Refractory acute respiratory failure due to Pneumocystis jiroveci (PCP) and Cytomegalovirus (CMV) pneumonitis: A case report and review of literature

Pneumocystis jiroveci pneumonia with cytomegalovirus infection diagnosed by metagenomic next-generation sequencing in a patient with nephrotic syndrome: A case report

INTRODUCTION

Opportunistic infection with multiple pathogens currently has become less uncommon since the application of immunosuppressant or corticosteroid in non- Human immunodeficiency virus patients. However, the clinical diagnosis of the co-infection remains difficult since the uncertainty and deficiency of the microbiologic testing methods.

PATIENT CONCERNS

A 66-year-old male patient was admitted to our hospital with chest stuffiness, shortness of breath and elevated body temperature.

DIAGNOSIS

He was diagnosed with the co-infection of Pneumocystis jiroveci and cytomegalovirus by metagenomic next-generation sequencing of bronchoalveolar lavage fluid after bronchoscopy.

INTERVENTIONS

The patient was empirically treated with broad-spectrum antibiotics, trimethoprim/ sulfamethoxazole and ganciclovir in the beginning of the admission.

OUTCOMES

The condition of this patient was not improved even with the intervention at the early stage of the disease. His family requested discharge after 24 inpatient days.

LESSONS

This case highlights the application of metagenomic next-generation sequencing in the clinical diagnosis of pulmonary co-infection. Suitable prophylaxis, necessary clinical awareness and accurate diagnosis are indispensable for immunocompromised patients with pulmonary infection.

Case Report: Next-Generation Sequencing in Diagnosis of Pneumonia Due to Pneumocystis jirovecii and Cytomegalovirus in a Patient With HIV Infection

Background: Pulmonary infections remain a significant cause of morbidity and mortality in immunocompromised patients. The pathogens spectrum of pulmonary infection that can affect patients with human immunodeficiency virus (HIV) is wide such as bacterial, fungal, viral, parasitic organisms, and so on. The risk of multi-pathogenic pneumonia is higher in HIV-infected patients. However, the fast and accurate diagnosis of multi-pathogenic pneumonia is challenging because of the limitations of current conventional tests. Case Presentation: Here, we report a case of pneumonia due to Pneumocystis jirovecii and cytomegalovirus (CMV) in a 22-year-old male with newly diagnosed HIV infection. Blood tests revealed a low CD4 count, a chest computed tomography (CT) scan showed extensive ground-glass opacities in the bilateral lung with multiple cavity lesions in the left upper lung. Microscopic examination of stained sputum and bronchoalveolar lavage fluid (BALF) smear specimens did not find any pathogens. There was also no evidence of pathogens known to cause pneumonia in bacteria and fungi culture tests and virus antibodies such as EBV, CMV, and COVID-19. The nucleic acid of CMV in blood was reported by quantitative PCR. Next-generation sequencing (NGS) analysis of BALF specimens identified a large number of P. jirovecii and CMV reads, and confirmed the diagnosis of pneumonia due to P. jirovecii and CMV. Following the patient's treatment with anti-PCP and anti-CMV, the patient was cured and discharged. Conclusions: This case highlights the combined application of NGS in the clinical diagnosis of multi-pathogenic pneumonia in an HIV-infected patient. NGS is proposed as an important adjunctive diagnostic approach for identifying pathogens of multi-pathogenic pneumonia in HIV-infected patients.

A Molecular Window into the Biology and Epidemiology of Pneumocystis spp

Pneumocystis, a unique atypical fungus with an elusive lifestyle, has had an important medical history. It came to prominence as an opportunistic pathogen that not only can cause life-threatening pneumonia in patients with HIV infection and other immunodeficiencies but also can colonize the lungs of healthy individuals from a very early age. The genus Pneumocystis includes a group of closely related but heterogeneous organisms that have a worldwide distribution, have been detected in multiple mammalian species, are highly host species specific, inhabit the lungs almost exclusively, and have never convincingly been cultured in vitro, making Pneumocystis a fascinating but difficult-to-study organism. Improved molecular biologic methodologies have opened a new window into the biology and epidemiology of Pneumocystis. Advances include an improved taxonomic classification, identification of an extremely reduced genome and concomitant inability to metabolize and grow independent of the host lungs, insights into its transmission mode, recognition of its widespread colonization in both immunocompetent and immunodeficient hosts, and utilization of strain variation to study drug resistance, epidemiology, and outbreaks of infection among transplant patients. This review summarizes these advances and also identifies some major questions and challenges that need to be addressed to better understand Pneumocystis biology and its relevance to clinical care.