Ella, 17, is a science student and enthusiast of all things quantum physics. She has recently completed a research project in Caenorhabditis elegans, a nematode worm linked to epigenetics research. Provided she doesn't fail her upcoming exams, she hopes to study medicine with a focus on forensic pathology.
.To understand this question, we first need to understand malaria. Malaria is caused by the Plasmodium protoctist (a tiny eukaryotic organism that is not plant, animal or fungi). There are several different types of Plasmodia parasites, but only five cause malaria in humans, most notably Plasmodium falciparum. The Plasmodium parasite is spread by the bite of the female Anopheles mosquito. When an infected mosquito bites a human, it passes the parasites into the bloodstream in a form called the sporozoite (1) . This travels through the blood vessels to liver cells, where it asexually reproduces, resulting in merozoites. These infect new red blood cells and asexually reproduce, thus producing more merozoites. The cell then bursts, and the cycle continues (2).
Typically, the time between infection and when symptoms start (incubation period) is 7 to 18 days, and this depends on the Plasmodium which has infected the host. The initial symptoms of malaria are flu-like and include headache, fever, vomiting and nausea. It can be difficult to identify as malaria, as the symptoms are generic and often mild. With some types of malaria, the fever occurs in 48-hour cycles. The most severe cases of malaria are caused by Plasmodium falciparum. Without rapid treatment, this type can lead to the host developing severe complications, such as breathing problems and organ failure (1).
Now that we’ve seen how malaria infects a human and how it develops, we can talk about preventative methods. The most efficient way to combat malaria would be a vaccine, but this presents several problems.
The first problem is that the immune system rarely detects the pathogen until it’s too late; the pathogen uses the host’s own cells to prevent detection, and are only free in the bloodstream for short periods of time, while they are infecting other cells (3).
An additional problem is that creating a vaccine typically involves inactivating the whole bacterium or virus, then injecting it as the vaccine. This is very difficult, albeit doable, with malaria. However, the protoctist is difficult to grow in the lab, so has not been possible so far (4).
Protoctists also mutate rapidly; as a result, another method of creating vaccines (the removal of antigens) is inefficient. One such mutation is a resistance to the strongest drugs against malaria, artemisinin. Despite this significant setback, scientists have developed a marker which can be used to identify artemisinin resistant strains, allowing them to pursue alternative treatments, saving time, money and resources (5).
Because of the difficulty of creating a vaccine, other means of preventing malaria must be used; these include the ABCD approach to prevention:
Despite these difficulties, there have been breakthroughs in malarial research. One such development is research into how the parasite enters red blood cells – there's a vital pathway by which it must infect a cell, hence when antibodies are used to block this pathway, it can neutralise the spread of the parasite (4).
Often, malaria is preventable and with the correct measures taken, it can be avoided, so remember to speak to your GP if you're planning a holiday in a malarial risk zone!
References & Further Reading
1. Malaria - NHS Choices [Internet]. nhs.uk. 2015 [cited 5 August 2017]. Available from:
2. Patricia Schlagenhauf-Lawlor. Travelers’ Malaria, 2nd ed. Ontario, Canada: BC Decker; 2007.
3. Burke D, Choi J. Malaria [Internet]. Healthline. 2017 [cited 5 August 2017]. Available from: http://www.healthline.com/health/malaria#overview1
4. Draper S. Simon Draper: Progress in Malaria Vaccine Research - Nuffield Department of Medicine [Internet]. ndm.ox.ac.uk. 2017 [cited 5 August 2017]. Available from: https://www.ndm.ox.ac.uk/simon-draper-progress-in-malaria- vaccine-research
5. Study shows parasite mutation behind drug-resistant malaria in Cambodia - Fogarty International Center @ NIH [Internet]. fic.nih.gov. 2014 [cited 5 August 2017]. Available from: https://www.fic.nih.gov/News/GlobalHealthMatters/january-february- 2014/Pages/malaria-drug- resistance-mutation-niaid.aspx