Malaria is a mosquito transmitted deadly disease. It can be fatal if not diagnosed quickly. The first reported case of malaria was in 1880, following an investigation by Mr. Alfons Lavarn. The epidemic caused 405,000 deaths in 2018 alone. Malaria kills more than 400,000 people each year and most of them are children under age five. Normally, around 250,000 of these deaths occur in African region. This article mainly focuses on how to prevent malaria and microbial contribution for it.
Causes of Malaria
- Plasmodium falciparum – These are the main types of parasites that cause malaria. This species is found mainly in Africa and the highest number of deaths in the world due to Plasmodium falciparum.
- Plasmodium vivax – This species, which is mainly found in Asia and South Africa, is not as dangerous as Plasmodium falciparum. But these parasites can live in the host’s liver cells for about 3-4 days, resulting in relapses
- Plasmodium malariae – This type is not so common. Found only in Africa.
- Plasmodium ovale – This species is less common and usually found in West Africa. But parasites of this species can live for many years without showing any symptoms in people’s liver. This species is very rare and found only in South Asia.
- Plasmodium knowlesi – This type is not so common. Found only in South Asia .
These Plasmodium parasites transmitted from one person to another using predominantly female Anopheles mosquitoes. About 460 species of Anopheles mosquitoes have been identified and about hundred of them contribute to the spread of malaria to humans.
How Malaria is spread?
Anopheles females’ mosquitoes can transmit the disease, and malaria does not spread directly from person to person. Most viral diseases spread through air, but malaria is not spread through air. When an infected mosquito bites an infected person, who has not already been infected with malaria, the mosquito will also spread to other people.
After Infected Anopheles mosquito bites, the parasites enter the bloodstream of the human and travel to the liver. There are two stages of disease development. One is the exoerythrocytic phase in the liver and the other is the erythrocytic phase in red blood cells. When bitten by an infected mosquito, sporozoites of the mosquito’s saliva enter into the bloodstream. Then sporozoites migrate to the liver and infect the hepatocyte tissues, while they multiply asymmetrically and asexually within 10 to 30 days.
After the breakdown of the host’s cells, the merozoites enter the bloodstream and infect the blood cells, which in turn initiate the erythrocytic phase of the blood cells. In red blood cells, parasites multiply further. They can break from host cells and invade new red blood cells. Several such cycles can occur in one infection. The fever arises simultaneously due to merozoites escaping and infecting red blood cells.
Human immune system is unable to detect Plasmodium parasites. Because, the parasites most likely live in the liver and red blood cells. Similarly, sequestered red blood cells can break down the barrier between the blood and the brain, resulting in cerebral malaria. Sometimes, red blood cells are unable to carry enough oxygen around the body, leading to drowsiness that resulted Severe anemia.
Can Malaria be 'completely stopped' by microbes?
Nowadays, scientists are more interested in using biological pest control to prevent diseases. As a result, a bug that lives in the guts of mosquitoes has been found to fight against malaria. The researchers found an amazing organism called Microsporidia MB from shores of Lake Victoria in Kenya. Microsporidia are a group of spore-forming single-celled microbes, Earlier Scientists considered them to be protozoans or protists, but are now known to be fungi, or a related group to fungi. They are unicellular parasites and commonly infect insects, but they are also responsible for common diseases of fish and crustaceans. Usually they live in the gut and genitals of the insects.
Researchers suppose the bug may either be priming the mosquito’s immune system to fight against the malaria parasite, or it may cause an effect on the insect’s metabolism. Therefore, they make mosquitos inhospitable for the malaria parasite. Actually, the researchers are unable to find a single mosquito carrying the Microsporidia that was harboring the malaria parasite. Therefore, they confirmed the microbe gave the mosquitoes protection. Dr. Jeremy Herren, who led the research told the BBC; “According to data available so far, this bug will be blocking malaria 100%“.
When can we see a result?
This research recently published on their findings in the journal Nature Communications. They said that, now they are searching for ways to increase the number of bug infected mosquitoes. Because, at least 40% of mosquitoes in any area should need to be infected with the bug to significantly against malaria. Microsporidia can transmit between adult mosquitoes and is also transmitted from the female to their offspring. Researchers are going to use two strategies for increasing the number of infected mosquitoes. First one is the making of a large number of Microsporidia spores that can infect mosquitoes. Second one is the effect of male mosquitoes with Microsporidia’s that can transmit bugs to females when they mate.
Other prevention methods of malaria
- Awareness of risk – The public should be made aware of malaria regularly through social media networks and family planning doctors. It is also important to understand about the spread of malaria in different countries of the world before travelling to them. Because, if you go to a country where there is no malaria, you have a higher risk of contracting the disease.
- Bite prevention – There are many different ways to guard against mosquitoes. Mosquito repellents lotions apply on the body to reduce the mosquito attraction. You can also use mosquito coils. Keeping your surroundings clean is also important. Because, if there are no places to put eggs of Mosquitoes, their population goes down with the time.
- Check whether you need to take antimalarial drugs – if you do, make sure you take the right antimalarial tablets at the right dose, and finish the course.
- Diagnosis – Take immediate medical advice if you develop any malaria symptoms.
In 1955, the World Health Organization (WHO) launched the Global Malaria Eradication Programme (GMEP), and the ambition of it is to eradicate malaria worldwide. Few countries ( Bulgaria, Cyprus, Dominica, Grenada, Hungary, Italy, Jamaica, Netherlands, Poland, Romania, Saint Lucia, Spain, Taiwan, Trinidad and Tobago, Australia, Brunei, Cuba, Mauritius, Portugal, Réunion, Singapore, Yugoslavia United States of America, Venezuela, Sri Lanka) noticed as malaria-free by the World Health Organization. This success was the result of over a century of efforts that combined disease surveillance, vector control, disease prevention programmes and treatment.
Pasindu Chamikara – Microbiologist