How Long Does it Take to Feel Ill from Malaria?

by

QUESTION

How soon does a person usually to feel ill after malaria infection?

ANSWER

After being bitten by an infected mosquito, there is an “incubation period” before the person begins to suffer from symptoms of malaria. This time corresponds to the period the malaria parasite spends in the liver; it is once it enters the blood and begins to destroy red blood cells that initiate the onset of symptoms. The length of the incubation depends on a number of factors, including the type of malaria and whether the person has been taking anti-malarial preventative medication (prophylaxis), but the usual length of time is between 1-4 weeks.

Can I Catch Malaria from Someone?

by

QUESTION

My fiancee contracted malaria a few years ago. It was diagnosed as recurring. Could I contract malaria from the infected person, I have had similar symptoms which last a day or two, recurring with regular two week intervals, of which the most concerning are malaise, fever, stiff neck, headaches and severe pains over abdomen spreading into my mid back. What should I do?

ANSWER

Malaria cannot be directly transmitted between two people—it is almost always transmitted by the bite of an infected mosquito, and cannot survive at low temperatures (under about 17 degrees C). In some very rare cases, malaria can be transmitted through organ transplant, blood transfusion and pregnancy, since it infects red blood cells. Given these restrictions, it is close to impossible that you contracted malaria from your fiancee, and you should talk to your doctor about alternative explanations.

Also, if your girlfriend has recurring malaria, she should talk to her doctor about taking primaquine. While not suitable for everyone (namely people with G6DP deficiency should not take it), it can kill the dormant stages of the malaria parasite and prevent recurrence.

Malaria Symptoms

by

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.”

Malaria Causes

by

QUESTION

What are the causes of malaria?

ANSWER

Malaria is caused by a parasite called Plasmodium, which is transmitted via the bites of infected mosquitoes. In the human body, the parasites multiply in the liver, and then infect red blood cells. Usually, people get malaria by being bitten by an infective female Anopheles mosquito. Only Anopheles mosquitoes can transmit malaria and they must have been infected through a previous blood meal taken on an infected person. When a mosquito bites an infected person, a small amount of blood is taken in which contains microscopic malaria parasites. About 1 week later, when the mosquito takes its next blood meal, these parasites mix with the mosquito’s saliva and are injected into the person being bitten.

Please see “Malaria Symptoms and Causes” for more.

What are the symptoms of malaria?

by

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.

Malaria in Mosquitoes

by

QUESTION

Why can’t mosquitoes become sick of malaria? What do they have in their system that prevent them from becoming sick yet they transmit the disease to humans?

ANSWER

First of all, mosquitoes do get “sick” when infected with malaria, though not in the same way as humans. This is due to the major differences between human and mosquito physiology and also differences in the life stage of the malaria parasite between the different hosts.

Humans get sick from malaria because the malaria parasite, when inside the human host, sequentially infects red blood cells, multiplying inside them and then destroying them. This process of destruction and the resultant debris in the blood results fever and other symptoms (some of which are exacerbated by the body’s immune response).

Mosquitoes are insects, and do not have blood in the same way as humans. Instead, in the mosquito, the malaria parasites differentiate into male and female life stages (called gametocytes) which fuse into the mosquitoes gut. After further reproduction, they eventually produce sporozoites that rupture out of the mosquito gut wall and migrate to the salivary glands, where they can be infected into a new human host.  

Mosquitoes also have a very different immune system to humans, and so the concept of “sick” is not the same for them as for humans. However, there is a lot of evidence that infection with malaria results in reduced reproductive success for the mosquito, as well as lower survival. This could be due to protective responses on the part of the mosquito, but also could be mediated by the malaria parasite, by diverted resources towards its own development that could have been used for mosquito reproduction or survival.

Malaria Causes

by

QUESTION

What are the causes of malaria?

ANSWER

Malaria is caused by a parasite called Plasmodium, which is transmitted via the bites of infected mosquitoes. In the human body, the parasites multiply in the liver, and then infect red blood cells. Usually, people get malaria by being bitten by an infective female Anopheles mosquito. Only Anopheles mosquitoes can transmit malaria and they must have been infected through a previous blood meal taken on an infected person. When a mosquito bites an infected person, a small amount of blood is taken in which contains microscopic malaria parasites. About 1 week later, when the mosquito takes its next blood meal, these parasites mix with the mosquito’s saliva and are injected into the person being bitten.

Because the malaria parasite is found in red blood cells of an infected person, malaria can also be transmitted through blood transfusion, organ transplant, or the shared use of needles or syringes contaminated with blood. Malaria may also be transmitted from a mother to her unborn infant before or during delivery (“congenital” malaria).

How does one catch malaria?

by

QUESTION

How do you get malaria?

ANSWER

Malaria is caused by a parasite called Plasmodium, which is transmitted via the bites of infected mosquitoes. In the human body, the parasites multiply in the liver, and then infect red blood cells. Usually, people get malaria by being bitten by an infective female Anopheles mosquito. Only Anopheles mosquitoes can transmit malaria and they must have been infected through a previous blood meal taken on an infected person. When a mosquito bites an infected person, a small amount of blood is taken in which contains microscopic malaria parasites. About 1 week later, when the mosquito takes its next blood meal, these parasites mix with the mosquito’s saliva and are injected into the person being bitten.

Because the malaria parasite is found in red blood cells of an infected person, malaria can also be transmitted through blood transfusion, organ transplant, or the shared use of needles or syringes contaminated with blood. Malaria may also be transmitted from a mother to her unborn infant before or during delivery (“congenital” malaria).

Dangerous

by

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

by

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.