2018年11月10日
Recent prevalence of human malaria caused by Plasmodium knowlesi in communities in Kudat area, Sabah, Malaysia: mapping of infection risk and environmental factors detected by remote sensing
第59回日本熱帯医学会大会
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- 記述言語
- 英語
- 会議種別
- ポスター発表
Plasmodium knowlesi is a protozoan parasite that naturally infects macaque monkeys in South East Asia. This parasite has been known to cause a zoonotic Pk malaria in humans. The health of people is under threat especially in northern part of the Borneo Island in Malaysia. Following the pioneering works carried out in Sarawak, investigation in Pk malaria was started in Sabah in early 2010s. An early epidemiological study carried out in the Kudat district, close to the northern tip of Borneo, suggested that transmission of the zoonotic malaria may occur close to or inside the houses of people living in the area. However, Pk malaria has been believed to transmit to a human only very close to or within a deep forest in any other part of the world including Sarawak. To confirm the uniqueness and for a better understanding of Pk malaria in the Kudat district, we need to keep update our knowledge in the diseases.
We analysed the clinical record of malaria cases in one of malaria endemic areas in the Kudat district. There are 25 communities where 4032 people lived in 2017 in the study area which is under the jurisdiction of the Lotong subsector office (PSS Lotong) of Kudat health. In total, 126 malaria cases were reported in this area between 2013 and 2017, and all of these cases were confirmed to be Pk malaria. Space-time scan analysis with the SaTScan software detected a positive and a negative clusters of malaria cases present in the area. This finding suggests that distribution of Pk malaria cases was affected by some spatial factor.
To identify common features present around the positive cluster of Pk malaria, we quantified environmental factors such as rainfall, temperature and the Land-Use and Land-Cover (LULC), analysing the time-series satellite data recorded by MODIS (MODerate-resolution Imaging Spectroradiometer). Because Pk malaria often suffers oil palm plantation workers in PSS Lotong area, the LULC analysis was particularly focused on the spread of oil palm plantation. We will visualise the geographical distribution of the Pk malaria on the map to demonstrate how the environment contributes on the Pk malaria risk in the study area.
We analysed the clinical record of malaria cases in one of malaria endemic areas in the Kudat district. There are 25 communities where 4032 people lived in 2017 in the study area which is under the jurisdiction of the Lotong subsector office (PSS Lotong) of Kudat health. In total, 126 malaria cases were reported in this area between 2013 and 2017, and all of these cases were confirmed to be Pk malaria. Space-time scan analysis with the SaTScan software detected a positive and a negative clusters of malaria cases present in the area. This finding suggests that distribution of Pk malaria cases was affected by some spatial factor.
To identify common features present around the positive cluster of Pk malaria, we quantified environmental factors such as rainfall, temperature and the Land-Use and Land-Cover (LULC), analysing the time-series satellite data recorded by MODIS (MODerate-resolution Imaging Spectroradiometer). Because Pk malaria often suffers oil palm plantation workers in PSS Lotong area, the LULC analysis was particularly focused on the spread of oil palm plantation. We will visualise the geographical distribution of the Pk malaria on the map to demonstrate how the environment contributes on the Pk malaria risk in the study area.