Geographic Concentration of Malaria Burden in Indonesia: A Provincial Spatial Analysis of Elimination Progress and Programme Indicators, 2020–2024

Malaria is a disease carried by mosquitoes that has long plagued parts of the world, causing fever and illness in millions of people. For decades, global health efforts have focused on reducing the number of cases and deaths, with a specific goal for Indonesia to eliminate the disease entirely from its entire territory by the year 2030. To track progress, health officials count how many people are confirmed to have the disease in different areas and measure how well local clinics are testing for it and treating patients. They also award a special status to districts that have gone three years without any local transmission of the disease. However, looking at the total number of cases for the whole country can sometimes hide the true picture. Just as a national average income can mask the difference between a wealthy city and a struggling rural village, a national malaria count can obscure where the disease is actually concentrated. Understanding exactly where the disease remains and why is crucial for knowing if a country can truly reach its goal of being malaria-free.

A new study by Jema Kiazolu from Hasanuddin University takes a close look at Indonesia's fight against malaria between 2020 and 2024. The researcher analyzed data from all thirty-four provinces of the country to see how the disease was distributed and how it related to the health programs in place. The study found that while the country as a whole seemed to be making steady progress, the reality on the ground was becoming more uneven. The number of malaria cases reported across the entire nation more than doubled during this five-year period, rising from about 254,000 in 2020 to nearly 544,000 in 2024. Yet, this dramatic increase was not happening everywhere. In fact, the vast majority of these cases were coming from just two provinces in the eastern part of the country, Papua and Papua Barat. These two provinces alone accounted for between 89 and 93 percent of all malaria cases in Indonesia every single year of the study. While most other provinces saw their malaria rates stay low and stable, the burden in the east grew significantly, creating a sharp divide between the malaria-free majority of the country and the high-risk east.

The study used maps and statistical tools to show that this pattern was not random. The high number of cases in the eastern provinces formed a distinct cluster, separate from the rest of the archipelago. In the western and central parts of Indonesia, including the large island of Java and the island of Bali, the disease had largely been pushed back, with most districts achieving a status of being free from local transmission. In contrast, the eastern provinces remained a stronghold for the disease. The researcher also looked at how well the health system was working in these areas. They examined three main indicators: how many suspected cases were actually tested in a lab, how many confirmed patients received the standard correct treatment, and what percentage of a province's districts had been officially certified as malaria-free.

The analysis revealed an interesting relationship between these health system actions and the number of cases. Provinces with a higher percentage of certified malaria-free districts tended to have far fewer cases overall. This makes sense, as certification is a sign that a place has already succeeded in stopping the disease. However, the study found that provinces with higher rates of testing and treatment did not have fewer cases; instead, they reported more cases. This does not mean that testing or treating people causes malaria. Rather, it suggests that health workers in the hardest-hit areas, like Papua, are likely working harder to find and treat every single case they can. Because these areas have a higher true burden of the disease, they naturally have more people to test and more people to treat. The data supports the idea that the health system is responding to the need, concentrating its resources where the disease is most active, rather than the testing itself creating the problem.

To understand if these patterns were due to the specific conditions of each province or just changes over time, the researcher looked at how things changed within the same province from year to year. When they isolated the changes that happened inside a single province over the five years, the strong link between having certified districts and having fewer cases became much weaker and was no longer statistically significant. This suggests that the difference between the high-burden provinces and the low-burden provinces is not just about what happened in the last few years, but about deeper, long-standing differences. These differences likely include factors like the local geography, the types of mosquitoes present, the density of the population, and the history of the health system in those areas. The study concludes that the remaining challenge for Indonesia is not a uniform problem across the whole country, but a specific, concentrated problem in the east.

The researchers then created a priority list to help health officials decide where to focus their efforts to meet the 2030 goal. They identified twelve provinces that need the most attention, most of which are in the eastern part of Indonesia. These areas are classified as high priority because they still have a significant number of cases and have not yet certified all their districts as malaria-free. The study suggests that a single, uniform plan for the whole country will not work. Instead, the strategy needs to be different for different places. The high-priority provinces need intensified, tailored responses that address their specific barriers to stopping the disease. The moderate-priority provinces need to strengthen their surveillance to catch any remaining pockets of transmission. The low-priority provinces, many of which have already eliminated the disease, need to focus on keeping it out and preventing it from coming back.

This research provides a clear, data-driven map of where Indonesia stands in its fight against malaria. It shows that while the country has made remarkable progress in many areas, the final stretch to elimination will require a targeted approach for the specific regions where the disease persists. The findings confirm that the path to a malaria-free Indonesia is not a straight line for the whole nation, but a journey that requires different tools and strategies for different landscapes. By understanding exactly where the disease is concentrated and how the health system is responding, officials can direct their resources more effectively to ensure that the goal of elimination is reached by 2030.