Detection of Chlamydia psittaci in both blood and bronchoalveolar lavage fluid using metagenomic next-generation sequencing

Abstract

Rationale: Chlamydia psittaci ( C psittaci ) is a gram-negative obligate intracellular parasite, with birds as main hosts. The main route of infection in humans is inhalation of aerosols from contaminated animal excreta through the respiratory tract. The main manifestation of C psittaci infection is pneumonia. Patients suffering from severe infection are prone to sepsis and multiple organ failure. We report a case of simultaneous detection of C psittaci in blood and bronchoalveolar lavage fluid using metagenomic next-generation sequencing (mNGS) technology. Patient concerns: The 71-year-old male patient was a farmer with a long history of raising poultry and initial symptoms of fever and muscle pain accompanied by limb weakness and paroxysmal cough. Diagnoses: The patient was diagnosed with sepsis, severe pneumonia, and multiple organ failure. Interventions: Anti-infective therapy with doxycycline and meropenem was applied. Outcomes: The patient's body temperature and infection indicators improved and the chest X-ray findings showed the amelioration of lesions after 18 days of treatment. The patient was discharged without treatment on hospital day 19 due to financial constraints and subsequently died after 7 days. Lessons: mNGS is an excellent diagnostic tool when specific pathogens are undetected by traditional assays.

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

“…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.…”

A cluster of Psittacosis cases in Lishui, Zhejiang Province, China, in 2021

“…Psittacosis is a zoonotic disease caused by Chlamydia psittaci infection. C. psittaci is a Gram-negative pathogen that infects humans throughout the world ( Yuan et al., 2021 ). Its infection most commonly occurs in persons with a history of contact with birds or poultry in either occupational settings or companion bird exposure.…”

High-Dose Tigecycline for the Treatment of Progressive Pneumonia Caused by Chlamydia psittaci: Case Series and Literature Review

“… 10 , 11 The detectable rate of mNGS for pathogens is nearly 89%, which is higher than that of traditional pathogens (25.73%). 12 In our case series, mNGS test of BALF accurately found the pathogen in only three days. Compared to traditional detection methods, mNGS has the advantages of shorter detection time, higher detection sensitivity, and broader pathogen coverage.…”