Blanca, you are right, long time use of these mosquito repellents are very harmful to us. Use mosquito net it is best. I heard some natural remedies which work against the mosquito.
I would love to share which I heard maybe it can help someone.
Neem has the best antibacterial quality. It is a plant which usually finds in tropical area’s country. Its every part is very effective against bacteria and fungus.
If you are applying neem oil on the body mosquito will away from you.
Tribal and villagers burn neem leaves(green) and produce smoke. Neem smoke kills every type of bacterias in the air. It purifies the air and kills the mosquito.
Neem is full of blessings if you want more about neem benefits read here http://www.askprob.com/forums/topic/what-are-the-benefits-of-the-neem-plant/