Pneumocystis pneumonia in the COVID-19 pandemic era: similarities and challenges

Comparative Dosing of Adjunctive Corticosteroids Therapy for Pneumocystis Pneumonia with ARDS in Non-HIV Immunocompromised Patients

Background

Adjuvant corticosteroids are effective in patients with human immunodeficiency virus (HIV)-associated Pneumocystis jirovecii pneumonia (PCP) patients, but the effectiveness of adjuvant corticosteroids in non-HIV PCP remained controversial. This study aimed to evaluate the effectiveness of standard-dose compared with low-dose steroids in non-HIV PCP patients with acute respiratory distress syndrome (ARDS).

Methods

This retrospective observational study included non-HIV PCP patients with ARDS admitted to the respiratory intensive care unit (RICU) of Beijing Chao-Yang Hospital from 2015 to 2022. Demographics, clinical characteristics, and outcomes were compared between patients receiving standard-dose and those receiving low-dose steroids. Survival times were assessed using Kaplan-Meier curves and compared with the Log rank test. Cox proportional hazards regression analysis was conducted to identify independent risk factors for 28-day and 60-day mortality.

Results

A total of 105 non-HIV PCP with ARDS were included, with 48 patients in the standard-dose steroid group (66.7% male, 50.5±12.6 years) and 57 in the low-dose steroid group (61.4% male, 55.5±14.2 years). The 60-day mortality was lower in the standard-dose group than in the low-dose group (63.2% vs 48.3%, p=0.04), while 28-day mortality showed no significant difference (50.8% vs 35.4%, p=0.11). After adjusting for confounders, standard-dose steroids reduced 28-day mortality (aHR: 0.339, 95% CI: 0.147-0.780) and 60-day mortality (aHR: 0.328, 95% CI: 0.152-0.709), particularly in patients aged <65 years, non-smokers, those requiring mechanical ventilation, with albumin<30 g/L, or a PaO2/FiO2 ratio <150 mmHg. No differences in co-infections or gastrointestinal bleeding were observed.

Conclusion

The standard-dose steroid therapy significantly reduced 28-day and 60-day mortality without major complications in the non-HIV immunocompromised population with severe PCP with ARDS. These findings highlight the potential survival benefit of standard-dose corticosteroid regimen in this population.

Strengths and limitations of molecular diagnostics for Pneumocystis jirovecii pneumonia

INTRODUCTION

While Pneumocystis pneumonia (PcP) remains a major AIDS-defining disease, the majority of cases of PcP now present in the HIV-negative cohort, causing significant mortality. PcP PCR diagnosis is not novel, and the optimal route of diagnosis remains unclear, with an imperfect reference method and complexity in result interpretation for alternative tests.

AREAS COVERED

This extensive review utilizing a literature search underpinning a recent systematic review/meta-analysis discusses the technical and clinical performance of PcP PCR, the added benefits of PCR testing, future aspects/considerations, and how PCR may be best used in clinical algorithms to provide a probability of PcP.

EXPERT OPINION

Given the current imperfect reference test for PcP, an alternative would be beneficial. Concerns over PcP PCR generating false positive results are valid but can be resolved by using positivity thresholds that drive specificity. Unfortunately, the extensive range of PCR assays complicates the provision of a PCR reference method. Combination testing incorporating PCR and B-D-Glucan, along with clinical and host risk factors, is key to understanding the individual probability of PcP. It is critical that access to PcP PCR testing is improved through technical and logistical development. Conversely, syndromic approaches including PcP need to be fully evaluated.

Fungal pathogens and COVID-19

COVID-19 pandemic highlighted the complications of secondary fungal infections that occurred globally in severe cases of coronavirus disease managed in the intensive care units. Furthermore, varied underlying host factors, such as preexisting immunosuppression, the use of immunomodulatory agents, and invasive procedures predisposing lung tissues to fungal colonization and proliferation, caused increased susceptibility to fungal infections in COVID-19 patient populations. These invasive fungal infections directly impact the overall length of hospitalization and mortality. The most commonly reported fungal infections in patients with COVID-19 include aspergillosis, invasive candidiasis, and mucormycosis. An overall worldwide increase in the prevalence of candidiasis and aspergillosis was observed in COVID-19 patients , whereas outbreaks of mucormycosis were mainly recorded from India. Diagnostic challenges and limited antifungal treatment options make secondary fungal infections among COVID-19 patients more burdensome, which results in improper management and increased mortality.

The conventional diagnosis challenge: Real-time PCR and nested PCR correlation with the scoring system for individuals at high-risk of Pneumocystis jirovecii pneumonia

INTRODUCTION

Pneumocystis jirovecii is an opportunistic fungus that affects mainly people living with HIV (CD4 cell count lower than 200 cells/ml) and other immunosuppressed patients. Since P. jirovecii does not grow on routine mycological media, diagnosis of P. jirovecii pneumonia relies on indirect evidence of its presence in respiratory samples.

OBJECTIVES

To associate the results of direct immunofluorescence and two molecular methods with a score to predict P. jirovecii pneumonia in patients with AIDS.

MATERIALS AND METHODS

A prospective study was conducted with 40 patients. A respiratory sample collected before treatment was subjected to direct immunofluorescence using the Merifluor kit, to nested PCR targeting the mitochondrial large subunit ribosomal RNA, and to the VIASURE real-time PCR kit.

RESULTS

These three techniques revealed P. jirovecii in 6, 12, and 15 samples, respectively. All positive samples by direct immunofluorescence were positive by nested PCR, and all positive samples by nested PCR amplified by real-time PCR. There was a statistically significant association between the P. jirovecii pneumonia score and the molecular methods. Two patients were early diagnosed and responded well to treatment.

CONCLUSION

Molecular methods, especially real-time PCR, are recommended for early diagnosis of P. jirovecii pneumonia in AIDS patients.

Trends in the Epidemiology of Pneumocystis Pneumonia in Immunocompromised Patients without HIV Infection

The increasing morbidity and mortality of life-threatening Pneumocystis pneumonia (PCP) in immunocompromised people poses a global concern, prompting the World Health Organization to list it as one of the 19 priority invasive fungal diseases, calling for increased research and public health action. In response to this initiative, we provide this review on the epidemiology of PCP in non-HIV patients with various immunodeficient conditions, including the use of immunosuppressive agents, cancer therapies, solid organ and stem cell transplantation, autoimmune and inflammatory diseases, inherited or primary immunodeficiencies, and COVID-19. Special attention is given to the molecular epidemiology of PCP outbreaks in solid organ transplant recipients; the risk of PCP associated with the increasing use of immunodepleting monoclonal antibodies and a wide range of genetic defects causing primary immunodeficiency; the trend of concurrent infection of PCP in COVID-19; the prevalence of colonization; and the rising evidence supporting de novo infection rather than reactivation of latent infection in the pathogenesis of PCP. Additionally, we provide a concise discussion of the varying effects of different immunodeficient conditions on distinct components of the immune system. The objective of this review is to increase awareness and knowledge of PCP in non-HIV patients, thereby improving the early identification and treatment of patients susceptible to PCP.

COVID-19-Associated Pulmonary Aspergillosis in Intensive Care Unit Patients from Poland

Coronavirus disease 2019 (COVID-19) has been shown to be a favoring factor for aspergillosis, especially in a severe course requiring admission to the intensive care unit (ICU). The aim of the study was to assess the morbidity of CAPA among ICU patients in Poland and to analyze applied diagnostic and therapeutic procedures. Medical documentation of patients hospitalized at the temporary COVID-19 dedicated ICU of the University Hospital in Krakow, Poland, from May 2021 to January 2022 was analyzed. In the analyzed period, 17 cases of CAPA were reported with an incidence density rate of 9 per 10 000 patient days and an incidence rate of 1%. Aspergillus fumigatus and Aspergillus niger were isolated from lower respiratory samples. Antifungal therapy was administered to 9 patients (52.9%). Seven patients (77.8%) received voriconazole. The CAPA fatality case rate was 76.5%. The results of the study indicate the need to increase the awareness of medical staff about the possibility of fungal co-infections in ICU patients with COVID-19 and to use the available diagnostic and therapeutic tools more effectively.

Pneumocystis jirovecii pneumonia complicated a case of SARS-CoV-2 infection and multiple sclerosis after treatment with rituximab

Although immunodeficient patients are less prone to develop Coronavirus disease 2019 (COVID-19)-mediated cytokine storm, secondary infections can cause serious complications in this vulnerable population. They are more likely to develop opportunistic infections that can mimic the symptoms of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Herein, we presented a 27-year-old male patient of SARS-CoV-2 infection, who was complicated with Pneumocystis jirovecii pneumonia (PJP), following treatment with rituximab. First, he was hospitalized for 5 days with fever, cough, and dyspnea due to COVID-19 infection, and treated with remdesivir and glucocorticoid. Then, he has been referred to our center with cough, dyspnea, body pain, and fever. Due to persistent fever, the progression of pulmonary lesions, and reduced oxygen saturation, we began treatment with piperacillin + tazobactam, vancomycin, and levofloxacin. Nevertheless, the patient's fever did not stop after the aforementioned empiric treatment and his condition got worse and he was admitted to the intensive care unit. The result of BAL fluid, tested for P. jirovecii by RT-PCR, turned out to be positive. Therefore, we started trimethoprim-sulfamethoxazole and dexamethasone, which improved his condition. We hope this article helps clinicians consider causes other than COVID-19, especially opportunistic infections such as PJP, in patients with respiratory symptoms and fever.

How to diagnose and treat a non-HIV patient with Pneumocystis jirovecii pneumonia (PCP)?

BACKGROUND

Pneumocystis jirovecii Pneumonia (PCP) incidence is increasing in non-HIV infected patients. In contrast to PCP in patients infected with HIV, diagnosis is often delayed, and illness is associated with an increased mortality.

OBJECTIVE

To provide a comprehensive review of clinical presentation, risk factors, diagnostic strategies, and treatment options of PCP in non-HIV-infected patients.

SOURCES

Web-based literature review on PCP for trials, meta-analyses and systematic reviews using PubMed. Restriction to English language was applied.

CONTENT

Common underlying conditions in non-HIV-infected patients with PCP are haematological malignancies, autoimmune and inflammatory diseases, solid organ or haematopoietic stem cell transplant and prior exposure to corticosteroids. New risk groups include patients receiving monoclonal antibodies and immunomodulating therapies. Non-HIV-infected patients with PCP present with rapid onset and progression of pneumonia, increased duration of hospitalization and a significantly higher mortality rate than patients infected with HIV. PCP is diagnosed by a combination of clinical symptoms, radiological and mycological features. Immunofluorescence microscopy from bronchoalveolar lavage (BAL) or PCR testing CT imaging and evaluation of the clinical presentation are required. The established treatment regime consists of trimethoprim and sulfamethoxazole.

IMPLICATIONS

While the number of patients immunosuppressed for other causes than HIV is increasing, a simultaneous rise in PCP incidence is observed. In the group of non-HIV-infected patients, a rapid onset of symptoms, a more complex course, and a higher mortality rate are recorded. Therefore, time to diagnosis must be as short as possible to initiate effective therapy promptly. This review aims to raise awareness of PCP in an increasingly affected at-risk group and provide clinicians with a practical guide for efficient diagnosis and targeted therapy. Furthermore, it intends to display current inadequacies in research on the topic of PCP.

Coincidence of Candida Endophthalmitis, and Aspergillus and Pneumocystis jirovecii Pneumonia in a COVID-19 Patient: Case Report

INTRODUCTION

Coronavirus disease 2019 (COVID-19) is associated with immune system dysfunction and makes patients vulnerable to opportunistic infections. This report presents a patient with a history of COVID-19, suffering from opportunistic infections.

CASE DESCRIPTION

We reported a 64-year-old man complaining of progressive visual loss in his left eye, who had previously been hospitalized for three weeks due to COVID-19. In the ophthalmologic assessment, large foci of dense subretinal and intraretinal infiltrations involving the macula were observed (compatible with endogenous fungal endophthalmitis). Real-time PCR result of intraocular fluid was positive for Candida spp. During subsequent hospitalization, the patient also suffered from fever and productive coughs (manifestations of pneumonia caused by Aspergillus fumigatus and Pneumocystis jirovecii). In response to antibiotic therapy, the fever and coughs subsided, and the ocular examination revealed a dramatic decrease in the size of retinal infiltrations.

CONCLUSIONS

In patients with severe COVID-19, long-term ICU admission and immunosuppressive drugs lead to immune system dysfunction and make the patient more susceptible to opportunistic infections. Consequently, fungal pathogens such as Aspergillus, Pneumocystis jirovecii, and Candida spp. may cause infection in different body organs. Thus, clinicians should be alert and have clinical suspicion to diagnose accurately and manage patients accordingly.

Risk Factors of Severe COVID-19: A Review of Host, Viral and Environmental Factors

The clinical course and outcome of COVID-19 are highly variable, ranging from asymptomatic infections to severe disease and death. Understanding the risk factors of severe COVID-19 is relevant both in the clinical setting and at the epidemiological level. Here, we provide an overview of host, viral and environmental factors that have been shown or (in some cases) hypothesized to be associated with severe clinical outcomes. The factors considered in detail include the age and frailty, genetic polymorphisms, biological sex (and pregnancy), co- and superinfections, non-communicable comorbidities, immunological history, microbiota, and lifestyle of the patient; viral genetic variation and infecting dose; socioeconomic factors; and air pollution. For each category, we compile (sometimes conflicting) evidence for the association of the factor with COVID-19 outcomes (including the strength of the effect) and outline possible action mechanisms. We also discuss the complex interactions between the various risk factors.

Post-COVID-19 Pneumocystis pneumonia cases from Pakistan: an observational study

Background. Concurrent coronavirus disease 2019 (COVID-19) and Pneumocystis jirovecii pneumonia (PJP) has been described in various reports, with a recent study describing a 9.3 % P. jirovecii detection rate in critically ill COVID-19 patients. Methods. Patients with PCR-confirmed PJP following COVID-19 infection who were admitted to Aga Khan University Hospital, Karachi, Pakistan from March 2020-June 2021 were identified through a laboratory database. Detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus was performed by RT-PCR Cobas SARS-CoV-2 qualitative assay. P. jirovecii PCR was performed using the RealStar Pneumocystis jirovecii PCR kit. Clinical, radiological and laboratory data for PJP patients were recorded. Results. During the study period, 3707 patients were admitted with COVID-19 at our hospital. P. jirovecii PCR was requested for 90 patients and was positive in 10 (11 %). Five out of 10 patients were discharged from the hospital and later developed cough and dyspnoea. Five patients remained hospitalized with severe COVID-19 and developed PJP. Eight patients in our study received systemic steroids. The trends of lymphocyte counts of all patients showed a lymphocyte count of <1000 mm^-3 (<1.0×10⁶ cells µl^-1) in the week of PJP diagnosis. Four patients did not survive; one of these patients did not receive co-trimoxazole due to late diagnosis, one patient had concomitant nosocomial pneumonia and bacteraemia with multidrug-resistant Acinetobacter species, and two patients had concomitant aspergillosis. Conclusion. In summary, invasive fungal infections such as PJP should be considered as a complication in COVID-19 patients, with prompt evaluation and management.

Molecular and microscopy detection of Pneumocystis jirovecii in hospitalized patients during the COVID-19 pandemic

Introduction

Early detection of Pneumocystis jirovecii as an opportunistic pathogen that may endanger predisposed persons, including COVID-19 patients, may help to choose the optimal management.

Methods

In this study, 585, including 530 COVID-19 patients, with clinical and radiological evidence of respiratory diseases, were investigated for P. jirovecii screening. Clinical specimens were examined by direct microscopy and PCR, and randomly selected positive PCR products were confirmed through DNA sequence analysis.

Results

Thirty-one (5.3%) samples were positive in P. jirovecii-specific nested-PCR, while by direct microscopic tests, Pneumocystis was observed in 22 (3.76%) samples. Males (61.7%) and patients over 50 years old (75.6%) were more commonly affected than others, and malaise and fatigue (84%), and wheezing (75%) were the most common symptoms, followed by fever (40.48%) and dyspnea (39.51%). Among the Pneumocystis-positive patients, three cases had coinfection with Aspergillus fumigatus, A. flavus, and A. niger (each n = 1), as documented by direct microscopy, culture, and species identification by PCR-sequencing.

Conclusion

Pneumocystis pneumonia is still a diagnostic challenge; therefore, additional large-scale studies are needed to clarify the epidemiology of the disease in immunocompromised or COVID-19 patients.

Clinical cases of pneumocystis pneumonia in patients with HIV infection and underlying COVID-19

During the COVID-19 pandemic, additional difficulties have emerged in the differential diagnosis of interstitial pulmonary abnormalities, especially in patients with HIV infection, in whom this kind of injury can be caused by a wide range of pathogens, including opportunistic diseases. The high probability of an adverse outcome of pulmonary disease in patients with severe immunodeficiency requires an urgent choice of effective therapy.

The article describes clinical cases of pneumocystis pneumonia in two COVID-19 patients with newly diagnosed HIV infection, illustrating the difficulties of differential diagnosis in these conditions.

Case Report: Pneumonia in a Patient With Combined Variable Immunodeficiency: COVID-19 or Pneumocystis Pneumonia?

Combined variable immunodeficiency (CVID) is a primary immunodeficiency, characterized by impairment in immune system function. These patients are susceptible to opportunistic infections, which may mimic COVID-19 manifestations. Also, misdiagnosis or delayed diagnosis of opportunistic infections can lead to perilous consequences. We report a 28-year-old woman with a history of combined variable immunodeficiency disorder (CVID) and ulcerative colitis (UC) complained of fever, cough, and dyspnea. According to the clinical and radiological manifestations and the COVID-19 epidemic, she was admitted with a primary diagnosis of COVID-19 pneumonia. After a week, the patient did not respond to treatment, so she underwent bronchoscopy. Using polymerase chain reaction (PCR) methodology, we detected DNA of Pneumocystis jirovecii, the causative agent of a life-threatening pneumonia (PCP), in respiratory specimens. The patient was hypersensitive to common PCP treatments, so she was treated with high-dose clindamycin. However, the patient's clinical condition aggravated. Besides, we found evidence of pneumothorax, pneumomediastinum, and pneumopericardium in chest CT scan. We inserted a catheter for the patient to evacuate the air inside the mediastinum. Also, we added caspofungin to the treatment. The patient eventually recovered and was discharged from the hospital about a week later. Thus, during the COVID-19 epidemic, in febrile patients with respiratory symptoms, physicians should not think only of COVID-19. They must consider opportunistic infections such as PCP, especially in immunocompromised patients.

Fungal Infections Other Than Invasive Aspergillosis in COVID-19 Patients

Invasive fungal disease (IFD) associated with Coronavirus Disease 2019 (COVID-19) has focussed predominantly on invasive pulmonary aspergillosis. However, increasingly emergent are non-Aspergillus fungal infections including candidiasis, mucormycosis, pneumocystosis, cryptococcosis, and endemic mycoses. These infections are associated with poor outcomes, and their management is challenged by delayed diagnosis due to similarities of presentation to aspergillosis or to non-specific features in already critically ill patients. There has been a variability in the incidence of different IFDs often related to heterogeneity in patient populations, diagnostic protocols, and definitions used to classify IFD. Here, we summarise and address knowledge gaps related to the epidemiology, risks, diagnosis, and management of COVID-19-associated fungal infections other than aspergillosis.

COVID-19 in Immunocompromised Patients: A Systematic Review

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) was first identified as a novel coronavirus in Wuhan, Hubei province, central China, in December 2019, and is responsible for the 2019-to-present pandemic. According to the most recent data released by the World Health Organization, more than 200 million people have been infected by SARS-CoV-2 so far, and more than 4 million people died worldwide. Although our knowledge on SARS-CoV-2 and COVID-19 is constantly growing, data on COVID-19 in immunocompromised patients are still limited. The aim of the present systematic review is to describe clinical picture, disease severity, proposed treatment regimen, and response to vaccination in patients with different types and severity of immunosuppression.