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

Human herpesvirus-6 (HHV-6) may cause serious diseases in immunocompromised individuals. SARS-CoV-2/HHV-6 coinfection has been emphasized in previous works, mostly case reports, small series, or epidemiological studies, but few are known about its real clinical outcomes. Here we present a real-world pilot study aiming to understand the frequency and the clinical impact of HHV-6 coinfection in moderate to critically ill patients hospitalized due to COVID-19. SARS-CoV-2 and HHV-6 were evaluated in nasopharyngeal samples at the hospital admission of suspected COVID-19 patients. From 173 consecutive cases, 60 were SARS-CoV-2 positive and 13/60 (21.7%) were HHV-6 positive after identified as the HHV-6B species by a Sanger sequencing. The SARS-CoV-2+/HHV-6+ group was younger but not significant for cardiovascular diseases, diabetes, obesity, and cancer, but significant among therapeutic immunosuppressed patients (as systemic lupus erythematosus and kidney transplant patients). In the medical records, only sparse data on cutaneous or neurological manifestations were found. Biochemical and hematological data showed only a trend towards hyperferritinemic status and lymphopenia. In conclusion, despite the impressive high frequency of HHV-6 coinfection in SARS-CoV-2 positive cases, it did not impact general mortality. We suggest larger future prospective studies to better elucidate the influence of HHV-6 reactivation in cases of COVID-19, designed to specific assessment of clinical outcomes and viral reactivation mechanisms.

Viral and Prion Infections Associated with Central Nervous System Syndromes in Brazil.

Virus-induced infections of the central nervous system (CNS) are among the most serious problems in public health and can be associated with high rates of morbidity and mortality, mainly in low- and middle-income countries, where these manifestations have been neglected. Typically, herpes simplex virus 1 and 2, varicella-zoster, and enterovirus are responsible for a high number of cases in immunocompetent hosts, whereas other herpesviruses (for example, cytomegalovirus) are the most common in immunocompromised individuals. Arboviruses have also been associated with outbreaks with a high burden of neurological disorders, such as the Zika virus epidemic in Brazil. There is a current lack of understanding in Brazil about the most common viruses involved in CNS infections. In this review, we briefly summarize the most recent studies and findings associated with the CNS, in addition to epidemiological data that provide extensive information on the circulation and diversity of the most common neuro-invasive viruses in Brazil. We also highlight important aspects of the prion-associated diseases. This review provides readers with better knowledge of virus-associated CNS infections. A deeper understanding of these infections will support the improvement of the current surveillance strategies to allow the timely monitoring of the emergence/re-emergence of neurotropic viruses.