoxing Second Hospital from July 2014 to May 2018 were selected as the experimental group, 60 normal healthy persons as the control group, and 60 patients with lung cancer as the lung cancer group. The levels of CK7 and TTF-1 in the three groups were determined by enzyme-linked immunosorbent assay (ELISA), and the differences were compared. The relationship between the expression levels of CK7 and TTF-1 and clinicopathological characteristics of patients, the correlation between CK7 and TTF-1 in lung cancer patients complicated with SVCS, and their 3-year survival rate were analyzed. RESULTS: CK7 and TTF-1 levels in experimental group were significantly higher than those in control group (P<0.05). The levels in lung cancer group were significantly higher than those in control group (P<0.05). In experimental group, the expression of CK7 and TTF-1 was not related to gender, age, weight, histological classification and tumor size (P>0.05)). CK7 expression was positively correlated with TTF-1 expression in lung cancer patients (P<0.001). The 3-year survival rate in CK7 and TTF-1 high expression group was significantly lower than that in low expression group (P<0.05). CONCLUSION: The expressions of CK7 and TTF-1 are increased in patients with lung cancer complicated with SVCS, and are related to TNM stage, lymph node metastasis and differentiation degree. The high expressions of CK7 and TTF-1 in serum of patients are expected to be potential prognostic indicators for lung cancer complicated with SVCS.