Antimalarial Drugs During pPregnancy

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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.

Malaria Prophylaxis for Indonesia

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QUESTION

I have been working a 4-week rotation between the USA and East Kalimantan (Borneo) for about 2 years. While on Borneo, I am in the jungle much of the time. I have never contracted malaria. I am embarrassed to say I thought I had been inoculated for malaria when I first started working here. I just spent 10 days in a hospital last month fighting a blood degenerating viral infection not unlike hemophiliac dengue. Is there a preferred Rx I should take for malaria? I have no allergies to medicines that I am aware of. I am 57 year-old male.

ANSWER

Given the amount of time you spend in rural areas of Borneo, you probably should consider anti-malarial medication to prevent infection. There are three types of drug which are recommended against malaria in Indonesia: atovaquone-proguanil (sold as Malarone), mefloquine (sold as Lariam) and doxycycline. Each has pros and cons: Malarone and doxy have to be taken every day, while Lariam is only taken weekly, which might make it more convenient. However, both doxy and Lariam should be taken for a full 4 weeks after leaving the malarial area, while Malarone is only taken for a week after leaving.

In my opinion, Malarone has the fewest and mildest side effects (though some people complain of upset stomachs and disturbed sleep patterns), while doxycycline is sometimes a problem in the tropics since it can cause sun sensitivity. Lariam is not recommended for people with a history of mental illness, and has been reported to have psychiatric side effects, including nightmares, hallucinations and even altered behavior. Of the three, Malarone is the most expensive, and doxycycline usually the cheapest.

In terms of taking them long term, I don’t know of any studies that look at long term usage of Malarone (it is expensive enough that I doubt anyone takes it for very long trips!), while people do safely take doxycycline for periods of several months, and Peace Corps volunteers and American expats routinely take Lariam for periods of several years.

Of course, many people living long term in malarial areas do not find it convenient to take pills to prevent malaria, and focus on other preventative measures, mainly revolving around killing mosquitoes and avoiding being bitten. Sleeping under a long-lasting insecticide treated bednet is one such method, which is cheap, easy and very effective.

Incidentally, the area you are in is interesting from a malaria point of view since it is one of the few places where transmission of Plasmodium knowlesi occurs. This is a type of malaria which was thought to be only present in macaque monkeys, until human cases started becoming more prevalent a few years ago. Now it is considered a “human” type of malaria, and an emerging threat in south-east Asia. It’s important to be aware of it as the mosquitoes which transmit it tend to be forest-dwelling (since that is where the macaques live), and although very easily treated with chloroquine or other anti-malarials, an infection can progress rapidly into quite severe disease.

If you suspect you might have malaria at any point, therefore, it is crucial to get out and get tested at a clinic or hospital, where they can promptly treat you if you test positive. Be aware also that if tested via microscopy, P. knowlesi can often be confused with P. malariae or P. vivax; while the initial treatment is likely to be the same for all three, if you had P. vivax you might be told about taking an additional medication, called primaquine, to prevent future relapses, whereas relapses do not occur with P. knowlesi.

Duration of Malaria Symptoms

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QUESTION

If untreated how long will a person suffer symptoms caused by Malaria?

ANSWER

The answer to that depends a lot on what type of malaria they have as well as their own immune status, and particularly if they have been infected with malaria before. So, for example, P. falciparum is the most severe and deadly kind of malaria, and without treatment, many people who do not have acquired immunity (from previous infections) are likely to die within just a few days. This is the type of malaria that causes the most deaths, and explains why most of the fatalities occur in young children, who have not had the chance to acquire immunity.

In contrast, other kinds of malaria are less severe, and so symptoms can persist before the malaria parasite is naturally cleared by the parasite, usually within 1-2 weeks. In extreme cases, this can last much longer; Plasmodium malariae is the slowest replicating form of malaria, and so frequently causes mild infections which can last weeks, if not months. In some cases, people are infected with low levels of P. malariae for years without even experiencing symptoms, since their own immune system is able to keep levels of the parasite low enough so that they don’t cause noticeable disease.

New Malaria Parasites

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QUESTION

I heard researchers have found a new malaria parasite—what is the name?

ANSWER

New malaria parasites are found quite regularly—the parasite that causes malaria, Plasmodium, actually infects birds, reptiles, rodents and non-human primates like monkeys and apes as well as humans. As such, non-human forms of malaria are discovered relatively frequently in other species. For example, a few years ago, some researchers looked at malaria in apes in Central Africa, and found a new species in gorillas, which is so new it has not even been fully described to science yet, and so remains unnamed! It is thought to be very closely related to Plasmodium falciparum, which is the most dangerous type of malaria in humans. Also recently, two new species were observed in chimpanzees, also in Central Africa, and names P. billcollinsi and P. billbrayi.

Even in humans, new infections are sometimes observed. One which has gained a lot of recent attention is not a new species, but what seems to be increasing numbers of cases of a monkey type of malaria (called P. knowlesi) in humans. It is unclear whether this is due to changes within the parasite, or changes to the landscape which might be creating more favorable conditions for the transmission of this malaria to humans. It is even possible that this malaria has always infected humans, and so this is not a new development, but due to diagnostic issues, it was mistaken for other, human malaria species, such as P. vivax and/or P. malariae.

Malaria Parasite

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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

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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

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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?

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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. ovale, P. 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.

What is malaria and when was it discovered?

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QUESTION

What is malaria and when was it diagnosed?

ANSWER

Malaria is a disease caused by a single-celled parasite of the genus Plasmodium. Five types of malaria infect humans: P. falciparum, P. ovale, P. vivax, P. malariae and P. knowlesi. It was first observed in the blood of a patient who had died of malaria in 1880 by Charles Louis Alphonse Laveran, a French physician working in Algeria.

What is Malaria

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QUESTION

What is malaria?

ANSWER

Malaria is a serious and sometimes fatal disease caused by a parasite, of the genus Plasmodium, that commonly 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. ovale, P. 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.