Malaria Treatment While Pregnant?

QUESTION:

1) I am two months pregnant. Please, what drug can I use to treat malaria? 2) How often should I treat malaria?

ANSWER:

The specific answer to your question depends a bit on whether you believe you are already actively infected with malaria (in other words, you are feeling ill right now, or have done recently) or if you would like information on preventing malaria during your pregnancy.

In both cases, there are certain drugs which have been tested as safe for pregnant women, but whether these drugs are appropriate for you depends on where you live, what types of malaria you might have been exposed to, and, as I mentioned first, whether you are seeking treatment for an existing episode of malaria or want to prevent future illness.

I have asked one of our board members, who is an expert on maternal health and pregnancy, to comment further, so please check back here soon!

How does malaria infect the body?

QUESTION:

How does malaria infect the body?

ANSWER:

Malaria is transmitted to humans via certain species of mosquito. The parasite that causes malaria, called Plasmodium (there are several species, which cause slightly different forms of the disease), lives in the saliva of the mosquito and is introduced into the human blood when the mosquito bites through the skin. It is interesting to note that only female mosquitoes transmit malaria; male mosquitoes don’t feed on blood, only on nectar and other plant juices, and their mouth parts are too soft to break human skin!

Once the parasite is in the human bloodstream, it undergoes several different life stages. Throughout, it must evade the human immune system, and it has a number of clever ways to do this. One method is by producing a protein which it attaches to its surface; this acts as a “cloak” against the human immune system and hides the parasite. The parasite also uses other proteins to complete its life cycle, for example several are used to enter red blood cells, where part of the reproductive cycle of the parasite is carried out. Finally, after several transformations and cycles of reproduction, the malaria parasites are released again into the bloodstream, where they can be picked up by another female mosquito, and transported to a different human.

For more information about some of the mechanisms for evading the immune system, check out this article from the BBC website, which summarises some recent findings about Plasmodium falciparum, the malaria parasite which causes some of the most debilitating and deadly malaria cases worldwide.

 

 

How Many Deaths Result from Malaria?

QUESTION:

Can you tell me, how many deaths result from malaria till today?

ANSWER

A lot! I think it is impossible to get an exact number, or even a decent guess – data on malaria deaths even in modern times are estimates at the best of times, and we have no way of knowing how many people were exposed to and/or died of malaria in ancient times.

Current estimates as to the annual number of deaths from malaria vary depending on which source you look at, but most agree that somewhere around 1 million people die every year from being infected with malaria. Of course, that number would have been lower in the past when total population numbers were also lower.

However, I think it would be fair to say that probably hundreds of millions of people have, over the course of history, died from being infected with malaria. More to the point, malaria continues to be a huge public health burden on huge portions of the world’s population, and disproportionately on the world’s poorest people, which makes it a top priority for disease advocacy, research and control initiatives.

Is there malaria in Papua New Guinea?

QUESTION:

Is Papua New Guinea infected of malaria?

ANSWER:

There is malaria in many parts of Papua New Guinea, and especially in the coastal regions. Chloroquine-resistant malaria has been reported from PNG so if travelling to malarial zones in the country you should ask your doctor about getting a prescription for another form of prophylaxis (preventative drugs), such as Malarone, Lariam or doxycycline. it is also recommended to sleep under an insecticide-treated bednet.

Parts of the country which are above 1800 metres of altitude (5900 ft) are considered free of transmission but you should consult with local doctors before travelling to specific areas to see what they recommend in terms of preventative measures you can take.

How did malaria start?

QUESTION:

When did malaria happen?

ANSWER:

It is believed that Plasmodium, the parasite which causes malaria in a wide variety of animals, first evolved in reptiles. Even today, reptiles are infected by species of Plasmodium that are related to those that infect humans. The parasite probably then evolved to infect birds, and then, more recently, to infect mammals. Many mammals can be infected with malaria-like parasites, but most commonly rodents (like rats and mice) and primates (including humans).

The exact origins of human malaria are less clear, and indeed, there are several different types of malaria, caused by different Plasmodium species, so it would be expected that there were different evolutionary origins for these different types. The most common and deadly form of human malaria, P. falciparum, was long believed to have crossed over about 500,000 years ago from a closely related chimpanzee malaria species called P. reichnowi, and evolved to infect humans.

However, a recent paper in Nature (Liu et al., “Origin of the human malaria parasite Plasmodium falciparum in gorillas,” in volume 467 and pages 420-425) has used molecular evidence, from almost 3000 samples and several genetic regions, has instead suggested that P. falciparum evolved from a type of malaria which is found in western lowland gorillas. However, the paper did not remark on when this cross-over might have occurred. No doubt more studies will be done on this subject in the near future, which will give us a better idea of when the first cases of truly “human” malaria might have occurred!

Malaria Prevention for Seniors

QUESTION:

I am a healthy senior citizen (73 years) and I am considering a trip with Semester at Sea. One of the ports they plan to visit is Ghana. I see the CDC says Ghana is a “high risk” area for malaria.

I think I remember being told (at the U of W Travel Medicine Clinic) a few years ago that the malaria drugs are problematic for Seniors.

With the Semester at Sea ship stopping at Takoradi, Ghana, how high a risk is malaria and what preventative measures could/should I take?

I have had no malaria treatment (preventive or due to illness) in the past.

Thank you.

ANSWER:

It is correct that Ghana is a high risk zone for malaria, and wise of you to investigate ways to prevent infection. This is especially the case given that there is evidence to suggest that senior citizens and travellers over the age of 60 may be more at risk of serious complications from malaria. As such, it is especially important for these high risk groups, which also includes pregnant women and children, to be well aware of ways to reduce the risk of exposure and infection.

Having said that, I have done some research and I don’t think there is any evidence that the standard drugs for preventing malaria work less well in older people. In fact, one study I found suggested that younger people were more likely to report side effects from taking malaria preventative medicine (see Mittelholzer et al., “Malaria prophylaxis in different age groups” in volume 3 of the Journal of Travel Medicine, published in 2006).

The only potential problem could be cross-reaction of the malaria drugs with other prescribed medicine. As such, I would recommend you enquire with your doctor prior to the trip, to ask about being prescribed drugs to prevent malaria that are appropriate for the region you are travelling to (probably Malarone, Lariam or doxycycline, since you will be travelling to an area with chloroquine-resistant forms of malaria) that furthermore won’t harmfully interact or have reduced efficacy when ingested alongside other medication you might already be taking.

Safety of Bed Net Insecticides

QUESTION:

Are the insecticides used on the bed nets safe? What are the brand names and chemical names of those insecticides, and can you point me to any studies that have been done to determine their safety?

ANSWER:

The short answer is yes, the insecticides used in bednets are safe under the conditions in which people are exposed to them through using bednets.

Most standard bednets are treated with a chemical known as a pyrethroid, and usually permethrin or deltramethrin. Both of these chemicals have low toxicity to most mammals and are poorly absorbed by the skin, making them safe for treating bednets. There are some studies on mice which suggest that pyrethroids such as permethrin can be carcinogens when ingested, though once bound to the fibre of a bednet the chemical is not ingested by the person sleeping under the net so this is not a danger.

The World Health Organisation maintains a comprehensive set of specifications (PDF) for maintaining quality and safety in insecticide treated bednets.

There is another WHO report on the safety of pyrethroids (PDF) for public health use, which gives more details about conditions under which these compounds are considered toxic and the risk of exposure through bednet use.

Reduce Risk of p.falciparum

QUESTION:

I am laboratories man. My question is the risk of P. falciparum especially for mother and children is very high.  How can we reduce this risk?

ANSWER:

That’s a crucial question for malaria control. Certainly, as you say, the risk of severe malaria is much greater for young children and for pregnant women. As such, these high risk groups should be targeted during prevention campaigns, as well as for diagnosis and treatment.

There are several methods of prevention, which are suitable for all types of malaria, including P. falciparum. Probably the most effective, and also the most simple, is through the proper use of insecticide-treated bednets. These are often handed out at antenatal clinics to pregnant women, but ensuring that the nets are used properly is more difficult. Proper training, and emphasising that children and pregnant women will benefit most from reduced exposure to mosquitoes, is required. For more on the difficulties and challenges of bednet distribution, you can see Hugo Gouvras’ comment on an earlier question in this Q&A forum – see here: http://www.malaria.com/questions/free-malaria-bednet

The other main method for malaria prevention is through the use of prophylactic drugs, although these have to be taken every day, and so the cost is usually prohibitive for residents of malarial areas. In these areas, there have been successful trials of so-called SP IPT, which stands for sulfadoxine-pyrimethamine intermittent protective treatment. In this regime, malaria in pregnant women is prevented by administering intermittent doses of sulfadoxine-pyrimethamine; usually two doses during the pregnancy (one in the second and one in the third trimester), but monthly doses have also been tested. More frequent doses may be better for women who are also HIV positive, some studies have shown.

Intermittent preventative treatment has also been trialled on young children as a way of reducing the severity and frequency of malarial episodes when the child is most vulnerable. I’m not up to date on the most recent studies on this work, so will ask another one of our experts to comment on the efficacy of IPT, both in children and pregnant women.

Thanks for the question!

Is there Malaria in Naboomspruit, South Africa?

QUESTION:

Is Naboomspruit in South-Africa a malaria area?

ANSWER:

Naboomspruit (also known as Mookgopong) is located in Limpopo province in South Africa; malaria is endemic in parts of this province, namely the eastern border of South Africa (next to Mozambique and Swaziland), and including popular tourist areas such as Kruger National Park. In these regions, precautions against malaria, such as sleeping under an insecticide-treated bednet and taking preventative (prophylactic) medicine against malaria are highly recommended.

However, regions further away from the border, such as Naboomspruit, are generally considered zones of low to no transmission. However, transmission may still occur at some points in the year (particularly after rains) so some precautions would be advisable, although medication against malaria is probably not necessary. Instead, if visiting, or indeed if living in the area, it would be recommended to avoid getting bitten by mosquitoes by using insect repellant, wearing long-sleeved and dark clothing at dawn and after dusk and if being particularly cautious, by sleeping under an insecticide-treated bednet.

Bear in mind also that these are simply recommendations, and things may change over time and with variations in local climate; it would be worth asking a local doctor or hospital what the immediate risks of malaria are before travelling to a particular location.

How to Prevent Malaria

QUESTION:

What is the prevention of malaria?

ANSWER:

Malaria can be prevented in a number of ways, the main three of which are bite reduction, prophylaxis and vector control.

Bite reduction just means steering clear of mosquitoes, and specifically those that transmit malaria. These bite mostly between dusk and dawn, so if walking around at these times of day in a malarial area, it is worth wearing long sleeves and pants, and applying an insect repellant – ones containing DEET are the most effective at keeping off mosquitoes, in my opinion, but they also contain very toxic chemicals so should be used with care.

Specifically, 100% DEET shouldn’t be applied directly to bare skin, since it can be absorbed and cause problems for the liver. Natural insecticides, such as those containing citronella, are also an option. At night, it is advised to sleep under a bednet, which prevents mosquitoes from biting you while you sleep. Nets which are infused with pyrethrin, or other insecticides, are recommended.

Pyrethrin spray can also be used on clothing, to stop mosquitoes biting through light cloth. On a broader scale, bite reduction can also be achieved through better screening of windows and doors, and other ‘environmental’ controls.

Prophylaxis, when referring to malaria, means taking certain medication in order to prevent the onset of the disease. Several different drugs exist, and different ones are recommended depending on the type of malaria you are likely to encounter. Moreover, each has different potential side effects, different schedules of ingestion and come at a range of prices.

Since they do cost money, and are sometimes very expensive, prophylaxis against malaria is usually only used by short term visitors to malarial zones, although since pregnant women are more susceptible to malaria, they may choose to take prophylaxis during their term in order to prevent infection – it should be noted that most of the drugs used for malaria prophylaxis are NOT recommended for pregnant women so it is important to check carefully before starting on any of these medications.

For more info on malaria prevention while pregnant, why not check out the Q&A question about pregnancy and travelling to Belize?

For info on malaria prophylaxis in general, there is a Prophylaxis Forum dedicated to this here on this website, so have a look!

Finally, there is vector control. This means reducing the number of mosquitoes around so that there are less to transmit malaria! Spraying households with insecticides has been very effective in reducing malaria transmission in a number of settings, and although it suffers from a lack of cost-effectiveness and sustainability in the long run, may still be very useful in high-endemicity regions or those where drug-resistant malaria is rife.

Another approach to vector control is to eliminate habitat for the mosquito larvae. The larvae breed in pools of stagnant water, such as ditches or puddles; filling these in can reduce the number of larvae that can mature into biting mosquitoes. Obviously, some water sources, such as wells and irrigation ditches, are required by communities, particularly in rural areas, and so cannot be removed. As such, larval control is probably mostly an effective strategy in urban transmission settings.

Finally, on a slight tangent to traditional vector control, there has long been interest in the idea of controlling malaria through manipulation of mosquito genetics in such a way that populations could be replaced with individuals that cannot transmit the disease. A research article on this subject is available on this website. See: Malaria Control with Transgenic Mosquitos.