The diagnostic challenge of pandemic H1N1 2009 virus in a dengue-endemic region: a case report of combined infection in Jeddah, Kingdom of Saudi Arabia.

It is difficult to distinguish dengue fever from other febrile illnesses in a dengue-endemic area. This issue was compounded during the H1N1 2009 pandemic of influenza, which also presents as a febrile illness. This first laboratory-confirmed case of co-infection with dengue and influenza A H1N1 2009 strain in Jeddah, Saudi Arabia, highlights the importance of considering co-infections because not only is influenza an ongoing concern in Jeddah, but several viral hemorrhagic fever viruses circulate in this region.