Can a zombie apocalypse really occur?
There are many examples of parasite manipulation in nature, if you want more examples you can look up the paper of Lefevre and Thomas (2008). I think the key is, in order for a parasite to develop such behaviour, that it should be giving them a fitness advantage. So I don't think it would ever happen for no reason. The paper discusses a few examples where the manipulation results in a higher transmission rate by the parasite.

I guess that because parasite manipulation is happening in many other organisms, it's probable that it happens to some extent in humans too. There are for example indications that when we are infected with  malaria, the malaria parasites can change our odour profile to make us more attractive to mosquitoes, thus increasing it's transmission (Batista et al. 2014, De Moraes et al. 2014). There are also indications that our gut microbiota have an influence on our brain and behaviour, regulating anxiety, mood, cognition and pain, by communicating with our CNS (Cryan and Dinan 2012).