HHV-6 DNA found in spinal fluid of 8% of patients with aseptic meningitis

Multiplex testing using Biofire FilmArray found HHV-6 to be the second most common virus after enterovirus in patients suspected of meningitis/encephalitis.

Aseptic meningitis is defined by symptoms and physical examination findings indicating inflammation of the meninges, no cognitive or focal neurological deficits indicating encephalitis, white blood cells in the cerebrospinal fluid and negative bacterial and fungal cultures of the spinal fluid. Various viruses are well-recognized causes of aseptic meningitis, but in many cases the causative agent cannot be identified.

Investigators from the King Saud bin Abdulaziz University of Health Sciences aimed to investigate the viral pathogens associated with aseptic meningitis in the Saudi Arabian population. Researchers conducted a retrospective study of 240 pediatric and adult patients using a qualitative multiplex real-time PCR assay to test spinal fluid. The assay was designed to detect enteroviruses, herpes simplex virus type 1 and 2 (HSV-1/HSV-2), varicella-zoster virus (VZV), cytomegalovirus (CMV), human herpesvirus 6 (HHV-6), and human parechovirus (HPeV). 

Viral DNA was found in 40.4% (n=97), with the rest of the cases having unknown etiology. Of the viruses detected, HHV-6 was the second most prevalent (7.9%, n =19), behind enteroviruses (25%, n=60), and ahead of varicella-zoster virus (VZV) (3.8%, n=9). No significant seasonal correlations were found. The PCR test did not distinguish between HHV-6A and HHV-6B.

The rate of detectable viral infections in this study was much higher than a similar study in the US (40.4% vs 8.8%). HHV-6 was also the second most common pathogen found after enterovirus (Radmard 2019).

The FilmArray panel is a qualitative assay that cannot distinguish infection with exogenous virus from inherited chromosomally integrated HHV-6.

Other limitations of this study include lack of a control group and uncertainty about whether the viral DNA was coming from free virus in spinal fluid or from white blood cells in the spinal fluid. Also, the generalizability of these findings to other geographic areas and populations is uncertain.  The study also highlights the need for better testing for the etiology of aseptic meningitis as causative agents were unable to be identified in 59.6% of patients in this study. 

Read the full article: Aldriweesh 2020