Am I more susceptible to malaria?

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QUESTION

I contracted common malaria, vivax?, when i was 20 yrs old from long visit to Papua NewGuinea, 1970. Returned to USA and was treated with chloro, primaquine drugs and really no problems since treatment.

Now going to Thailand for week, Chiang Mai and region. If bitten by local malarial mosq. am i more likely to recur? And should I certainly choose prophylaxis? thnx

ANSWER

If you were treated successfully with chloroquine and primaquine then there is no reason for your malaria to reoccur. Since it has been a long time since you had malaria, you probably also don’t have any antibodies against the parasite in your system anymore; this just means you don’t have any extra immunity against P. vivax (which you might have done if you had returned to a malaria area, and particularly one with the same strain of P. vivax as that which infected you, within a few months or years of being infected the first time), but it doesn’t mean you will be any more susceptible than someone who never had malaria.

In terms of where you are going, the city of Chiang Mai itself is not considered to have malaria transmission, but the areas surrounding it are, particularly as you get closer to the Burmese border. As such, if you will be travelling in rural and/or forested areas, you might want to consider taking prophylactic medication (and other preventative measures, like sleeping under a long-lasting insecticide treated bednet).

Thailand unfortunately has seen the emergence of resistance to a couple widely used prophylactic measures, namely chloroquine and mefloquine (sold as Lariam), so these are not appropriate preventative medicine in this region. Instead, you should consider taking doxycycline or atovaquone-proguanil (sold as Malarone).

Repeated Malaria Cases, New Guinea

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QUESTION

Hello, I live in Papua New Guinea. Myself, my wife and my 2 kids (both under 4 years old), get diagnosed with malaria approximately 3-4 times a year, usually vivax or falciparum. Our GP uses a prick of blood and examines under a microscope. Is it that easy/obvious to diagnose under this method and is it common to get this many attacks in a year? I also fear the affects of taking malaria tabs (eg Fansidar, Primaquin, Artemeter, Amodiaquine) this many times, especially for my young kids. Please help!

ANSWER

In high transmission areas, particularly in rural areas in sub-Saharan Africa, it certainly isn’t unusual for children to get as many a 5 or 6 malaria attacks in a year; adults tend to present with fewer clinical episodes, usually because they were heavily exposed as children and thus developed a significant level of immunity against malaria.

If you and your wife didn’t grow up in a malarial area, then you would not have that acquired immunity, and so you would be expected to get sick almost as often as your young children. Papua New Guinea certainly is a high transmission zone, and I think one thing which might help your family is to focus more on malaria prevention. Since malaria is transmitted by mosquitoes, the best way to avoid getting malaria is to avoid getting bitten by mosquitoes. You should all be sleeping under log-lasting insecticide-treated bednets, which kill and/or repel mosquitoes that try to bite you while you sleep (the mosquitoes that transmit malaria, of the genus Anopheles, are most active at dusk, at night, and at dawn—during the heat of the day they usually don’t feed, but may be found in cooler, heavily shaded areas).

You could also try spraying the walls of your house with a long-lasting insecticide like permethrin, which will also kill adult mosquitoes. Making sure your house is well-screened will also prevent mosquitoes from getting in and biting you at night and in the evenings, and if you are going out during these times, you and your family should wear long-sleeved clothing, and exposed skin should be covered with insect repellent. A DEET-based insect repellent is best, but you may not be comfortable using these regularly on young children, since it can have some potentially dangerous long-term effects, particularly on the liver.

In terms of your other questions, looking at your blood under the microscope is the normal way to diagnose malaria in many places, so it sounds like your GP is doing a good job. There is no indication of adverse effects from taking multiple, repeated doses of anti-malarials, but as I mention above, taking additional preventive measures may further help in reducing your family’s malaria incidence.

One thing you might want to talk to your doctor about is the fact that in some cases, Plasmodium vivax can cause relapses of infection weeks or even months after the initial infection. The reason is that P. vivax can form dormant life stages, which can hide out in the liver, and cannot be killed by the normal anti-malarial treatment. However, there is a medication, called primaquine, which can kill these liver forms, and prevent future relapse. People with a deficiency in a particular enzyme, called G6DP, may not be able to take this medication, as it may cause severe anaemia, so prior to taking the drug you might have to be tested for this deficiency. However, it is definitely something you should talk to your GP about.

Please take a moment to complete our Malaria Survey, as it will help us better understand the effects of malaria medications.

Distribution of Malaria

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QUESTION

Where does malaria mostly take place?

ANSWER

Malaria is mainly transmitted in tropical regions of the world; while some transmission does occur outside of the tropics, it tends to be seasonal in these areas (i.e. usually only during periods of high temperature/high rainfall). Within the tropics, malaria is found on all continents, though the highest number of cases is in Africa, which is also where over 90% of deaths due to malaria occur (of these, most are children under the age of 5). Outside Africa, the next highest levels of malaria are in India and south-east Asia and the western Pacific (such as Papua New Guinea).

Intermittent Preventive Treatment for Malaria in Papua New Guinean Infants Exposed to Plasmodium falciparum and P. Vivax

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Intermittent preventive treatment in infants (IPTi) has been shown in randomized trials to reduce malaria-related morbidity in African infants living in areas of high Plasmodium falciparum (Pf) transmission. It remains unclear whether IPTi is an appropriate prevention strategy in non-African settings or those co-endemic for P. vivax (Pv).

Methods and Findings

In this study, 1,121 Papua New Guinean infants were enrolled into a three-arm placebo-controlled randomized trial and assigned to sulfadoxine-pyrimethamine (SP) (25 mg/kg and 1.25 mg/kg) plus amodiaquine (AQ) (10 mg/kg, 3 d, n = 374), SP plus artesunate (AS) (4 mg/kg, 3 d, n = 374), or placebo (n = 373), given at 3, 6, 9 and 12 mo. Both participants and study teams were blinded to treatment allocation. The primary end point was protective efficacy (PE) against all episodes of clinical malaria from 3 to 15 mo of age. Analysis was by modified intention to treat. The PE (compared to placebo) against clinical malaria episodes (caused by all species) was 29% (95% CI, 10–43, p≤0.001) in children receiving SP-AQ and 12% (95% CI, −11 to 30, p = 0.12) in those receiving SP-AS. Efficacy was higher against Pf than Pv. In the SP-AQ group, Pf incidence was 35% (95% CI, 9–54, p = 0.012) and Pv incidence was 23% (95% CI, 0–41, p = 0.048) lower than in the placebo group. IPTi with SP-AS protected only against Pf episodes (PE = 31%, 95% CI, 4–51, p = 0.027), not against Pv episodes (PE = 6%, 95% CI, −24 to 26, p = 0.759). Number of observed adverse events/serious adverse events did not differ between treatment arms (p>0.55). None of the serious adverse events were thought to be treatment-related, and the vomiting rate was low in both treatment groups (1.4%–2.0%). No rebound in malaria morbidity was observed for 6 mo following the intervention.

Conclusions

IPTi using a long half-life drug combination is efficacious for the prevention of malaria and anemia in infants living in a region highly endemic for both Pf and Pv.

Trial registration

ClinicalTrials.gov NCT00285662

Please see later full article for the Editors’ Summary (link below).

Citation: Senn N, Rarau P, Stanisic DI, Robinson L, Barnadas C, et al. (2012) Intermittent Preventive Treatment for Malaria in Papua New Guinean Infants Exposed to Plasmodium falciparum and P. vivax: A Randomized Controlled Trial. PLoS Med 9(3): e1001195. doi:10.1371/journal.pmed.1001195

Academic Editor: Sanjeev Krishna, St George’s Hospital Medical School, United Kingdom

Received: July 5, 2011; Accepted: February 9, 2012; Published: March 27, 2012

Funding: This work was supported by a grant to the PNG Institute of Medical Research from the Bill & Melinda Gates Foundation’s Global Health Program (Grand ID# 34678). The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. This work was made possible through Victorian State Government Operational Infrastructure Support and Australian Government NHMRC IRIISS.

Competing interests: SJR is a member of the PLoS Medicine Editorial Board. The authors have declared that no competing interests exist.

Abbreviations: AE, adverse event; AQ, amodiaquine; AS, artesunate; ATP, according to protocol; EPI, Expanded Programme on Immunization; Hb, hemoglobin; IPT, intermittent preventive treatment; IPTi, intermittent preventive treatment in infants; IRR, incidence rate ratio; LDR-FMA, ligase detection reaction/fluorescent microsphere assay; mITT, modified intention to treat; PE, protective efficacy; Pf, Plasmodium falciparum ; PNG, Papua New Guinea; Pv, Plasmodium vivax ; PYAR, person-year at risk; SAE, serious adverse event; SP, sulfadoxine-pyrimethamine

Authors: Nicolas Senn1,2,3,4#, Patricia Rarau1#, Danielle I. Stanisic1,5, Leanne Robinson1,5, Céline Barnadas1,5, Doris Manong1, Mary Salib1, Jonah Iga1, Nandao Tarongka1, Serej Ley1, Anna Rosanas-Urgell1, John J. Aponte6, Peter A. Zimmerman7, James G. Beeson5,8, Louis Schofield5, Peter Siba1, Stephen J. Rogerson2, John C. Reeder8, Ivo Mueller1,5,6*

1 Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea, 2 Department of Medicine, University of Melbourne, Melbourne Australia, 3 Swiss Tropical and Public Health Institute, Basel, Switzerland, 4 University of Basel, Basel, Switzerland, 5 Infection and Immunity Division, Walter and Eliza Hall Institute, Melbourne, Australia, 6 Barcelona Centre for International Health Research (CRESIB), Barcelona, Spain, 7 Center for Global Health and Diseases, Case Western Reserve University, Cleveland, Ohio, United States of America, 8 Burnet Institute, Melbourne, Australia

Full Article:Intermittent Preventive Treatment for Malaria in Papua New Guinean Infants Exposed to Plasmodium falciparum and P. vivax: A Randomized Controlled Trial (PDF)

Source: PLOS Medicine

Copyright: © 2012 Senn et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Duo-Cotecxin and Fansidar as Treatment

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QUESTION

My husband weighs and has malaria. He was told by the pharmacist to take 2 tablets stat, then 1 daily for five days followed by 3 Fansidar tablets. We live in Papua New Guinea. I see on the Duo-Cotecxin web site the dose is three tabs daily. Which is correct?

ANSWER

Fansidar is a very different drug to Duo-Cotecxin—it is made of a combination of sulfadoxine and pyrimethamine, whereas Duo-Cotecxin is an artemisisin-based combination therapy (ACT), consisting of dihydroartemisinin together with piperaquine. As such, the dosages and time courses of therapy are likely to be different. However, Fansidar is not usually recommended as treatment anymore—it appears to have low efficacy against Plasmodium vivax and in the 1980s and 1990s, the World Health Organisation and Center for Disease Control (CDC in the US) only recommended it for use against chloroquine-resistant P. falciparum.

However, nowadays, both organisations recommend ACTs (like Duo-Cotexcin) to treat all uncomplicated P. falciparum infection as well. Therefore, unless your husband has been diagnosed with P. ovale or P. malariae malaria (both of which are sometimes found in PNG), Fansidar probably should not have been the first-line treatment given to him. Keep a close watch over his recovery, and if there is any sign of reccurrence of the symptoms, go back to the doctor for another malaria test.

When to Seek Malaria Treatment

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QUESTION

I have been in New Guinea recently and 2 weeks on am exhibiting all the signs and symptoms of malaria. What is best course of action, considering I do not know what sort of mosquito was hovering about?

ANSWER

You should visit your physician or a clinic immediately. Depending on where you are, you may have to visit a specialist travel medicine clinic, to be sure that you will be seen by someone who understands how best to diagnose malaria. They should take blood and examine it under a microscope (using thick and thin blood films), or they may utilise a rapid diagnostic test. Either way, they will be able to determine whether you have malaria and if so, which type of malaria you have. 

This is important because some types of malaria, such as Plasmodium vivax (which is very common in PNG) can remain dormant in the liver after the initial infection has been treated, which leads to relapses months or years later. In order to prevent relapses, if you find you are infected with P. vivax you should inquire about the possibility of also being given primaquine, which is a drug that can kill these liver stages.

Malaria Relapse

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QUESTION

I had malaria in Papua New Guinea 40 years ago and had many relapses. I had one 11 years ago and was in hospital for 3 weeks. I have been to a massage therapist who used a hand machine giving out pulses rather strong a bit like tiny electric shots could this activate malaria?

ANSWER

The reasons why malaria relapses are not well known. Malaria acquired in different places tends to have different relapse times (faster in the tropics, less frequent in sub-tropical or temperate regions) and there is also some evidence that being bitten again by mosquitoes can trigger relapse. I am not aware of any evidence that electric pulses could trigger relapse, but likewise cannot discount the possibility! On another note, there is medicine that can be taken to prevent further relapse, by killing the dormant liver forms of the malaria parasite. It is called primaquine, and is only effective is taken exactly as prescribed for a 2 week period. Some people with G6DP deficiency may also not be recommended this medicine, so before prescribing it, your doctor should test you for this deficiency.

In What Countries is Malaria Found?

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QUESTION

What countries can malaria be found in?

ANSWER

Malaria is found on every continent of the world except Antartica—however, regular transmission every year mainly only occurs in Central and South America, Africa, parts of the Middle East, Asia and parts of Oceania/the Pacific Islands.

The world’s highest areas of malaria prevalence and transmission occur in sub-Saharan Africa, followed by India, south-east Asia (especially the Indo-Pacific islands, such as Papua New Guinea) and parts of Central America and northern South America.

Based on the latest available data, the top five countries reporting the most annual malaria deaths were Kenya, the Democratic Republic of Congo, Cote d’Ivoire and Burkina Faso. However, the top five countries with the highest number of malaria cases per 100,000 members of the population were Guinea, Botswana, Burundi, Zambia and Malawi.

The Solomon Islands have the highest number of malaria cases per 100,000 outside of Africa, followed by Yemen. Note that these statistics are highly dependent on quality of diagnosis, treatment and reporting!

Chloroquine Resistant Malaria

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QUESTION

What is chloroquine resistant malaria?

ANSWER

Chloroquine-resistant malaria is exactly what it sounds like—particular types of malaria which are not cured by treatment with chloroquine.

Chloroquine was first discovered in the 1930s in Germany and began to be widely used as an anti-malaria post-World War II, in the late 1940s. However, resistance to the drug also rapidly emerged, with the first cases of Plasmodium falciparum not being cured by administration of chloroquine being reported in the 1950s.

Since then, resistance has spread rapidly (since obviously it is beneficial to the parasite to be resistant, so various mutations conferring this protection have arisen multiple times in different areas in the world and also been passed on preferentially to new generations of malaria parasites), and now chloroquine resistant P. falciparum can be found globally in malaria-endemic areas.

Chloroquine resistance in Plasmodium vivax has also now arisen, though more recently—the first reports came from 1989, in Australia, in travellers returning from Papua New Guinea. Now, chloroquine resistant forms of P. vivax are found in multiple locations in south-east Asia, such as Myanmar and India, as well as from Guyana in South America.

Nowadays, other drugs, and notably ones containing artemisinin-based compounds, are preferentially used to treat uncomplicated malaria and especially in areas where chloroquine resistance is known to occur. However, due to fears of resistance to these compounds also developing, the World Health Organisation recommends that artemisinin-based compounds only be administered in conjunction with other anti-malaria drugs, such as lumefantrine (which in combination with artemether forms the widely-used anti-malarial treatment Coartem). These combinations are known as artemisinin-based combination therapies, or ACTs for short.

Malaria on Bougainville Island, Papua New Guinea

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QUESTION:

Is there malaria on Bougainville Island?

ANSWER:

Yes, Bougainville Island (an autonomous region of Papua New Guinea) is considered a malaria transmission zone, and precautions against malaria are advised when visiting. These include sleeping under an insecticide treated bednet, wearing long-sleeved clothing and insect repellent in the evenings and talking with your doctor about potentially also taking anti-malaria medication (called prophylaxis) as a further step to prevent infection.