"The worse part is that ..."

[Odessa Dawn]

The worse part is that you cannot muster the energy to funnel your multi-tasked consciousness and concentrate, single-mindedly, to counter the nausea, the headache, the grated throat, the throbbing limb, whatever it may be. If you resort to drugging yourself, you are even more in the thrall of the afflicter, rendering yourself incapable of anything but listless oblivion, unaware of healing.
http://www.theage.com.au/lifestyle/...become-a-source-of-wisdom-20140331-35tir.html

I don’t know why the comparative of bad is used in this context. Why not the superlative- worst, please?

Here it says that ...
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Australian English differs from other varieties of English in vocabulary, accent, pronunciation, register, grammar and spelling.
http://en.wikipedia.org/wiki/Australian_English

Is using the comparative form OK in the given context, please?

 

[Raymott]

He's just chosen to use the comparative to describe a worse aspect of illness than what he has just been discussing - without becoming potentially entangled in questions of whether that is indeed, the worst part of illness. He could, and probably should have used "A worse part ..." because there isn't only one worse aspect. But "A worse part" is not idiomatic either.
No, this isn't a feature of AusE.

 

[5jj]

I think it's a typo.

 

[MikeNewYork]

I agree with 5jj. I think it was a typo for "worst". It is obvious that this illness had more than two bad parts.