Undiagnosed Cases of Human Pneumonia Following Exposure to Chlamydia psittaci from an Infected Rosella Parrot.
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ABSTRACT:
SUBMITTER: Chaber AL
PROVIDER: S-EPMC8399200 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:BackgroundThis is a retrospective cross-sectional study aiming to explore the clinical and imaging manifestations of Chlamydia psittaci pneumonia (CPP), thus improving its diagnosis, guiding its early clinical treatment, and reducing its mortality rate.MethodsFifty cases of CPP diagnosed by hospitals across the country with metagenomics next-generation sequencing (mNGS) from January 2019 to March 2021 were collected. Its clinical symptoms, laboratory test results, and computed tomography (CT) features were discussed.ResultsForty patients had a history of poultry exposure; 37 experienced respiratory symptoms, 48 had a fever, 14 experienced gastrointestinal symptoms, and 12 experienced neurological symptoms; 34 patients had normal blood cell counts, 49 patients had elevated C-reactive protein, and 24 showed decreased serum sodium. Imaging manifestations: (I) Distribution: lesions were limited to a single lung in 31 patients, lesions were distributed in bilateral lungs in 19 patients; (II) Signs: 37 patients developed the "fine mesh sign". Necrosis, cavity and "tree-in-bud" were not observed. Pleural effusion occurred in 33 patients, mediastinal lymphadenopathy in 18, and splenomegaly in 15 patients.ConclusionsPatients with CPP often have a history of poultry exposure and present with fever and increased C-reactive protein. White blood cells may be slightly increased or completely normal. Hyponatremia may occur in some patients, and multiple systems may be clinically involved. The imaging can show lesions with unilateral or bilateral lung distribution and a rapid progression. Both the lung parenchyma and the interstitium are involved. Fine mesh sign is the most common sign. Necrosis, cavitation, and tree-in-bud signs are not observed. In conclusion, imaging examinations are helpful for the early diagnosis of this disease and the evaluation of the treatment effect.
| S-EPMC10102789 | biostudies-literature
Project description:Chlamydia psittaci is an avian pathogen and zoonotic agent of atypical pneumonia. The most pathogenic C. psittaci strains cluster into the 6BC clade, predicted to have recently emerged globally. Exposure to infected parrots is a risk factor with limited evidence also of an indirect exposure risk. Genome sequencing was performed on six Australian human and a single avian C. psittaci strain isolated over a 9 year period. Only one of the five human patients had explicit psittacine contact. Genomics analyses revealed that the Australian C. psittaci strains are remarkably similar, clustering tightly within the C. psittaci 6BC clade suggested to have been disseminated by South America parrot importation. Molecular clock analysis using the newly sequenced C. psittaci genomes predicted the emergence of the 6BC clade occurring approximately 2,000 years ago. These findings reveal the potential for an Australian natural reservoir of C. psittaci 6BC strains. These strains can also be isolated from seriously ill patients without explicit psittacine contact. The apparent recent and global spread of C. psittaci 6BC strains raises important questions over how this happened. Further studies may reveal whether the dissemination of this important zoonotic pathogen is linked to Australian parrot importation rather than parrots from elsewhere.
| S-EPMC4973220 | biostudies-literature
Project description:IntroductionChlamydia psittaci pneumonia has been a global public health hotspot in recent years. Although some scattered cases of C. psittaci pneumonia have been reported, there is a lack of large case studies worldwide.MethodsIn this multicenter, observational study, we recruited all consecutive patients with confirmed C. psittaci pneumonia from October 4, 2018, to October 23, 2020, in nine tertiary general hospitals in Central-South China. Epidemiologic and clinical data from patients' electronic medical records were collected and analyzed.ResultsOne hundred and sixteen patients with C. psittaci pneumonia were included in the study. The mean age was 59.7 years. Fever (96.6%) and cough (65.5%) were the most common clinical symptoms. Most patients presented with an increase in the proportion of neutrophils, neutrophil to lymphocyte ratio, LDH, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and a significant decrease in lymphocytes. The main CT lung findings were consolidation (81%) and pleural effusion (35.3%), and bilateral lung consolidation was mainly found in severe patients. Chlamydia psittaci DNA was detected in BALF (bronchoalveolar lavage fluid) or blood samples by metagenomic next-generation sequencing (mNGS) in all patients. Use of quinolone was associated with shorter length of hospital stay and fever duration after antibiotic use. Multivariate logistic regression analysis indicated that respiratory support was associated with both severe pneumonia and in-hospital death.ConclusionsThe clinical phenotype of C. psittaci pneumonia is complex and variable. mNGS is helpful in the diagnosis and treatment of C. psittaci pneumonia, and early treatment with quinolone may benefit patients.
| S-EPMC9207437 | biostudies-literature
Project description:To clarify the host inflammatory response in psittacosis,we compared transcriptome data and concentrations of serum cytokines and chemokines in pneumonia and bronchitis cases.
2022-05-16 | GSE202947 | GEO
Project description:Factors and mechanisms determining the differences in virulence and host specificity between the zoonotic agents Chlamydia psittaci and Chlamydia abortus are still largely unknown. In the present study, two strains were compared for their invasiveness, virulence, and capability of eliciting an immune response in chicken embryos. On breeding day 10, embryonated chicken eggs were inoculated with 5 × 10(4) inclusion-forming units. As shown by immunohistochemistry and quantitative real-time PCR, C. psittaci displayed a significantly better capability of disseminating in the chorioallantoic membrane (CAM) and internal organs than C. abortus. The higher infectious potential of C. psittaci in birds was underlined by significantly higher mRNA expression rates of essential chlamydial genes, such as incA, groEL (in CAM, liver, and spleen), cpaf, and ftsW (in CAM). Although the immune responses to both pathogens were similar, C. psittaci elicited higher macrophage numbers and a stronger expression of a subset of immune-related proteins. The data imply that invasiveness of Chlamydia spp. and propagation in the host are not solely dependent on the level of host immune response but, even to a greater extent, on the expression of bacterial factors related to virulence. The fact that C. psittaci has coped far better than C. abortus with the avian embryo's response by upregulating essential genes may be a key to understanding the mechanisms underlying host adaptation and etiopathology.
| S-EPMC3418749 | biostudies-literature
Project description:Chlamydia psittaci, a strictly intracellular bacterium, is an underestimated etiologic agent leading to infections in a broad range of animals and mild illness or pneumonia in humans. In this study, the metagenomes of bronchoalveolar lavage fluids from the patients with pneumonia were sequenced and highly abundant C. psittaci was found. The target-enriched metagenomic reads were recruited to reconstruct draft genomes with more than 99% completeness. Two C. psittaci strains from novel sequence types were detected and these were closely related to the animal-borne isolates derived from the lineages of ST43 and ST28, indicating the zoonotic transmissions of C. psittaci would benefit its prevalence worldwide. Comparative genomic analysis combined with public isolate genomes revealed that the pan-genome of C. psittaci possessed a more stable gene repertoire than those of other extracellular bacteria, with ~90% of the genes per genome being conserved core genes. Furthermore, the evidence for significantly positive selection was identified in 20 virulence-associated gene products, particularly bacterial membrane-embedded proteins and type three secretion machines, which may play important roles in the pathogen-host interactions. This survey uncovered novel strains of C. psittaci causing pneumonia and the evolutionary analysis characterized prominent gene candidates involved in bacterial adaptation to immune pressures. The metagenomic approach is of significance to the surveillance of difficult-to-culture intracellular pathogens and the research into molecular epidemiology and evolutionary biology of C. psittaci.
| S-EPMC10265514 | biostudies-literature
Project description:Psittacosis is an uncommon disease which mainly presents as community-acquired pneumonia (CAP). We aim to apply metagenomic next-generation sequencing (mNGS) as a promising tool in the diagnosis of psittacosis pneumonia and to describe its clinical spectrum to provide physicians with a better understanding and recognition of this disease. Thirteen cases of psittacosis pneumonia were diagnosed by using mNGS. A retrospective analysis of the data on clinical manifestations, laboratory data, computed tomography (CT) images, new diagnosis tools, treatments, and outcomes was summarized. These patients had common symptoms of fever and weakness; some had poor appetite, cough, myalgia, and headache. Ten patients developed acute respiratory distress syndrome (ARDS), among which six patients were severe pneumonia cases and needed ventilator therapy. Most patients got psittacosis pneumonia during the cold season. Ten cases were sporadic, but three were family clustering. All of the 13 patients were traced to an exposure history to birds, cat, or poultry, among which 2 only touched the innards of killed poultry before cooking, which may be an atypical exposure history not been reported before, to our knowledge. Most patients had various degrees of liver dysfunction. Air-space consolidations, along with ground-glass opacities and reticular shadows, were detected on chest CT scan. mNGS takes 48 to 72 h to provide results and helps to diagnose psittacosis. After being diagnosed by mNGS, with effective medicines, all patients finally had complete recoveries. The use of mNGS can improve the diagnostic rate of psittacosis pneumonia and shorten the course of disease control. IMPORTANCE Psittacosis pneumonia is easily underdiagnosed and misdiagnosed. In this study, we use mNGS in the diagnosis of psittacosis pneumonia. We found this disease is prone in the cold season, and touching the innards of killed poultry during cooking may be an atypical exposure history which has not been reported before to our knowledge. There are sporadic cases and family outbreak cases as well. Except for typical symptoms of fever and weakness, headache may be the main and only symptom in some patients. The rate of severe pneumonia is high among inpatients with psittacosis pneumonia, and the incidence of hepatic involvements is also high. Psittacosis pneumonia can be cured if the diagnosis is accurate and in time, even if it is severe pneumonia on admission. Some problems worthy of our attention about psittacosis pneumonia were put forward, such as its sick season, special exposure history, the rate of severe disease, and the high cure rate. mNGS can quickly and objectively detect more rare pathogenic microorganisms in clinical specimens without the need for specific amplification and has an advantage in the diagnosis of rare pathogenic bacteria in difficult cases such as psittacosis pneumonia. The use of mNGS can improve the accuracy and reduce the delay in the diagnosis of psittacosis, which shortens the course of disease control.
| S-EPMC9431268 | biostudies-literature
Project description:Here, we aimed to retrospectively analyze the clinical characteristics of 27 patients with severe pneumonia caused by Chlamydia psittaci 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 C. psittaci depends on effective molecular testing, and most patients recover after treatment.
| S-EPMC8770948 | biostudies-literature
Project description:BackgroundWith the widespread application of metagenomic next-generation sequencing (mNGS) in pathogen detection, the reports of severe Chlamydia psittaci (C. psittaci) pneumonia are increasing. It is essential to determine the best management of severe C. psittaci pneumonia.Case descriptionThis report describes a 51-year-old male patient who presented with symptoms of expectoration, relative bradycardia, and dyspnea. Lung computed tomography (CT) on day 1 (D1) showed consolidation of the left lower lobe. He was intubated and transferred to the intensive care unit (ICU). The symptoms of high fever and progressive dyspnea [the lowest level of arterial partial pressure of oxygen/fractional inspired oxygen (PaO2/FiO2): 52 mmHg] persisted on D3. Meanwhile, he produced a large volume of golden-yellow, watery sputum, due to which endotracheal suction was repeatedly performed to maintain patency of the airway. The repeat radiography showed extensive deterioration of diffuse exudation in bilateral lobes. An early treatment with methylprednisolone was initiated on D3, after which the watery sputum decreased and turned viscous. The mNGS of the bronchoalveolar lavage fluid (BALF) identified C. psittaci on D7, and combined targeted antimicrobial therapy (azithromycin and doxycycline) was subsequently initiated. After 1 week of treatment, the patient was extubated on D14. He was transferred to the respiratory department on D17 and discharged on D25 with oral medications (azithromycin and doxycycline for 2 weeks). The repeat chest CT on D68 showed that the bilateral exudation and left lower lobe consolidation had almost disappeared, without pleural effusion.ConclusionsIn severe C. psittaci pneumonia, although the presentations differ, the rapid pathogen identification through BALF mNGS may facilitate the early use of effective antibiotics. Timely and comprehensive treatment is important for improving outcomes in severe C. psittaci pneumonia.
| S-EPMC10789907 | biostudies-literature
Project description:Psittacosis is a zoonotic infectious disease caused by the transmission of the bacterium Chlamydia psittaci from birds to humans. Infections in humans mainly present as community-acquired pneumonia (CAP). However, most cases of CAP are treated without diagnostic testing, and the importance of C. psittaci infection as a cause of CAP is therefore unclear. In this meta-analysis of published CAP-aetiological studies, we estimate the proportion of CAP caused by C. psittaci infection. The databases MEDLINE and Embase were systematically searched for relevant studies published from 1986 onwards. Only studies that consisted of 100 patients or more were included. In total, 57 studies were selected for the meta-analysis. C. psittaci was the causative pathogen in 1·03% (95% CI 0·79-1·30) of all CAP cases from the included studies combined, with a range between studies from 0 to 6·7%. For burden of disease estimates, it is a reasonable assumption that 1% of incident cases of CAP are caused by psittacosis.
| S-EPMC9148753 | biostudies-literature