Prevalence & Distribution of Malaria
Prevalence, Distribution and Seasonal Incidence of Malaria
- Malaria is a communicable (infectious) disease found in tropical areas
- It is biologically spread by disease vectors - parasites carried by female mosquitoes
- Prevalence means the proportion of a population who have a specific characteristic in a given time period
- Nearly half of the world’s population is at risk of malaria
- In 2020, an estimated 241 million people contracted malaria in 85 countries, killing around 627,000 people
- Infants and children under 5 years of age, pregnant women and patients with HIV/AIDS are most susceptible to dying from severe malaria
- Migrants, mobile populations and travellers are also vulnerable if they enter areas with intense malaria transmission
- Some adults in areas where malaria is common will develop partial immunity which reduces the risk that malaria infection will cause severe disease
- Distribution refers to the pattern of health events in a population
Distribution of confirmed cases of malaria per 1000 population, 2015
- Seasonal incidence of malaria depends on physical factors
- Greatest incidence of the disease occurs during and soon after the season of highest rainfall
- Due to mosquitoes breeding in stagnant water supplies
- Malaria can be present throughout the year in equatorial regions where seasonal variations are less marked - known as ‘malaria endemic’ areas
- E.g. Central African belt of the Congo basin, including parts of Equatorial Guinea, Cameroon, Congo, Democratic Republic of Congo, Rwanda, Uganda and Kenya
Exam Tip
When revising, try and learn some specific countries or regions where malaria is most prevalent. For example, rather than just saying it is found in Africa, be more specific with where in Africa.