Incorrect or outdated beliefs about malaria are very
common. On your travels, you are likely to meet people
who will offer you advice about malaria prevention.
Some of these suggestions may be reasonable
alternatives, but some are actually dangerous. Here are
a few of the most common misunderstandings about
malaria and its prevention.
1. Malaria isn’t such a big deal - it’s just like the flu!
There are five species of human malaria — some cause
an unpleasant, but rarely if ever fatal, illness. Plasmodium
falciparum causes more than a million deaths a year
worldwide. P. falciparum malaria has a high death
rate if not diagnosed promptly and treated properly,
particularly in people with no immunity to malaria (e.g.
most Canadians). Hundreds of cases of malaria occur
in Canadian travellers every year and a number of
Canadians have died of malaria in the last several years.
2. Drug prevention just ‘masks’ the disease. Strictly
speaking, prophylaxis (medication to prevent malaria)
prevents disease, it doesn’t prevent infection. It stops the
parasite from replicating in the blood stream, the stage
of infection that causes illness. In this way it prevents
people from getting sick, which after all, is the point!
3. Prophylaxis doesn’t really work. No preventive
measure is 100% effective. However, taking the right
drug correctly will decrease the risk of malaria by
well over 90% in most circumstances. When cases of
prophylaxis ‘failure’ are investigated carefully, most are
found to be due to one of two explanations:
(a) The traveller had taken the medication inconsistently,
or
(b) He/she didn’t have malaria at all — the diagnosis was
incorrect because of the limited lab facilities in many
developing countries.
4. Most people taking antimalarial medications have side
effects. The majority of people who take antimalarials
(example: Chloroquine, Mefloquine [Larium™],
Doxycycline, Atovaquone/Proguanil [Malarone™]) for
malaria prevention have no problems with the drugs.
Some people may experience mild side effects as might
be seen with other medications, such as upset stomach,
nausea, loose stools, dizziness, difficulty sleeping, and
vivid dreams. These side effects are usually tolerable,
tend to occur soon after starting the medication and
usually subside with continued use. Side effects from
antimalarials are often difficult to distinguish from the
effects of jet lag, culture shock, and other stresses
of travel. A few travellers, I% - 4%, experience more
troublesome side effects that lead them to stop the
medication, in which case they would normally need to
start taking an alternative medication.
5. Malaria is incurable. Not yet! Increasing drug
resistance to malaria parasites is a serious concern.
At present, however, there have been no cases where
malaria could not be treated successfully as long as it is
diagnosed before the development of fatal complications.
It is sometimes difficult to prevent recurrences of some
of the non-fatal strains of malaria.
6. If I take preventive medicine there will be nothing
left that will work if I do get sick. That is not the case.
Several drugs are available to successfully treat any
person with acute malaria.
7. It’s better to treat malaria if you get it rather than
take all the medication to try to prevent it. At first
glance, that might seem logical but it doesn’t seem to
work in real life. The first problem is that self diagnosis is
so inaccurate. Even an expert cannot reliably distinguish
between malaria and the many other causes of illness
in the tropics without a blood examination. The best
alternative, finding a reliable source of diagnosis and
treatment quickly, can be difficult for a traveller in
an unfamiliar developing country. Finally, P. falciparum
malaria can progress from first symptoms to death in a
matter of a few days. For all these reasons, preventing
malaria is a much safer and more effective plan than
diagnosing and treating it after it occurs. Most experts
would recommend the self-treatment strategy only in
very unusual circumstances.
8. Malaria prophylaxis can only be taken for a limited
period of time. There is no fixed limit on the duration
of prophylaxis with standard antimalarial drugs as long
as the individual is not experiencing significant side
effects. Neither the drugs nor their effects build up in a
person’s body over time (with the theoretical exception
of chloroquine).Those people who do develop side
effects usually do so in the first few weeks of taking the
medication. In fact, it could be very dangerous for an
individual who is at risk of malaria to stop his or her
prophylaxis. People with long term exposure should
review their need for prophylaxis periodically.
9. Everybody travelling to the tropics needs to take
antimalarial drugs. Definitely not! Some of the tropics
are malaria free. Even in countries with malaria, the
disease may be absent at high elevations or in some
urban areas. A few examples: there is no malaria risk
in the mountains of Nepal, but there is malaria in the
lowland valleys; there is minimal risk of malaria in most
tourist areas of Thailand but drug-resistant malaria is a
risk in specific border areas; in South America and South
East Asia, malaria is generally found in rural areas only
and not in cities but in tropical sub-Saharan Africa and
India there is malaria risk in both rural and urban areas.
These are the reasons that travellers need expert advice
tailored to their own travel plans.
10. Pregnant women and small children can’t take, or
don’t need malaria prophylaxis. Dead wrong! Pregnancy
increases the susceptibility to, and severity of, malaria
in the mother. It can cause premature labour or even
death of the baby in the womb. Newborn babies and
small children of non-immune mothers may be very
susceptible to malaria and can quickly become seriously
ill after infection. Malaria can also be harder to diagnose
and treat in small children. Travellers should obtain
reliable advice and weigh the risks very carefully before
going to areas with malaria during pregnancy or with
small children. Travel to malaria endemic areas should be
avoided, when possible, by these groups of people.
There are preventive medications that are safe and
effective for most children or pregnant women if malaria
exposure is unavoidable. For example, chloroquine
is known to be safe for children and in pregnancy;
however it is not effective in many parts of the world.
If a pregnant women or child must travel to malaria
endemic areas where chloroquine is not effective
then mefloquine (Larium™) can be used. Doxycycline,
however, should not be used in pregnancy or in children
less than 8 years old. The safety of atovaquone/proguanil
(Malarone™) in pregnancy has not been determined;
however, the Committee to Advise on Tropical Medicine
and Travel (CATMAT) recommend its use for children
as small as 5 kg. Along with the preventive medication,
remember that careful attention must also be paid to
preventing mosquito bites through the use of insecticide
treated bednets and other protective measures.
11. The Australians (British, Kenyans, Thai, etc.) know
more about malaria than Canadians. Canadian guidelines
for malaria prevention are based on advice from
internationally recognized malaria experts and the best
available medical and scientific information from all
over the world. They are updated regularly. Canadian
recommendations also take into account the particular
needs and characteristics of Canadian travellers. British,
Canadian, American, Australian, and World Health
Organization malaria recommendations all differ
somewhat, but usually in relatively minor details.
12. Local doctors in Zimbabwe (Guyana, India, etc.)
told me I was causing a serious problem for malaria
control in their country by taking Larium ™. They said
I was encouraging development of local drug resistance
so that Larium ™ would no longer work in local
people. Promoting drug resistance, whether in malaria,
pneumonia bacteria, or tuberculosis, by irresponsible
use of medication is a serious concern. However, in
this case, Western travellers are not the problem. They
account for an immeasurably small fraction of the total
burden of malaria infections in the country so they
have no detectable effect on local development of drug
resistance. In any case, Larium™ is not widely used for
treatment in most countries.
13. There are better drugs available for malaria
prevention in other countries. Unfortunately there are
not. One new drug, Malarone™ has recently become
available and a few others are at various stages of
development. Older drugs such as chloroquine, although
still effective in parts of the Caribbean, Central America,
middle east, North Africa and west/central China, have
become much less useful due to the development of
drug resistance. Artemesinin and related drugs (based on
the Chinese medicine qinghaosu) are extremely effective
for treatment but are not useful for prevention.
14. I am immune to malaria because I grew up with
it. No. Immunity to malaria is gradually acquired by
repeated exposure to malaria infection over many years.
This immunity is incomplete, meaning you still can get
malaria, you just don’t get as sick. Immunity declines
rapidly within months to a few years after moving away
from an area of malaria transmission.
About AATHP
Alberta Association of Travel Health
Professionals is a nongovernmental
professional association formed in
November 1996. AATHP exists to
provide professional support to travel
health providers t meet our objectives.
To order more pamphlets refer to the
website at www.aathp.com
15. Taking medication is the only preventive measure
against malaria. Not at all. Measures to reduce the risk
of mosquito bites are an important part of malaria
prevention. Travellers at risk of malaria should use the
following measures in combination with appropriate
drug prophylaxis:
• Sleep under a bed net which has been treated with
permethrin or a related substance. This is one of the
most effective measures since malaria mosquitoes bite
almost exclusively at night. A treated bednet should be
used by every traveller to malaria-endemic areas unless
they are staying in a rigorously closed space, e.g. an air
conditioned room. Be sure to tuck the net in under
the mattress at night and tie up during the day. The
insecticide treatment adds considerably to the bednet’s
protection without demonstrable adverse effects to the
user.
• Stay in a protected area during the hours when
mosquitoes are actively biting.
• Use insect repellent containing DEET when outdoors
between dusk and dawn.
• Spray your room with flying insect spray (e.g. RAID).
Mosquito coils or insecticide mats placed on an
electrically heated grid can also be used.
• Wear protective clothing such as long sleeve shirts
and long pants, ideally light coloured, when outdoors
between dusk and dawn.
• DEET and sunscreen combinations are not
recommended. If DEET and sunscreen application are
both required, apply the sunscreen first and allow it
to penetrate the skin for 20 minutes before DEET
application.
Soybean oil 2% “blocker” repellents and Lemon
Eucalyptus oil can be used as alternatives when DEET
use is not possible (i.e. allergy to DEET). However, the
duration of protection is significantly shorter than DEET.
Repellents containing citronella oil are not effective.
16. The higher the DEET the better. There is still
no more effective insect repellent than DEET. DEET
has an incredibly good safety record after billions
of applications. The benefit of higher concentration
products is that the effect lasts longer. However,
this effect plateaus at 30-35% where the duration of
protection lasts for approximately 6 hours. Therefore,
any insect repellent with a DEET concentration
of greater than 35% has no additional benefit.
The reapplication intervals on the labels of DEET
formulations are a general guide only. There are many
variables such as sweating and swimming that can affect
the duration of effectiveness. As a general rule, if you
notice insect biting, then it is time to reapply the DEET.
17. DEET shouldn’t be used on children. Caution is
warranted in small children because they have a larger
skin surface area/body mass and more permeable skin.
But in a child at risk of exposure to malaria, that risk
could be overwhelmingly greater. CATMAT recommends
the judicious use of insect repellents containing DEET
on children of any age as a complement to other
protection methods when travelling to areas where this
is serious risk of disease from insects.
CATMAT recommendations for DEET use in Children:
• On children 6 months to 12 years, repellents up to
35% DEET should be applied sparingly to exposed areas
only and be washed off with soap and water once they
come indoors.
• On children younger than 6 months of age, first line
of protection against mosquitoes should be permethrin
impregnated mosquito nets and light coloured clothing.
Utilize portable mosquito nets including the self
standing type placed over a car seat, crib, playpen, or
stroller. Use of DEET on these children should NOT
be withheld if the risk for malaria outweighs the risk
for DEET toxicity. In rare instances (1:10 million users)
application of DEET has been associated with seizures in
young children. Consult with a travel health professional
regarding use of DEET in children younger than 6
months.
MALARIA
MISUNDERSTANDINGS