A case of chlamydia psittaci caused severe pneumonia and meningitis diagnosed by metagenome next-generation sequencing and clinical analysis: a case report and literature review

Abstract

Background Psittacosis, which is also known as parrot fever, is Chlamydia psittaci (C. psittaci) caused infectious disease. The clinical manifestations vary from asymptomatic infection to severe atypical pneumonia or even fatal meningitis. Early recognition of psittacosis is difficult because of its nonspecific clinical manifestations. Culture and gene probe techniques for C. psittaci are not available for routine clinical use, which makes the diagnosis difficult too. Although psittacosis has increasingly been recognized and reported in recent years, cure of severe pneumonia complicated with meningitis, with etiologic diagnosis aided by the use of metagenomic next-generation sequencing (mNGS), is still uncommon. So, it is necessary to report and review such potentially fatal case. Case presentation This report describes a 54-year-old woman with C. psittaci caused severe atypical pneumonia and meningitis. She presented with symptoms of fever, dry cough and dyspnea, accompanied by prominent headache. Her condition deteriorated rapidly to respiratory failure and lethargy under the treatment of empirical antibacterial agents, and was treated with invasive mechanical ventilation soon. She denied contact with birds, poultry or horses, but unbiased mNGS of both the bronchoalveolar lavage fluid (BALF) and the cerebrospinal fluid (CSF) identified sequence reads corresponding to C. psittaci infection, and there was no sequence read corresponding to other probable pathogens. Combined use of targeted antimicrobial agents of tetracyclines, macrolides and fluoroquinolones was carried out, and the patient’s condition improved and she was discharged home 28 days later. Her status returned close to premorbid condition on day 60 of follow-up. Conclusions When clinicians come across a patient with atypical pneumonia accompanied by symptoms of meningitis, psittacosis should be taken into consideration. mNGS is a promising detection method in such condition and is recommended.

Clinical Symptoms and Outcomes of Severe Pneumonia Caused by Chlamydia psittaci in Southwest China

“…As previously reported, nearly 63.7% of patients with C. psittaci infection are male (Yung and Grayson, 1988), which was in agreement with the rate in our study (69% male).The majority of infections reported in previous studies were in adults between the ages of 30 and 60 years (Shi et al, 2021), as was the case in our cohort. Usually, 90% of the patients have a history of exposure to poultry (Saeki et al, 1996), but in our study, only 31% of the patients reported a contact.…”

“…For critically ill patients, successful treatment depends on accurate diagnosis and appropriate support. With the rapid development of molecular methods, especially metagenomic next generation sequencing (mNGS), the early diagnosis of diseases is possible, and the number of related cases reported has increased ( Shi et al., 2021 ; Teng et al., 2021 ; Yuan et al., 2021 ). In this study, we summarize the epidemiology, clinical characteristics, laboratory data, and clinical outcomes of 27 cases of severe pneumonia caused by C. psittaci diagnosed by mNGS, to provide a basis for effective diagnosis and treatment.…”

Metagenomic next‐generation sequencing for the diagnosis of Chlamydia psittaci pneumonia

“…Serious conditions can occur if appropriate medical treatments are delayed 4 . Microbiologic diagnosis of psittacosis is the ‘rate‐limiting’ step for timely treatment.…”

“…In regions with frequent bird exposures, the prevalence could periodically rise up to 10–15% 3 . Patients who do not undergo timely diagnosis and treatment can develop severe pneumonia and multiple organ failure, which may sometimes lead to death 4 . Metagenomic next‐generation sequencing (mNGS), which can rapidly and precisely identify potential pathogens, has become the most promising approach for infectious disease diagnosis 5 .…”

“…Metagenomic next‐generation sequencing (mNGS), which can rapidly and precisely identify potential pathogens, has become the most promising approach for infectious disease diagnosis 5 . With increasing applications of mNGS in diagnosis, the number of reported cases of Chlamydia psittaci pneumonia has gradually increased 4 . Herein, we report 44 cases of Chlamydia psittaci pneumonia diagnosed by mNGS, describe their demographic and clinical features, laboratory data and imaging findings, clinical outcomes and the diagnostic performance of mNGS.…”