Zoonoses is the term used to describe those diseases which can be, and routinely are, transferred, from animals to humans, with the category currently including the likes of: Ebola, Rabies, Leprosy and Anthrax. However, in recent years another disease has been increasingly making the transition from animals to humans, this is Plasmodium Knowlesi, also known as ‘Monkey Malaria’.
Commonly found in primates in South-East Asia, the first reported case of infection in a human was in 1965 and it currently accounts for up to 70 percent of all malaria cases in areas where it is mostly found, such as Sarawak. Though many Asian nations have reported cases of the virus, such as Thailand and Cambodia, it is yet to be discovered in Africa.
As periods of treatment become ever smaller, due to the continuing evolution of the virus, the chances of permanent damage are increasing.
Transmitted through infected blood, the disease is carried from mosquitos who have ingested an infected primate’s blood and is then passed to humans through a second bite, with the loop of infection generally remaining closed. However, recent research has revealed the disease appears to be adapting in such a way that it will soon be easily transferable from human to human. A recent academic article examining the reproduction of the virus and its effect on red blood cells, suggests that the virus is adapting more readily to human blood by making use of older blood cells, which previously could not have been infected, causing it to spread through the human body quicker and more efficiently, as it does in the macaques it usually inhabits.
This is in part due to deforestation in areas, especially in Malaysia, which is forcing infected primates out of their natural environment and into close proximity to humans.This in turn is leading more humans being bitten and infected, exposing the virus to more human cells and allowing it more opportunities to adapt and mutate within the human body.
Manoj Duraisingh, a professor of immunology and infectious disease at the Chan School of Public Health at Harvard, and one of the lead authors of the latest paper to examine Plasmodium Knowlesi has noted that in certain areas with higher rates of virus, the normally milder virus than other strands of Malaria has become increasingly more potent. Symptoms include spikes of high fever and respiratory distress, with higher death rate amongst those who have the virus, showing just how the virus is adapting to human red blood cells. Due to the viruses 24 hour erythrocytic cycle, the amount of corrupted cells in the body can grow quickly, making this adaptation to human cells even more worrying in regards to the ability to treat patients. Currently the disease is treated with Chloroquine and primaquine which when applied aggressively in the earlier stages of the disease can serve as a complete cure. However as periods of treatment become ever smaller, due to the continuing evolution of the virus, the chances of permanent damage are increasing. This is especially true in regards to the liver, where the virus initially travels to when the human host contracts it.
Plasmodium Knowlesi could prove to be one of the next severely infectious diseases.
Another fear is that, with the clear adaption abilities of the virus, it may not be long before the virus has the ability to transfer directly from human to human through bodily liquids. This combined with the short time it takes to corrupt a large amount of cells in the human body could lead to Plasmodium Knowlesi proving to be one of the next severely infectious diseases.