'deteriorate'

Hi everybody,

There is this nice verb 'deteriorate'. Cambridge, Oxford, and Macmillan define it as an only-intransitive verb:

http://dictionary.cambridge.org/dictionary/british/deteriorate?q=deteriorate
http://www.macmillandictionary.com/dictionary/british/deteriorate
http://oald8.oxfordlearnersdictionaries.com/dictionary/deteriorate

Merriam Webster (I think it is more or less a US dictionary) additionally defines it as transitive verb:
http://www.merriam-webster.com/dictionary/deteriorate

One of my book (English-Hungarian bilingual, but it is considered as a good source here) contains this sentence:

There are also wars, revolutions, ethnic clashes resulting in ethnic cleansing, which deteriorates the situations that are already bad enough.

Now I can't decide whether it is
-only intransitive
-transitive and intransitive
-only intransitive in UK English but both transitive and intransitive in US English
-I don't know, the fourth possibility

What is the truth? I just thought that the transitive meaning is considered as an important one (in this case I can't understand why it isn't mentioned in Cambridge, Macmillan, Oxford).

Thanks for your help in advance.