Age and West Nile virus patterns in eastern Hungarian CNS infections

A ten-year retrospective cohort from eastern Hungary found distinct clinical and cerebrospinal fluid patterns among suspected or microbiologically confirmed viral central nervous system infections. The study included 120 patients hospitalized at a tertiary referral center from January 2014 through November 2024. West Nile virus accounted for half of the cohort, and both older age and a higher cerebrospinal fluid protein concentration were independently associated with West Nile virus infection.

The investigators primarily divided patients into two age groups: 17 to 49 years and 50 years or older. They repeated age-stratified analyses using a 60-year cutoff as a sensitivity analysis, and the main findings were largely consistent between the two approaches. Patients in the older group more frequently presented with impaired consciousness, neuropsychiatric manifestations and cranial nerve symptoms. They also had lower Glasgow Coma Scale scores, higher serum C-reactive protein concentrations and longer hospital stays. Headache was reported more often by younger patients. Across the full cohort, increasing age correlated with longer hospitalization and lower cerebrospinal fluid white blood cell counts.

West Nile virus infection had a distinct etiological profile. In addition to being associated with older age, it was linked to higher cerebrospinal fluid protein levels, a predominance of polymorphonuclear cells in the fluid and less frequent headache than in the other groups examined. Multivariable analysis quantified the independent associations with West Nile virus infection: the odds ratio was 1.040 per additional year of age, with a 95% confidence interval of 1.015 to 1.065 and a reported p-value of 0.002. For cerebrospinal fluid protein, the odds ratio was 1.003 per additional milligram per liter, with a 95% confidence interval of 1.001 to 1.004 and a reported p-value of 0.001. These observational estimates do not establish that age or protein concentration causes infection, but they identify factors statistically associated with West Nile virus in this hospitalized cohort.

Other confirmed viral infections and cases of unidentified etiology showed different patterns. Seizures and skin manifestations were more often associated with other microbiologically confirmed viral infections, although the supplied findings do not specify their comparative frequencies with West Nile virus. Patients whose etiology remained unidentified generally had milder cerebrospinal fluid abnormalities and shorter hospital stays than those in the etiologically defined groups. The researchers assessed demographic characteristics, presenting symptoms, cerebrospinal fluid findings, microbiological results, neuroimaging data, hospital stay and clinical outcomes. The supplied report does not give detailed frequencies for imaging abnormalities or long-term outcomes, so those dimensions cannot be characterized further from the available evidence.

The retrospective single-center design limits generalizability. The cohort consisted of hospitalized patients with suspected or confirmed viral central nervous system infection at one tertiary referral center in an endemic region, so the results may not represent milder cases treated elsewhere or infections in other geographic settings. The analysis also covers a specific period and uses age-stratified sensitivity analyses rather than providing evidence of change over time. Nevertheless, the substantial share of cases in which no pathogen was identified demonstrates persistent diagnostic limitations in this setting. The authors conclude that regional epidemiological data should inform routine diagnostic evaluation and that etiology-specific diagnostic strategies are needed in endemic areas.

Subject of Research: Age- and etiology-related clinical patterns of viral central nervous system infections in eastern Hungary

Article Title: Aseptic central nervous system infections: age-related and etiological differences in a ten-year cohort from eastern hungary

Article References: Szegedi, I., Hodossy-Takács, R., Ali, L. A., Bencs, V., Várkonyi, I. Z., & Kozák, M. (2026). Aseptic central nervous system infections: age-related and etiological differences in a ten-year cohort from eastern hungary. BMC Infectious Diseases. https://doi.org/10.1186/s12879-026-14421-0

Image Credits: AI Generated

DOI: 10.1186/s12879-026-14421-0

Keywords: West Nile virus, viral encephalitis, central nervous system infections, cerebrospinal fluid, age-related symptoms, retrospective cohort, eastern Hungary, neuroinfectious disease, diagnostic uncertainty, Aseptic, central, nervous