This is the 1281st most frequent Swedish word.
sjuka
"Sjuka" means "sickness" or "illness" in English.
Here 'sjuka' is an adjective meaning 'sick' that describes the people being visited.
De besökte sjuka personer på sjukhuset.
They visited sick people at the hospital.
Here 'sjuka' is a noun meaning 'illness' that affects the subject of the sentence.
Han tog ledigt från jobbet på grund av sin sjuka.
He took leave from work because of his illness.
Here 'sjuka' is also a noun and refers specifically to the sickness or disease spreading among the people.