topic1c-endemicity.qmd

# Malaria Endemic Regions

## Geographical distribution

Malaria remains endemic in over 85 countries and territories, with the highest transmission occurring in Sub-Saharan Africa, Southeast Asia, the Eastern Mediterranean, and parts of the Western Pacific and the Americas. In these regions, climatic conditions such as temperature, humidity, and rainfall create favorable environments for the Anopheles mosquitoes that transmit malaria.

Interactive maps, such as those provided by the [Malaria Atlas Project](https://malariaatlas.org/), can visually depict the distribution of malaria cases and highlight regions with the highest burden.

```{=html}
<iframe src="https://data.malariaatlas.org/maps?layers=Malaria:202406_Global_Pf_Parasite_Rate" style="border:none; width:100%; height:600px;"></iframe>
```

## High-Risk Populations

Certain populations are at higher risk of contracting malaria. These include:

-   **Children under five years old**: Due to their developing immune systems, young children are particularly susceptible to severe malaria and death.

-   **Pregnant women**: Pregnancy reduces a woman's immunity to malaria, increasing the risk of severe illness, maternal death, and adverse pregnancy outcomes.

-   **Travelers and migrants**: Individuals traveling to or migrating from non-endemic to endemic areas may lack immunity, putting them at greater risk of severe malaria.

-   **People living in poverty**: Limited access to healthcare, preventive measures, and information increases the vulnerability of impoverished communities to malaria.

## Seasonality and Environmental Factors

Malaria transmission varies seasonally, with peaks often corresponding to rainy seasons when mosquito breeding conditions are optimal. Environmental factors such as standing water, vegetation, and climate changes can influence mosquito populations and malaria transmission dynamics.

For instance, in Sub-Saharan Africa, malaria transmission intensifies during and after the rainy season, while in some parts of Asia and Latin America, transmission can occur year-round but peaks during specific months.

## Global Statistics

Each year the World Malaria Report published by the WHO provides a comprehensive and up-to-date assessment of trends in malaria control and elimination across the globe.

According to the [2023 World Malaria Report](https://www.who.int/teams/global-malaria-programme/reports/world-malaria-report-2023) Globally in 2022, there were an estimated 249 million malaria cases in 85 malaria endemic countries and areas, an increase of 5 million cases compared with 2021. The main countries contributing to the increase were Pakistan (+2.1 million), Ethiopia (+1.3 million), Nigeria (+1.3 million), Uganda (+597 000) and Papua New Guinea (+423 000). In 2015, the baseline year of the Global technical strategy for malaria 2016--2030 (GTS), there were an estimated 231 million malaria cases.

Malaria case incidence declined from 81 per 1000 population at risk in 2000 to 57 in 2019. Following a small increase of 3% in 2020, incidence rates have remained stable over the past 3 years. In 2022, malaria case incidence was 58 per 1000 population at risk.

Twenty-nine countries accounted for 95% of malaria cases globally. Globally the WHO Africa Region carries a disproportionately high burden of malaria and inndefined and four countries -- Nigeria (27%), the Democratic Republic of the Congo (12%), Uganda (5%) and Mozambique (4%) -- accounted for almost half of all cases globally and The WHO African Region, with an estimated 233 million cases in 2022, accounted for about 94% of cases globally.

Children under five years of age are particularly vulnerable to malaria and around 77% of global malaria deaths occurred in this age group, predominantly in SSA. About 96% of malaria deaths globally were in 29 countries. Four countries accounted for just over half of all malaria deaths globally in 2022 -- Nigeria (31%), the Democratic Republic of the Congo (12%), Niger (6%) and the United Republic of Tanzania (4%).