Question: What is the trend of malaria in different regions of Ethiopia?
Answer: Overall, malaria is highly seasonal in Ethiopia, and has the highest incidence in areas of the country with lower elevation (below 2000 meters above sea level), meaning that the central and southern plateau and mountain regions (corresponding to Addis Ababa and Oromia regions) are generally lower risk for malaria than the eastern and western portions of the country. According to the 2017 World Health Organization (WHO) World Malaria Report, the highest incidence region in 2016 was Benishangul-Gumaz, followed by Gambela. Unlike most other countries in sub-Saharan Africa, a relatively high proportion of malaria cases in Ethiopia are caused by Plasmodium vivax, in addition to P. falciparum.
Long-term data since 1990 show almost a 95% reduction in the number of deaths due to malaria in Ethiopia, with approximately a 75% decrease just between 2010-2016. However, during the 2010-2016 time period, the number of annual new cases (incidence) increased by about 35%. Fortunately, according to the 2017 WHO World Malaria Report, more recent data show more positive trends: Ethiopia as a whole had an estimated 250,000 fewer malaria cases in 2016 compared to 2015.
Trends vary between regions. In some regions (for example South Wollo, in this study), there are signs that P. vivax is increasing in incidence (or as a proportion of total cases), suggesting that changes may need to be made in control strategies to address this form of malaria more directly (for example, improved species testing and availability of primaquine as a treatment). Other studies show quite consistent patterns of infection over time, albeit with high seasonal fluctuation (see this study from North Shoa and this study from South Omo Zone). Overall, there are indications that while deaths due to malaria have been drastically reduced in Ethiopia, additional efforts will be needed to make more of an impact on the total number of cases.