Association Between Herpes Simplex Virus Type 1 IgG Seropositivity and Dementia at a University Hospital in Bangladesh

Introduction: Dementia has emerged as a significant global public health challenge among the aging population.Emerging evidence suggests that exposure to herpes simplex virus type 1 (HSV-1) immunoglobulin G (IgG) seropositivity has been associated with dementia in some epidemiological studies.This study aimed to examine the association between HSV-1 IgG seropositivity, dementia, and cognitive performance as measured by Mini-Mental State Examination (MMSE) scores among hospital-attending individuals presenting with memory complaints in the elderly population of Bangladesh.Methods: This cross-sectional analytical study was conducted among 136 patients with complaints of memory loss during the period of November 2024 to April 2025.The study was conducted at the Department of Neurology and Virology at the Bangladesh Medical University (BMU).The patients were categorized as memory loss patients with or without dementia based on the MMSE.Additionally, blood samples were collected aseptically for the detection of anti-HSV-1 IgG seropositivity using the enzyme-linked immunosorbent assay (ELISA) method.Demographic, clinical, and laboratory results were collected and analyzed using IBM SPSS v25 (IBM Corp., Armonk, NY, USA) and Microsoft Excel (Microsoft Corp., Redmond, WA, USA).A p-value <0.05 was considered statistically significant.Results: The mean age of memory loss patients with dementia infected with HSV-1 was 74.9 (±8.1), and 58 (85.3%) were HSV-1 IgG positive.Thirty-eight (88.4%) male and 20 (80.0%) female patients were HSV-1 IgG seropositive among memory loss patients with dementia (p=0.347).HSV-1 IgG-seronegative (median (interquartile range (IQR)): 26.0 (11.0-29.0))individuals demonstrated significantly higher cognitive performance (MMSE) scores compared with seropositive (median (IQR): 25.0 (12.0-28.0))individuals (p<0.05).However, this study could not found any significant association of dementia with HSV-1 IgG seropositivity (adjusted OR=0.865, 95% CI: 0.34-2.22,p=0.763), age (adjusted OR=0.974, 95% CI: 0.93-1.03,p=0.311), and male sex (adjusted OR=0.680, 95% CI: 0.34-1.37,p=0.283), respectively.Conclusion: This study found no statistically significant association between prior HSV-1 IgG seropositivity and dementia or cognitive performance among hospital-attending individuals presenting with memory complaints, in the first study of its kind in Bangladesh.Nevertheless, multidimensional prospective studies are required to elucidate the potential infectious aetiology of dementia in older adults.