I'm traveling to zanzibar in december. do i need to take anti - malaria medication? is there any medication that i may need to take for that area?

Antimalarial: Zanzibar is malarial. Therefore you would be taking a chance not taking antimalarial prevention medications starting 2 days before you travel there. Simply using mosquito repellent is not sufficient. You could also get advice from a respectable travel service or an infectious disease specialist or a public health officer in your country or the office in Zanzibar.