both Babesia and bartonella alter the membrane of the red blood cells they infect that makes the red blood cells much more able to stick together
they also cause excessive fibrin deposits - and fibrinogen deposits - both are glue like molecules that are part of the clotting system and stick things together
see this slide where you can see the pale halo of glue like substance around the red blood cells keeping them stuck together but evenly spaced
VIEW IMAGEand here fibrin sticking red blood cells together in a mesh - via electron microscope
VIEW IMAGEhere is a slide of mine - where Rouleaux - or stacked coins appearance is visible in thicker areas of the slide.
VIEW IMAGE