Disease Prevalence countries

malaria- Sub Saharan Africa, south Asia(India, Pakistan),Arabian gulf region, western and southern parts of china, south east Asia (Thailand, Malaysia, Indonesia ),south amarica,mexico,panama,few pockets in Australia

Dengue fever- Sub Saharan Africa, south Asia(India,Pakistan,sri lanka),oman,Kuwait,malayasia,few pockets in thiland,indunisia,sumathra,java,nothen part of austraila,northern countries of south America.
Yellow fever- Sub Saharan Africa,brazile and middle part of south America

plague- East costal area of north amarica,brazil,Colombia,central Africa, south Africa,china,Russia some parts of India

The presentation or the initial symptoms has great value for diagnosis. Fever with out localizing sings such as joint pain, muscle pain, headache, fever with rash, fever with hemorrhage and fever following a tick bites are some of important presentations.