The atherogenicbacterium Porphyromonas gingivalis evades circulating phagocytes by adhering to erythrocytes.

Porphyromonas gingivalis is one of the causes of gum disease which has been linked to both atherosclerosis and Alzheimer's disease: The bacteria stick to complement component C3 and in doing so interfere with complement receptor 1 on red blood cells. Herpes simplex and influenza viruses also bind to complement receptor 1 Refs
A neat link between susceptibility genes (CR1) and risk factors

Risk factors: Alzheimer's :
Kegg pathways
Alzheimer's  Herpes simplex infection