The phrase "same sickness" refers to people having or experiencing the exact same problem or issue. It means that they are facing similar challenges or difficulties. Full definition
I wonder why a big club like arsenal will be suffering from same sickness for, many years. (suburbangooners.com)
It went something along the lines of the church often merely reflects the same sicknesses of the surrounding culture. (nakedpastor.com)
So far it is only Jack Wilshere that is set to miss the game against the Belgian champions, but Aaron Ramsey apparently had the same sickness last week and we have seen before how these things can spread through a squad. (justarsenal.com)