Solve if u can…

It is a 9 letter word 123456789,
If you lose it u die,
If u have 234, you can 1234,
56 is one type of disease,
89 indicates exact location and time,
2 and 7 r same letter, 3 and 8 are same letter, 5 and 9 are same letter.
Guess the word????

Its a Challenge for all masterminds!!