My husband has fever since 6 days.. fever is not very High but it's persistent. It is normal during the day and increases in evening and night. It's 98.6-7 in daytime and at night it goes upto 99.8-100. Hes advised anti-inflammatory and udiliv tab as he has mild hepatomegaly.His CBC,ESR are normal.  Widal is negative. Blood culture is negative. C reactive protein is High and mild hepatomegaly. Liver function tests are normal. The fever pattern is consistent. Normal in day and rises in evening and night. What can be the reason? Dr is suspecting viral infection.( He had preceding history of loose motions for which he took NTZ tab which controlled loose motions). Kindly advise. Any more investigation needed?