Did Brain Parasites Send Breivik Over the Edge?

Parasites feature prominently in numerous grade B or C science fiction films, for example, The Puppetmasters (1994). But what I'm about to ask readers to consider is no daffy scifi plot, but the possibility that an infestation of brain parasites impelled Anders Breivik to go over the edge and carry out his dastardly deed. This in no way is meant to excuse it, but rather to raise the question of degree of culpability for his actions. (Which in the end, let's admit, only an autopsy at his death may be able to ascertain for sure!)

In the meantime, consider the parasite (a protozoan), Toxoplasma gondii. As the horrific book Parasite REX (p. 67) observes:

Few people know about Toxoplasma even though there's a fair chance they are carrying it by the thousands in their brains. A third of all the people in the world are infected by it, and in parts of Europe almost everyone is a host

It further notes that in Norway and Germany the infection rates are 90% and more.

While cats are the primary destination hosts for the parasite, humans are the secondary hosts and can pick it up from just about any place a cat has been, or left droppings, even in the vicinity of food. Indeed, the parasite's oocysts can lie in wait for many YEARS (ibid.) before being picked up by another animal, a bird, a dog...or a human being.

The author, Carl Zimmer, goes on to describe this critter's nasty habits (ibid.):

Once Toxoplasma has invaded a cell, it starts feeding and reproducing. after it has divided into 128 new copies, it tears the cell open and the new parasites spill out ready to invade fresh cells. Now, instead of invading cells, it builds shells, each of which hides a few hundred Toxoplasma individuals. Every now and then one of the cysts will break open and the parasites inside will invade new cells and produce Toxoplasma

Among the favorite destinations for these parasites are the neurons of the human brain. Indeed, a thoroughly parasitized brain might hold thousands of these cysts each with hundreds of individuals. If they rupture on the average of one per day it is easy to see that millions of parasites can occupy a badly infected brain within a year.

How do you know the thing is even getting into you, to possibly commence its voyage to your brain? As the author notes, you don't. If you were to swallow the eggs of the parasite, say from an infected animal (raw or poorly cooked pork or whatever) the only first sign you'd notice is a light fever or maybe some sniffles (as a result of the body's immune reaction) not unlike a mild case of flu. Most people would dismiss it as that and not remotely think of a parasitic invasion.

Again, note that Toxoplasma is not a killer per se. Why would it if it can happily survive in a host by manipulating its immune system, or brain?

Speaking of the latter, what happens in that case? The author observes (p. 93):

"Psychologists have found that Toxoplasma changes the personality of its human hosts, bringing different shifts to men and women. Men become less willing to submit to the moral standards of a community, less worried about being punished for breaking a society's rules and more distrustful of other people.."

In the case of women, he notes that they "become more outgoing and warm-hearted".

Now a conjecture: What if Anders Breivik's brain harbored millions of these Toxoplasma parasites and they effected not just a mild change in his personality but a major one? Not merely becoming more distrustful of others (which he indeed was, of Norway's reigning Labor Party and its newcomers) but prepared to break his society's rules not in a small way, but via mass murder. Clearly if the parasites affected his personality to this degree, they'd also influence his thinking and get him to crank out the insane manifesto he did (most of which was really copied from Unabomber Ted Kasczinski's).

If these parasites were responsible for pushing Breivik over the edge, then how does one measure or inflict "justice"? Can a man be held accountable for what millions of parasites effect via massive personality change? Inquiring minds want to know!

Also, if half the world's population is infested, and likely a quarter in a massive form, to what extent are they responsible for their actions? if they died, after committing some horrific act spawned by the brain parasites, are they to be sent by the Fundies to their Hell? (Or more accurately, do the Fundies seriously expect this is a just destination, given parasite infestation and massive personality change?)

Again, inquiring minds want to know! Maybe, just maybe, most of humanity's most bestial crimes and genocides have not been spawned by "evil" per se, but a lowly parasite that fond the perfect niche in the human brain, and was able to even manipulate its personality toward evil ends.

Then, in that case, maybe we need to blame the parasite!