Malaria is an acute febrile illness caused by a parasite called Plasmodium. This parasite is transmitted through bites of infected female Anopheles mosquitoes. Malaria is life-threatening and kills thousands every year, however, it’s curable and preventable.
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Table 1: A) Malaria Sporozoites B) Anopheles mosquitoes
To better understand this disease, we should start with the life cycle of the parasite.
An illustration to show the life cycle of the malaria parasite. Image credit: Laura Olivares Boldú / Wellcome Connecting Science
A mosquito carrying the malaria parasite bites a human, injecting the parasite present in its saliva into the human bloodstream. The sporozoites travel to the liver infecting the liver cells quickly and firmly. After infecting the hepatic cells, the parasite acquires a new form called merozoite multiplying into thousands till the cells burst. After burst, they infect red blood cells and keep multiplying.
When the red blood cells burst, they infect new ones, and this process goes on.
If a mosquito bites an infected person, the mosquito becomes infected becoming a disease vector.
Symptoms
The physical effects of malaria occur essentially because of parasite invasion of red blood cells, producing toxins, and causing anaemia, in other words, it decreases red blood cell function.
High temperature, sweats and chills
Headaches and feeling confused
Feeling very tired and sleepy (especially in children)
Feeling and being sick, tummy pain and diarrhoea
Loss of appetite
Muscle pains
Yellow skin or whites of the eyes
A sore throat, cough, and difficulty breathing
Treatment
Malaria is treated with prescription drugs to kill the parasite. The types of drugs and the length of treatment will vary, depending on:
Type of malaria parasite
Severity of symptoms
Age
Pregnancy
Prevention
Vector control is the main way to prevent and reduce malaria transmission. WHO recommends insecticide-treated mosquito nets (reduce contact between mosquitoes and humans) and indoor residual spraying.
Anti-malaria drugs can also be used to prevent malaria. For travelers, malaria can be prevented through chemoprophylaxis, which suppresses the blood stage of malaria infections, thereby preventing malaria disease.
Vaccine
Parasites can adapt and change through the various stages of their lives even in the human host, presenting different antigens in the distinct stages of life. This fact complicates the development of vaccines.
Despite that currently WHO recommends the use of 2 vaccines RTS,S/AS01 and R21/Matrix-M to prevent malaria in infants.
Both vaccines use adjuvants and if you want to know more about vaccines check or post about vaccination.
References
https://www.verywellhealth.com/malaria-signs-symptoms-and-complications-4160602
https://www.who.int/news-room/fact-sheets/detail/malaria
https://www.mayoclinic.org/diseases-conditions/malaria/diagnosis-treatment/drc-20351190
https://www.jenner.ac.uk/about/resources/about-malaria
https://www.malariavaccine.org/malaria-and-vaccines/vaccine-development/life-cycle-malaria-parasite
https://www.malariavaccine.org/malaria-and-vaccines/rtss
Maxmen, A. (2021). Scientists hail historic malaria vaccine approval — but point to challenges ahead. Nature. https://doi.org/10.1038/d41586-021-02755-5
World. (2023, October 2). WHO recommends R21/Matrix-M vaccine for malaria prevention in updated advice on immunization. Who.int; World Health Organization: WHO. https://www.who.int/news/item/02-10-2023-who-recommends-r21-matrix-m-vaccine-for-malaria-prevention-in-updated-advice-on-immunization
Laurens, M. B. (2019). RTS,S/AS01 vaccine (MosquirixTM): an overview. Human Vaccines & Immunotherapeutics, 16(3), 480–489. https://doi.org/10.1080/21645515.2019.1669415
Beeson, J. (2023, February 27). A review of the RTS,S malaria vaccine - efficacy, impact and mechanisms of protection. Research Communities by Springer Nature; Springer Nature. https://communities.springernature.com/posts/a-review-of-the-rts-s-malaria-vaccine-efficacy-impact-and-mechanisms-of-protection
What is malaria? (2021). Yourgenome.org; Wellcome Connecting Science. https://www.yourgenome.org/theme/what-is-malaria/
Malaria Sporozoites vs. Natural Killer Cells 4 | KI Image Awards Archive. (2019). Mit.edu. https://ki-images.mit.edu/2019/demas-4
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