Whether parvoviruses are significant players in meningitis/meningoencephalitis?

Meningitis and meningoencephalitis are neurological inflammatory diseases. Although routine diagnostics include testing of a wide range of pathogens, still in many cases, no causative agent is detected. Human parvovirus B19 (B19V), human bocaviruses 1–4 (HBoV1–4), and human parvovirus 4 (hPARV4) are members of the Parvoviridae family associated with a wide range of clinical manifestations including neurological disorders. The aim of this study was to determine whether human parvoviruses infection markers are present among patients with meningitis/meningoencephalitis in Latvia as well as to clarify if these viruses affect the clinical course of the diseases. In total, 42 cases of confirmed or unknown etiology of meningitis (n = 31; 73.81%) or meningoencephalitis (n = 11; 26.19%) were evaluated. Of all the patients, 20 (47.6%) were males and 22 (52.4%) were females, with the mean age 50 and 58.9 years, respectively. In all cases, whole blood and cerebrospinal fluid (CSF) samples were obtained on admission. Total DNA was extracted from peripheral blood, cell-free blood plasma, and CSF samples using a phenol-chloroform extraction method. The presence of parvovirus genomic sequences in DNA samples was determined using nested PCRs. All calculations and statistical analysis were performed using the program Prism 7.04 (GraphPad, San Diego, USA). Our study revealed HBoV1–4 and B19V genomic sequences in 52.38% and 16.67% of patients, respectively. Presence of hPARV4 genomic sequences was not detected. Furthermore, symptoms such as the presence of a headache and its severity, fatigue, disorientation, and difficulties to concentrate were significantly frequently present in patients with active parvovirus infection in comparison with parvoviruses negative patients. Study results shows that the infection markers of human parvoviruses are present among patients with meningitis/meningoencephalitis in Latvia. Furthermore, we suggest that HBoV1–4 and B19V infection should be included in the diagnostics to reduce the number of meningitis/meningoencephalitis with unknown/unexplained etiology.