Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and rapidly escalated into a global pandemic. Severe illness of COVID-19 predominantly occurs in older people and in individuals with underlying medical comorbidities. Dementia, including Alzheimer’s disease (AD) is a common cause of morbidity and mortality in the aging population. The majority of people living with dementia are also living with one or two additional chronic health conditions. Sadly, there is currently limited data on the risks, disparity, and outcomes for COVID-19 in patients living with dementia in the United States.
In a study published in Alzheimer’s & Dementia The Journal of the Alzheimer’s Association, patients living with dementia were at significantly increased risk for COVID-19 compared to patients without dementia after adjusting for demographics and COVID-19 risk factors, many of which are also risk factors for dementia. Reasons for this observed high risk for viral infection include:
- Confounding factors such as socioeconomic determinants, behavioral factors, lifestyle, may have contributed to the increased risk for COVID-19 in patients living with dementia. For example, patients living with dementia may be particularly prone to SARS-CoV-2 infection because their impaired memory limits their ability to comply with recommendations for social distancing, mask-wearing, or handwashing;
- Dementia as a disease entity may have direct effects on patients’ increased susceptibility to SARS-CoV-2 infection because of the damaged blood-brain barrier (BBB). Prior studies suggested that increased BBB permeability in patients living with dementia including vascular dementia and AD predisposes them to bacterial and viral infections including herpes, pneumonia, syphilis, Lyme disease, and gum disease.
There is evidence for a bidirectional relationship between viral infections and dementia; people living with dementia have an increased risk for infection while a poor immune response to infection places individuals at increased risk for dementia. These findings highlight the need to protect patients living with dementia as a part of the strategy to control the COVID-19 pandemic. Stay the course, stay well, mask up, get vaccinated, and stay tuned!