Viral reactivations and co-infections in COVID-19 patients: a systematic review

Reactivation of Latent Tuberculosis Following COVID-19 and Epstein-Barr Virus Coinfection: A Case Report

Background: This case is unique in demonstrating the reactivation of latent tuberculosis (TB) following co-infection with SARS-CoV-2 and Epstein-Barr virus (EBV) in an otherwise healthy young adult. It highlights a rare clinical scenario in which viral immune dysregulation likely facilitated TB progression. To date, few reports have explored the complex interplay between COVID-19, EBV reactivation, and TB in a single patient, particularly with isolated extrapulmonary involvement. Case Presentation: A 24-year-old woman presented with persistent low-grade fever, fatigue, night sweats, unintentional weight loss, and progressive cervical and supraclavicular lymphadenopathy. These symptoms emerged shortly after a moderate COVID-19 infection. Laboratory studies revealed elevated inflammatory markers and pronounced lymphopenia. EBV reactivation was confirmed via serology and PCR. Despite antiviral therapy, symptoms persisted, and imaging revealed necrotic lymphadenopathy. Tuberculous lymphadenitis was diagnosed through fine-needle aspiration cytology and PCR detection of Mycobacterium tuberculosis. The patient was treated with a standard anti-tuberculosis regimen, resulting in clinical, radiological, and immunological improvement. Conclusions: This case underscores the importance of considering latent TB reactivation in patients with persistent lymphadenopathy and recent viral infections, particularly in regions with high TB prevalence. It also emphasizes the need for thorough immunological and microbiological assessment in complex post-viral syndromes. The main clinical takeaway is that COVID-19 and EBV co-infection may create a permissive environment for TB reactivation through immune system compromise.

Viral Infections in Elderly Individuals: A Comprehensive Overview of SARS-CoV-2 and Influenza Susceptibility, Pathogenesis, and Clinical Treatment Strategies

As age increases, the immune function of elderly individuals gradually decreases, increasing their susceptibility to infectious diseases. Therefore, further research on common viral infections in the elderly population, especially severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza viruses, is crucial for scientific progress. This review delves into the genetic structure, infection mechanisms, and impact of coinfections with these two viruses and provides a detailed analysis of the reasons for the increased susceptibility of elderly individuals to dual viral infections. We evaluated the clinical manifestations in elderly individuals following coinfections, including complications in the respiratory, gastrointestinal, nervous, and cardiovascular systems. Ultimately, we have summarized the current strategies for the prevention, diagnosis, and treatment of SARS-CoV-2 and influenza coinfections in older adults. Through these studies, we aim to reduce the risk of dual infections in elderly individuals and provide a scientific basis for the prevention, diagnosis, and treatment of age-related viral diseases, thereby improving their health status.

Co-infections and Reactivation of some Herpesviruses (HHV) and Measles Virus (MeV) in Egyptian Cancer Patients infected with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2)

BACKGROUND

Coinfections and reactivation of persistent or latent viral infections such as herpesviruses (HHV) and/or measles virus (MeV) have been reported among COVID-19 patients. However, there is limited information regarding cancer patients who experienced severe acute respiratory syndrome corona virus-2 (SARS-CoV-2). The primary purpose of this study was to investigate the interplay between SARS-CoV-2, HHV and MeV in cancer patients, aiming to provide insights into the pathophysiology of these infections and to enhance the patients' health outcomes.

METHODS

A prospective observational study was conducted on 4 groups (n = 147): newly diagnosed cancer patients infected with SARS-CoV-2 (n = 37), newly diagnosed cancer patients non-infected with SARS-CoV-2 (n = 13), apparently normal individuals infected with SARS-CoV-2 (n = 82) and finally a normal control group (n = 15). All samples were tested for SARS-CoV-2 infection using the real-rime quantitative reverse transcription polymerase chain reaction (qRT-PCR). Antibody responses were analyzed using indirect enzyme-linked immunosorbent assay (ELISA), and antibody levels were compared between patients and controls. Potential re-activation was investigated using fourfold (i.e. 400%) rise model criterion.

RESULTS

In all positive cases of SARS-CoV-2, recent infections or re-infection of herpes simplex viruses 1 and 2 (HSV1/2 or HHV1-2) were found to be significantly increased approximately three-fold higher in COVID-19 patients (p = 0.007) identified via pooled HSV1/2 IgM levels in plasma. Furthermore, reactivation of HSV1/2 was 29.7% in cancer/COVID-19 patients (n = 37) versus 0.0% of normal/COVID-19 group (n = 22) (p = 0.008). Likewise, Epstein-Barr Nuclear Antigen-1 (EBNA-1) IgG levels showed a ≥ fourfold increase in 20% (p = 0.034) of cancer patients (n = 50) versus 4.9% of controls (n = 41) for reactivation of Epstein-Barr virus (EBV or HHV-4). Obviously, MeV IgG levels increased up to 78.0% in cancer patients (n = 50) versus 17.5% in non-cancerous group (n = 40, p < 0.001). Reactivation of MeV in cancer and COVID-19 patients was 43.2% versus 30.8% cancer non-COVID-19 group, 3.3% normal COVID-19, and 0.0% in healthy volunteers (p < 0.001).

CONCLUSION

Cancer patients infected with SARS-CoV-2 were at increased risk of HHV and MeV co-infection and reactivation.

COVID-19, Epstein-Barr virus reactivation and autoimmunity: Casual or causal liaisons?

The coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2 virus infection, has been associated with a substantial risk of autoimmune disease development or exacerbation. The postulated pathophysiological mechanisms linking COVID-19 with autoimmunity include reactivation of latent Epstein-Barr virus (EBV), whose dysregulated infection in the host can trigger or promote an autoimmune response. This review summarizes recent studies highlighting a potential immunopathogenetic link between SARS-CoV-2 infection and EBV reactivation, which could underlie autoimmunity onset or worsening, as well as immune-related long COVID manifestations in COVID-19 patients. We offer our perspective on the direction that research should take to disentangle the nature (whether causal or casual) of the "COVID-19-EBV-autoimmunity" liaisons. Further advances in this research area may be crucial for designing strategies to prevent or treat EBV reactivation-related autoimmune conditions in COVID-19 patients, or patients with inflammatory co-infectious diseases, at the same time promising to improve our knowledge on the viral contribution to autoimmune phenomena.

Incidence and Temporal Dynamics of Combined Infections in SARS-CoV-2-Infected Patients With Risk Factors for Severe Complications

BACKGROUND

Coronavirus disease 2019 (COVID-19) is a newly emerged infectious disease that needs further clinical investigation. Characterizing the temporal pattern of combined infections in patients with COVID-19 may help clinicians understand the clinical nature of this disease and provide valuable diagnostic and therapeutic guidelines.

METHODS

We retrospectively analyzed COVID-19 patients isolated in four study hospitals in Korea for one year period from May 2021 to April 2022 when the delta and omicron variants were dominant. The temporal characteristics of combined infections based on specific diagnostic tests were analyzed.

RESULTS

A total of 16,967 COVID-19 patients were screened, 2,432 (14.3%) of whom underwent diagnostic microbiologic tests according to the clinical decision-making, 195 of whom had positive test results, and 0.55% (94/16,967) of whom were ultimately considered to have clinically meaningful combined infections. The median duration for the diagnosis of combined infections was 15 (interquartile range [IQR], 5-25) days after admission. The proportion of community-acquired coinfections (≤ 2 days after admission) was 11.7% (11/94), which included bacteremia (10/94, 10.63%) and tuberculosis (1/94, 1.06%). Combined infections after 2 days of admission were diagnosed at median 16 (IQR, 9-26) days, and included bacteremia (72.3%), fungemia (19.3%), cytomegalovirus (CMV) diseases (8.4%), Pneumocystis jerovecii pneumonia (PJP, 8.4%) and invasive pulmonary aspergillosis (IPA, 4.8%).

CONCLUSION

Among COVID-19 patients with risk factors for severe complications, 0.55% had laboratory-confirmed combined infections, which included community and nosocomial pathogens in addition to unusual pathogens such as CMV disease, PJP and IPA.

Age and Latent Cytomegalovirus Infection Do Not Affect the Magnitude of De Novo SARS-CoV-2-Specific CD8+ T Cell Responses

Immunosenescence, age-related immune dysregulation, reduces immunity upon vaccinations and infections. Cytomegalovirus (CMV) infection results in declining naïve (Tnaïve) and increasing terminally differentiated (Temra) T cell populations, further aggravating immune aging. Both immunosenescence and CMV have been speculated to hamper the formation of protective T-cell immunity against novel or emerging pathogens. The SARS-CoV-2 pandemic presented a unique opportunity to examine the impact of age and/or CMV on the generation of de novo SARS-CoV-2-specific CD8+ T cell responses in 40 younger (22-40 years) and 37 older (50-66 years) convalescent individuals. Heterotetramer combinatorial coding combined with phenotypic markers were used to study 35 SARS-CoV-2 epitope-specific CD8+ T cell populations directly ex vivo. Neither age nor CMV affected SARS-CoV-2-specific CD8+ T cell frequencies, despite reduced total CD8+ Tnaïve cells in older CMV- and CMV+ individuals. Robust SARS-CoV-2-specific central memory CD8+ T (Tcm) responses were detected in younger and older adults regardless of CMV status. Our data demonstrate that immune aging and CMV status did not impact the SARS-CoV-2-specific CD8+ T cell response. However, SARS-CoV-2-specific CD8+ T cells of older CMV- individuals displayed the lowest stem cell memory (Tscm), highest Temra and PD1+ populations, suggesting that age, not CMV, may impact long-term SARS-CoV-2 immunity.

Long COVID - a critical disruption of cholinergic neurotransmission?

BACKGROUND

Following the COVID-19 pandemic, there are many chronically ill Long COVID (LC) patients with different symptoms of varying degrees of severity. The pathological pathways of LC remain unclear until recently and make identification of path mechanisms and exploration of therapeutic options an urgent challenge. There is an apparent relationship between LC symptoms and impaired cholinergic neurotransmission.

METHODS

This paper reviews the current literature on the effects of blocked nicotinic acetylcholine receptors (nAChRs) on the main affected organ and cell systems and contrasts this with the unblocking effects of the alkaloid nicotine. In addition, mechanisms are presented that could explain the previously unexplained phenomenon of post-vaccination syndrome (PVS). The fact that not only SARS-CoV-2 but numerous other viruses can bind to nAChRs is discussed under the assumption that numerous other post-viral diseases and autoimmune diseases (ADs) may also be due to impaired cholinergic transmission. We also present a case report that demonstrates changes in cholinergic transmission, specifically, the availability of α4β2 nAChRs by using (-)-[18F]Flubatine whole-body positron emission tomography (PET) imaging of cholinergic dysfunction in a LC patient along with a significant neurological improvement before and after low-dose transcutaneous nicotine (LDTN) administration. Lastly, a descriptive analysis and evaluation were conducted on the results of a survey involving 231 users of LDTN.

RESULTS

A substantial body of research has emerged that offers a compelling explanation for the phenomenon of LC, suggesting that it can be plausibly explained because of impaired nAChR function in the human body. Following a ten-day course of transcutaneous nicotine administration, no enduring neuropathological manifestations were observed in the patient. This observation was accompanied by a significant increase in the number of free ligand binding sites (LBS) of nAChRs, as determined by (-)-[18F]Flubatine PET imaging. The analysis of the survey shows that the majority of patients (73.5%) report a significant improvement in the symptoms of their LC/MEF/CFS disease as a result of LDTN.

CONCLUSIONS

In conclusion, based on current knowledge, LDTN appears to be a promising and safe procedure to relieve LC symptoms with no expected long-term harm.

Clinical Characteristics and Outcomes in Patients with Chronic HBV Infection and Hospitalized for COVID-19 Pneumonia: A Retrospective Cohort Study

The effects of a concomitant infection of hepatitis B virus (HBV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are still debated, with a recognized major risk of HBV reactivation during immune-suppressive treatments. The aim of this study was to determine the prevalence and predictive factors of HBV reactivation in a cohort of hospitalized patients with coronavirus disease 2019 (COVID-19) and a current or past hepatitis B infection. In a monocentric retrospective observational study, we enrolled all consecutive hospital admitted patients with COVID-19 pneumonia and a positive HBV serology (N = 84) in our Infectious Diseases Unit from April 2021 to December 2023. We identified 18 (21%) HBsAg-positive/anti-HBc-positive, 41 (49%) HBsAg-negative/anti-HBc-positive/anti-HBs-positive, and 25 (30%) HBsAg-negative/anti-HBc-positive/anti-HBs-negative subjects. The overall rate of hepatitis flare was 10.7%, without any HBsAg seroreversion, severe HBV reactivation, and/or need for new HBV antiviral therapy introduction. Systemic corticosteroid treatment for COVID-19 and baseline anti-HBsAg status were associated with this risk of HBV reactivation. In conclusion, the overall risk of hepatitis flares in hospitalized COVID-19 was reasonably low, with higher doses of corticosteroids treatment being the major risk factor for HBV reactivation, and anti-HBs-positive serological status as a protective element.

Is Respiratory Viral Infection an Inciting Event in the Development of Melioidosis? A Systematic Evaluation of Co-infection With Burkholderia pseudomallei and SARS-CoV-2 or Influenza

Respiratory viral infection may increase infection with Burkholderia pseudomallei progressing to clinical disease (melioidosis). This data linkage study evaluated associations between melioidosis and SARS-CoV-2 or influenza. Among 160 melioidosis cases, there was no difference in risk factors, vaccine status, or disease severity between 17 with viral co-infection and 143 without.

Beyond acute infection: mechanisms underlying post-acute sequelae of COVID-19 (PASC)

Immune dysregulation is a key aspect of post-acute sequelae of coronavirus disease 2019 (PASC), also known as long COVID, with sustained activation of immune cells, T cell exhaustion, skewed B cell profiles, and disrupted immune communication thereby resulting in autoimmune-related complications. The gut is emerging as a critical link between microbiota, metabolism and overall dysfunction, potentially sharing similarities with other chronic fatigue conditions and PASC. Immunothrombosis and neurological signalling dysfunction emphasise the complex interplay between the immune system, blood clotting, and the central nervous system in the context of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Clear research gaps in the design of PASC studies, especially in the context of longitudinal research, stand out as significant areas of concern.

A Case of Triple Respiratory Coinfection: COVID-19, Enterovirus, and Parainfluenza

We report a case of a 34-year-old female who presented to the emergency department with fever, nausea, vomiting, and diarrhea following a suspected foodborne illness. She tested positive for COVID-19, human parainfluenza virus type 4, and enterovirus/rhinovirus in the hospital. She subsequently developed hypoxia, hypotension, and sepsis. Blood work revealed leukocytosis and elevated inflammatory markers. Imaging of her abdomen showed fluid-filled bowel loops suggesting acute gastroenteritis and colitis of infectious or inflammatory etiology. She was initially treated with antibiotics for a suspected bacterial infection. However, her cultures resulted negative and her symptoms slowly improved with supportive care including probiotics and a low-fat diet. Due to her persistent shortness of breath related to her COVID-19 infection, she was started on a course of oral prednisone due to the anti-inflammatory effects of steroids. She was discharged home in stable condition with close outpatient follow-up. This study highlights the clinical challenges of managing multiple viral infections, particularly with concurrent COVID-19.

Infectious mononucleosis due to Epstein-Barr virus reactivation in an immunocompromised 60-year-old patient with COVID-19

Epstein-Barr virus (EBV) reactivation in COVID-19 patients has been reported, but studies on its clinical significance are lacking. We herein report the occurrence of infectious mononucleosis (IM) due to EBV reactivation in a 60-year-old man with rheumatoid arthritis being treated with methotrexate and tocilizumab. The patient presented with a fever and tested positive for COVID-19. Laboratory findings revealed an increased atypical lymphocyte count, decreased platelet count, and elevated liver enzyme levels. Flow cytometry showed predominant expansion of reactive T cells. EBV reactivation was confirmed using real-time polymerase chain reaction. The patient was treated with remdesivir, and clinical improvement was observed after 10 days of treatment. Follow-up showed a gradual decrease in the EBV-DNA load with no recurrence of atypical lymphocytes. These findings suggest that COVID-19 in immunocompromised patients may lead to unexpected EBV reactivation and IM, even for patients outside the age at which IM is likely to occur.

Highlights from the Respiratory Failure and Mechanical Ventilation Conference 2024

The Respiratory Intensive Care Assembly of the European Respiratory Society gathered in Berlin to organise the third Respiratory Failure and Mechanical Ventilation Conference in February 2024. The conference covered key points of acute and chronic respiratory failure in adults. During the 3-day conference ventilatory strategies, patient selection, diagnostic approaches, treatment and health-related quality of life topics were addressed by a panel of international experts. In this article, lectures delivered during the event have been summarised by early career members of the Assembly and take-home messages highlighted.

Sensory Dysfunction, Microbial Infections, and Host Responses in Alzheimer's Disease

Sensory functions of organs of the head and neck allow humans to interact with the environment and establish social bonds. With aging, smell, taste, vision, and hearing decline. Evidence suggests that accelerated impairment in sensory abilities can reflect a shift from healthy to pathological aging, including the development of Alzheimer's disease (AD) and other neurological disorders. While the drivers of early sensory alteration in AD are not elucidated, insults such as trauma and infections can affect sensory function. Herein, we review the involvement of the major head and neck sensory systems in AD, with emphasis on microbes exploiting sensory pathways to enter the brain (the "gateway" hypothesis) and the potential feedback loop by which sensory function may be impacted by central nervous system infection. We emphasize detection of sensory changes as first-line surveillance in senior adults to identify and remove potential insults, like microbial infections, that could precipitate brain pathology.

Antibody responses to common viruses according to COVID-19 severity and postacute sequelae of COVID-19

Limited research suggests that certain viruses reactivate in severe-acute-respiratory-syndrome-coronavirus 2 infection, contributing to the development of postacute sequelae of COVID-19 (PASC). We examined 1083 infected individuals from a population-based cohort, and assessed differences in plasma immunoglobulin (Ig)G and immunoglobulin A levels against Epstein-Barr virus (EBV), cytomegalovirus, varicella zoster virus (VZV), BK polyomavirus, KI polyomavirus, WU polyomavirus (WUPyV), respiratory syncytial virus, and Adv-36 according to the severity of previous COVID-19 and PASC history. Individuals who had experienced severe COVID-19 had higher antibody responses to latent viruses. Ever PASC, active persistent PASC, and PASC with neuropsychiatric symptoms were associated with higher immnoglobulin G to EBV early antigen-diffuse, VZV, and WUPyV even among individuals without previous severe COVID-19.

Pathophysiological, immunological, and inflammatory features of long COVID

The COVID-19 pandemic continues to cause severe global disruption, resulting in significant excess mortality, overwhelming healthcare systems, and imposing substantial social and economic burdens on nations. While most of the attention and therapeutic efforts have concentrated on the acute phase of the disease, a notable proportion of survivors experience persistent symptoms post-infection clearance. This diverse set of symptoms, loosely categorized as long COVID, presents a potential additional public health crisis. It is estimated that 1 in 5 COVID-19 survivors exhibit clinical manifestations consistent with long COVID. Despite this prevalence, the mechanisms and pathophysiology of long COVID remain poorly understood. Alarmingly, evidence suggests that a significant proportion of cases within this clinical condition develop debilitating or disabling symptoms. Hence, urgent priority should be given to further studies on this condition to equip global public health systems for its management. This review provides an overview of available information on this emerging clinical condition, focusing on the affected individuals' epidemiology, pathophysiological mechanisms, and immunological and inflammatory profiles.

Developing a Tool for Differentiation Between Bacterial and Viral Respiratory Infections Using Myxovirus Resistance Protein A and C-Reactive Protein

INTRODUCTION

The aim was to assess the performance of a blood assay combining measurements of MxA (myxovirus resistance protein A) and CRP (C-reactive protein) to differentiate viral from bacterial respiratory infections.

METHODS

In a prospective study, MxA and CRP were measured in the blood by the AFIAS panel in adults admitted with respiratory infection. Patients were split into discovery and validation cohorts. Final diagnosis was adjudicated by a panel of experts. Microbiology-confirmed cases comprised the discovery cohort, and infections adjudicated as highly probable viral or bacterial comprised the validation cohort.

RESULTS

A total of 537 patients were analyzed: 136 patients were adjudicated with definitive viral infections and 131 patients with definitive bacterial infections. Using logistic regression analysis, an equation was developed to calculate the probability for bacterial infection using the absolute value of MxA and CRP. Calculated probability ≥ 0.5 and/or MxA to CRP ratio less than 2 applied as the diagnostic rule for bacterial infections. This rule provided 91.6% sensitivity and 90.4% negative predictive value for the diagnosis of bacterial infections. This diagnostic sensitivity was confirmed in the validation cohort. A MxA/CRP ratio less than 0.15 was associated with unfavorable outcome.

CONCLUSION

The calculation of the probability for bacterial infection using MxA and CRP may efficiently discriminate between viral and bacterial respiratory infections.

Bilateral interstitial keratitis following COVID-19: a case report

BACKGROUND

Although the primary target of severe acute respiratory syndrome coronavirus 2 is the respiratory tract, the expression of the angiotensin-converting enzyme 2 receptor in other tissues facilitates viral entry in others parts of the body, including ocular structures. Ocular manifestations may occur before, during, or after systemic infection.

CASE PRESENTATION

We report the case of a 60-year-old male who presented with bilateral interstitial keratitis after the onset of COVID-19, with ocular symptoms starting within 7 days after systemic symptoms. Laboratory investigation did not identify any alternative etiology for his disease, although the possibility of Epstein-Barr virus or herpes simpex virus could not be definitively ruled out. The patient had already developed significant corneal scarring and visual debilitation by the time topical steroids were initiated, and his final corrected visual acuity with rigid gas permeable contact lenses was 20/50 and 20/80 in the right and left eye, respectively.

CONCLUSIONS

The involvement of ocular tissue by the virus can lead to permanent sequelae such as severe visual loss, and clinicians should be aware of and recognize ophthalmic manifestations of this disease to prompt early intervention.

Shared Pathogenicity Features and Sequences between EBV, SARS-CoV-2, and HLA Class I Molecule-binding Motifs with a Potential Role in Autoimmunity

Epstein-Barr virus (EBV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are extraordinary in their ability to activate autoimmunity as well as to induce diverse autoimmune diseases. Here we reviewed the current knowledge on their relation. Further, we suggested that molecular mimicry could be a possible common mechanism of autoimmunity induction in the susceptible individuals infected with SARS-CoV-2. Molecular mimicry between SARS-CoV-2 and human proteins, and EBV and human proteins, are present. Besides, relation of the pathogenicity associated with both coronavirus diseases and EBV supports the notion. As a proof-of-the-concept, we investigated 8mer sequences with shared 5mers of SARS-CoV-2, EBV, and human proteins, which were predicted as epitopes binding to the same human leukocyte antigen (HLA) supertype representatives. We identified significant number of human peptide sequences with predicted-affinities to the HLA-A*02:01 allele. Rest of the peptide sequences had predicted-affinities to the HLA-A*02:01, HLA-B*40:01, HLA-B*27:05, HLA-A*01:01, and HLA-B*39:01 alleles. Carriers of these serotypes can be under a higher risk of autoimmune response induction upon getting infected, through molecular mimicry-based mechanisms common to SARS-CoV-2 and EBV infections. We additionally reviewed established associations of the identified proteins with the EBV-related pathogenicity and with the autoimmune diseases.