COVID-19 and Pneumocystis jirovecii pneumonia: Back to the basics

Pneumocystis jirovecii Infections Among COVID-19 Patients: A Case Series and Literature Review

Background

Pneumocystis jirovecii pneumonia (PCP) is a serious, emerging complication of coronavirus disease 2019 (COVID-19).

Methods

We performed a systematic review of published cases. We describe 6 new cases of PCP/COVID-19 coinfection. Among our cases (n = 6) and those in the literature (n = 69) with available data, the median age (interquartile range [IQR]) was 59 (44-77) years (n = 38), 72% (47/65) were male, and the mortality rate was 30.9% (21/68).

Results

Long-term corticosteroid use was noted in 45.1% (23/51), advanced HIV infection (defined as a CD4 count <200 cells/μL) in 17.6% (9/51), and antineoplastic chemotherapy in 13.7% (7/51), consistent with known PCP risk factors. Notably, 56.7% (38/47) had verifiable risk factors for PCP (high-dose corticosteroids, immunosuppressive therapy, and HIV infection) before COVID-19 infection. A median absolute lymphocyte count (IQR) of 0.61 (0.28-0.92) ×103 cells/mm3 (n = 23) and CD4 count (IQR) of 66 (33-291.5) cells/mm3 (n = 20) were also discovered among the study population.

Conclusions

These findings suggest a need for greater attention to PCP risk factors among COVID-19 patients and consideration of PCP prophylaxis in these high-risk populations.

Pneumocystis pneumonia in COVID-19 patients: A comprehensive review

The admitted patients of intensive care units with coronavirus disease 2019 (COVID-19) meet the challenges of subsequent infections. Opportunistic fungal infections such as Pneumocystis pneumonia (PCP) are among the important factors in the context of COVID-19 patients affecting illness severity and mortality. We reviewed the literature on COVID-19 patients with PCP to identify features of this infection. Although studies confirmed at least the presence of one immunosuppressive condition in half of PCP patients, this disease can also occur in immunocompetent patients who developed the immunosuppressive condition during Covid-19 treatment. The major risk factors associated with COVID-19 patients with PCP can be considered low lymphocyte counts and corticosteroid therapy. Diagnostic and treatment options are complicated by the overlapping clinical and radiologic characteristics of PCP and COVID-19 pneumonia. Therefore, physicians should comprehensively evaluate high-risk patients for PCP prophylaxis.

Revised Guidelines for Coronavirus Disease 19 Management in Hematopoietic Cell Transplantation and Cellular Therapy Recipients (August 2022)

This document is intended as a guide for diagnosis and management of Coronavirus Disease 2019 (COVID-19), caused by the virus SARS-CoV-2, in adult and pediatric HCT and cellular therapy patients. This document was prepared using available data and with expert opinion provided by members of the (ASTCT) Infectious Diseases Special Interest Group (ID-SIG) and is an update of pervious publication. Since our original publication in 2020, the NIH and IDSA have published extensive guidelines for management of COVID-19 which are readily accessible ( NIH Guidelines , IDSA Guidelines ). This update focuses primarily on issues pertaining specifically to HCT/cellular therapy recipients. Information provided in this manuscript may change as new information becomes available.

Concurrent Infection with SARS-CoV-2 and Pneumocystis jirovecii in Immunocompromised and Immunocompetent Individuals

Coronavirus disease 2019 (COVID-19) may occur with concurrent infections caused by bacterial and fungal microorganisms. This systematic review evaluated studies reporting concomitant COVID-19 and Pneumocystis jirovecii pneumonia (PJP). We found 39 patients (74% male, median age: 56.8 (range: 11-83) years), including 66% immunosuppressed individuals (23% HIV-infected and 41% on long-term corticosteroid therapy). Patients were characteristically severely ill (mechanical ventilation: 70%), associated with 41% mortality. The median lymphocyte count was 527 cells/mm3 (range: 110-2200), and the median CD4+ T cell count was 206 cells/mm3 (range: 8-1021). We identified three patterns of concurrent COVID-19 and P. jirovecii infection. The first pattern (airway colonization with a low burden of P. jirovecii) does not seem to modify the COVID-19 course of illness. However, P. jirovecii superinfection, typically occurring weeks after COVID-19 diagnosis as a biphasic illness, and P. jirovecii coinfection characteristically results in progressive multilobar pneumonia, which is associated with poor outcomes. To support this categorization, we reported three patients with concurrent PJP and COVID-19 identified in our institution, presenting these clinical scenarios. The diagnosis of PJP requires a high index of suspicion, since clinical and radiological characteristics overlap with COVID-19. Observational studies are necessary to determine the PJP burden in patients with COVID-19 requiring hospitalization.

Co-Infection of COVID-19 and Pneumocystosis Following Rituximab Infusion—A Case Report

Immunocompromised patients with respiratory viral infections are at increased risk of fungal superinfections, including Pneumocystosis. Within the scope of the COVID-19 pandemic, Pneumocystis jirovecii co-infections are being increasingly reported. Differential diagnosis often creates a dilemma, due to multiple overlapping clinical and radiographic features. Awareness of fungal co-infections in the context of the COVID-19 pandemic is crucial to initiate prophylactic measures, especially in high-risk individuals. We report the second case of Pneumocystis jirovecii pneumonia and COVID-19 co-infection in a renal transplant recipient in Poland.

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-associated opportunistic infections: a snapshot on the current reports

Treatment of the novel Coronavirus Disease 2019 (COVID-19) remains a complicated challenge, especially among patients with severe disease. In recent studies, immunosuppressive therapy has shown promising results for control of the cytokine storm syndrome (CSS) in severe cases of COVID-19. However, it is well documented that immunosuppressive agents (e.g., corticosteroids and cytokine blockers) increase the risk of opportunistic infections. On the other hand, several opportunistic infections were reported in COVID-19 patients, including Aspergillus spp., Candida spp., Cryptococcus neoformans, Pneumocystis jiroveci (carinii), mucormycosis, Cytomegalovirus (CMV), Herpes simplex virus (HSV), Strongyloides stercoralis, Mycobacterium tuberculosis, and Toxoplasma gondii. This review is a snapshot about the main opportunistic infections that reported among COVID-19 patients. As such, we summarized information about the main immunosuppressive agents that were used in recent clinical trials for COVID-19 patients and the risk of opportunistic infections following these treatments. We also discussed about the main challenges regarding diagnosis and treatment of COVID-19-associated opportunistic infections (CAOIs).

Coronavirus Disease 2019-Associated Invasive Fungal Infection

Coronavirus disease 2019 (COVID-19) can become complicated by secondary invasive fungal infections (IFIs), stemming primarily from severe lung damage and immunologic deficits associated with the virus or immunomodulatory therapy. Other risk factors include poorly controlled diabetes, structural lung disease and/or other comorbidities, and fungal colonization. Opportunistic IFI following severe respiratory viral illness has been increasingly recognized, most notably with severe influenza. There have been many reports of fungal infections associated with COVID-19, initially predominated by pulmonary aspergillosis, but with recent emergence of mucormycosis, candidiasis, and endemic mycoses. These infections can be challenging to diagnose and are associated with poor outcomes. The reported incidence of IFI has varied, often related to heterogeneity in patient populations, surveillance protocols, and definitions used for classification of fungal infections. Herein, we review IFI complicating COVID-19 and address knowledge gaps related to epidemiology, diagnosis, and management of COVID-19-associated fungal infections.

Imaging of Pulmonary Superinfections and Co-Infections in COVID-19

New challenges in imaging and management of COVID-19 pneumonia emerge as the pandemic continues across the globe. These arise not only due to the COVID-19 pneumonia but also related to various superinfections and co-infections. Limited use of bronchoscopic and other aerosol generating procedures to obtain representative lower respiratory samples from these patient groups for accurate identification of organism, increases the responsibility of radiologists in suggesting the most likely cause of secondary infection. Imaging features of many of these infections overlap with features of COVID-19 pneumonia. In this review, we highlight imaging findings that can aid in the diagnosis of superinfections and co-infections in patients with COVID-19 pneumonia, and also help in predicting the likely causative organism.

Epidemiology of Systemic Mycoses in the COVID-19 Pandemic

The physiopathologic characteristics of COVID-19 (high levels of inflammatory cytokines and T-cell reduction) promote fungal colonization and infection, which can go unnoticed because the symptoms in both diseases are very similar. The objective of this work was to study the current epidemiology of systemic mycosis in COVID-19 times. A literature search on the subject (January 2020–February 2021) was performed in PubMed, Embase, Cochrane Library, and LILACS without language restrictions. Demographic data, etiological agent, risk factors, diagnostic methods, antifungal treatment, and fatality rate were considered. Eighty nine publications were found on co-infection by COVID-19 and pneumocystosis, candidiasis, aspergillosis, mucormycosis, coccidioidomycosis, or histoplasmosis. In general, the co-infections occurred in males over the age of 40 with immunosuppression caused by various conditions. Several species were identified in candidiasis and aspergillosis co-infections. For diagnosis, diverse methods were used, from microbiological to molecular. Most patients received antifungals; however, the fatality rates were 11–100%. The latter may result because the clinical picture is usually attributed exclusively to SARS-CoV-2, preventing a clinical suspicion for mycosis. Diagnostic tests also have limitations beginning with sampling. Therefore, in the remainder of the pandemic, these diagnostic limitations must be overcome to achieve a better patient prognosis.

Narrative review of the relationship between COVID-19 and PJP: does it represent coinfection or colonization?

Background

Pneumocystis jirovecii (P. jirovecii) is increasingly identified on lower respiratory tract specimens of COVID-19 patients. Our narrative review aims to determine whether the diagnosis of pneumocystis jirovecii pneumonia (PJP) in COVID-19 patients represents coinfection or colonization based on the evidence available in the literature. We also discuss the decision to treat COVID-19 patients with coinfection by PJP.

Methods

A literature search was performed through the Pubmed and Web of Science databases from inception to March 10, 2021.

Results

We identified 12 COVID-19 patients suspected to have PJP coinfection. All patients were critically ill and required mechanical ventilation. Many were immunosuppressed from HIV or long-term corticosteroids and other immunosuppressive agents. In both the HIV and non-HIV groups, severe lymphocytopenia was encountered with absolute lymphocyte and CD4+T cell count less than 900 and 200 cells/mm, respectively. The time to PJP diagnosis from the initial presentation was 7.8 (range 2–21) days. Serum lactate dehydrogenase and beta-D-glucan were elevated in those coinfected with PJP. All patients were treated with anti-PJP therapy, predominantly sulfamethoxazole-trimethoprim with corticosteroids. The overall mortality rate was 41.6%, and comparable for both HIV and non-HIV groups.

Conclusion

As the current evidence is restricted to case reports, the true incidence, risk factors, and prognosis of COVID-19 patients with PJP coinfections cannot be accurately determined. Comorbidities of poorly controlled HIV with lymphocytopenia and multiple immunosuppressive therapies are likely predisposing factors for PJP coinfection.

High mortality co-infections of COVID-19 patients: mucormycosis and other fungal infections

Severe COVID-19 disease is associated with an increase in pro-inflammatory markers, such as IL-1, IL-6, and tumor necrosis alpha, less CD4 interferon-gamma expression, and fewer CD4 and CD8 cells, which increase the susceptibility to bacterial and fungal infections. One such opportunistic fungal infection is mucormycosis. Initially, it was debated whether a person taking immunosuppressants, such as corticosteroids, and monoclonal antibodies will be at higher risk for COVID-19 or whether the immunosuppresive state would cause a more severe COVID-19 disease. However, immunosuppressants are currently continued unless the patients are at greater risk of severe COVID-19 infection or are on high-dose corticosteroids therapy. As understood so far, COVID-19 infection may induce significant and persistent lymphopenia, which in turn increases the risk of opportunistic infections. It is also noted that 85% of the COVID-19 patients' laboratory findings showed lymphopenia. This means that patients with severe COVID-19 have markedly lower absolute number of T lymphocytes, CD4+T and CD8+ T cells and, since the lymphocytes play a major role in maintaining the immune homeostasis, the patients with COVID-19 are highly susceptible to fungal co-infections. This report is intended to raise awareness of the importance of early detection and treatment of mucormycosis and other fungal diseases, such as candidiasis, SARS-CoV-2-associated pulmonary aspergillosis, pneumocystis pneumonia and cryptococcal disease, in COVID-19 patients, to reduce the risk of mortality.