No. An infected person cannot spread dengue fever to other people. It is a mosquito-borne viral infection and is very common during the monsoon season, which is a very most favorable time for mosquitos to breed. If one has been spending time with an infected person, there is the possibility that they may have been bitten by the same mosquito, so it is always the safer choice to undergo a diagnostic test for dengue fever if that is the case or if one starts displaying symptoms of the infection.