Presence and clinical impact of human herpesvirus-6 infection in patients with moderate to critical coronavirus disease-19

Human herpesvirus reactivation and its potential role in the pathogenesis of post-acute sequelae of SARS-CoV-2 infection

The emergence of SARS-CoV-2 has precipitated a global pandemic with substantial long-term health implications, including the condition known as post-acute sequelae of SARS-CoV-2 infection (PASC), commonly referred to as Long COVID. PASC is marked by persistent symptoms such as fatigue, neurological issues, and autonomic dysfunction that persist for months beyond the acute phase of COVID-19. This review examines the potential role of herpesvirus reactivation, specifically Epstein-Barr virus (EBV) and cytomegalovirus (CMV), in the pathogenesis of PASC. Elevated antibody titers and specific T cell responses suggest recent herpesvirus reactivation in some PASC patients, although viremia is not consistently detected. SARS-CoV-2 exhibits endothelial trophism, directly affecting the vascular endothelium and contributing to microvascular pathologies. These pathologies are significant in PASC, where microvascular dysfunction may underlie various chronic symptoms. Similarly, herpesviruses like CMV also exhibit endothelial trophism, which may exacerbate endothelial damage when reactivated. Evidence suggests that EBV and CMV reactivation could indirectly contribute to the immune dysregulation, immunosenescence, and autoimmune responses observed in PASC. Additionally, EBV may play a role in the genesis of neurological symptoms through creating mitochondrial dysfunction, though direct confirmation remains elusive. The reviewed evidence suggests that while herpesviruses may not play a direct role in the pathogenesis of PASC, their potential indirect effects, especially in the context of endothelial involvement, warrant further investigation.

Cytomegalovirus in Adenoma and Carcinoma Lesions: Detecting Mono-Infection and Co-Infection in Salivary Glands

Salivary glands' neoplasms are hard to diagnose and present a complex etiology. However, several viruses have been detected in these neoplasms, such as HCMV, which can play a role in certain cancers through oncomodulation. The co-infections between HCMV with betaherpesviruses (HHV-6 and HHV-7) and polyomaviruses (JCV and BKV) has been investigated. The aim of the current study is to describe the frequency of HCMV and co-infections in patients presenting neoplastic and non-neoplastic lesions, including in the salivary gland. Multiplex quantitative polymerase chain reaction was used for betaherpesvirus and polyomavirus quantification purposes after DNA extraction. In total, 50.7% of the 67 analyzed samples were mucocele, 40.3% were adenoma pleomorphic, and 8.9% were mucoepidermoid carcinoma. Overall, 20.9% of samples presented triple-infections with HCMV/HHV-6/HHV-7, whereas 9.0% were co-infections with HCMV/HHV-6 and HCMV/HHV-7. The largest number of co-infections was detected in pleomorphic adenoma cases. All samples tested negative for polyomaviruses, such as BKV and JCV. It was possible to conclude that HCMV can be abundant in salivary gland lesions. A high viral load can be useful to help better understand the etiological role played by viruses in these lesions. A lack of JCV and BKV in the samples analyzed herein does not rule out the involvement of these viruses in one or more salivary gland lesion subtypes.

Specific sequelae symptoms of COVID-19 of Omicron variant in comparison with non-COVID-19 patients: a retrospective cohort study in Japan

Background

The specific long-term sequela of coronavirus disease 2019 (COVID-19), also known as long COVID of the Omicron variant remain unclear, due to a lack of cohort studies that include non-COVID patients with cold-like symptoms. The study was conducted to examine specific sequelae symptoms after severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection, which is considered the Omicron variant, compared with patients who were never-infected.

Methods

In this retrospective cohort study, we sent questionnaires in November 2022, targeting those who visited our fever outpatient unit of a single institution from July to September 2022. SARS-CoV-2 infection status was determined by SARS-CoV-2 polymerase chain reaction (PCR) test results during the study period collected in electronic medical records. Clinical characteristics at 30 days or more since the date of SARS-CoV-2 PCR test were assessed by the questionnaires. Multiple logistic regression was performed to investigate the independent association between SARS-CoV-2 infection and possible sequelae symptoms.

Results

In total, valid responses were received from 4,779 patients (mean age: 41.4 years, standard deviation: 19.8 years old). Among them, 3,326 (69.6%) and 1,453 (30.4%) were SARS-CoV-2 PCR test positive and never-infected, respectively. We found that patients with SARS-CoV-2 infection were more likely to have a loss of taste or smell [odds ratio (OR) 4.55, 95% confidence interval (CI): 1.93, 10.71], hair loss (OR 3.19, 95% CI: 1.67, 6.09), neurocognitive symptoms (OR 1.95, 95% CI: 1.43, 2.65), and respiratory symptoms (OR 1.23, 95% CI: 1.03, 1.47) than never-infected patients. SARS-CoV-2 infection was not associated with common cold symptoms, chronic physical distress, or diarrhea as sequelae symptoms. Further, SARS-CoV-2 vaccination showed protective effects on sequelae of loss of taste or smell and hair loss.

Conclusions

Loss of taste or smell, hair loss, neurocognitive symptoms, and respiratory symptoms were found to be specific sequelae of the SARS-CoV-2 Omicron variant. It is important not to miss these symptoms that follow SARS-CoV-2 infection and to recognize and manage the long COVID.

Clinical features and outcomes of COVID-19 patients with concomitant herpesvirus co-infection or reactivation: A systematic review

Background

Since the first case of COVID-19 was diagnosed in Wuhan, China in late 2019, concomitant infections with Herpesviridae were documented that were presented from simple skin manifestations to severe life-threatening conditions that may lead to mortality. In this systematic review, we have included studies conducted in different parts of the world to find out the association of clinical features and outcomes of COVID-19 infection and concomitant Herpesviridae infection.

Methods

A comprehensive search was conducted in electronic databases including Medline through PubMed, Cochrane database, Scopus and Web of science (core collection). Two review authors independently screened the articles and extracted data. The Risk of bias assessment was done by using RoBANS tool.

Results

A total of 919 studies were retrieved and 19 studies were included having data of 539 patients who were infected with both COVID-19 and Herpesviridae. Herpes Simplex-1, Varicella Zoster, Cytomegalovirus, Epstein-Barr virus and Human Herpes Virus-6 were the detected viruses in the included studies. Cytomegalovirus (CMV) reactivation was the most detected concomitant infection. In case of reactivation with more than one Herpes virus mortality among patients were detected along with single viral infection in some studies. Significant association was noted in dosage and usage of steroid and Herpesviridae reactivation in COVID-19 patients. Blood markers such as D-dimer, CRP along with length of stay in the ICU and usage of invasive mechanical ventilation were found to be the significantly associated markers.

Conclusion

Findings from this study will aid clinicians to assess and treat COVID-19 cases with co-infections.

miRNAs in Neurological Manifestation in Patients Co-Infected with SARS-CoV-2 and Herpesvírus 6 (HHV-6)

Human herpesviruses (HHVs) can establish latency and be reactivated, also are neurotropic viruses that can trigger neurological disorders. HHV-6 is a herpesvirus that is associated with neurological disorders. Studies have reported the detection of HHV-6 in patients with COVID-19 and neurological manifestations. However, specific diagnoses of the neurological disorders caused by these viruses tend to be invasive or difficult to interpret. This study aimed to establish a relationship between miRNA and neurological manifestations in patients co-infected with COVID-19 and HHV-6 and evaluate miRNAs as potential biomarkers. Serum samples from COVID-19 patients in the three cohorts were analyzed. miRNA analysis by real-time polymerase chain reaction (qPCR) revealed miRNAs associated with neuroinflammation were highly expressed in patients with neurological disorders and HHV-6 detection. When compared with the group of patients without detection of HHVs DNA and without neurological alterations, the group with detection of HHV-6 DNA and neurological alteration, displayed significant differences in the expression of mir-21, mir-146a, miR-155 and miR-let-7b (p < 0.01). Our results reinforce the involvement of miRNAs in neurological disorders and provide insights into their use as biomarkers for neurological disorders triggered by HHV-6. Furthermore, understanding the expression of miRNAs may contribute to therapeutic strategies.

Systematic review with meta-analysis of active herpesvirus infections in patients with COVID-19: Old players on the new field

OBJECTIVES

Herpesviruses are ubiquitous and after primary infection they establish lifelong latency. The impairment of maintaining latency with short-term or long-term consequences could be triggered by other infection. Therefore, reactivation of herpesviruses in COVID-19 patients represents an emerging issue.

DESIGN AND METHODS

This study provided the first systematic review with meta-analysis of studies that evaluated active human herpesvirus (HHV) infection (defined as the presence of IgM antibodies or HHV-DNA) in COVID-19 patients and included 36 publications collected by searching through PubMed, SCOPUS, and Web of science until November 2022.

RESULTS

The prevalence of active EBV, HHV6, HSV, CMV, HSV1, and VZV infection in COVID-19 population was 41% (95% CI =27%-57%), 3% (95% CI=17%-54%), 28% (95% CI=1%-85%), 25% (95% CI=1%-63%), 22% (95% CI=10%-35%), and 18% (95% CI=4%-34%), respectively. There was a 6 times higher chance for active EBV infection in patients with severe COVID-19 than in non-COVID-19 controls (OR=6.45, 95% CI=1.09-38.13, p=0.040), although there was no difference in the prevalence of all evaluated active herpesvirus infections between COVID-19 patients and non-COVID-19 controls.

CONCLUSIONS

Future research of herpesvirus and SARS-CoV-2 coinfections must be prioritized to define: who, when and how to be tested, as well as how to effectively treat HHVs reactivations in acute and long COVID-19 patients.

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

BACKGROUND

Viral reactivations and co-infections have been reported among COVID-19 patients. However, studies on the clinical outcomes of different viral reactivations and co-infections are currently in limit. Thus, the primary purpose of this review is to perform an overarching investigation on the cases of latent virus reactivation and co-infection in COVID-19 patients to build collective evidence contributing to improving patient health. The aim of the study was to conduct a literature review to compare the patient characteristics and outcomes of reactivations and co-infections of different viruses.

METHODS

Our population of interest included confirmed COVID-19 patients who were diagnosed with a viral infection either concurrently or following their COVID-19 diagnosis. We extracted the relevant literature through a systematic search using the key terms in the online databases including the EMBASE, MEDLINE, Latin American Caribbean Health Sciences Literature (LILACS), from inception onwards up to June 2022. The authors independently extracted data from eligible studies and assessed the risk of bias using the Consensus-based Clinical Case Reporting (CARE) guidelines and the Newcastle-Ottawa Scale (NOS). Main patient characteristics, frequency of each manifestation, and diagnostic criteria used in studies were summarized in tables.

RESULTS

In total, 53 articles were included in this review. We identified 40 reactivation studies, 8 coinfection studies, and 5 studies where concomitant infection in COVID-19 patients was not distinguished as either reactivation or coinfection. Data were extracted for 12 viruses including IAV, IBV, EBV, CMV, VZV, HHV-1, HHV-2, HHV-6, HHV-7, HHV-8, HBV, and Parvovirus B19. EBV, HHV-1, and CMV were most frequently observed within the reactivation cohort, whereas IAV and EBV within the coinfection cohort. In both reactivation and coinfection groups, patients reported cardiovascular disease, diabetes, and immunosuppression as comorbidities, acute kidney injury as complication, and lymphopenia and elevated D-dimer and CRP levels from blood tests. Common pharmaceutical interventions in two groups included steroids and antivirals.

CONCLUSION

Overall, these findings expand our knowledge on the characteristics of COVID-19 patients with viral reactivations and co-infections. Our experience with current review indicates a need for further investigations on virus reactivation and coinfection among COVID-19 patients.

Reactivation of herpesviruses during COVID-19: A systematic review and meta-analysis

To provide a comprehensive systematic review and meta-analysis regarding the cumulative incidence (incidence proportion) of human herpesvirus (HHV) reactivation among patients with coronavirus disease 2019 (COVID-19), we searched PubMed/MEDLINE, Web of Science, and EMBASE up to 25 September 2022, with no language restrictions. All interventional and observational studies enrolling patients with confirmed COVID-19 and providing data regarding HHV reactivation were included. The random-effects model was used in the meta-analyses. We included information from 32 studies. HHV reactivation was considered a positive polymerase chain reaction result taken at the time of COVID-19 infection. Most of the included patients were severe COVID-19 cases. The pooled cumulative incidence estimate was 38% (95% Confidence Intervals [CI], 28%-50%, I²  = 86%) for herpes simplex virus (HSV), 19% (95% CI, 13%-28%, I²  = 87%) for cytomegalovirus (CMV), 45% (95% CI, 28%-63%, I²  = 96%) for Epstein-Barr virus (EBV), 18% (95% CI, 8%-35%) for human herpesvirus 6 (HHV-6), 44% (95% CI, 32%-56%) for human herpesvirus 7 (HHV-7), and 19% (95% CI, 14%-26%) for human herpesvirus 8 (HHV-8). There was no evidence of funnel plot asymmetry based on visual inspection and Egger's regression test for the results of HSV (p = 0.84), CMV (p = 0.82), and EBV (p = 0.27) reactivation. In conclusion, the identification of HHV reactivation in severe COVID-19 patients is helpful in the management of patients as well as the prevention of complications. Further research is required to elucidate the interaction between HHVs and COVID-19. Systematic review registration: PROSPERO CRD42022321973.

Persistent SARS-CoV-2 Infection, EBV, HHV-6 and Other Factors May Contribute to Inflammation and Autoimmunity in Long COVID

A novel syndrome called long-haul COVID or long COVID is increasingly recognized in a significant percentage of individuals within a few months after infection with SARS-CoV-2. This disorder is characterized by a wide range of persisting, returning or even new but related symptoms that involve different tissues and organs, including respiratory, cardiac, vascular, gastrointestinal, musculo-skeletal, neurological, endocrine and systemic. Some overlapping symptomatologies exist between long COVID and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Very much like with long ME/CFS, infections with herpes family viruses, immune dysregulation, and the persistence of inflammation have been reported as the most common pattern for the development of long COVID. This review describes several factors and determinants of long COVID that have been proposed, elaborating mainly on viral persistence, reactivation of latent viruses such as Epstein-Barr virus and human herpesvirus 6 which are also associated with the pathology of ME/CFS, viral superantigen activation of the immune system, disturbance in the gut microbiome, and multiple tissue damage and autoimmunity. Based on these factors, we propose diagnostic strategies such as the measurement of IgG and IgM antibodies against SARS-CoV-2, EBV, HHV-6, viral superantigens, gut microbiota, and biomarkers of autoimmunity to better understand and manage this multi-factorial disorder that continues to affect millions of people in the world.

COVID-19, SARS-CoV-2 Vaccination, and Human Herpesviruses Infections

There are several human herpesviruses. A common characteristic of infection by these viruses is latency, by which the virus assumes a non-replicative state, subverting the attentions of the host's immune response. In immunocompetent hosts, herpesviruses are immunologically controlled, although periodic virus shedding can occur. In situations where immunological control is lost, herpesviruses can reactivate and produce clinically apparent disease. It is now becoming apparent that COVID-19 or exposure to COVID-19 vaccines can exert several effects on the immune system. The pandemic of COVID-19 shows no sign of abating, with new severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) variants continuing to evolve. Several COVID-19 vaccines have been developed, and much of the world's population has either experienced COVID-19 or been vaccinated against it. There are an increasing number of reports of associations between herpesvirus infections or reactivations and COVID-19 or COVID-19 vaccination. For instance, a positive cytomegalovirus serostatus may indicate a greater likelihood of severe COVID-19, and herpes simplex virus reactivation may be linked to increased mortality. Epstein-Barr virus reactivation appears to be associated with post-acute sequelae of COVID-19. Finally, herpes zoster has been reported to be associated with COVID-19 vaccination. This brief narrative review will provide several insights into associations between herpesvirus infections or reactivations and COVID-19 or SARS-CoV-2 vaccination.

Herpesvirus and neurological manifestations in patients with severe coronavirus disease

Background

Certain clinical manifestations of coronavirus disease (COVID-19) mimic those associated with human herpesvirus (HHV) infection. In this study, we estimated the prevalence of herpesvirus in patients with COVID-19 and determined if coinfection is associated with poorer outcomes and neurological symptoms.

Methods

We analyzed samples of 53 patients diagnosed with COVID-19. The samples were evaluated for the presence of alphaherpesviruses, betaherpesviruses, and gammaherpesviruses, and the viral loads were quantified using quantitative polymerase chain reaction (qPCR) method.

Results

Among the patients, in 79.2% had detection at least one type of herpesvirus. HHV-6 (47.2%), cytomegalovirus (43.3%), and HHV-7 (39.6%) showed the highest detection rates. Patients with a high severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) load were more likely to show herpes simplex virus 1 detection (p = 0.037). Among patients coinfected with SARS-CoV-2 and HHVs, 26.4% showed central nervous system-associated neurological symptoms and herpetic manifestations. A statistically significant association was observed between neurological changes and HHV-6 detection (p = 0.034).

Conclusions

The findings showed a high prevalence of herpesvirus in patients with COVID-19. Furthermore, even though SARS-CoV-2 and HHV coinfection was not associated with poorer outcomes, the findings demonstrated the association between neurological symptoms and HHV-6 detection.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12985-022-01828-9.