1000/1000
Hot
Most Recent
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. In situations where immunological control is lost, herpesviruses can reactivate and produce clinically apparent disease. It is 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.
Human Herpesvirus | Clinical Presentation | Predisposing/Risk Factors |
---|---|---|
Herpes simplex viruses [13] | Herpes simplex virus encephalitis (type not differentiated) | HIV infection, malignancies, transplantation, immunosuppressive agents for connective tissue disorders |
Herpes simplex virus 1 [14] | Stomatitis | Haematopoietic stem cell transplant for acute myeloid leukaemia |
Varicella-zoster virus [15] | Herpes zoster/shingles | Autoimmune diseases, inflammatory bowel disease, chronic obstructive pulmonary disease, asthma, chronic kidney disease, depression, malignancies |
Varicella-zoster Virus [16] | Meningitis/pneumonitis | Transplantation |
Cytomegalovirus [17] | Retinitis | HIV infection |
Cytomeglovirus [18] | Pneumonitis | Lung transplant |
Epstein–Barr Virus [19] | Post-transplant lymphoproliferative disorder | Heart transplant |
Epstein–Barr virus [20] | Haemophagocytic lymphohistiocytosis | Chronic active EBV infection |
Human herpesvirus 6 (type not differentiated, but most likely 6B) [21] | Encephalitis | Leukaemia requiring haematopoietic stem cell transplant |
Herpesvirus Reactivation and Study Reference | Total Patients and Clinical Characteristics of Study Group | Results | Conclusions/Comments |
---|---|---|---|
HSV-1 Luyt et al. [27] |
Retrospective monocentric cohort study of 145 patients with severe COVID-19 pneumonia requiring invasive mechanical ventilation. | Among 145 COVID-19 patients, a total of 50% and 42% had HSV and CMV lung reactivations, respectively, compared to 63% and 28% HSV and CMV lung reactivations in a control group of 89 influenza patients. | HSV and CMV lung reactivations are frequent in COVID-19 patients subject to invasive mechanical ventilation; however, they are no more frequent than in controls with influenza. HSV and CMV reactivations were defined by a positive PCR test result in bronchoalveolar lavage fluid samples or whole blood samples. |
HSV Meyer et al. [28] |
Observational study using prospectively collected data, as well as HSV-1 blood and respiratory samples from 153 critically ill COVID-19 patients admitted to a regional intensive care unit (ICU) for at least 48 h, from February 2020 to February 2021. | Respiratory and blood samples were tested from 61/153 (39.9%) and 146/153 (95.4%) patients, respectively. On the basis of respiratory sample testing, HSV PCR was positive in 19/61 (31.1%) of patients, and on the basis of blood sample testing, HSV PCR was positive in 36/146 (24.7%) of patients. | Overall, 40/153 (26.1%) patients had an HSV PCR positive sample. HSV reactivation was defined as testing positive by HSV PCR. Day-60 mortality in the whole cohort was 39.9% higher in patients with HSV-1 reactivation (57.5% versus 33.6% in patients without HSV-1 reactivation, p = 0.001). |
CMV Gatto et al. [32] |
Observational study using prospectively collected data of all the patients with moderate to severe acute respiratory distress syndrome admitted to three COVID-19 ICUs at the University Hospital of Modena over the period from 22 February 2020 to 21 July 2021. | A total of 431 patients met the study’s inclusion criteria. COVID-19 was confirmed by laboratory detection of SARS-CoV-2. CMV reactivation was evidenced in whole blood samples by CMV PCR with a cut-off of >62 IU/mL. | Blood CMV reactivation was detected in 88/431 (20.4%) patients, with a median onset of 17 days following ICU admission. Patients with CMV reactivation had prolonged hospital stays and a higher mortality rate than patients without reactivation. CMV reactivation was not independently associated with higher mortality. |
CMV and HSV Weber et al. [35] |
National German COVID-19 bio-sample and data banks were used to retrospectively analyse the CMV and HSV status of patients. Serum samples were collected from patients who experienced mild (n = 101), moderate (n = 130), or severe to critical (n = 80) COVID-19. | CMV seropositivity was 43.6% in cases of mild COVID-19, 72.3% in cases of moderate COVID-19, and 77.5% in cases of severe to critical COVID-19. HSV seropositivity was 71.3%, 93.8%, and 96.2%, respectively, in the same groups. | Patients aged <60 years with severe COVID-19 had a very high prevalence of CMV seropositivity. CMV seropositivity, unlike HSV, might be a strong biomarker for identifying patients <60 years with a higher risk of developing severe COVID-19, particularly in the absence of other co-morbidities. |
EBV Chen et al. [39] |
A retrospective, single-centre study from 9 January 2020 to 29 February 2020: a total of 188 hospitalised patients were recruited with PCR-confirmed SARS-CoV-2 infection. | EBV serology was available for 78 patients, and 11 failed to meet the study inclusion criteria. Of the remaining 67 patients, 37 (55.2%) had laboratory evidence of EBV reactivation. EBV viral load testing was not undertaken. | Patients with laboratory evidence of EBV reactivation had a 3.09-fold risk of having a fever symptom. C-reactive protein levels were significantly elevated in patients with EBV reactivation. |
EBV Xie et al. [40] |
Retrospective, single-centre, observational study of ICU admissions over the period from 31 January 2020 to 27 March 2020. | 145 critically ill patients with SARS-CoV-2/PCR-confirmed COVID-19 were recruited into the study, and 128 met the study’s inclusion criteria. EBV viral load testing (≥500 copies/mL) and serology were used as evidence of EBV reactivation. | Patients with EBV reactivation had higher (29.4%) day-14 and day-28 mortality rates compared to 7.8% and 10.9%, respectively, for patients without EBV reactivation. Patients with evidence of EBV reactivation showed more severe symptoms and received more immunosupportive treatment. |
HHV-6 Lino et al. [42] |
Retrospective, single-centre study of hospitalised patients with moderate to severe COVID-19 | 173 patients with suspected COVID-19 were recruited, of which 60 had a positive PCR test for SARS-CoV-2. Of these 60 confirmed cases, 13/60 (21.7%) were also had positive PCR tests for HHV-6. | HHV-6 reactivation did not impact general mortality. |