Malaria prophylaxis

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QUESTION:

What name brand medicine should you take if you are traveling to area where malaria is present?

ANSWER:

That depends on a few factors, such as where exactly you are going, whether you have had bad experiences with any malaria preventative drugs (prophylactics) in the past, and how much money you want to spend! Common brand names of malaria prophylactic drugs include Lariam (generic name mefloquine) and Malarone (a combination of atovaquone and proguanil). Doxycycline is also a popular antimalarial, which is often sold under its generic name.

Malaria Eradication and Water Quality

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QUESTION:

How will the eradication process of the mosquito larva influence the quality of the water?

ANSWER:

That’s a very interesting question. The answer is that it depends a lot on the way in which the mosquito larva are controlled. The usual, traditional method is through the application of insecticides. Many of these are known to have severe negative effects on water quality, particularly through being non-selectively toxic and therefore killing lots of other aquatic life as well as the mosquitoes. Moreover, some are known for their effects on animals further up the foodchain; the most famous example of this being DDT, which was used to kill adult mosquitoes. It was discovered that this pesticide resulted in birds laying eggs that had very thin shells, preventing the chicks from hatching successfully. As such, it was banned in most developed countries. Modern insecticides used for mosquito larva reduction have been developed to target mosquitoes specifically; a popular one in the USA is methoprene, which interferes with the mosquitoes’ growth hormones, preventing development into adults. Microbial compounds, which are not dangerous to other organisms, are also sometimes used.

Another approach is through the use of natural enemies of the mosquito larvae, notably certain species of fish and dragonflies. These will eat mosquito larvae and pupae, thus naturally reducing numbers, and with little undue effect on water quality (although in some contexts, such as reservoir water, there may be concerns with stocking the water source with large numbers of fish).

G6PD and Malaria

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QUESTION:

Does one need to have a normal result in G6PD screening before he can take Malarial pills?

ANSWER:

In some cases, yes. When a patient has been diagnosed with Plasmodium ovale or Plasmodium vivax infection, in addition to medication such as chloroquine to target the blood stages of the parasite, an additional drug, called primaquine, may also be required. Primaquine kills the liver stages, known as hypnozoites, of these forms of malaria, preventing relapse of infection later on.

However, primaquine is known to cause severe haemolytic anaemia in people who are G6PD deficient. G6PD deficiency is restricted to certain populations or segments of populations; therefore it may be that not every person requiring primaquine will be tested for their G6PD status, only those considered high risk for potential deficiency. Patients with severe G6PD deficiency should not take primaquine; unfortunately at this stage there are no alternative drug regimens available. Patients with mild forms of G6PD deficiency should take primaquine at an alternative dose to G6PD-normal patients, usually 0.75mg/kg bodyweight once a week for 8 weeks (as opposed to 0.25mg/kg bodyweight once a day for 5 or 14 days, depending on the case history of the patient and the physician’s recommendation).

There is also some evidence that quinine can cause haemolysis in patients with G6PD deficiency; such patients may also have increased blood concentrations of mefloquine when taken concurrently with primaquine. As such, combinations of quinine or mefloquine with primaquine in G6PD-deficient patients is not recommended.

Will malaria come back?

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QUESTION:

As a result of a blood test I have just been informed that at some time I have had malaria. Though I have no idea when this was. I once was ill for 4 days with what I thought was flu and that is the only occasion I can remember. Therefore I have never been treated for malaria. Could you please tell me if there is any chance the disease will come back.

ANSWER:

That will depend on the type of malaria you had. I presume you found out you were infected through a blood test – it is likely a test that looked for antibodies to malaria in your blood. These tests can sometimes differentiate between the different species of malaria, and so it is definitely worth asking the clinic or doctor that performed the test if they can give you this information. Your location, or places where you have travelled in the last 4 years, may also assist in determining which type of malaria you had. Given that you barely registered being sick, I would suspect that you probably didn’t have Plasmodium falciparum, which is usually the most severe kind; it also cannot survive dormant in your system for long periods of time, so if you happened to have this kind, you wouldn’t need to worry about it coming back (though of course you can still be re-infected by all types of malaria, so prevention is still important!).

However, the other three main types of malaria can linger in a patient’s body. P. malariae is the least acute of all the malaria species, and can survive for a long time in the bloodstream, meaning that some people can have the infection for long periods of time without really feeling sick. If the blood test you took looked directly for parasites in your blood, and you tested positive, it is likely you have this kind. Like all uncomplicated cases of malaria, it is easily treatable, and once cured, you won’t have worry about it coming back (again, you do still need to watch out for being bitten by mosquitoes and getting re-infected though!).

The final two types of malaria are P. vivax and P. ovale. These persist in the body in a slightly different way than P. malariae – these have a special life stage which can lie dormant in the liver. Months or even years later, these dormant stages can re-activate and enter the blood stream, causing the patient to feel symptoms again, such as fever and nausea. Therefore, if you find you tested positive for one of these two forms, it is very important to ask your doctor about receiving medication (called primaquine) that will specifically target the liver stages of the parasites, to ensure you don’t get a recurrence of the infection later on.

As I’ve mentioned a couple of times earlier in this response, a key thing to be aware of is that even if you don’t have a recurring form of malaria, or treat it successfully, you will still be susceptible to re-infection if you are bitten by an infected mosquito. As such, if you live in or travel to a region known to have malaria transmission, it is crucial to take steps to prevent infection. For example, sleeping under a long-lasting insecticide treated bednet greatly reduces your risk of being bitten by the mosquitoes that carry malaria; similarly, wearing long-sleeved clothing and insect repellent, especially at night when malaria mosquitoes are most active, is recommended. Finally, medication is available that can be taken to prevent malaria (these are called prophylactics). As they can be expensive and are not recommended to be taken over long periods of time, these tend to be used primarily by people travelling to malarial areas rather than residents. There are several different forms of these prophylactics available commercially; the one to use will depend on several factors, including where you are travelling to.

Drugs to Treat Pregnant Woman with Malaria

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QUESTION:

What are the drugs for a pregnant woman who has malaria for the first to third trimester?

ANSWER:

The treatment of malaria in pregnant women has become more challenging in recent years, as many types of malaria are developing resistance to the standard arsenal of drugs. In locations where the dominant form of malaria is still chloroquine-sensitive, chloroquine can be used safely throughout pregnancy.

However, given the high levels of chloroquine-resistance, other drug regimens may be required. Currently, first-line treatment options for uncomplicated malaria caused by Plasmodium falciparum (many strains of which are resistant to chloroquine), is quinine plus clindamycin (doxycycline is contraindicated in pregnant women). In the second and third trimesters, artesunate plus clindamycin can be administered, or the artemisinin-based combination therapy (ACT) commonly used in that region, although some of these combinations, particularly those containing artemether, have limited safety testing in pregnant women. In general, the paucity of controlled, randomized trials has posed a problem to creating safe and effective recommendations for the treatment of malaria in pregnant women.

Why do people die of malaria?

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QUESTION:

Why is it that people die of malaria?

ANSWER:

The symptoms of malaria are caused by the malaria parasite reproducing inside the patient’s red blood cells and eventually destroying them. In this process, the malaria parasites also produce toxic waste chemicals and debris which build up in the patient’s blood stream. The body produces a strong immune response as a reaction to these toxic products and debris; most of the systemic symptoms associated with malaria, such as fever, aching muscles and joints and nausea, are related to this immune response. Infected red blood cells can also build up in internal organs, notably the spleen and the liver, causing them to swell.

Despite these nasty-sounding effects, most cases of malaria are relatively benign and don’t lead to death. However, in some cases, the manifestation of the disease can become more severe. Most commonly, this occurs when a patient is infected with Plasmodium falciparum, one of the four main kinds of malaria that infect humans, and by far the most severe. P. falciparum reproduces very rapidly in the human host, causing extremely high fever and a fast onset of symptoms. It also changes the structure of the red blood cells it infects, causing them to become “stuck” deep within tiny blood vessels and especially in major organs such as the brain, intestines, liver, heart and lungs. Stuck within these blood vessels, the infected red blood cells are effectively hidden from the immune system and are not cleared from the body via the spleen. This allows the malaria parasite’s reproduction to go unchecked, resulting in very high numbers of the parasite in the patient’s blood.

If left untreated, the build-up of infected red blood cells can result in severe anaemia, reduced local oxygen flow and the blocking of the immune reaction; the exact mechanisms are not fully understood. When these processes occur in the brain, the result is so-called “cerebral malaria”, characterised by impaired consciousness, and which can lead to convulsions, coma and death. Even if a patient recovers from the disease episode, they may be left with permanent neurological damage. Luckily, malarial comas are often rapidly reversed after treatment is administered, and in many cases, neurological damage is not permanent.

Cases of Malaria

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QUESTION:

What are reasons for the increasing number of cases of malaria?

ANSWER:

As I recently wrote in answer to another Q&A post, it is difficult to determine whether cases of malaria are indeed increasing or not. For one, a large number of cases are not reported every year, making accurate estimates difficult. Secondly, the world’s population is growing, and it is growing at the greatest rate in Africa, where the majority of malaria cases occur. As such, even if the proportion of people with malaria decreases over time, due to health initiatives such as distributing long-lasting insecticide treated bednets or free treatment, the total number of cases may still rise. Another problem we face in the fight against malaria is climate change: as the world’s patterns of rainfall and temperatures change, new areas become susceptible to malaria transmission, putting more people at risk. However, what is very encouraging is that deaths from malaria seem to be decreasing on a global scale. Malaria No More is an organisation dedicated to eliminating deaths from malaria by the year 2015; more information about their methods and some of their success stories can be found on their website.

What does malaria cause?

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QUESTION:

What does malaria cause?

ANSWER:

Malaria is a disease. It is caused by tiny single-celled parasites called Plasmodium, which are transmitted through the bite of infected Anopheles mosquitoes. There are many symptoms that occur as a result of infection with malaria, namely fever, chills, headaches and nausea, among others. Malaria can be a very serious disease, especially if not treated promptly, and so when spending time in malaria-infection areas (such as many areas of low to moderate elevation in the tropics and sub-tropics) precautions should be taken to avoid mosquito bites and thus infection. If a person finds themselves suffering from some of the above symptoms after being in a malaria transmission region, it is crucially important they get diagnosed straight away; if they do indeed have malaria, then they can be given treatment to facilitate a quick and safe recovery.

Helping Those Affected with Malaria in Africa

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QUESTION:

What are some things that might be done to make the situation better for those most affected with malaria in Africa?

ANSWER:

Currently, the emphasis on decreasing the burden of malaria on those most affected in Africa is based on a combination of prevention, education, research and treatment. In more detail:

Prevention: This is arguably one of the keys to sustainably reducing malaria burdens and even eliminating infections. Central to this goal has been the distribution of long-lasting insecticide treated bednets, which prevent people from being bitten by infected mosquitoes while they sleep at night. Unfortunately, some recent research has just been published which suggests that bednets might be contributing to insecticide resistance in mosquitoes, as well as increased rates of malaria in adults due to decreasing natural immunity. As such, it may be that more research is needed in order to determine the most effective and efficient ways of using bednets to prevent malaria infection, particularly in high-risk groups like young children and pregnant women.

Education: Through education, people living in at-risk areas for malaria transmission can learn about ways to prevent the disease, as well as what to do if they suspect they are infected. Similarly, education is important for travellers visiting malarial areas, so they know the best ways in which to avoid being infected.

Research: Understanding the distribution, factors affecting transmission and the development of new strategies for control and treatment is going to be crucial in the fight against malaria, and particularly in high-burden areas such as Africa. Similarly, scientists are busily looking for new compounds to treat malaria, as well as the ever-elusive malaria vaccine. If such a vaccine could be developed, it would be a huge step forward in the fight against malaria.

Treatment: Hand in hand with treatment comes diagnosis; if a person can have their infection easily, accurately and cheaply diagnosed, then they will be able to access effective treatment more rapidly, thus improving their chances of a swift recovery. As such, countries in Africa are working hard to provide health systems capable of local diagnosis and availability of treatment, so that people don’t have to travel far to have their infections cured.

Taken together, these four strategies are having some success even in the world’s poorest and most malaria-endemic regions, especially in decreasing the number of malaria deaths. Decreasing the overall number of infections will be yet a greater challenge, but one which the world, especially through commitment to the Millenium Development Goals, is dedicated to overcoming.

When was malaria first found in humans?

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QUESTION:

When was the first case of malaria in humans discovered? What did the name malaria originate from?

ANSWER:

Malaria has been known to humans for thousands of years; its earliest record is from around 2700 BCE in an ancient Chinese medical text. The ancient Greeks, Egyptians and Indians also recorded cases of malaria and described its symptoms. However, the parasite that causes malaria was first observed in a suffering patient in 1880; in 1897 mosquitoes were discovered to be the agents transmitting the parasite, finally allowing doctors to understand the true nature of the disease. The word “malaria” comes from “mala aria”, Italian for “bad air”, hinting at the long-held association between malaria and foul marshy regions with bad smelling air, which dates back as far as the ancient Romans. Indeed, the mosquitoes that spread malaria breed in stagnant water, so the Romans weren’t too far off!