Occupationally Acquired Plasmodium knowlesi Malaria in Brunei Darussalam

Simian malaria is a zoonotic disease caused by Plasmodium knowlesi infection. The common natural reservoir of the parasite is the macaque monkey and the vector is the Anopheles mosquito. Human cases of P. knowlesi infection has been reported in all South East Asian countries in the last decade, and it is currently the most common type of malaria seen in Malaysia and Brunei. Between 2007-2017, 73 cases of P. knowlesi infection were notified and confirmed to the Ministry of Health in Brunei. Of these, 15 cases (21%) were documented as work-related, and 28 other cases (38%) were classified as probably related to work (due to incomplete history). The occupations of those with probable and confirmed work related infections were border patrol officers, Armed Forces and security personnel, Department of Forestry officers, boatmen and researchers. The remaining cases classified as most likely not related to work were possibly acquired via peri-domestic transmission. The risk of this zoonotic infection extends to tourists and overseas visitors who have to travel to the jungle in the course of their work. It can be minimised with the recommended use of prophylaxis for those going on duty into the jungles, application of mosquito/insect repellants, and use of repellant impregnated uniforms and bed nets in jungle camp sites.