We did travel a few times with children to India when there were min outbreaks of Dengue fever.

I too agree that it is important to not take the risk lightly. A highly under-rated protection is mosquito nets. We almost always use air conditioning, repellants and mosquito nets for protecting children. With young infants, it is easier to carry portable nets and set them up around roll-ons or cribs.

This is one area, where despite our emphasis on organic foods and avoidance of pesticides in CA, we tend to use chemical repellants in India, Mexico, Africa and other high-risk areas. (We now have West Nile virus in many parts of the US as well). WSJ once did a very detailed article on the use of various repellents and DEET still works out to be the most effective protection for outdoors.