Blood parasites can cause long term infections in their hosts where they can affect the birds health, especially when the birds are under stress, for exemple during breeding season.
Blóðsníkjudýr valda langvarandi sýkingu hýsla sinna og geta leitt til skertrar heilsu fugla þegar þeir eru undir stressi eða álagi, sérstaklega á varptíma.