Malaria is caused by parasites that are transmitted to people through bites of infected female Anopheles mosquitoes. In a non-immune individual, symptoms appear 10-15 days after the infective mosquito bite, as per WHO. The common symptoms of malaria include fever, chills, headache, sweats, fatigue, nausea, vomiting and body aches. April 25 is marked as World Malaria Day.