We are visiting Castaway in the next few days, and are travelling with an infant (15 months old). The Australian traveller website says to beware of dengue fever. Is the mosquito that carries dengue prevalent on Castaway island? I'm not keen on using an insect repellant on my son, but am also wary of dengue given my husband had it last time we were on holidays (in Bali) and it can be a lot worse if you get it the second time round. Can we buy insect repellant on Castaway island?