Primaquine for Malaria Treatment

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QUESTION:

In India what is the duration of primaquine therapy in confirmed Malaria infection?

ANSWER:

Primaquine is usually used to kill the hypnozoite stages of Plasmodium vivax or P. ovale. This life stage of the malaria parasite can reside, dormant in the liver’s hepatocyte cells, even after the patient has completed the normal course of treatment for the infection; at this stage, the patient might not have visible malaria parasites in the bloodstream, and thus be considered “cured”. Despite this, the patient is actually potentially at risk from recurrence of malaria if the dormant liver hepatocytes re-enter the blood stream.

For this reason, patients with P. vivax or P. ovale should complete a course of primaquine in addition to the standard malaria treatment offered. The usual adult dosage for primaquine is 15-30mg base, taken orally, once a day for 14 days.

Malaria cure?

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QUESTION:

How do you cure malaria?

ANSWER:

There are a number of different types of treatment for malaria, depending on the kind you have and its severity. Most cases of malaria can be treated with orally administered medication; it is only in the most severe cases, for example if the patient is already in a coma or has had multiple convulsions, that intravenous medication is given. [Read more…]

What are the treatment options for malaria?

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QUESTION:

What is the treatment for Malaria?

ANSWER:

There are a number of different types of treatment for malaria, depending on the kind you have and its severity. Most cases of malaria can be treated with orally administered medication; it is only in the most severe cases, for example if the patient is already in a coma or has had multiple convulsions, that intravenous medication is given.

Chloroquine sulphate is the drug of choice for non-resistant strains of malaria; unfortunately, resistance has been detected in most of the main forms of malaria, in certain geographic regions of the world. In places known to suffer from chloroquine-resistant malaria, other options are available, such as quinine sulfate, doxycycline, tetracycline and atovaquone-proguanil (sold as Malarone, and also used to prevent malaria as a prophylaxis). More recently, treatment known as ACTs, or artemisinin-based combination therapies, have been introduced to treat cases of malaria which are known to be resistant to chloroquine. These ACTs combine various drugs in order to combat malaria effectively, though worryingly some cases of patient-level resistance to ACTs are also beginning to be reported. As such, there is a continual need for drug discovery research with regards to malaria, in order to control this global, deadly disease.

Can I get malaria again?

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QUESTION:

Hello, I have had malaria four times in Papua New Guinea, the last time was the “brain” type – sorry don’t know the name. The other times were ‘regular’ malaria. I have been free of it for 21 years now; could it still recur in me?
thanks,
Jay

ANSWER:

Hi Jay, thanks for your question. The “brain” type you are referring to is probably Plasmodium falciparum, which is known for causing cerebral malaria in serious cases. Actually, the majority of malaria cases in PNG are caused by this parasite, even the so-called “normal” cases, which don’t get as serious as to become cerebral.

The good news about P. falciparum is that it does not have a latent stage in the body, so patients cannot get relapses. However, there is another type of malaria in PNG, called Plasmodium vivax, which is less virulent (doesn’t cause as severe symptoms), but if not treated properly, does have the ability to leave latent stages of the parasite in the liver. These liver forms can become active a long time after the initial infection; usually the maximum limit for relapse is a couple of years though (one case in Italy reported a patient with relapse after 4 years, which was considered very unusual – the citation for this paper is Mangoni et al., 2003, ‘Case report: An unusual late relapse of Plasmodium vivax malaria, in American Journal of Tropical Medicine and Hygiene, volume 68, pages 159-160), so you should be fine after 21 years being malaria-free!

In your case, unless you were diagnosed otherwise at the time, I would think you probably were infected with P. falciparum all four times, and so there is no chance of a relapse; if you’re really worried about it, you can have a malaria test to see if you still possess antibodies against malaria, which would suggest there are still parasites in your body, and might indicate P. vivax infection (there are some blood tests which can distinguish between these different types of malaria). Then, you can take a drug called primequine, which eliminates the liver stages and ensures no further relapse.

Cases and Deaths of Malaria in the USA, 2005-2010

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QUESTION: Where can I find a list of reported cases and deaths from Malaria in the USA, 2005-2010? I understand that most cases were acquired outside the US and the remaining were transmitted via blood transfusions. But I can not find a source for the data.

Tom Yerg

ANSWER: We found statistics for the years 2005-2009. The number of reported cases in the United States, according to the Centers for Disease Control are:

  • U.S. Malaria Cases – 2005: 1,528 (7 fatal)
  • U.S. Malaria Cases – 2006: 1,564 (6 fatal)
  • U.S. Malaria Cases – 2007: 1,505 (1 fatal)
  • U.S. Malaria Cases – 2008: 1,298 (2 fatal)
  • U.S. Malaria Cases – 2009: 1,484 (4 fatal)

Source:

How do mosquitoes cause malaria?

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QUESTION:

How can the mosquito cause malaria?

ANSWER:

Actually, mosquitoes don’t cause malaria themselves, they just transmit it from one person to another! The disease is actually caused by a tiny parasite, of the genus Plasmodium, several species of which infect humans. Part of the parasite’s life cycle takes place in the human host, and the other part in the mosquito; it needs to go through both to survive. Mosquitoes become infected when they feed on the blood of a human host that is infected; the parasites are then transmitted to a new, uninfected human hosts in the mosquitoes saliva, when they again take a blood meal.

Having Malaria after being tested negative

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QUESTION:

In April 2010 I was in India, had symptoms of malaria, had blood work done, platelets low but rapid antigen and smear were negative. One year later, May 2011, had low platelet count, chills, no fever or fever spikes. Could this be malaria again even though I was tested negative.

ANSWER:

This response is courtesy of Dr Jaya Swarup Mohanty, a physician in India:

Malaria doesn’t affect the platelet count or the white blood cell count. The Plasmodium species causing malaria are either lodged in the hepatocytes (liver cells) or the RBCs (red blood cells) where they undergo asexual multiplication.
Any change in platelet count would rather indicate dengue (another mosquito borne disease with fever, chills, prostration, bone pain, low platelet count) or some blood disorders (where there would only be decrease or increase in platelet count). In this case there is only low platelet count and chills with no fever or fever spikes which may indicate some disorder in blood or immune system or as a reaction to some medication. It would be advisable to consult a physician as soon as possible for further work up.

Is there malaria in North America?

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QUESTION:

Are there malaria-infected mosquitoes in North America?

ANSWER:

North America is usually defined as including Canada, the United States and Mexico. Of these, Mexico has known regions of regular malaria transmission; specifically the regions bordering Guatemala and Belize in the south (Chiapas, Quintana Roo and Tabasco), rural areas in the tropical lowlands slightly further north (parts of Oaxaca, Nayarit and Sinaloa) and a very localised section of northern Mexico, located across the states of Chihuahua, Sonora and Durango. Travellers to these areas are recommended to take measures to prevent against malaria infection, such as minimising mosquito bites or taking prophylactic medication. Both P. falciparum and P. vivax are known to be transmitted in Mexico, so you should consult with a travel physician before deciding which form of preventative (prophylactic) medication to take, depending on the length of your stay, your budget and the type of malaria most commonly found in the area to which you are travelling.

Malaria was once also widespread in the southern USA, though a concerted public health campaign that started in 1947 (mainly consisting of reducing the number of mosquitoes through insecticide spraying and control of stagnant water bodies) greatly reduced transmission and led to the disease being considered eliminated by the 1950s. Occasionally, small pockets of transmission will be reported, though stringent diagnosis and treatment quickly places these outbreaks under control once more.

However, there are additional cases of malarial mosquitoes occasionally also reported even from northern parts of the United States and Canada; these are when mosquitoes are accidentally transported from malarial regions, for example in airplanes, in luggage or in shipping containers. These mosquitoes almost never transmit the disease to people, and in most temperate regions, do not live long enough to be a public health threat or to enable the persistance of the disease.

Causes of malaria, treatment with drugs and emerging resistance

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QUESTION:

What is malaria and what causes it besides bacteria? What is the name of the causal agent for malaria, which drug is used to cure it and how do the pathogens become resistant to the drugs?

ANSWER:

There are many questions in there! Malaria is actually caused by a single-celled animal, called a protozoan; it’s not a bacterial disease. There are different species of these protozoans, which form a genus called Plasmodium; the different species cause different types of malaria, for example Plasmodium falciparum, the most deadly and severe form, and Plasmodium vivax, which is widespread throughout the world but is a less acute infection. These different forms of malaria are each treated with different medications, depending on what is most effective and available; P. vivax, for example, can be treated with chloroquine, whereas in many places, P. falciparum has become resistant to this drug. In areas where resistance to chloroquine has emerged, other drugs are used; in Africa, artemisinin-based combination therapies (ACTs) are commonly used against chloroquine-resistant P. falciparum. Other drugs used to treat malaria include quinine compounds such as quinine sulphate, mefloquine, sulfadoxine-pyrimethamine and medications combining proguanil with atovaquone (marketed as Malarone).

The emergence of resistance to these drugs is a worrying phenomenon with respect to malaria; it is such a widespread and deadly disease, that the consequences of failed treatment are very high. Resistance can be caused by many factors, at the level of the drug, the human host, the mosquito host and also the malaria parasite itself. For example, poor drug compliance during treatment can lead to a failure to clear an infection completely, allowing the remaining parasites, which were less susceptible to the drug, to survive and reproduce. With successive generations, natural selection will lead to the evolution of strains of malaria parasites which are firmly resistant to that drug. The same process occurs when mass drug administration programmes, for example in areas of high malaria endemicity, give people sub-therapeutic doses of medication (in other words, doses of the drug that are too low to kill the parasite). Another problem is when people are not checked for their infection status after having been treated for malaria; if treatment fails for some reason, they will still have parasites in their blood, and should be treated again to ensure that all the malaria has been killed. If this doesn’t happen, the parasites can carry on reproducing, as in the processes described above. For these reasons, it is crucially important for people to be given accurate doses of medication, to ensure that they complete the full course of treatment, and that once treatment has been completed, they are accurately tested as negative for the malaria parasite. Finally, there are factors related to the affinity of the malaria parasite to its vector mosquito hosts which can lead to the emergence of drug resistant strains. For example, it has been shown that strains of malaria which are resistant to chloroquine are better able to survive and reproduce inside their mosquito hosts, leading to a greater population size of resistant parasites compared to drug-susceptible ones. It is for these reasons that malaria treatment and control programmes are now being very careful with the ways in which they administer drugs and monitor infections, in order to limit any further reisstance developing; similarly, pharmaceutical and biochemical researchers are constantly on the look-out for new compounds or methods of killing malaria parasites, which can be developed into new forms of treatment.

Malaria effects on body’s digestive system

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QUESTION:

How does Malaria affect the digestive system?

ANSWER:

Malaria does not usually affect the digestive system directly, although nausea and abdominal pain can be symptoms of the disease, usually due to the high fevers caused by the infection. Having said that, some of the drugs given as treatment or prevention of malaria are also known to have gastrointestinal side effects; both chloroquine and proguanil (one of the active ingredients in Malarone) are known to cause nausea and abdominal pain as common side effects, and both can also sometimes (in rare cases) result in gastrointestinal bleeding. It is recommended that these medications be taken with food, to reduce the likelihood of experiences any such side effects.