Monkey malaria: No risk to the tourists
Kota Kinabalu: Preliminary results from clinical study on Plasmodium knowlesi, an emerging human malaria, found that the malaria can also be contracted by children. Professor Chris Drakeley of the London School of Hygiene and Tropical Medicine, however, said there is currently no evidence to say tourists are at increased risk, nor that people can transmit the disease to other people via mosquitoes. “Transmission so far always seems to be purely zoonotic, requiring the monkey hosts to be involved in the transmission pathway,” he said, adding that the disease has also been shown to respond well to current malaria treatments.
The new malaria was found in Sabah and has recently been added to the list of known human malarias. Its natural hosts are macaque monkeys in Southeast Asia, but over the last decade, it has been found in the human population and now is the most common human malaria in Borneo.
Over the past two decades, Malaysia has made extraordinary progress in eliminating malaria and because of this, the importance of P.knowlesi has become apparent.
“Relatively little is known about how and why it has crossed over into the human population. Investigators from the ‘Monkeybar’ project, which aimed to explore the new malaria, are working with scientists from the UK, Australia and the Philippines to better understand the workings of this malaria and the risk it poses to the human population in Sabah,” he said.
The five-year project is now in its third year and is in the midst of collecting some unique data through a case control study that provides clinical information on people with malaria. The data were collected based on human movement (collected using handheld GPS devices), monkey movement (from GPS collars on wild monkeys), mosquito densities and biting behaviours (from mosquito traps placed in a variety of habitats) and land use (using a drone or unmanned aerial vehicle to map the area) to see where and when the disease is being transmitted.
According to the data, macaque movement has shown that they will move when the forest they are in is disturbed, which supports the theory that changes in land use are somehow implicated in transmission to humans.
However, this hypothesis needs more work before any conclusions can be made. Drakeley said this during a workshop attended by scientists from Malaysia, the Philippines, United Kingdom and Australia last week, aimed to review the ‘Monkeybar’ project.
The plans formed at the workshop will determine what work needs to be done in the final two years of the project to see how much of the disease is really present in Sabah and what the risk factors are for acquiring it.
The workshop was hosted by Principal Investigator for the Malaysian activities from the Malaysian Ministry of Health, Dr Timothy William and Drakely who is the Principal Investigator from the United Kingdom.
