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Malaria in plain english Vol II

Virus or disease transmitted by mosquito illustration conceptWelcome to Malaria in plain english volume II. Yep, you guessed it, this is the second installment of the “Malaria in plain english” series. It is highly recommended that you start with ”Malaria in plain english Volume I” if you haven’t already read it… it is a nice segue to this article, and will give you a generally decent historical understanding of the disease.

In this installment of the malaria in plain english series, we’ll discuss some of the important scientific concepts that are central to understanding how this lethal disease works. In line with the usual conversational tone that most of the articles on our blog are written in, we will convey most of this information as answers to frequently asked questions that everyday folks like us tend to have about malaria.

 

Malaria Science 101

Why do mosquitoes bite us?
Simple answer. They need the proteins found in animal blood to nourish their eggs, and we happen to be a type of animal.
 
What causes malaria?
A lot of people probably erroneously think that malaria is caused by mosquitoes. The truth is that malaria is actually caused by a family of parasites. You know how you have that one absentee friend that always asks you for money, is never around to help, and just generally drains your energy? Yep… same general idea here. The family of parasites that causes malaria is referred to as “plasmodium”… the most deadly member of that family and the one that I encountered in my youth is called “plasmodium falciparum”. Please don’t get intimidated by the big Latin/German word… all you really need to know is that malaria is caused by a family of parasites with the “surname” plasmodium.
 
How many parasites are there in the plasmodium family?
Well, there are quite a few plasmodium parasites, but when it comes to those that can cause human malaria, there are four of them. Plasmodium falciparum, Plasmodium malariae, Plasmodium ovale and Plasmodium vivax.
 
What’s the connection between malaria and mosquitoes?
OK so if mosquitoes aren’t the cause of malaria, how did that rhetoric sprout up and stay in our collective consciousness for so long? Well the simple answer is that some female anopheles mosquitoes carry the plasmodium falciparum parasite in their salivary glands, transferring them directly to humans when they bite us in search of a blood meal to nourish their eggs. So even though mosquitoes aren’t technically the cause of malaria, they are probably the single most effective carriers of the parasites that cause the disease. Please note that the terms “malaria carrier” and “malaria vector” are used interchangeably in scientific circles.
 
Where do mosquitoes lay their eggs?
Those of you who grew up in a tropical climate like I did know that mosquitoes like to lay their eggs in relatively warm stagnant water. This is why you tend to find a ton of mosquitoes around swampy areas and filthy gutters with poor drainage. To state the obvious, both swamps and nasty gutters tend to smell epically bad, and this fact of life actually led people in ancient times to think that foul smelling air was the cause of malaria. Interestingly, the disease actually got its name from the medieval Italian term for bad air – “mala aria” – which has since morphed into the adopted english word “malaria”.
 
What happens internally when a female anopheles mosquito carrying the malaria parasite bites someone?
When an infected female anopheles mosquito bites someone, the plasmodium parasite gets transferred into the individual along with the saliva of the mosquito. Once in the human system, the plasmodium falciparum parasites find their way to the liver where they incubate for an average of about 1.5 weeks, multiplying thousands of times over. This is why people usually don’t feel any ill effects of a malaria infection immediately after a mosquito bite. Next, the legion of parasites are released from the liver into the bloodstream where they infect and take over red blood cells to further multiply. This infection and destruction of red blood cells occurs in a cycle which is to say that after a parasite multiplies thousands of times over and destroys a red blood cell, the numerous offspring of that parasite seek out other red blood cells to multiply in and effectively destroy. This mass depletion of red blood cells causes general weakness because without red blood cells to transport oxygen to the organs and tissues, the body has a very hard time functioning optimally.

Malaria. Normal and infected red blood cells. Malaria is a disease caused by a parasite called Plasmodium that is spread to humans by the bite of an infected mosquito
Malaria. Normal and infected red blood cells. Malaria is a disease caused by a parasite called Plasmodium that is spread to humans by the bite of an infected mosquito

The astute amongst us might be wondering why the immune system doesn’t detect and destroy the malaria parasites after they are released from the liver into the bloodstream before they have a chance to infect red blood cells. This is partly because the parasites are actually “clever” enough to use the remnants of the liver cells they destroy through mass replication as a protective coat to shield themselves from the agents of the immune system.
 
Is malaria contagious?
Not unless your blood gets directly contaminated by something that carries the plasmodium parasite such as an infected mosquito, sharing a syringe with a malaria carrier etc. So unlike the common cold or flu, you won’t catch malaria by virtue of the fact that you are in the same room as someone who has taken ill with it. Unless of course the mosquito that did the infecting is still flying around with bad intentions.
 
What are some common symptoms of malaria?
Malaria symptoms typically include fever, fatigue, vomiting, and persistent headaches. It should be noted that although symptoms of a disease are generally unpleasant to experience, they are usually a good sign that the immune system is fighting like hell to get the body back to normal. Symptoms of malaria only start to occur when the parasites have been released from the liver into the bloodstream. Typically, no symptoms are evident during the initial phases of infection and replication that occur in the liver.
 
Can a human immune system fight off malaria all by itself?
Although I don’t personally know of any cases where someone’s immune system was able to dispose of the malaria parasite without any outside help, I cannot say that it is completely impossible. For the most part however, you will generally need medical care and externally administered medication to overcome a bout with malaria.
 
Is malaria a lethal disease?
Oh you better believe malaria can be lethal. If you have recently been to a tropical climate and have since developed a fever/are vomiting all over the place, please stop what you are doing and go see a Doctor immediately.
 
Is there an antidote to malaria?
Thankfully, the answer to that question is YES. There are a few malaria medications out there but the one I took every time I got malaria growing up is “Chloroquine”… a major active ingredient of which is “quinine”. If you’re interested in how the name “quinine” came about, read volume I. Fun fact is that quinine is also the stuff that is responsible for the characteristic bitter taste of tonic water.
 
How can one prevent malaria?
There are a couple of preventative measures you can take to stay protected from malaria if you live in a tropical climate. I’ve listed some of them (not necessarily in order of importance) below.

  1. Sleep under a mosquito net:
  2. Keeping the mosquitoes out while you sleep ensures that they cannot bite and/or infect you

  3. Sleep in an air conditioned room:
  4. Mosquitoes don’t like the cold… enough said

  5. Do not allow areas of stagnant water to persist in your environment:
  6. Areas of relatively warm stagnant water attract mosquitoes because they are prime locations for laying eggs. Consistently ridding your environment of stagnant water will make it less attractive to mosquitoes.

  7. Take malaria medication:
  8. That’s right… the same drugs that cure malaria such as chloroquine are also pretty effective at preventing it. So if you are going to a tropical climate, make sure you take some malaria medication as a preventative measure. Be warned too that some plasmodium parasites have adapted to become resistant to some malaria medications so be sure to talk to a health care professional who can select one that is still effective.

 
What’s this business with malaria resistant sickle cell carriers?
For some weird reason that the scientific community still doesn’t fully understand as I type this in 2016, people who are carriers of the autosomal recessive sickle cell trait are more resistant to malaria. Let’s break that down.

Under normal circumstances, almost all of us humans have two copies of each gene. For those of us who might not know, a gene is a DNA sequence that carries the information the body needs to construct very important functional proteins. Nature in her infinite wisdom allows for this redundancy so that if there is a problem with one copy of a particular gene, the body can make do with the other copy most of the time. The “problems with particular genes” that we refer to here are technically known as mutations. No… these mutations don’t usually give you adamantium claws like Wolverine, or Telekinetic abilities like Jean Gray. For mere mortals like us, these mutations can actually have a devastating effect on our health and quality of life.

One such potentially harmful mutation is the autosomal recessive sickle cell trait. Just so you know, the term “autosomal recessive gene” refers to a gene where just one functional copy is sufficient for any of us to live completely normal healthy lives. Anyhow, people with this mutation have red blood cells that are sickle shaped rather than the normal biconcave disc shape. Scientists have speculated that perhaps this change in the shape of some of the red blood cells in carriers of the sickle cell trait makes it extra difficult for the plasmodium parasites to invade them and use them as self replication tools. All speculation aside, the truth is we still don’t know the exact story behind why this mutation confers malaria resistance, but I can personally attest to the truth of this fact. Personally, neither of my sickle cell genes are mutated, but my mom has one mutant copy. As a young lad growing up in Nigeria, I fell ill with malaria probably upwards of 7 times and recovered each time thanks to my family. On the other hand, I can’t remember even one instance where my mom who is a carrier of the sickle cell trait ever took ill with malaria. As I look back now with a more developed brain and a deeper scientific understanding, it seems fairly plausible that her sickle cell mutation must have protected her to some extent.
 
 
In conclusion, malaria is a powerfully lethal disease. So powerful in fact that for better or worse, it has had a hand in shaping the genetics of the people of my native Western Africa by virtue of the fact that individuals with a specific mutation of the sickle cell gene continue to be selected for because of the resistance to malaria it confers upon them. Thankfully, our current level of scientific understanding has given us proven antidotes to this disease that save a multitude of lives each day. That being said, there are still corners of the globe in which children are robbed of the time required to truly discover their potential because their lives are tragically cut short by this disease. There are some amazing individuals such as Bill and Melinda Gates who are doing their best to eradicate this disease from the planet. I salute them. It buoys the spirit to know that people who have it all still have the compassion in their hearts to voluntarily help the less fortunate. From all us here at chubaoyolu.org, please take care of yourselves and each other.
 
 
Without Wax
Oyolu B.C. Ph.D.
chubaoyolu.org
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One thought on “Malaria in plain english Vol II

  1. […] to have a look at the science behind this rather deadly disease. That will be the focal point of the second part of this article series so stay tuned for the next installment. From all of us here at chubaoyolu.org, please take care of […]

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