A new retrospective study shows a low and stable malaria incidence in Kuala Lumpur
Image credit: Dr. Zulkarnain Md Idris
Malaysia is a country that is in the pre-elimination phase of malaria and continues to progress towards elimination. The country reoriented its intent from malaria control to elimination in 2011, with a phased goal of achieving zero local transmission in Peninsular Malaysia by 2015, and in Sabah and Sarawak by 2020. Malaysia is vulnerable to malaria importation, primarily from regional migrant workers seeking employment in Malaysia’s growing economy. In addition, many documented and undocumented migrants from Myanmar, Bangladesh and Nepal also enter Peninsular Malaysia to serve the low-skilled and semi-skilled sectors of the economy, especially in the urban areas. In a new study published in Tropical Medicine and Infectious Disease, researchers at the Department of Parasitology and Medical Entomology (JPEP) have shown that nearly half of malaria cases reported at UKM Hospital from 2005-2020 were from foreigners with the majority of them were males and came from Southeast Asian countries.
“Although the proportion of malaria cases from local and foreign patients was not significantly different between years, we found that foreign cases contributed to essentially half (49%) of all positive cases. Interestingly, of the total foreign cases, 86% were males, and 66% came from Southeast Asian countries”, says Dr. Zulkarnain Md Idris, senior lecturer at JPEP, and corresponding author of the study.
“As of January 2021, of the approximately 164,620 refugees and asylum-seekers registered with the United Nations High Commissioner for Refugees (UNHCR) in Malaysia, 86.5% were from Myanmar, 67% were males, and 16.8% of them had resettled in Kuala Lumpur. As Malaysia moves toward elimination, malaria will begin to cluster among certain high-risk groups, including migrants and displaced populations” Dr. Zulkarnain adds.
Furthermore, the study shows a significant decrease in cases due to human malaria, but increases for zoonotic malaria due to Plasmodium knowlesi during the 16 years.
“Our work has provided insight into P. knowlesi cases in an urban area. It is unlikely that patients admitted to UKM hospital acquired the P. knowlesi infection in the capital Kuala Lumpur (Federal Territory), which is considered a malaria-free area. However, it is interesting to note that Kuala Lumpur is located within the State of Selangor, a malaria-endemic area in Peninsular Malaysia” says Dr. Nor Diyana Dian, the study’s first author and Master student at JPEP.
The researchers note that Improved surveillance, collaboration with key industries and other government agencies, and cross-border cooperation with neighboring endemic countries are critical for addressing the ongoing threat of malaria importation and achieving elimination. With regards to zoonotic malaria, there is a need to improve current public health policies to better understand the cause and consequence of changing epidemiological patterns of zoonotic malaria in urban/peri-urban contexts in the country.
This study was supported by the ASEAN Science Technology and Innovation Fund (FF-2019-124) from the ASEAN Secretariat and Geran Pembiayaan Sepadan (FF-2019-124/1) from the Faculty of Medicine UKM.
Publication
“Malaria Cases in a Tertiary Hospital in Kuala Lumpur, Malaysia: A 16-Year (2005–2020) Retrospective Review” Nor Diyana Dian, Ahmad Firdaus Mohd Salleh, Mohd Amirul Fitri A Rahim, Mohd Bakhtiar Munajat, Siti Nor Azreen Abd Manap, Nuraffini Ghazali, Noor Wanie Hassan, Zulkarnain Md Idris. Tropical Medicine and Infectious Disease, online Sept. 29, 2021, doi: https://doi.org/10.3390/tropicalmed6040177