Malaria, the subtle world killer disease

Malaria transmission: Anopheles Mosquito feeding on a victim's blood
EJ
Emeh Joy

Before COVID-19 came into the picture, ask people to list top killer diseases and listen to them reel off diseases like cancer, HIV/AIDS, tuberculosis etc. but hardly malaria. It is easy for people to skip this disease, but it will shock you to know that it is among the top killer diseases globally.

Most people don't know this, but malaria is a life-threatening disease; it can be fatal. World Health Organization estimated that in 2015 alone, up to 438,000 people died of malaria. The Institute of Health Metrics and Evaluation (IHME) put this figure at 620,000 in 2017.

As of 2011, BBC reported that the disease kills an estimate of 800,000 people annually and tagged its ravages second only to that of tuberculosis.

Maybe we do not notice people dropping dead as it was reported in the case of Ebola and Covid-19 but do you know that Ebola which first appeared in 1976 (according to WHO) killed approximately a total of 6,250 people as of 2014.

Malaria, in contrast, has led to the death of up to 50 billion people, according to report from journalist Sonia Shah's book, "The Fever: How Malaria Has Ruled Mankind for 500,000 Years". The book did explore the history of this deadly disease.

Worldwide malaria situation report according to WHO

And I hear people ask, "Do people still die of malaria". Yes, the malaria days are not yet gone. People still die of malaria except that nowadays there are available treatment options and more drugs available for managing the ailment.

What is malaria?

Malaria is a life-threatening blood disease caused by mosquito infection. It is transmitted through the bite of an anopheles mosquito which has been infected by the Plasmodium parasite. The mosquito bites its victim, thus, releasing the parasite into the victim's bloodstream.

Once the parasites gain entrance into the body, they travel to the liver where they mature. They can lie dormant here for up to a year before maturity, but when they mature, they get into the bloodstream where they start causing damages infecting the red blood cells.

They multiple inside the red blood cells within 48 to 72 hours, thus causing the infected cells to burst open. Continous infection of the cells results in cycles of symptoms that last 2-3 days at a time.

Malaria is more common in the tropical and subtropical climates like Africa because this is where the parasites live and thrive.

Causes of malaria and mode of transmission

Malaria is caused by a bite from an anopheles mosquito infected with the Plasmodium parasite. Four primary species of the Plasmodium infects humans- Plasmodium falciparum, Plasmodium vivax, Plasmodium ovale and Plasmodium malariae.

The Plasmodium falciparum causes the most severe form of the disease as those infected by this particular specie have a higher risk of dying. See how the cycle plays out:

  • An uninfected mosquito gets infected when it feeds on someone who already has malaria.
  • The mosquito bites someone without malaria and transmits the parasite (in the form of sporozoites) to the new person
  • The parasite now in the body of the bitten victim travels to the liver where it lies dormant multiplying asexually over the next 7-10 days and causing no symptoms.
  • After maturity, they are released into the bloodstreams where they invade the red blood cells. It is at this point that people typically start developing malaria symptoms.
  • An uninfected Anopheles could bite this new victim at this point and become infected with the malaria parasite. It further transmits this parasite to another victim and on and on the cycle goes.

Life cycle of the plasmodium parasite from the vector (mosquito) to the host (humans)thus, causing malaria

So, you can see mosquitoes are the culprits that carry this disease around. But, since malaria is a blood disease, there other ways it can be transmitted such as:

  • Transmission from mother to her unborn child
  • Via blood transfusions
  • Through the sharing of needles

Signs and symptoms of malaria

Common signs and symptoms of malaria include:

  • Headache
  • Fever
  • Chills
  • Nausea and vomiting
  • Muscle pain and fatigue
  • Sweating
  • Pain in the chest or abdominal region
  • Cough

Risk factors for malaria

There are different malaria parasites causing havoc in different parts of the world. Certain factors increase the risk for malaria and predispose people to the ailment. Some of the risk factors or people at higher risk include:

  • Living in African countries especially in the south of the Sahara desert
  • Living in the Asian subcontinent
  • Residing in the Dominican Republic, New Guinea and Haiti
  • Younger children and infants
  • The elderly ones
  • Pregnant women and their unborn babies
  • Travellers migrating to areas of high risk from areas with no malaria

Malaria complications

Malaria can be fatal, particularly in the tropical part of Africa. According to the Centers for Disease Control (CDC), about 91 per cent of all malarial deaths are in Africa continents, and childer under the age of five are mostly affected.

Every 2 minutes, a child dies of malaria

Most times, malaria infections cause serious health complications which in turn lead to death. Some complications that can arise from malaria infections include:

  • Anaemia: This is a condition characterized by a reduced supply of oxygen to the tissues either as a result of the shortage of haemoglobin or shortage of red blood cells. This complication is not surprising considering the fact that the parasites invade and destroys the red blood cells.
  • Cerebral malaria: This is a more extreme case of malaria where blood cells which have already been invaded by the parasites block small blood vessels located in the brain. It can cause the brain to swell. It can also cause seizures, coma or brain damage.
  • Organ damage and failure: Malaria can cause liver and kidney failure. In some cases, it causes rupture of the spleen. These conditions are all life-threatening.
  • Breathing problems: Malaria can make fluid to accumulate in your lungs, a case known as pulmonary oedema. This can make breathing difficult.

How can malaria be prevented?

It is noteworthy to say that advances have been made when it comes to devising drugs and treatment methods for malaria, but as we know, prevention is better than cure.

One of the challenges of the treatment options is the issue of drug resistance and the fact that each specie of malaria has a treatment method that is more effective for it.

There are things we can do to evade this deadly disease and at least reduce its rate of transmission, especially in the high-risk area of Africa.

We can take measures that will help cut down the population of mosquitoes such as clearing up gutters to we would not have stagnant waters lying around and also filling up ditches which are breeding grounds for mosquitoes.

The Populace should also be educated on malaria, its symptoms and the havoc it wrecks. Early diagnosis of the condition can also help it to be treated successfully.

People staying in the mosquito prone areas should take it upon themselves to protect themselves from these monster insects by covering up their skin, wearing long pants and long-sleeve shirts. Applying insect repellants containing DEET is also helpful in combating mosquitoes and their bites.

Insecticide-coated bednets should also be made available to the public. According to a report by the World Health Organization, the use of such bednets was able to reduce the incidence of the disease by as much as 35%.

Is there available malaria vaccine?

So far, no malaria vaccine has been approved for use in humans. However, scientists are working towards having a vaccine available to help combat malaria.

Scientists all over the world are working to see that an effective vaccine is developed for malaria, but so far, no vaccine has been approved for use on humans.

Different factors have made it quite challenging to develop a vaccine for malaria. The malaria parasite has a complex genetic structure and infection presents with as much as thousands of antigens in the body of the infected.

Also, the parasite passes through different life stages with each stage presenting different antigens to the immune system. It is difficult understanding which of these should be targeted for vaccine development.

These and other factors have caused an impediment to the formation of an effective malaria vaccine.

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