Chlamydia psittaci Screening of Animal Workers from Argentina Exposed to Carrier Birds.

Different syndromes are involved in human psittacosis (flu-like syndrome, atypical pneumonia up to lacrimal gland lymphoma). Diagnostic methods include serology, culture, and PCR. The rate of Chlamydia psittaci (Cp) positive tests among exposed workers is still unknown. Our study aimed to assess the rate of positive tests among workers who have contact with carrier birds in natural reserves from Buenos Aires, Argentina. Secondary aims were to analyze risk factors linked to these outcomes and the occurrence of signs that suggest psittacosis. Nasopharyngeal swabs and serum pairs were collected from employees who had interacted with confirmed carrier birds. Those with detectable DNA of Cp and/or anti-Chlamydia spp. antibody baseline titer ≥ 160 mUI/ml, or at least quadruplicating, were considered positive. Activities performed with or near birds, personal protective equipment use, and previous chronic conditions were assessed. Possible Cp-related pathologies were evaluated during follow-up. A total of 63 exposed workers (71.4% men) with a median age of 35.7 years (IQR 26-39) were evaluated to detect 28.6% positives. Respiratory chronic conditions were the unique factor associated with positive tests (OR 5.2 [1.5-18.5] p < .05). Surprisingly, about a third of the workers resulted positive and all responded to medical treatment, none developing an acute atypical pneumonia syndrome associated with classical presentation of psittacosis. Active testing for early diagnosis and proper treatment in zoological workers exposed to carrier or potentially carrier birds is strongly suggested as part of zoonotic diseases preventive measures.

Diagnosis of a Familial Psittacosis Outbreak with Clinical Analysis and Metagenomic Next-Generation Sequencing Under COVID-19: A Case Series.

Purpose: To explore the clinical characteristics, diagnosis, and treatment of family outbreak of psittacosis and to improve the success rate of treatment. Patients and Methods: The clinical characteristics, diagnosis, treatment, and outcome of family outbreak of psittacosis, which consists three patients, diagnosed by clinical analysis and metagenomic next-generation sequencing (mNGS) in our hospital were analyzed retrospectively. Results: We report on three instances of clustered atypical pneumonia, which were caused by Chlamydia psittaci during the COVID-19 pandemic. All patients exhibited symptoms of fever and cough, while one patient also experienced gastrointestinal symptoms such as nausea, vomiting, and diarrhea. Laboratory tests indicated no significant increase in leukocytes and neutrophils, but a mild increase in C-reactive protein was observed in all three patients. Chest computed tomography (CT) scans revealed a consolidation shadow in a unilateral lung lobe in all three patients. Both patients were treated with empirical moxifloxacin, yielding unsatisfactory outcomes. mNGS was conducted on sputum samples from one adult patient, revealing the presence of Chlamydia psittaci. Additional doxycycline was prescribed immediately, and then the patients' temperatures were stabilized, and the lesion in chest CT was absorbed. The pediatric patient exhibited less severe symptoms compared to the adult patients and exhibited a favorable response to azithromycin administration. Conclusion: This study reports a cluster of a family outbreak of atypical pneumonia caused by C. psittaci in China. The occurrence of a family outbreak during the COVID-19 pandemic may be attributed to familial aggregation resulting from the epidemic. The three cases reported in this study did not experience severe complications, which can be attributed to the prompt medical intervention and swift diagnosis. This finding implies the need to enhance patients' awareness and vigilance towards their health. Additionally, mNGS emerges as a valuable technique for accurately identifying pathogens causing pulmonary infections.

Postmortem diagnosis of gestational psittacosis: A case report.

Background: Gestational psittacosis is one of the causes of unanticipated maternal death but has been difficult to diagnose early in clinical practice. Case Presentation: A 28-year-old woman who was 7 months pregnant experienced flu-like symptoms, which deteriorated. She was brought to our hospital in shock, and the fetus was nonviable. The patient was diagnosed with pneumonia and septic shock and administered meropenem. Despite aggressive resuscitation, she died 7 h after symptom onset. After obtaining consent from the patient's family, the autopsy was done to identify the cause of death. Microscopically, there was intervillous neutrophil accumulation in the placenta. Genetic analysis detected the Chlamydia psittaci gene in several organs, including placenta. Conclusion: Gestational psittacosis should be considered for a pregnant woman with flu-like symptoms. Moreover, unanticipated death of a pregnant woman might warrant a detailed autopsy to reveal the cause of death.

Chlamydia psittaci causing severe pneumonia with an initial complaint of massive watery sputum: a case report.

Background: With 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 Description: This 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. Conclusions: In 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.

Clinical characteristics of 14 cases of Chlamydia psittaci pneumonia.

Among 14 patients with C. psittaci pneumonia, there were 9 critical and 5 non-critical cases. Ten patients improved clinically and were discharged to home; however, four patients died. Seven patients had a history of contact with birds or poultry. All 14 patients had a high fever as the presenting symptom, but most had a normal white blood cell count. Most of the patients had a significant increase in high-sensitivity C-reactive protein and procalcitonin levels. The lymphocyte count in the critical group was considerably lower than in the non-critical group. Patients in the critical group were more advanced in age than in the non-critical group. In addition, serum urea nitrogen, creatinine, procalcitonin, and lactate dehydrogenase levels were significantly higher in the critical group than in the non-critical group (P<0.05). The 4 patients who died had significantly increased procalcitonin levels compared to the 10 patients who survived (P<0.05). In summary, a high fever is usually the presenting complaint of patients with C. psittaci pneumonia. Such patients often progress to severe disease; however, early diagnostic confirmation by mNGS and appropriate treatment dramatically improve the prognosis. Age, lymphocyte count, procalcitonin, blood urea nitrogen, creatinine, and lactate dehydrogenase levels were shown to predict disease severity.

Venous-arterial extracorporeal membrane oxygenation for psittacosis pneumonia complicated with cardiogenic shock: case report and literature review.

INTRODUCTION: Dilated cardiomyopathy (DCM) is characterized by the enlargement of the left ventricle or biventricular, accompanied by myocardial systolic dysfunction. Chlamydia psittacosis (CP) is a zoonotic pathogen, which can cause severe pneumonia, respiratory failure, and acute organ dysfunction. The deterioration of DCM caused by CP infection is extremely rare, and few cases of successful management were reported. CASE PRESENTATION: We reported a 67-year-old male patient with DCM and chronic heart failure. Who was admitted to ICU with severe pneumonia, acute hypoxemic respiratory failure, acute decompensated heart failure, arrhythmia, and cardiogenic shock. Mechanical ventilation (MV) and venous-arterial extracorporeal membrane oxygenation (VA-ECMO) were established for respiratory and circulatory support. Broncho alveolar lavage fluid(BALF)was collected for culture and metagenomics next-generation sequencing (mNGS) test. Repeated mNGS tests indicated the high possibility of CP pneumonia, thereafter, moxifloxacin and doxycycline were prescribed. After targeted antibiotics and organ support treatment, pneumonia, respiratory and circulatory failure were gradually resolved, patient was successfully weaned from MV and VA-ECMO. Finally, the patient was recovered and discharged alive. CONCLUSIONS: Severe respiratory and circulatory failure caused by CP infection in DCM patients is a rare life-threatening clinical condition. Early accurate diagnosis, targeted antibiotic therapy, coupled with extracorporeal life support posed positive impact on the patient's disease course and outcome.

Belgian Cross-Sectional Epidemiological Study on Zoonotic Avian Chlamydia spp. in Chickens.

Chlamydia psittaci, Chlamydia gallinacea, and Chlamydia abortus are the most common Chlamydia spp. in chickens and have a confirmed or suggested zoonotic potential. No recent data are available on their prevalence and impact in the Belgian chicken industry or in the recreational chicken branch. Therefore, a cross-sectional epidemiological study was executed where samples were collected from both factory-farmed and backyard chickens. More specifically, pharyngeal chicken swabs were obtained from 20 chicken farms, 5 chicken abattoirs, and 38 different backyard locations and were analyzed using species-specific Polymerase Chain Reactions (PCRs) for the presence of the three avian Chlamydia spp. To investigate their zoonotic potential, samples were simultaneously collected from 54 backyard chicken caretakes and 37 professional chicken caretakers or abattoir employees and analyzed using species-specific PCRs as well. This study confirmed the presence of DNA of all three Chlamydia species in both the chicken industry and backyard settings. Chlamydia psittaci was the most prevalent in the industry chickens (11.0%), whereas Chlamydia gallinacea was the dominant species in the backyard chickens (14.5%). Chlamydia abortus infections were more common in the commercial chickens (9.0%) compared to the backyard chickens (2.6%). The DNA of all three species was also detected in humans (3.9% Chlamydia psittaci, 2.9% Chlamydia gallinacea, and 1.0% Chlamydia abortus).

SNP-based high-resolution typing of Chlamydia psittaci from humans and wild birds in Sweden: circulation of the Mat116 genotype reveals the transmission mode to humans.

The incidence of Chlamydia psittaci respiratory tract infections in humans has increased in Sweden in recent years. This study aimed to identify the transmission route by genotyping C. psittaci from infected humans and birds. 42 human C. psittaci samples and 5 samples from C. psittaci-infected birds were collected. Genotyping was performed using ompA sequencing, Multi-locus sequence typing, and/or SNP-based high-resolution melting-PCR. Epidemiological data was also collected, and a phylogenetic analysis was conducted. Analysis of ompA provided limited resolution, while the SNP-based PCR analysis successfully detected the Mat116 genotype in 3/5 passerine birds and in 26/29 human cases, indicating a high prevalence of this genotype in the human population. These cases were associated with contact with wild birds, mainly through bird feeding during winter or other outdoor exposure. Human cases caused by other genotypes (psittacine and pigeon) were less common and were linked to exposure to caged birds or pigeons. The SNP-genotype Mat116 is rare, but predominated in this study. The use of SNP-based PCR provided a better understanding of the C. psittaci transmission from birds to humans compared to ompA analysis. In Sweden, human psittacosis appears mainly to be transmitted from garden birds during bird feeding in the winter season.

Clinical features of psittacosis in 46 Chinese patients / Características clínicas de 46 pacientes con psittacitis China

Background: Psittacosis is a relatively uncommon cause of community-acquired pneumonia, often leading to diagnostic difficulty.Methods: A retrospective study was conducted on the clinical features of psittacosis patients in China. Forty-six cases of Chlamydophila psittaci infection with atypical pneumonia of varying severity in the last two years were described retrospectively.Results: Fever, relative bradycardia, and other systemic upsets were the main clinical presentation. The most common radiographic abnormality was segmental or lobar shadowing or consolidation. The total white cell counts were usually normal or slightly increased. The concentration of creatine kinase, C reactive protein, and lactic dehydrogenase increased, while albumin decreased remarkably. These cases exhibited good recovery after being treated with tetracycline or quinolone antibiotics.Conclusion: These features may help differentiate psittacosis from other traditional bacterial pneumonia. However, they do not provide a definitive diagnosis. Psittacosis diagnosis must perform the whole-genome sequencing for Chlamydophila psittaci in respiratory, blood, or sputum specimens. Increased awareness of psittacosis can shorten diagnostic delays and improve patient outcomes.(AU)

Antecedentes: La psitacosis es una causa relativamente poco común de neumonía adquirida en la comunidad, y a menudo conduce a dificultades diagnósticas.Métodos: Se realizó un estudio retrospectivo sobre las características clínicas de los pacientes con psitacosis en China, en el que se describen retrospectivamente 46 casos de infección por Chlamydia psittaci con neumonía atípica de gravedad variable en los últimos dos años.Resultados: La fiebre, la bradicardia relativa y otros trastornos sistémicos fueron la presentación clínica principal. La anomalía radiográfica más común fue el sombreado o consolidación segmentaria o lobular. Los recuentos totales de glóbulos blancos fueron generalmente normales o ligeramente aumentados. Las concentraciones de creatina quinasa, proteína C reactiva y deshidrogenasa láctica aumentaron, mientras que la albúmina disminuyó notablemente. Estos casos mostraron una buena recuperación después de ser tratados con antibióticos de tetraciclina o quinolona.Conclusión: Estas características pueden ayudar a diferenciar la psitacosis de otras neumonías bacterianas tradicionales. Sin embargo, no proporcionan un diagnóstico definitivo. El diagnóstico de psitacosis debe realizar la secuenciación del genoma completo de Chlamydia psittaci en muestras respiratorias, sanguíneas o de esputo. Una mayor conciencia de la psitacosis puede acortar los retrasos en el diagnóstico y mejorar los resultados de los pacientes.(AU)

Acute abdominal pain as the first symptom of Chlamydia psittaci pneumonia complicated by acute pancreatitis: a case report.

Background: Chlamydia psittaci infections primarily cause damage to the lungs but may also affect the cardiovascular system, gastrointestinal tract, liver, kidney, and brain, resulting in a variety of extrapulmonary complications. However, reports regarding C. psittaci infection-associated pancreatitis are rare. In this report, a patient with C. psittaci pneumonia complicated by acute pancreatitis is presented. Case description: The patient presented with acute upper abdominal pain and developed severe pyrexia and dyspnoea one day later. A chest computed tomography image revealed patchy consolidation in the left lung. The disease progressed rapidly, and the patient exhibited liver and kidney damage and type 1 respiratory failure within a short period of time. Metagenomic next-generation sequencing of alveolar lavage fluid revealed the presence of C. psittaci. The patient was administered doxycycline and moxifloxacin, after which the patient's abdominal pain and lung infection significantly resolved. Conclusion: This case report demonstrates that extrapulmonary C. psittaci infections due to secondary acute pancreatitis can manifest as abdominal pain, although the exact mechanisms of C. psittaci caused by acute pancreatitis remain unclear. Timely diagnoses and treatments of such infections are necessary to achieve favorable clinical outcomes.

Chlamydia psittaci seropositivity in workers exposed to birds and review of the literature: Evidence of circulation in Antioquia / Seropositividad de Chlamydia psittaci en trabajadores expuestos a aves y revisión de la literatura: evidencia de circulación en Antioquia.

Introduction: Psittacosis is a zoonotic disease caused by Chlamydia psittaci, a bacterium classified as an agent with bioterrorist potential. It has caused multiple outbreaks in exposed poultry workers around the world. Colombia has no epidemiological follow-up of the infection and a big knowledge gap. Objectives: To determine the antibodies' frequency against C. psittaci in workers with occupational exposure to birds and to review the literature on studies conducted in Colombia. Materials and methods: We conducted a cross-sectional descriptive study with analytical intent on workers in contact with birds and reviewed the related literature in Colombia. IgM and IgG serum antibodies against C. psittaci were detected by microimmunofluorescence. The sociodemographic and exposure characteristics were expressed as frequencies and summary measures. Associated factors were explored by bivariate and multivariate analysis. The scientific and gray literature review was done with a structured search. Results: We analyzed 54 workers in contact with birds. Antibody prevalence was 31.5%. Slaughtering and evisceration by non-veterinarians was a risk factor for antibody presence. There are only four previous studies on C. psittaci in Colombia. Conclusions: Here, we present the first evidence of C. psittaci circulation among workers exposed to birds in Antioquia and the second report in the country. These findings contribute to the "One Health" public health strategy.

Introducción: La psitacosis es una enfermedad zoonótica causada por Chlamydia psittaci. Esta bacteria es catalogada como un agente con potencial bioterrorista y ha causado múltiples brotes en trabajadores con exposición laboral a aves en diferentes lugares del mundo. En Colombia, no se hace seguimiento epidemiológico de la infección y existe una gran brecha en el conocimiento. Objetivos: Determinar la frecuencia de anticuerpos contra C. psittaci en trabajadores con exposición laboral a aves y sus factores asociados. Además, revisar la literatura en relación con los estudios sobre el tema realizados en Colombia. Materiales y métodos: Se llevó a cabo un estudio descriptivo, transversal, con intención analítica, en trabajadores en contacto con aves y se revisó la literatura científica relacionada en Colombia. Se detectaron anticuerpos IgM e IgG contra C. psittaci en suero por microinmunofluorescencia. La descripción de las características sociodemográficas y de exposición se hizo con frecuencias y medidas de resumen. Se exploraron factores asociados por análisis bivariados y multivariados. La revisión de la literatura científica y gris se hizo con búsqueda estructurada. Resultados: Se analizaron 54 trabajadores en contacto con aves y se encontró una prevalencia de anticuerpos del 31,5 %. El ejercer funciones de sacrificio y faenado de las aves sin ser médico veterinario fue un factor de riesgo para la presencia de anticuerpos. Solo se encontraron cuatro estudios previos sobre C. psittaci hechos en Colombia. Conclusiones: Este estudio constituye la primera evidencia de la circulación de C. psittaci en trabajadores en contacto con aves en Antioquia y el segundo reporte en el país. Estos hallazgos aportan desde la salud pública a la estrategia One Health.

Case Report: Metagenomic next-generation sequencing applied in diagnosing psittacosis caused by Chlamydia psittaci infection.

Background: Chlamydia psittaci is the causative agent of psittacosis in humans, while its rapid identification is hampered due to the lack of specificity of laboratory testing methods. Case presentation: This study reports four cases of C. psittaci infection after contact with a domestic parrot, all belonging to the same family. Common manifestations like fever, cough, headache, nausea, and hypodynamia appeared in the patients. Metagenomic next-generation sequencing (mNGS) aided the etiological diagnosis of psittacosis, revealing 58318 and 7 sequence reads corresponding to C. psittaci in two cases. The detected C. psittaci was typed as ST100001 in the Multilocus-sequence typing (MLST) system, a novel strain initially reported. Based on the results of pathogenic identification by mNGS, the four patients were individually, treated with different antibiotics, and discharged with favorable outcomes. Conclusion: In diagnosing psittacosis caused by a rare C. psittaci agent, mNGS provides rapid etiological identification, contributing to targeted antibiotic therapy and favorable outcomes. This study also reminds clinicians to raise awareness of psittacosis when encountering family members with a fever of unknown origin.

Successful treatment of near-fatal pulmonary embolism and cardiac arrest in an adult patient with fulminant psittacosis-induced severe acute respiratory distress syndrome after veno-venous extracorporeal membrane oxygenation rescue: A case report and follow-up.

Background: Veno-venous extracorporeal membrane oxygenation (ECMO) was successfully performed for the rescue of an adult patient with severe acute respiratory distress syndrome (ARDS) induced by fulminant psittacosis, and then a near-fatal pulmonary embolism (PE) and cardiac arrest (CA) of the same patient was cured through catheter-directed thrombolysis. Case presentation: A 51-year-old female patient was admitted to the hospital on September 10, 2021 due to slurred speech, weakness in lower limbs, dizziness, and nausea. Subsequently, she developed confusion and was transferred to the intensive care unit (ICU), where she received anti-shock, antibiotics, invasive mechanical ventilation (IMV), and veno-venous ECMO due to the diagnosis of severe pneumonia, severe ARDS, and septic shock based on comprehensive physical examination, laboratory tests, and imaging findings. The metagenomic next-gengeration sequencing (m-NGS) in the bronchoalveolar lavage fluid (BALF) suggested that the pathogen was chlamydia psittaci, so the antibiotics were adjusted to doxycycline combined with azithromycin. After withdrawal from ECMO, ultrasound (US) re-examination of the left lower limb revealed inter-muscular vein thrombosis, following which heparin was replaced by subcutaneous injection of 0.4ml enoxaparin sodium twice daily for anti-coagulation therapy. After withdrawal from IMV, the patient suffered sudden CA and successful cardiopulmonary resuscitation (CPR), and emergency pulmonary angiography (PA) was performed to show bilateral main pulmonary artery embolism. After immediate catheter-directed thrombolysis and placement of an inferior vena cava filter, the patient's condition gradually stabilized. Conclusions: Veno-venous ECMO can be successfully performed as an emergency life-saving treatment for patients with severe ARDS induced by fulminant psittacosis, and during ECMO regular examinations should be conducted to detect and manage thrombosis in time, thereby avoiding the occurrence of near-fatal PE and CA.

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.

Psittacosis: An Underappreciated and Often Undiagnosed Disease.

The bacterial agent Chlamydia psittaci, and the resulting disease of psittacosis, is a little-known and underappreciated infectious disease by healthcare practitioners and in public health in general. C. psittaci infections can cause significant psittacosis outbreaks, with person-to-person transmission documented in the last decade. In this publication, we review the pathogen and its disease, as well as examine the potential for genetic manipulation in this organism to create a more deadly pathogen. Recent disease surveys indicate that currently, the highest incidences of human disease exist in Australia, Germany and the UK. We recommend the universal public health reporting of C. psittaci and psittacosis disease and increasing the promotion of public health awareness.

Seropositividad de Chlamydia psittaci en trabajadores expuestos a aves y revisión de la literatura: evidencia de circulación en Antioquia / Chlamydia psittaci seropositivity in workers exposed to birds and review of the literature: Evidence of circulation in Antioquia

Introducción. La psitacosis es una enfermedad zoonótica causada por Chlamydia psittaci. Esta bacteria es catalogada como un agente con potencial bioterrorista y ha causado múltiples brotes en trabajadores con exposición laboral a aves en diferentes lugares del mundo. En Colombia, no se hace seguimiento epidemiológico de la infección y existe una gran brecha en el conocimiento. Objetivos. Determinar la frecuencia de anticuerpos contra C. psittaci en trabajadores con exposición laboral a aves y sus factores asociados. Además, revisar la literatura en relación con los estudios sobre el tema realizados en Colombia. Materiales y métodos. Se llevó a cabo un estudio descriptivo, transversal, con intención analítica, en trabajadores en contacto con aves y se revisó la literatura científica relacionada en Colombia. Se detectaron anticuerpos IgM e IgG contra C. psittaci en suero por microinmunofluorescencia. La descripción de las características sociodemográficas y de exposición se hizo con frecuencias y medidas de resumen. Se exploraron factores asociados por análisis bivariados y multivariados. La revisión de la literatura científica y gris se hizo con búsqueda estructurada. Resultados. Se analizaron 54 trabajadores en contacto con aves y se encontró una prevalencia de anticuerpos del 31,5 %. El ejercer funciones de sacrificio y faenado de las aves sin ser médico veterinario fue un factor de riesgo para la presencia de anticuerpos. Solo se encontraron cuatro estudios previos sobre C. psittaci hechos en Colombia. Conclusiones. Este estudio constituye la primera evidencia de la circulación de C. psittaci en trabajadores en contacto con aves en Antioquia y el segundo reporte en el país. Estos hallazgos aportan desde la salud pública a la estrategia One Health.

Introduction. Psittacosis is a zoonotic disease caused by Chlamydia psittaci, a bacterium classified as an agent with bioterrorist potential. It has caused multiple outbreaks in exposed poultry workers around the world. Colombia has no epidemiological follow-up of the infection and a big knowledge gap. Objectives. To determine the antibodies' frequency against C. psittaci in workers with occupational exposure to birds and to review the literature on studies conducted in Colombia. Materials and methods. We conducted a cross-sectional descriptive study with analytical intent on workers in contact with birds and reviewed the related literature in Colombia. IgM and IgG serum antibodies against C. psittaci were detected by microimmunofluorescence. The sociodemographic and exposure characteristics were expressed as frequencies and summary measures. Associated factors were explored by bivariate and multivariate analysis. The scientific and gray literature review was done with a structured search. Results. We analyzed 54 workers in contact with birds. Antibody prevalence was 31.5%. Slaughtering and evisceration by non-veterinarians was a risk factor for antibody presence. There are only four previous studies on C. psittaci in Colombia. Conclusions. Here, we present the first evidence of C. psittaci circulation among workers exposed to birds in Antioquia and the second report in the country. These findings contribute to the "One Health" public health strategy.

Equine Psittacosis and the Emergence of Chlamydia psittaci as an Equine Abortigenic Pathogen in Southeastern Australia: A Retrospective Data Analysis.

Chlamydia psittaci is an important zoonotic pathogen. Although primarily a pathogen of birds, from which infection can spillover into humans and other mammalian hosts, the importance of C. psittaci as a cause of equine reproductive loss and the risk of infection to humans in contact with infected horses are increasingly being recognised in Australia and elsewhere. Despite the risks to both human and equine health, C. psittaci infection in horses is incompletely understood. This study aimed to update and summarise cases of equine psittacosis in Australia in the period 2018-2022, thus addressing a knowledge gap relating to recent cases in this country. These cases were identified from the examination of records held by state and federal veterinary authorities and from a review of published cases. A total of 31 cases were identified. Spatial and temporal trends were identified, with cases being more prevalent in winter and spring and geographically restricted to Victoria and New South Wales. The results show that cases of equine reproductive loss due to C. psittaci are consistent and ongoing and demonstrate the importance of routinely considering C. psittaci in diagnostic investigations. The need for ongoing study to better understand this important zoonotic pathogen is evident.

Case Report: Clinical analysis of a cluster outbreak of chlamydia psittaci pneumonia.

Objective: To explore the clinical characteristics and prognosis of clustered cases of psittacosis pneumonia. Method: We retrospectively analyzed the clinical data of a cluster outbreak of psittacosis pneumonia. The analysis included epidemiological data, clinical symptoms, laboratory results, and prognosis. The diagnosis was made using mNGS and nested PCR technology. Result: Of the four cases, two had direct contact with diseased poultry while the other two did not. All cases presented with more than 39.5 °C fever and chills. Additionally, significant increases in C-reactive protein, ferritin, creatine kinase, and lactate dehydrogenase were observed in all cases, while absolute lymphocyte count decreased. Case 2 also had increased calcitonin levels. Acute respiratory failure occurred during the treatment of case 1 and case 2, leading to tracheal intubation and ventilator-assisted ventilation. Unfortunately, case 2 passed away due to sepsis and multiple organ dysfunction, while the other cases had a positive prognosis. Conclusion: mNGS facilitated the early diagnosis of psittacosis pneumonia. It is important to note that there is still a substantial risk of human-to-human transmission in psittacosis pneumonia. Absolute lymphocyte count and calcitonin levels can predict the severity and prognosis of the disease.

A pediatric case of Chlamydia psittaci caused severe Acute Respiratory Distress Syndrome (ARDS) in Italy.

BACKGROUND: This case of psittacosis in children, is the first described in literature, in Italy. This respiratory infection can be transmitted to humans from the inhalation of respiratory secretions, feces and plumage aerosol of infected birds (and other animals). Usually it can have an asymptomatic or paucisymptomatic course, and the onset is often flu-like, but in this case the child risked his life for a severe respiratory failure. This report is unique because in children psittacosis is rare, and always misdiagnosed, or could cause a delayed diagnosis because of lack of awareness among the paediatricians and physicians. Furthermore, psittacosis enters a differential diagnosis with SARS-COV2 infection because both diseases may determine dyspnea and atypical pneumonia, up to acute respiratory failure. CASE PRESENTATION: This clinical case talks about a three-and-a-half-year-old male child affected by psittacosis (or ornithosis), with severe dyspnea and systemic symptoms who required oro-tracheal intubation for acute respiratory failure. The child had slept in a room at home, with some recently bought parrots affected by psittacosis. Initially the child was treated with empiric antibiotic therapy (i.v.ceftriaxone and teicoplanin), but after having isolated the DNA of the germ "Chlamydia psittaci" in both serological and through bronchoalveolar lavage (BAL), he was treated with targeted antibiotic therapy: tetracyclines (doxicillin). CONCLUSIONS: Psittacosis is an extremely contagious disease, caused by an intracellular germ, called "Chlamydia psittaci", a Gram-negative bacterium, transmitted to humans in particular by infected birds, responsible for atypical pneumonia, with acute and chronic respiratory symptoms, sometimes with multi-organ failure and disseminated intravascular coagulation. Even if it is a rare respiratory disease among children, a good doctor must think about psittacosis as cause of respiratory symptoms (and not only flu or SARS-COV2), above all through a correct medical history, in order to provide a targeted antibiotic therapy. An interesting case of psittacosis in a child is being reported here, which has been treated successfully with doxycillin.

Psittacosis caused severe community-acquired pneumonia accompanied by acute hypoxic respiratory failure: a multicenter retrospective cohort study from China.

INTRODUCTION: Psittacosis can cause severe community-acquired pneumonia (CAP). The clinical manifestations of psittacosis range from subclinical to fulminant psittacosis with multi-organ failure. It is essential to summarize the clinical characteristic of patients with severe psittacosis accompanied by acute hypoxic respiratory failure (AHRF). METHODS: This retrospective study included patients with severe psittacosis caused CAP accompanied by AHRF from 19 tertiary hospitals of China. We recorded the clinical data, antimicrobial therapy, respiratory support, complications, and outcomes. Chlamydia psittaci was detected on the basis of metagenomic next-generation sequencing performed on bronchoalveolar lavage fluid samples. Patient outcomes were compared between the treatment methods. RESULTS: This study included 45 patients with severe CAP and AHRF caused by psittacosis from April 2018 to May 2021. The highest incidence of these infections was between September and April. There was a history of poultry contact in 64.4% of the patients. The median PaO2/FiO2 of the patients was 119.8 (interquartile range, 73.2 to 183.6) mmHg. Four of 45 patients (8.9%) died in the ICU, and the median ICU duration was 12 days (interquartile range, 8 to 21) days. There were no significant differences between patients treated with fluoroquinolone initially and continued after the diagnosis, fluoroquinolone initially followed by tetracycline, and fluoroquinolone combined with tetracycline. CONCLUSION: Psittacosis caused severe CAP seems not rare, especially in the patients with the history of exposure to poultry or birds. Empirical treatment that covers atypical pathogens may benefit such patients, which fluoroquinolones might be considered as an alternative.