Hello. As per your history given, you should go for the following investigations as follows as soon as possible before the condition more worsened. Please the test are as follows : 1. NS 1 Antigen for Dengue fever 2. MP ANTIGEN AND PERIPHERAL SMEAR FOR MALARIA. 3. Serum Widal test and typhidot Igm rapid for typhoid fever. 4. Complete blood count (CBC). These test are utmost necessary and can be done on the urgent basis on the request. After getting the reports, kindly come to practo chat for your evaluation,counseling and treatment part. Regards.