CNS Infections Caused by Viruses of the Herpesviridae Family: Case Analysis in a Tertiary Infectious Diseases Center

The Herpesviridae family includes viruses with latency capacity, such as HSV-1, HSV-2, VZV, CMV, and Human herpesvirus 6, which can cause neurological manifestations such as meningitis, encephalitis, and encephalomyelitis. HSV-1 infection is the prototype of encephalitis, while HSV-2 and VZV are frequent causes of meningitis and meningoencephalitis. CMV mainly affects immunosuppressed patients, such as transplant recipients and people living with HIV/AIDS (PLWHA). This study describes clinical and laboratory aspects of central nervous system (CNS) infections by Herpesviridae between 2017 and 2022 in a tertiary infectious diseases hospital. Descriptive retrospective cohort study based on medical record review. Patients with CNS infection confirmed by multiplex PCR (BioFire FilmArray® Panel) in cerebrospinal fluid, from 2017 to 2022, were included. Of 1,562 patients evaluated, 64 (4%) had confirmed infection by viruses of the Herpesviridae family: HSV-1 (n=4; 6.25%), HSV-2 (n=14; 21.9%), Herpesvirus 6 (n=13; 20.3%), CMV (n=18; 28%), and VZV (n=15; 23.4%). Clinical syndromes were meningitis (n=42; 65.62%), encephalitis (n=17; 26.56%), and meningoencephalitis (n=5; 7.81%). The most frequent encephalitis agent was VZV (n=7; 41.17%), followed by CMV (n=6; 35.29%). In HSV-1 and HSV-2 infections, there was male predominance (ratio 14:5), with a mean age of 39 years. CMV infections showed male predominance, mean age 39 years, and association with HIV/AIDS in 94.4%. CSF showed a mean cell count of 315 cells/mm³ (lymphocytic predominance), mean protein level of 234 mg/dL, and mean glucose level of 55 mg/dL. ADA was assessed in 30 patients (mean 7.3 U/L) and lactate in 2 (mean 10.6 mg/dL). Treatment used was acyclovir (48.4%) for HSV-1, HSV-2, and VZV, and ganciclovir (77.7%) for CMV. Eleven patients had coinfections with other agents: CMV/Human herpesvirus 6/Cryptococcus neoformans/gattii (n=1), CMV/VZV (n=2), VZV/Human herpesvirus 6 (n=2), S. pneumoniae/HSV-2 (n=2), Enterovirus/Human herpesvirus 6 (n=2), HSV-2/Human herpesvirus 6 (n=2). A relevant number of CNS infections caused by Herpesviridae were identified. CMV was more prevalent in PLWHA. CSF in these infections generally shows a lymphomononuclear pattern, without hypoglycorrhachia and with elevated protein, and diagnosis depends on clinical–laboratory correlation. Molecular methods assist in identifying the etiologic agent.