Are there any other tests which can help identify all various kinds of infections in blood other then esa, coz it doesn't seem to b a comprehensive test?

No. There is no test that will identify all infections. A doctor uses information about medical history, exposures, signs and symptoms to decide what tests are appropriate for a given patient. Ordering too many tests for inappropriate reasons can lead to false positive results.
No such thing. There is no such thing as a test to tell you if you have any infection in your body. If you have an infection, or have reason to suspect one, you need to see a doctor so that it can be identified and evaluated properly.