OBJECTIVE:To analyze the clinical characteristics of Chlamydia psittaci pneumonia and to investigate the correlation between serum inflammatory biomarkers and severity of the disease. METHODS:Sixteen patients with Chlamydia psittaci pneumonia admitted to the Huizhou Municipal Central Hospital from January 2020 to July 2021 were selected as the study subjects, including 10 severe cases and 6 mild cases. Clinical data were collected and analyzed, such as baseline characteristics, clinical symptoms, laboratory inspection and chest imaging manifestations. RESULTS:(1) Thirteen Chlamydia psittaci pneumonia were associated with a definite bird or poultry contact history. Common symptoms included high fever, chill, cough, fatigue, and anorexia (16 cases), dyspnoea (12 cases), and other systemic symptoms. (2) Laboratory test results showed normal white blood cell count (WBC, 10 cases), decreased lymphocyte count (LYM, 13 cases), increased high sensitive C-reactive protein (hs-CRP, 16 cases), D-dimer (15 cases), lactate dehydrogenase (LDH, 13 cases), aspartate aminotransferase (AST, 16 cases) and alanine aminotransferase (ALT, 12 cases) levels, however, the albumin (Alb, 15 cases) lever was decreased. The numbers of CD3 T cells and CD4 T cells decreased in 10 patients. (3) The levels of D-dimer, interleukins (IL-2, IL-6, IL-10) in severe Chlamydia psittaci pneumonia were significantly higher than those in mild Chlamydia psittaci pneumonia [D-dimer (μg/L): 10 257±4 203 vs. 1 085±642, IL-2 (ng/L): 1.1 (0.8, 1.7) vs. 0.3 (0.1, 0.7), IL-6 (ng/L): 315 (182, 505) vs. 75 (18, 131), IL-10 (ng/L): 7.0±4.1 vs. 2.3±0.7], but the LYM was lower (×10/L: 0.4±0.1 vs. 1.1±0.4), with significant differences (all P < 0.05). (4) Chest imaging manifestations were exudative lesions and large consolidation of lungs. Large consolidation of both lungs can occur in some critically ill patients. CONCLUSIONS:Chlamydia psittaci pneumonia is mainly associated with a bird or poultry contact history. The clinical manifestations usually present high fever, dyspnea, normal or slightly increased leucocytes, and lung consolidation. The levels of LYM, D-dimer, IL-2, IL-6 and IL-10 in serum are expected to predict the severity of the Chlamydia psittaci pneumonia.

Here, we aimed to retrospectively analyze the clinical characteristics of 27 patients with severe pneumonia caused by between January 2019 and April 2021 in southwest China. To this end, we collected data on the exposure history, clinical symptoms, laboratory examination, imaging characteristics, evolution, etiology, treatment, and outcomes to suggest a better diagnosis and prevention system. Our results showed that a metagenomic next-generation sequencing test could provide early diagnosis. All patients were sensitive to quinolones and tetracyclines, and the recovery rate was relatively high. Overall, all patients were in critical condition with moderate to severe acute respiratory distress syndrome and shock. In conclusion, early diagnosis of pneumonia caused by depends on effective molecular testing, and most patients recover after treatment.

INTRODUCTION:Conventional etiological detection and pathogenic antibody methods make it challenging to identify the atypical pathogens among the community-acquired pneumonia (CAP). Metagenomic next-generation sequencing (mNGS) could rapidly detect all potentially infectious diseases and identifies novel or potential pathogens. METHODS:Eighteen patients diagnosed with atypical CAP were enrolled in this retrospective study, including nine Chlamydia psittaci pneumonia (C. p), four Legionella pneumonia (L. p) and five Mycoplasma pneumonia (M. p). We simultaneously tested bronchoalveolar lavage fluid (BALF) samples for conventional microbiological methods and mNGS, and blood specimens were analysed. We also collected and compared baseline and clinical characteristics and treatment responses. RESULTS:Patients with C. p and L. p had similar symptoms, including fever, cough, headache, dyspnoea, asthenia, shivering and headache, compared with M. p, whose symptoms were slight. C. p and L. p usually showed multiple lobar distributions with pleural effusion. Serologic testing indicated that L. p had higher levels of white blood cells (WBCs), neutrophils, C-reactive protein (CRP), procalcitonin (PCT), alanine aminotransferase (ALT), lactate dehydrogenase (LDH) and creatinine compared with M. p and L. p (p < 0.05). However, patients with C. p had lower levels of albumin (p < 0.05), and M. p had a minimum risk of cardiac volume loads (p < 0.05). CD4/CD8 ratio, lymphocytes, aspartate aminotransferase (AST), creatine kinase (CK), cell counting of BALF and coagulation had no difference (p < 0.05). Pathogenic IgM assay showed that 4/5 cases were positive for M. p and no positive detection for C. p and L. p infection. We timely adjusted the antibiotics according to the final mNGS results. Eventually, 16/18 patients recovered fully. Conditions of L. p patients were worse than those of C. p patients, and those of M. p patients were the least. CONCLUSION:Early application of mNGS detection increased the atypical pathogenic identification, improved the prognosis and made up for the deficiency of conventional detection methods.

To analyze the clinical characteristics and the diagnosis and treatment of pneumonia complicated with rhabdomyolysis. We reported a case of pneumonia complicated with rhabdomyolysis. We did a literature review on the published reports between January 1978 and May 2020 by searching with the key words of "psittacosis" or "i" and "rhabdomyolysis" in the PubMed database (time frame: January 1, 1967 to May 30, 2020). Our patient was a 64-year-old male presenting with high-grade fever, fatigue, myalgia and dyspnea. A computed tomographic scan of the chest revealed bilateral pneumonia, which was further complicated with rhabdomyolysis during disease progression. This prompted the metagenomic next-generation sequencing, revealing the sequences of in both the bronchoalveolar lavage fluid and blood. Of the 11 cases in the 3 literature reports that we retrieved, 5 had concomitant rhabdomyolysis (two of which did not have complete clinical information), and the other 6 cases had myositis complicated with an elevated level of creatine phosphokinase. This yielded 3 cases with complete clinical information for our analysis. We had further incorporated their information with the single case managed within our study site. Two were males and the other 2 were females. The patients were aged 66, 46, 44 and 64 years, respectively. All cases had fever and 3 had a contact history with live poultry. Two cases had myalgia and progressed rapidly into having respiratory failure, and the other 2 cases did not develop myalgia and improved significantly after a timely treatment. All 4 cases were cured and discharged after treatment with appropriate antibiotics. No adverse outcomes were observed. The prognosis of pneumonia complicated with rhabdomyolysis was poor in case of a delayed treatment. Early diagnosis would help reduce the mortality.

INTRODUCTION:Chlamydia psittaci pneumonia is a zoonotic infectious disease caused by Chlamydia psittaci. Its clinical manifestations are nonspecific. Diagnosis of the disease is difficult. In recent years, next-generation sequencing has played an important role in pathogen detection. We report two cases with severe Chlamydia psittaci pneumonia confirmed by next-generation sequencing. CASE STUDY:The first case is that of a 50-year old man who presented with high fever for four days and cough with sputum for two days. The second case is that of a 57-year-old man who was admitted with high fever for one week, dyspnea and cough with sputum for four days. The second man worked at a chicken farm in the last two months. In both cases, the usual laboratory examination for pathogens detection was negative, and the initial anti-infectious therapy had limited effect. The bronchoalveolar lavage fluid of case 1 and the blood and sputum of case 2 were sent for next-generation sequencing which resulted in sequence reads of Chlamydia psittaci. Antibiotics were adjusted according to the diagnosis. RESULTS:The diagnosis of the two cases was confirmed by next-generation sequencing detecting Chlamydia psittaci, and the patients had positive results after treatment. CONCLUSIONS:The two cases suggest that next-generation sequencing could be used in early diagnosis of Chlamydia psittaci infection to initiate specific anti-infection therapy in time.

Purpose:More and more patients with community-acquired pneumonia have been detected with () infected using metagenomic next-generation sequencing (mNGS). Previously, this was unheard of, and several patients presented with severe pneumonia and even required ECMO. We aimed to clarify the clinical characteristics of pneumonia and find out if there are any possible predictors of severe pneumonia. Methods:In this retrospective study, we included all confirmed cases of pneumonia in Wuxi. Epidemiological, clinical, and radiological features, as well as laboratory data, were collected and analyzed. Results:We enrolled 55 patients with pneumonia, with 30 (54.5%) having a history of exposure to birds or their internal organs. 50 (90.9%) patients were diagnosed by mNGS. Patients with pneumonia had many complications, among which, that deserve sufficient attention from clinicians were vascular embolic events (3, 5.5%). High fever was the most common clinical manifestation (41, 74.5%). The majority of patients had a significant increase in neutrophils ratio, neutrophils to lymphocytes ratio (NLR), rapid c-reactive protein, creatine kinase (CK), and lactate dehydrogenase (LDH), as well as a decrease in lymphocytes ratio, albumin, serum sodium, serum potassium, and serum phosphorus. Chest computed tomography scans revealed unilateral pneumonia (70.9%), consolidation (87.3%), air bronchogram (76.4%), and ground-glass opacity (69.1%). The neutrophil ratio, NLR, LDH, and CK were all factors that could identify severe pneumonia. Both AUCs exceeded 0.8; the respective 95% CIs were 0.715-0.944, 0.710-0.963, 0.677-0.937, and 0.718-0.950; all < 0.05 (0.01, 0.001, 0.007, 0.007 respectively). The ORs were 10.057, 9.750, 10.057, and 9.667, respectively; the 95% CIs were 2.643-38.276, 2.339-40.649, and 2.643-38.276, respectively; all -values were less than 0.05 (0.001, 0.002, 0.001, 0.001 respectively). Conclusion: pneumonia is a very complex disease that changes all the time. Some patients showed severe pneumonia. Patients will have a poor prognosis if they are not treated promptly and effectively. We discovered that many clinical indicators were typical. Meanwhile, significant increases in neutrophil ratio, NLR, LDH, and CK predicted severe pneumonia. Timely detection of mNGS provided substantial help for clinical diagnosis and early treatment.