QIMR Berghofer

Plasmodium knowlesi malaria in Sabah, Malaysia, 2015-2017: ongoing increase in incidence despite near-elimination of the human-only Plasmodium species.


BACKGROUND: Malaysia aims to eliminate malaria by 2020. However, while cases of Plasmodium falciparum and P. vivax have fallen substantially, the incidence of zoonotic malaria from P. knowlesi continues to increase, presenting a major challenge to regional malaria control efforts. Here we report incidence of all Plasmodium species in Sabah, including zoonotic P. knowlesi, during 2015-2017. METHODS: Microscopy-based malaria notification data and PCR results were obtained from the Sabah Department of Health and State Public Health Laboratory, respectively, from January 2015 to December 2017. From January 2016 this was complemented by a state-wide prospective hospital surveillance study. Databases were matched, and species was determined by PCR, or microscopy if PCR was not available. RESULTS: A total of 3867 malaria cases were recorded between 2015 and 2017, with PCR performed in 93%. Using PCR results, and microscopy if PCR was unavailable, P. knowlesi accounted for 817 (80%), 677 (88%), and 2030 (98%) malaria cases in 2015, 2016, and 2017, respectively. P. falciparum accounted for 110 (11%), 45 (6%), and 23 (1%) cases, and P. vivax 61 (6%), 17 (2%), and 8 (0.4%) cases, respectively. Of those with P. knowlesi, median age was 35 (IQR 24 - 47) years, and 85% were male. CONCLUSIONS: Malaysia is approaching elimination of the human-only Plasmodium species. However, the ongoing increase in P. knowlesi incidence presents a major challenge to malaria control and warrants increased focus on knowlesi-specific prevention activities. Wider molecular surveillance in surrounding countries is required.

Authors Cooper, Daniel J; Rajahram, Giri S; William, Timothy; Jelip, Jenarun; Mohammad, Rashidah; Benedict, Joseph; Alaza, Danshy A; Malacova, Eva; Yeo, Tsin W; Grigg, Matthew J; Anstey, Nicholas M; Barber, Bridget E
Journal Clinical Infectious Diseases
Pages 361-367
Volume 70
Date 1/03/2019
Grant ID R01 AI116472-03
Funding Body US National Institutes of Health
URL http://www.ncbi.nlm.nih.gov/pubmed/?term=10.1093/cid/ciz237
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