Final answer:
The word 'continued' in the given context is used as a synonym for 'ongoing' or 'persistent'. It emphasizes that the search for a cure is still in progress and has not stopped.
Step-by-step explanation:
The word 'continued' in the given context is used as a synonym for 'ongoing' or 'persistent'. It emphasizes that the search for a cure is still in progress and has not stopped. For example, in the sentence 'Despite continued antibiotic treatment, Mark's infection continued to progress rapidly', the word 'continued' shows that the treatment is ongoing but the infection is still spreading.