by Malaria Q&A
QUESTION
Will malaria present without splenic enlargement?
ANSWER
Splenomegaly is commonly one of the early and consistent signs of malaria, with the spleen being palpable sometimes as early as the first paroxysm but usually becoming noticeable after the first week of illness. However, absence of splenic enlargement does not eliminate malaria as the cause of illness, and a blood test should be used to confirm diagnosis.
by Malaria Q&A
QUESTION
What is a malaria parasite?
ANSWER
A malaria parasite is a single-celled protozoan of the genus Plasmodium. These parasites have a complex life-cycle, which involves sexual reproduction in a mosquito vector, plus cycles of asexual reproduction and multiplication in a human host (or other animal – other primates, rodents, birds and reptiles can also be infected with Plasmodium parasites). A diagram of the life cycle is below, courtesy of CDC.
by Malaria Q&A
QUESTION
My two year old daughter was affected by malaria 9 months back we took proper course and also the follow up course of 6 weeks. After 2 months post 6 weeks she was infected again by malaria and now again she is getting fever and fear this could be malaria again.
ANSWER
If you suspect she might have malaria again it is important you go and get her tested immediately, as then the doctor can prescribe appropriate treatment. This is particularly important for young children, as they are most susceptible to severe malaria. You should also try to find out what type of malaria she had/has. Repeated attacks of malaria can occur three ways. The first is re-infection – the first infection was cured by the medication, but then your daughter was exposed to malaria again, through the bite of an infected mosquito. Preventative measures, such as making sure she sleeps under a long-lasting insecticide treated bednet, can help reduce the risk of re-infection. Secondly, it could be what is called “recrudescence” – this is when the treatment brings the number of parasites in the blood below detectable levels, and low enough so that symptoms subside.
However, once the treatment course stops, the parasite is able to replicate in the blood again, and symptoms return. This is rare if the full, proper course of medication is taken – in most circumstances, Coartem (artemether plus lumefantrine) should be the first line of treatment and it is very effective against preventing recrudescence. Finally, there is relapse. This only occurs with two species of malaria: Plasmodium vivax and Plasmodium ovale. In this case, the parasite is cleared from the blood by the treatment, but some parasites escape by laying dormant in the liver. These can then reactivate weeks, months or even years after the initial infection. Normal malaria medication can be given to treat relapses of infection, but an additional drug, called primaquine, should also be given, to kill the remaining dormant liver stages. Your doctor should be able to tell you whether he would recommend this drug for your child – they should also be tested for G6DP deficiency prior to taking the drug.
by Malaria Q&A
QUESTION
When was malaria first detected?
ANSWER
Humans have known about malaria as a disease for thousands of years. The earliest written record of malaria is from ancient China, 2700 BCE. The ancient Romans and Greeks also described the symptoms of malaria, though none of these ancient people knew the true cause or had identified specifically how it was transmitted. This was first achieved in the 19th century, first in 1880 by Charles Louis Alphonse Laveran, who observed the parasites that cause malaria in the blood of a patient. A few years later, in 1897/1898, Ronald Ross discovered that the parasites were transmitted between hosts via mosquitoes, thus laying the foundations for future decades of malaria control efforts.
by Malaria Q&A
QUESTION
What is the largest outbreak in the world from malaria?
ANSWER
Most parts of the world don’t suffer from malaria “outbreaks” in the traditional sense of the world. Instead, malaria is “endemic,” which means that transmission is on-going all of the time. In some cases, transmission is seasonal, but each year’s level of disease incidence is similar to the next year’s. Having said this, despite no major and obvious “outbreaks” malaria has probably killed more people in history than any other disease.
Outbreaks of malaria do occur in places where malaria is not usually found, though these are usually small and isolated. For example, while Jamaica was previously malaria free, an outbreak in 2006/2007 resulted in 370 cases. By the end of 2007, it had been declared malaria-free once more, as transmission was interrupted. In 2002, a man with Plasmodium vivax caused an outbreak among 10 fellow campers at a camp site in Northern Queensland, Australia. In the US in 2008, almost a thousand cases of malaria were reported, though most of those were imported cases from travellers who had recently returned from malaria endemic areas, and therefore did not get infected within the US.
by Malaria Q&A
QUESTION
Who discovered malaria?
ANSWER
People have known about malaria for thousands of years—the first record of it comes from 2700 BCE, in an ancient Chinese medical text. Other ancient peoples, such as the Egyptians, Greeks and Romans, also knew the symptoms associated with malaria. But it wasn’t until the 19th century that the causes of malaria were understood. In 1880, a French physician named Charles Louis Alphonse Laveran first saw the parasites that cause malaria in the blood of a patient. By 1886, Camillo Golgi, an Italian physiologist, had observed that there were at least two separate types of malaria, which produced different length cycles of fever during the clinical presentation. These two forms were later called Plasmodium vivax and Plasmodium malariae. It wasn’t until more than a decade later, in 1897/1898, that the method of transmission of malaria was first understood – Ronald Ross, a British army doctor, showed that malaria could be passed from a human patient to a mosquito vector, and also between infected hosts using mosquitoes. He won the Nobel Prize for medicine for his work in 1902.
Since then, research on malaria has expanded exponentially, with particular attention giving to understanding ways in which the parasite can be therapeutically halted, thus leading to the discovery of new malaria medications.
by Malaria Q&A
QUESTION
does malaria still exist?
ANSWER
Yes, malaria still exists, and is responsible for 250 million cases of illness every year, of which about 700,000 result in death. So it is a very serious global health problem!
Some countries, such as the United States, have managed to successfully eliminate malaria through a combination of vector control strategies (i.e. spraying for mosquitoes, reducing the presence of water bodies where mosquitoes breed, etc) and better health infrastructure for diagnosis and treatment. This strategy has also been successful in other settings, such as the Mediterranean and much of the Middle East, as well as even in some high transmission tropical settings such as Malaysia (particularly in urban areas).
The widespread distribution of long-lasting insecticide treated bednets has further assisted in malaria prevention in high transmission areas. However, much of the rest of the world is still struggling to control malaria, though the number of deaths is dropping every year, and some organisations hope to reduce malaria mortality to zero by the year 2015.
If you have taken medications for malaria, please help Malaria.com by taking our Malaria Survey. Thank you!
by Malaria Q&A
QUESTION
How do I prevent malaria?
ANSWER
There are a number of ways to prevent malaria. These can be placed into two categories: medication and vector protection.
For medication, there are drugs you can take to prevent the malaria parasite from developing after someone is bitten by an infected mosquito. These drugs are known as “chemoprophylaxis”. There are several different kinds, such as doxycycline, mefloquine (marketed as Lariam), atovaquone-proguanil (marketed as Malarone) and chloroquine – the type you use depends on the type of malaria present in the area. For example, in much of Africa and India, malaria is resistant to chloroquine, so this cannot be used as a prophylactic. In parts of Thailand, resistance to mefloquine has emerged. However, if the appropriate type of prophylaxis is used, it is very effective against malaria. The problem is that these drugs have not been tested for long-term use, can be expensive and may have side-effects. Therefore they are of limited use for people who live in areas where malaria is endemic, and are more appropriate for travellers who are in malarial areas for short amounts of time. However, anti-malarial medication may be used in a very specific way for people at particularly high-risk for malaria, such as pregnant women and young children. In these cases, the high-risk individuals receive a dose or series of doses of malaria medication in order to prevent malaria. This form of prevention is known as intermittent preventive therapy (IPT).
Vector prevention involves protecting oneself against getting bitten by mosquitoes. This can involve wearing long-sleeved clothing in the evenings and at night, when malaria mosquitoes are most active, or wearing insect repellent on exposed skin. Indoor residual spraying, whereby repellent and insecticides are sprayed inside the house, can also be used to bring down the number of mosquitoes. Another very effective technique for preventing malaria is to sleep under a long-lasting insecticide-treated bednet. The mesh acts as a barrier against the mosquitoes, and the insecticide impregnated in the mesh further repells the mosquitoes and prevents them from biting through the mesh.
by Malaria Q&A
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.
by Malaria Q&A
QUESTION
My son is playing tennis in Rwanda, Africa. He feels terrible and I suspect it may be the Lariam. He has a fever and has been seeing stuff like snakes, etc. I am very worried as there is no doctor nearby. Is there anything to do to help him? The last Lariam he took was on Saturday.
ANSWER
Certainly Lariam is associated with some severe side effects, which include hallucinations such as that which you describe. Unfortunately, the best way to deal with the side effects of Lariam is to stop taking the drug.
If your son decides to do this, I strongly suggest he looks into taking a different malaria prophylactic for the remainder of his trip in Rwanda—doxycycline is readily available from most pharmacies in the region and is very modestly priced. Your son will probably need to take one tablet (100mg) every day (if he is under 8 years old the dosing is slightly different) and should be continued for 4 weeks after he leaves the malarial area. Side effects to look out for include severe sun sensitivity, so he should be diligent with sun block if he starts taking doxycycline.
A more expensive alternative is Malarone, which is also harder to find in Africa, but which has milder side effects and only needs to be taken for a week after returning home.
We are always very interested in our readers’ experiences with malaria preventative drugs and treatment, and we actually have a survey about malaria prophylaxis up on our home page at the moment&mdsh;please have your son take our Malaria Survey when he gets a chance.