Yes, Chas, Dengue Fever is a worry in the Philippines! When I was there in year 2010 in Manila and Southern Negros Oriental, October 15th through the 31st, I didn't see one single mosquito! It is a funny thing because my Mom and Dad would be right with each other, and Dad would get eaten alive by the mosquitos while Mom would not get one single bite! She had some Indian blood in her, and maybe the mosquitos didn't like Indian blood!
I somewhat take after my mother in that they don't bite me much, I usually don't itch or have any reaction much at all. I don't like them, and I keep busy killing them when they are thick, but they don't bother me much actually. Our youngerst daughter and her 2 kids are the worst affected in our family with multiple bites and each bite swells and looks terrible! They spray the deet on them too. When I walk at the time that there are the most mosquitos, it keeps me busy swatting them all the time! I get bit more when there are fewer of them, because I am not aware that they are there, and they can be biting me for a long time before I notice, then there is blood everywhere when I swat one of them!