Re: Grammer suggestion
1. It's "has" because it refers to the singular 'spectrum', and not to the plural 'Indians'.
2. By aforesaid reason, we, students endeavored to notice really malaria is under-diagnosed in our country by studying controls and cases.
Your main mistake is writing a sentence that no-one would ever speak. Keep it simple. I would express it as something like, " For this reason, [or "Because of this,"] we students studied controls and cases, and noticed [or "concluded"] that malaria is under-diagnosed in this country".
Last edited by Rover_KE; 22-Aug-2013 at 18:03.
Reason: Fixing typo.
I'm not a teacher of English, but I have spoken it for (almost) all of my life....