Testing for Dormant Malaria

QUESTION

When malaria is dormant in the body can it be detected in a blood test?

ANSWER

Not directly, no. A normal malaria blood test consists of a thick or thin smear, which is often stained and then looked at under a microscope; with these tests, you would not be able to see any sign of the malaria which is lying dormant in the liver. However, there is another type of blood test, known as serology, which looks for the body’s antibodies against malaria. These are proteins produced by the immune system when the patient becomes infected with malaria. These antibodies are specific to the type of malaria the person was infected with, and can persist for many months and even years. As such, if a patient was infected with one of the types of malaria which can become dormant (i.e. P. vivax and P. ovale), a serology test might be able to tell whether the patient had ever been infected with one of these two types, and then suggest that they might continue to have a dormant infection.

Malaria or Kidney Infection?

QUESTION

Two months ago my daughter was in Uganda working and when came back to the States she was hospitalized for 4 days with Malaria symptoms. Her tests came back negative they really didn’t act like they knew how to treat this. They kept telling her they didn’t know how to diagnosis Malaria. So they treated her for it. She now after 2 months is once again hospitalized with the same symptoms. They are telling her they think it is a kidney infection. Can malaria be misdiagnosed as a kidney infection. She once again has all the symptoms as malaria?

ANSWER

What tests did the doctors do to try to diagnose malaria in your daughter when she first got back to the States? Usually, malaria is diagnosed by a blood test, whereby a trained technician will look at the patient’s blood under a microscope. The technician looks for signs of the malaria parasite in the patient’s blood, and if seen, can determine the intensity of the infection as well as the species of malaria. This is important information for accurate treatment. Alternatively, rapid diagnostic tests, which utilize a droplet of blood in a device which looks similar to a pregnancy test, and can very quickly determine whether someone is infected with malaria. It is important to know that malaria cannot be diagnosed by looking at standard blood parameters. If you don’t think your doctors know what is afflicting your daughter, you should take her to a clinic which specializes in tropical or travel medicine. There, they will certainly know how to effectively diagnose your daughter.

Given that your daughter experienced a resurgence of symptoms two months after returning, if she did have malaria, then there are two kinds which she might have: Plasmodium ovale and Plasmodium vivax. The other types of malaria, including the most deadly kind, P. falciparum, are not able to come back and relapse once they are treated. However, in order to prevent future relapses, your daughter may also have to be treated with another form of medication called primaquine. I will emphasize again, however, that it is crucial to gain an accurate diagnosis before taking any form of treatment for malaria.

Recurrence of Malaria

QUESTION

If a person treated for malaria after being infected from a malaria endemic country of West Africa and cured then he travel back to his country which does not known for malaria endemic region of the world. Question is: Is there any chance of re-occurrence even he is not being exposed to malaria spreading mosquito for some time may be year?
Is it true Malaria parasites stays in liver as hibernation for a long period and attack after many months or year?
If so what treatment can prevent it?

Please advise.

ANSWER

There are several different types of malaria which are found in West Africa, and the most common and deadly form, Plasmodium falciparum, is not able to hibernate in the liver. However, two other types of malaria are able to lay dormant in the liver – these two kinds are called Plasmodium vivax and P. ovale. Both are not nearly as common as P. falciparum in West Africa, though P. ovale has been reported at prevalences of over 10% in some areas, which is double its usual prevalence elsewhere in the world. Weeks, months or even years after an initial infection with P. vivax or P. ovale, the patient may experience what is known as a relapse, which is when the dormant liver forms become active again and re-invade the blood stream, causing a renewal of malaria symptoms. These relapses can be treated with normal anti-malarial drugs (even chloroquine, in many cases), but a different drug is required to kill the dormant liver forms and prevent future relapse. This drug is called primaquine, and may not be suitable for people with certain types of G6DP deficiencies, so you should talk to your doctor about having a test for this condition before taking primaquine.

Antimalarial Drugs During pPregnancy

QUESTION

What is the safest antimalarial drug to be used by a pregnant woman in her second trimester?

ANSWER

With regards to treating malaria, intravenous artesunate (or quinine, if artesunate is not available) should be used for the treatment of severe/complicated Plasmodium falciparum malaria. Signs of severe and/or complicated malaria include impaired consciousness, organ failure, abnormal bleeding, hypoglycemia, severe anemia and/or inability to ingest medication orally. Treatment for uncomplicated malaria (where the above signs are absent) in pregnant women is usually chloroquine for P. vivax, P. ovale, P. knowlesi and P. malariae, as well as for P. falciparum if there are no reports of this parasite being resistant to chloroquine in the area. In places where P. falciparum is resistant to chloroquine, quinine and clindamycin should be used to treat this parasite in pregnant women.

As for preventative anti-malarials (chemoprophylaxis), if a pregnant woman is travelling to an area where only P. vivax, P. ovale, P. knowlesi, P. malariae or chloroquine-sensitive P. falciparum is transmitted, then she should take chloroquine to prevent malaria. In areas where P. falciparum is resistant to chloroquine, mefloquine is also suitable during pregnancy. Note that in some areas of south-east Asia, there are areas where P. falciparum is resistant to mefloquine, which may prevent its suitability as a prophylactic in this region. Preventing malaria during pregnancy is crucial, since the mother, particularly if it is her first baby, is especially vulnerable to the parasite. Moreover, malaria can have a negative impact on the fetus.

Recurrence of Malaria Symptoms

QUESTION

If a person suffering from malaria is given the proper treatment and he gets well but he again develops the symptoms of malaria..? These symptoms would arise from liver or blood? Who’ll be responsible for the recurrence of the symptoms?

ANSWER

Malaria can come back in three ways: first of all, the person could have been successfully treated, but then re-infected again by being bitten by an infected mosquito. In these cases, the person should focus on improved malaria prevention, such as sleeping under a long-lasting insecticide treated bednet.

Secondly, the patient could have recrudescence: when the patient takes medication, the treatment kills most of the malaria parasites in the blood, and enough so the patient feels better again, but some parasites still remain. Then, after the treatment finished, the parasite is able to replicate again, they increase in number in the blood and the patient feels ill again. In this case, you would say the infection came back from the blood, and the patient should take another dose of anti-malarials, but of a different kind to that which they originally had, in order to kill all of the parasites.

Finally, there is what is called relapse, which only occurs with two types of malaria: Plasmodium vivax and Plasmodium ovale. These are able to form dormant stages in the liver, so even when all the parasites are killed in the blood by the malarial treatment, these dormant forms survive. Many weeks, months or even years later, these dormant liver stages can re-activate and enter the blood again, causing new malaria symptoms. In this case, the liver was the source of the parasites. Again, the active blood infection should be treated with anti-malarials, but the patient should also talk to their doctor about taking primaquine, a drug which can kill any remaining dormant liver forms and thus prevent future relapses.

How is Malaria Prevented?

QUESTION

What are the methods to prevent malaria?

ANSWER

Malaria prevention consists of a combination of mosquito avoidance measures and chemoprophylaxis. Although very efficacious, none of the recommended interventions are 100% effective.

Mosquito Avoidance Measures

  • Because of the nocturnal feeding habits of Anopheles mosquitoes, malaria transmission occurs primarily between dusk and dawn.
  • Contact with mosquitoes can be reduced by remaining in well-screened areas, using mosquito bed nets (preferably insecticide-treated nets), using a pyrethroid-containing flying-insect spray in living and sleeping areas during evening and nighttime hours, and wearing clothes that cover most of the body.
  • All travelers should use an effective mosquito repellent.
  • The most effective repellent against a wide range of vectors is DEET (N,N-diethylmetatoluamide), an ingredient in many commercially available insect repellents. The actual concentration of DEET varies widely among repellents. DEET formulations as high as 50% are recommended for both adults and children older than 2 months of age (see the Protection Against Mosquitoes, Ticks, and Other Insects and Arthropods section later in this chapter). DEET should be applied to the exposed parts of the skin when mosquitoes are likely to be present.
  • In addition to using a topical insect repellent, a permethrin-containing product may be applied to bed nets and clothing for additional protection against mosquitoes.

Chemoprophylaxis

  • All currently recommended primary chemoprophylaxis regimens involve taking a medicine before travel, during travel, and for a period of time after leaving the malaria endemic area. Beginning the drug before travel allows the antimalarial agent to be in the blood before the traveler is exposed to malaria parasites.
  • Presumptive antirelapse therapy (also known as terminal prophylaxis) uses a medication towards the end of the exposure period (or immediately thereafter) to prevent relapses or delayed-onset clinical presentations of malaria caused by hypnozoites (dormant liver stages) of P. vivax or P. ovale. Because most malarious areas of the world (except the Caribbean) have at least one species of relapsing malaria, travelers to these areas have some risk for acquiring either P. vivax or P. ovale, although the actual risk for an individual traveler is difficult to define. Presumptive anti-relapse therapy is generally indicated only for persons who have had prolonged exposure in malaria-endemic areas (e.g., missionaries, volunteers).
  • In choosing an appropriate chemoprophylactic regimen before travel, the traveler and the health-care provider should consider several factors. The travel itinerary should be reviewed in detail and compared with the information on where malaria transmission occurs within a given country (see the Malaria Risk Information and Prophylaxis, by Country, section later in this chapter) to determine whether the traveler will actually be traveling in a part of the country where malaria occurs and if significant antimalarial drug resistance has been reported in that location.
  • The resistance of P. falciparum to chloroquine has been confirmed in all areas with P. falciparum malaria except the Caribbean, Central America west of the Panama Canal, and some countries in the Middle East. In addition, resistance to sulfadoxine–pyrimethamine (e.g., Fansidar) is widespread in the Amazon River Basin area of South America, much of Southeast Asia, other parts of Asia, and in large parts of Africa. Resistance to mefloquine has been confirmed on the borders of Thailand with Burma (Myanmar) and Cambodia, in the western provinces of Cambodia, in the eastern states of Burma (Myanmar), on the border between Burma and China, along the borders of Laos and Burma, and the adjacent parts of the Thailand–Cambodia border, as well as in southern Vietnam.
  • Additional factors to consider are the patient’s other medical conditions, medications being taken (to assess potential drug–drug interactions), the cost of the medicines, and the potential side effects.
      The medications recommended for chemoprophylaxis of malaria may also be available at overseas destinations. However, combinations of these medications and additional drugs that are not recommended may be commonly prescribed and used in other countries. Travelers should be strongly discouraged from obtaining chemoprophylactic medications while abroad. The quality of these products is not known, and they may not be protective and may be dangerous. These medications may have been produced by substandard manufacturing practices, may be counterfeit, or may contain contaminants. Additional information on this topic can be found in an FDA document

Purchasing Medications Outside the United States

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Malaria Parasite

QUESTION

Which parasite transmits malaria?

ANSWER

Malaria is caused by a parasite called Plasmodium, which is transmitted via the bite of an infected mosquito. The parasite passes into the blood of the human patient when the mosquito bites, via its saliva. There are five species of Plasmodium which normally infect humans: P. falciparum, P. malariae, P. ovale, P. vivax and P. knowlesi. 

Malaria with Liver and Kidney Problems

QUESTION

Can someone please tell me what kind of malaria this is. What part of the body it attacks, e.g., cerebral? Patient presenting with liver and kidney “problems”. What could these be?

ANSWER

I am not sure I fully understand your question, but the type of malaria which is associated with cerebral malaria, and also tends to have the most adverse effects on other organs (such as the kidneys) is Plasmodium falciparum. However, all species of malaria go through the liver as part of their life cycle, so all may invoke some kidney problems. The four other types of malaria which infect humans are P. vivax, P. ovale, P. malariae and P.knowlesi.

Classification of Malaria

QUESTION

Classification of malaria

ANSWER

Malaria is caused by a single celled protist of the genus Plasmodium. This genus is part of a Phylum of single-celled protist organisms called Apicomplexa.

The Apicomplexans mostly posses an organ called an apicoplast, which is part of an apical structure designed to aid entry into a host cell. The Apicomplexa is split into two Classes, of which Plasmodium belongs to the Aconoidasida (lacking a structure called a conoid, which is like a set of microtubules), and then to the Order Haemosporidia, which contains parasites which invade red blood cells. Within this Order, Plasmodium belongs to the Family Plasmodiidae, which all share numerous characteristics, including asexual reproduction in a vertebrate host and sexual reproduction in a definitive host (a mosquito, in the case of the Plasmodium species that infect all mammals, including humans).

In the case of human malarias, the definitive host is often referred to as the vector. The family contains about twelve genera, of which one is Plasmodium, which itself is now often divided up into numerous sub-genera, and then again into hundreds of different species, of which five infect humans (P. falciparum, P. vivax, P. ovale, P. malariae and P. knowlesi).

What is Malaria?

QUESTION

what is malaria?

ANSWER

Malaria is a serious and sometimes fatal disease caused by a parasite, of the genus Plasmodium, that infects a certain type of mosquito (of the genus Anopheles) which feeds on humans. People who get malaria are typically very sick with high fevers, shaking chills, and flu-like illness. Four kinds of malaria parasites can infect humans: Plasmodium falciparum, P. vivax, P. ovaleP. knowlesi and P. malariae. Infection with P. falciparum, if not promptly treated, may lead to death. Although malaria can be a deadly disease, illness and death from malaria can usually be prevented.