The Spectrum of Herpesvirus Infections of the Nervous System in Adult Patients in Ukraine: A Prospective Single Center Study

Background: Herpesviruses (HVs) are ubiquitous pathogens that infect humans usually during childhood, followed by a life-long persistence in a latent state in many sites of a body including the nerve cells. After reactivation HVs can affect the Central Nervous System (CNS) becoming a major cause of morbidity and mortality worldwide as well as long-term neurological sequelae. Despite being an important public health problem very few population-based studies were conducted so far in the world and none in Ukraine.

Objectives: To explore the clinical features and etiology of herpesvirus encephalitis (HVE) in a prospective single center study from January 2014 to January 2015.

Methods: 107 adult patients with confirmed herpesvirus infection and symptoms of possible encephalitis (CNS lesion) were analyzed in the study. CSF and blood contents, antibody for HVs M and G9 antibody classes, and MRI scans have been studied, but the crucial diagnostic sign was the presence of specific viral DNA in the CSF or blood.

Results: 74 (69.3%) out of 107 patients were females, the male to female ratio was 1:2.2. The median age of patients was 36.9 years (range 20-65 years). Most common clinical features were fever, (stiff neck), and focal neurological signs. The genome of HVs was detected in CSF samples obtained from all patients as follows: Herpes simplex virus 1 and 2 – 13 (12.1%), Varicella zoster virus – 2 (1.8), Cytomegalovirus – 14 (13%), Epstein Barr virus – 22 (20.5%), Human herpesvirus 6 – 5 (4.7%), Human herpesvirus 7 – 13 (12.1%). Co-infection (≥ 2 HVs) was observed in 38 patients (35.5%). CSF of 27 patients contained two viral DNA, and 11 – three one in various combination. Human herpesvirus 8 was not found.

Conclusion: The most frequently diagnosed infections in hospital based study were Human herpesvirus 5 (EBV), followed by HSV-1/2, CMV, and HHV-7. Significant part of patients (35.5%) was co-infected with two or three HVs. Predisposing factor for Ukrainian population is sex.