Question: can parasite blood cause infection if they had a diseases

Claire Bourke answered on 20 Jun 2016:

@Leo,
I’m not sure I completely understand your question, so have come up with a couple of answers and I hope at least one will address what you mean…

If you mean ‘can parasite infections be passed directly from blood’:
there is a low risk of direct infection occurring from parasite infected blood in humans – for example there is a very low risk of parasites like babesiosis, malaria, and Chagas disease which live in the blood, being passed on to a new person via a blood transfusion from an infected person. Now that there is lots of screening of blood prior to transfusions though the incidence of infections in this way is very low. What this means with respect to your question is that transmission of parasites from one parasite to another may also be possible, although I am not familiar with a parasite in which this occurs as a normal part of their life cycle (perhaps on of the other scientists has some ideas?).

If you mean ‘can a parasite of a parasite infect another parasite via their blood’:
One good example of a parasite that infects another parasite is the bacteria species Wolbachia, which is present in almost all fiarial worms, which infect people to cause diseases like river blindness and elephantiasis. Wolbachia have infected filarial worms for so long that the filarial worms now rely on them for survival and there are new methods of treating filarial worms that target the Wolbachia as a way to kill the filaria! Perhaps Wolbachia are spread from one filarial worm to another in the worm equivalent of blood, but I have no evidence to support that idea and I am not sure if it has been tested in a laboratory experiment before!

If you mean, ‘can a person pick up a parasite infection from the blood of an infected parasite’:
I’m not sure and I think that would be quite difficult to work out in some ways because when a person is infected with a parasite that lives in the blood, whenever one of the parasites die, they will release their blood and bits of their body into the bloodstream so it wouldn;t be clear whether the infection came from the parasite directly or got in via a different route. Similarly, if a biting parasite or one that burrows through the skin infects a person, it also creates a wound through which other infections can enter and it would be difficult to tell if the second infection came from the first parasite or through the wound it caused. That doesn’t mean that it doesn’t occur though!

Thanks for your really interesting question 🙂