Telogen effluvium is one of the most common reasons for abnormal hairfall I'm females.It can happen due to long standing fever, stress,vitamin deficiencies, pregnancy, etc. Usually dengue fever in adults don't last longer     and though this may be one if the reasons, ideally we need to do some blood tests to check for other reasons as well( for example vitamin d deficiency is very common). Once we have figured out all the possible reasons for abnormal hairfall and hair thinning,we can make a proper treatment plan which may take 3-6 months to recover hair completely.

Yes its telegen effluvium. Sometimes it may continue for months. You will require treatment you can use minoxidil 2% with hair supplements. But under supervision. Contact me for further details.