What Causes Malaria

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QUESTION

What are the causes of malaria?

ANSWER

Malaria is caused  by infection with certain single-celled parasites of the genus Plasmodium. Specifically, there are five species which infect humans: P. falciparum (the most severe and dangerous form of malaria), P. vivax, P. ovale, P. malariae and P. knowlesi.

The symptoms of the disease occur when the parasite enters the blood stream (after a brief 1-3 week period of development in the liver) and begins to enter red blood cells, reproduce inside them, and then burst out, destroying the cell. The debris caused by this bursting, as well as various other aspects of the process, cause the body to mount an intense immune reaction which results in high fever, chills, aches and nausea. For P. falciparum infection, the infection is particularly severe because the parasite causes red blood cells it infects to stick inside the small blood vessels that lead to major organs, reducing blood flow and causing oxygen deprivation. When this occurs in the blood vessels in the brain, the result is impaired consciousness, unconsciousness, coma and even death – hallmarks of what is known as “cerebral malaria,” which is implicated in many of the deaths related to malaria each year.

Malaria Effects on the Body

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QUESTION

What are the effects of malaria on the body?

ANSWER

Malaria has a number of effects on the body. The parasite passes from the blood (where it enters via the bite of an infected mosquito) into the liver, where it reproduces and changes form. After a period of 1-4 weeks (usually – it can be longer) in the liver, the malaria parasite re-enters the blood and begins to infect red blood cells, undoing more reproduction inside the cells and then, in synchrony, bursting out once the cycle is complete. This process of reproduction and destroying red blood cells results in a build-up of toxins and debris in the blood; the resultant immune reaction produces side effects which are the common observable symptoms of malaria, such as fever, chills, nausea and aches.

One particular type of malaria, Plasmodium falciparum, is also able to modify the surface of red blood cells it infects. It causes these cells to become “sticky”, so they lodge in the small blood vessels leading up to major organs. This build-up is called sequestration, and results in reduced blood flow and oxygen deprivation in the organs. When sequestration occurs in the blood vessels in the brain, the patient may experience impaired consciousness, psychological disruption, coma and even death – this manifestation is called “cerebral malaria”.

If diagnosed and treated promptly, the malaria parasites in the blood can usually be killed rapidly and the patient will soon enjoy a complete recovery. With two forms of malaria, P. vivax and P. ovale, the parasite can remain dormant in the liver for months or even years, resulting in relapse of disease at a later date. To prevent this from occurring, patients with these types of malaria can sometimes take primaquine, a drug which kills the liver stages of the malaria parasite as well.

Symtoms of Malaria

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QUESTION

Please tell me the symptoms of malaria.

ANSWER

Symptoms of malaria include fever and flu-like illness, including shaking chills, headache, muscle aches, and tiredness. Due to the way in which the malaria parasite reproduces in the human body, fevers occurring in a cyclical fashion (i.e. high fever one day, no fever the next day, then recurrence of fever on the third or fourth day, depending on the type of malaria) are a characteristic symptom of malaria, but may not be present in all cases. Nausea, vomiting, and diarrhea may also occur. Malaria may cause anemia and jaundice (yellow coloring of the skin and eyes) because of the loss of red blood cells. Symptoms usually appear between 10 and 15 days after the mosquito bite. If not treated, malaria can quickly become life-threatening by disrupting the blood supply to vital organs. When blood supply to the brain is disrupted during malarial infection, the resulting condition, characterised by seizures, mental confusion, coma, and death, is known as “cerebral malaria”, and is associated with Plasmodium falciparum, the most deadly form of malaria.

Please check your article: Symptoms and Causes of Malaria

Malaria Symptoms

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QUESTION

How does the virus cause the symptoms?

ANSWER

Malaria is actually not caused by a virus—it is caused by a microscopic single-celled parasite called Plasmodium. Several different species cause malaria in humans, the most common of which are P. vivax and P. falciparum.

To describe the process in a very oversimplified way, the malaria parasites cause disease by infecting red blood cells, multiplying inside them, then simultaneously bursting out again, destroying then red blood cell in the process. The sudden destruction of lots of red blood cells, plus the debris and waste products left behind by the malaria parasites, stimulate a rapid immune reaction, which itself causes the rapid spike of fever. The characteristic cycles of fever sometimes seen with malaria sufferers occurs because the malaria parasites synchronise their emergence from the red blood cells. The destruction of red blood cells, together with concurrent physiological changes associated with immune response and inflammation, can also lead to decreased haemoglobin levels and anaemia.

More severe clinical symptoms are often seen with P. falciparum malaria infection, particularly if not promptly diagnosed and treated. This is because the P. falciparum parasite infects a red blood cell, it changes the surface of the cell and makes it “sticky”; when the red blood cell then tries to pass through the small blood vessels that lead into the body’s organs, it becomes stuck. This process is known as “sequestration”. If enough red blood cells become sequestered in the organs, it can reduce blood flow to the organ, resulting in oxygen deprivation. When this happens in the blood vessels in the brain, the patient may experience impaired consciousness, confusion and even coma and death—this manifestation is known as “cerebral malaria.”

Celebral Malaria and Blindness

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QUESTION

I live in Nigeria. Good friend of mine complained of headaches in Dec 2011. Did an MRI went to Germany had a general check up. Back in Nigeria in January, headaches increase, she gets blind in one eye, following day the other eye, now in Germany where they have induced her into a coma. They said that she got a brain Haemorrage from the malaria. Can malaria bring blindness. What are the chances of surviving and getting back eyesight.

ANSWER

Although rare, brain hemorrhage is sometimes associated with severe cerebral malaria (caused by infection with Plasmodium falciparum, the most deadly form of malaria). This bleeding in the brain could cause blindness—whether the visual impairment is permanent or not depends on the extent of the bleeding and how much damage it caused.

I have found one case in the literature where severe malaria caused a brain hemorrhage which resulted in permanent blindness, and the authors report their case is only the second they have heard of, so this is rare indeed. Similarly, her survival will depend on how well she responds to treatment, which will likely be intravenous quinine, at least at first. Given that she is in Germany, where health care is excellent, I would say her chances are as good as they would be anywhere else in the world. I hope she makes a full and swift recovery!

What are the symptoms of malaria?

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QUESTION

What are the symptoms of malaria?

ANSWER

Symptoms of malaria include fever and flu-like illness, including shaking chills, headache, muscle aches, and tiredness. Nausea, vomiting, and diarrhea may also occur. Malaria may cause anemia and jaundice (yellow coloring of the skin and eyes) because of the loss of red blood cells.

Symptoms usually appear between 10 and 15 days after the mosquito bite. If not treated, malaria can quickly become life-threatening by disrupting the blood supply to vital organs. Infection with one type of malaria, Plasmodium falciparum, if not promptly treated, may cause kidney failure, seizures, mental confusion, coma, and death. In many parts of the world, the parasites have developed resistance to a number of malaria medicines.

Dangerous

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QUESTION

Why malaria so dangerous?

ANSWER

Malaria can be dangerous for a number of different reasons, some of which relate to each other. First of all, there are five different types of malaria that infect humans, and each varies in terms of its severity and potential for severe consequences. Even within these types, the severity of the disease caused (termed “virulence” by scientists and doctors), can even vary by strain or geography. Generally, the most dangerous form of malaria is caused by Plasmodium falciparum. One reason why this species of malaria is so dangerous is that is replicates very quickly in the blood. This means that infection levels can build up very quickly; if a person infected with P. falciparum does not get diagnosed and treated within a few days of feeling sick, the infection can progress to a point where the disease becomes very severe. This rapid accumulation of infection is also observed with P. knowlesi, a much rarer form of malaria found in south-east Asia. The parasites of P. knowlesi have a 24-hour reproductive cycle in the blood, the quickest for any type of malaria that infects humans. However, P. falciparum also has other characteristics which make it even more dangerous, and which do not occur with P. knowlesi. For example, when P. falciparum infects red blood cells, it causes their shape to change, and makes them “sticky”. This stickiness causes the red blood cells to become lodged in the blood vessels leading in to major organs, in a process known as sequestration. Sequestration creates blockages of these blood vessels, reducing blood flow and resulting in oxygen deprivation. When this process occurs in the blood vessels in the brain, the outcome is known as cerebral malaria, characterised by impaired consciousness, coma and even death. It is this pathology which is associated with most cases of severe malaria, and causes the most number of deaths.

However, if treated promptly with the correct drugs, even P. falciparum malaria is usually easily controlled. Therefore, one of the additional reasons why malaria is so dangerous is that in many places, and particularly sub-Saharan Africa, people do not have access to medication, or not the right types of medication. Many strains of P. falciparum have become resistant to chloroquine, once the first line treatment for malaria, and so this drugs is now ineffective in many cases. Instead, the World Health Organisation recommends now that artemisinin-based combination therapies (ACTs, such as Coartem) should be given as first-line treatment against all uncomplicated malaria, to prevent additional resistance from developing.

Malaria in the Brain

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QUESTION

I would like to know how dangerous is malaria in the brain?

ANSWER

Only a certain kind of malaria, Plasmodium falciparum, is usually associated with causing problems in the brain. The P. falciparum parasite infects red blood cells and changes their surface structure, causing them to become “sticky”. These sticky red blood cells become lodged in the small blood vessels that flow through organs, causing blockages and reducing oxygen flow.

When this process occurs in the brain, the result is called “cerebral malaria”, and can result in impaired consciousness, coma and even death. As such, once malaria-infected blood passes into the brain, it can be very dangerous. Luckily, however, if people are diagnosed promptly and given treatment, it is usually possible to stop the progression of P. falciparum malaria before it enters the brain, allowing for a swift and uncomplicated recovery.

Why is Malaria Dangerous?

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QUESTION

How does Malaria become so dangerous?

ANSWER

Malaria in humans can be caused by a number of different parasites – the most dangerous, and the one which is responsible for over 90% of the worldwide deaths from malaria, is Plasmodium falciparum.

The reason that P. falciparum is so dangerous is because it affects the behaviour of red blood cells. Red blood cells that are infected with P. falciparum become “sticky”, and as they pass through the the small blood vessels inside the body’s organs, they become stuck – this process is known as “sequestration”. As the number of red blood cells stuck inside the small blood vessels increases, blood flow to the organ is reduced, which can result in further complications. When sequestration occurs inside the blood vessels in the brain, the result is what is clinically recognised as cerebral malaria – complications can include impaired consciousness, coma and even death.

If diagnosed and treated promptly, most cases of P. falciparum can be resolved quickly and without complications, using oral medication. However, the parasite can reproduce very quickly, meaning that cases can become more serious within days and even hours. As such, if P. falciparum infection is suspected, and particularly in high-risk individuals such as young children, pregnant women and immunocompromised individuals, diagnosis should be sought immediately so that appropriate treatment can be delivered.

Aging and Malaria

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QUESTION

Is there any evidence that successfully treated malaria (when young or a young adult), has any deleterious effects for patients in their 70s and 80s? Is risk of vascular disease, stroke, or MIs any greater?

ANSWER

I don’t think there is any evidence for any long-term deleterious effects of malaria that was successfully treated, particularly if the malaria infection was non-complicated and did not result at the time in any severe cerebral complications (coma, impaired consciousness, etc).