Prevalence of Herpes Simplex Virus Infections in the Central Nervous System

Central nervous system (CNS) infections may cause life-threatening meningitis, encephalitis, or brain abscesses. CNS infections are progressive and can cause permanent neurological damage. As such, prompt diagnosis and management are required. CNS infections are caused by bacterial, viral, and fungal pathogens. Herpes simplex viruses (HSV-1 and -2) are critical causative agents of CNS infections. The gold standard method to detect HSV-DNA in cerebrospinal fluid (CSF) and diagnose a CNS infection is the polymerase chain reaction (PCR). This study retrospectively investigated the prevalence of HSV-1 and -2 in patients hospitalized with suspected meningitis/encephalitis in Konya province using the multiplex real-time PCR method.

A total of 525 CSF samples from patients hospitalized with suspected encephalitis/meningitis were tested between January 2015 and December 2017 using multiplex real-time PCR. Of the 525 CSF samples, 75% were from pediatric patients and 25% were from adult patients. The multiplex real-time PCR method (FTD NEURO9; Fast-Track Diagnostics, Esch-sur-Alzette, Luxembourg) was used to analyze the CSF samples. The presence of HSV-1 and -2 was measured qualitatively from the CSF samples.

HSV-DNA was detected in 10 of 525 specimens (1.9%). While seven of these patients were infected with HSV-1, three were infected with HSV-2. Of the seven patients who were HSV-1-positive, two were children and five were adult patients. Two of the five HSV-1-positive adult patients were diagnosed with encephalitis. All three patients positive for HSV-2 were in the pediatric age group. While seven patients with positive HSV-1 results were identified in June, July, August, and September, three patients positive for HSV-2 were identified in December, January, and February. The prevalence of HSV-1 was 1.33% and the prevalence of HSV-2 was 0.57% in the region.

Specific antiviral therapy significantly reduces the mortality and morbidity of CNS infections. Therefore, it is crucial to diagnose and treat HSV infections early. Rapid and sensitive identification of HSV with molecular methods to identify the local prevalence of HSV infection enables prophylactic measures against the virus so that infections can be effectively treated.