Journal of Travel Medicine, 2016, 1–2
doi: 10.1093/jtm/tav009
Perspective article
Perspective article
Malaria prevention—keep it simple and logical
Martin Haditsch, MD, PhD1,2*
1
TravelMedCenter Leonding, Leonding, Austria and 2Labor Hannover MVZ GmbH, Hannover, Germany
*To whom correspondence should be addressed TravelMedCenter Leonding, Hochstrasse 6a, A-4060 Leonding, Austria. Tel: þ43 732 670580.
Fax: þ43 732 670564. Email: [email protected]
Due to various activities—including those by the World Bank
and the Bill & Melinda Gates Foundation—we are happy to see a
global decrease in malaria cases. But too many still suffer and die
from malaria so malaria prevention or at least to prevent deaths
by malaria is of paramount importance, still. And this is not true
for the indigenous population only but for travellers as well.
Balancing the risk of disease with that of possible side effects
of chemoprophylaxis is a difficult task which mostly leads to
split decisions even in experts (as was shown in a thrilling ProCon debate at the CISTM14 in Quebec in May 2015). This lack
of guidance left and still leaves many colleagues (including qualified travel medicine practitioners) quite puzzled—not to talk
about those on target—i.e. the travellers.
For sustainable guidance my deep believe is: KEEP IT
SIMPLE—otherwise counselling doctors (not all of whom are
experts in tropical medicine or malariology) as well as travellers
will get lost in confusion for sure1 (‘The compliance is inversely
proportional to the complexity of the prescription’—Haynes
and Sackett 1976).
Insect bite precautions (IBP) from dusk until dawn are the
mainstay of malaria prophylaxis—so this is of paramount
importance for each traveller going to malaria endemic areas no
matter how high the risk actually is.
The first crucial decision of the binary decision tree is the
definition of high risk of exposure (but may consider high risk
of complications in vulnerable travellers as well). Whereas some
sources say that there is no method of quantifying the risk2
in other sources high risk is defined by a risk of 10:1000 in the
indigenous population3 or 1:100 (or higher)/month of stay (e.g.
for tropical Africa—older data: incidence of malaria per month
of exposure for travellers not taking chemoprophylaxis: 15.2
per 1000 in East Africa and 24.2 per 1000 in West Africa4).
Highly endemic throughout the year are most countries in tropical Africa, some islands in the Pacific Ocean and—at the
moment—shrinking areas of tropical South America (to be
looked up in actual malaria maps from various organizations).
In these regions, the recommended strategy is chemoprophylaxis
(with active compounds in addition to insect protection) —no
matter how long the stay is (in some areas in West Africa the
average likelihood of having an infectious bite is >1/night !5). In
regions with a high annual variability of risk chemoprophylaxis
(þIBP) should be limited to the high risk seasons, only.
MISCONCEPTIONS DUE TO WORDING
The wording “stand by therapy or treatment (SBT)”
[10] always leaves me with huge discomfort and I would
re-emphazise to replace it in general by the expression
“emergency self treatment” or “emergency self therapy”
(EST)**.
The reason to push “EST” is that “stand by” might be
dangerously misleading. At least it plays a critical strategy (which is not even state of the art globally) down in
putting travellers to increased risk based on misconception (which is - amongst several other cases dramatically
illustrated by an Austrian traveller to Lombok who died
in Austria due to malaria while still having atovaqone/
proguanil in his pocket).
For clarification: emergency self treatment (EST) is
applied by (mostly lay) people based on symptoms typical for malaria (which also means that they must know
the symptoms as well as the minimal incubation period)
if they have no or delayed access only to qualified medical care. The goal of this (primarily European) approach
is to bridge the gap in between onset of symptoms and
qualified medical care to positively impact the course of
a potentially life threatening disease. By using the expression “EST” the traveller knows that this is for emergency
use (i.e. dealing with a dangerous disease), done by her-/
himself (which indicates self-responsibility for correct
intake) as a pre-emptive treatment (i.e. highly active medical compounds which might cause side effects as well).
This kind of strategy implies that the traveller needs to
be trained and should get a written information on the
C International Society of Travel Medicine, 2016. All rights reserved. Published by Oxford University Press.
V
For permissions, please e-mail: [email protected]
2
Haditsch
Figure 1. Malaria prevention in travellers
initial symptoms (when to start the drug), the prescribed
drug (i.e. how to take it: dosing, interval, duration,
cofounding factors and additional aspects like impact of
food on absorption and possible side effects) and what to
do in case of vomiting. And most importantly to go and
see a doctor as soon as possible no matter whether the
symptoms improved after taking the drug since this
might be due to unspecific actions of the drug, to the
natural course of a disease other than malaria (e.g. a bacterial sepsis) or might camouflage partially resistant
malaria parasites, respectively.
Under the bottom-line if given in a correct way for the
counsellor giving instructions for EST are more time consuming by far as compared to providing those for
malaria chemoprophylaxis. And the action required, i.e.
self-medication based on clinical symptoms is by far
more difficult for the traveller. While this is adequately
reflected by the wording “emergency self treatment” the
expression “stand by” does not mirror this situation in
any instance - thus bearing the risk of gross underestimation. To avoid any further misconceptions I propose to
eliminate the term “stand by” from all official malaria
literature.
**IAMAT has already agreed to change all wordings
accordingly.
For other regions and/or seasons with moderate or low risk6
(in the actual scientific literature there are no clear data how to
discriminate these both groups; the API always relates to the
risk of the local population and is of limited—if any—value for
travellers; regions with a high annual variability between high
and low should not be addressed as ‘moderate’ just by calculating the average perennial risk) prophylaxis is limited to IBP. The
additional (and frankly spoken most confusing) challenge is
whether for these trips drugs for emergency self-treatment (EST)
should be recommended or not:
If the end of the trip to a non-high-risk region is earlier than
the minimal incubation period no additional action is needed.
So there is no need to carry drugs for EST, too.
If the stay is longer the decision should be based on the
accessibility to qualified medical care, which includes exact
diagnosis and proper treatment. Proper treatment excludes
over-the-counter products that might be fake or of bad quality
due to production, shipping or storage. As a result qualified
medical care usually is limited to hospitals and officially certified health care centres.
Since as to my knowledge not even P. knowlesi (the fastest
replicating plasmodial parasite) caused fatal courses of malaria
within 24 h from the first (!) signs of infection and the course of
disease is comparable to P. falciparum infection this time frame7
could be used for further decisions: if qualified medical services
can be provided within 24 h (which is true in general for most of
the travellers) no additional action is needed. So there is no need
to carry drugs for EST, too.
Consequently, EST should be provided only for travellers to
remote areas (i.e. when qualified medical services cannot be
approached within 24 h) where the malaria risk is (moderate to)
low.
As a summary
þ chemoprophylaxis in addition to insect bite prevention
should be recommended for (seasonal or perennial) high risk
areas (or for travellers with a high risk of complications in case
of malaria)
þ insect bite prevention only if the trip is to regions/in seasons/under conditions with (moderate to) low risk of exposure
and shorter than 6 days or for longer trips if medical care can be
accessed within 24 h and
þ EST for longer trips to remote areas (i.e. with no access to
qualified medical care within 24 h) with (moderate to) low malaria risk.
Since, we are dealing with a potentially life threatening disease
adherence to each detail of this decision-making process is crucial.
Anyhow a scheme based on three basic decisions (risk of exposure—duration of stay—access to qualified medical care: flowchart
see Figure 1) should make this complex challenge simple enough to
provide satisfying and uniform guidance for counselling nurses,
pharmacists and doctors and accomplish the goal to improve adherence of travellers to the recommendations given.8,9
Conflict of interest: None declared.
Journal of Travel Medicine, 2016, Vol. 0, No. 0
References
1. Shanks GD. Standby therapy to prevent Plasmodium falciparum
infections? J Travel Med 2014; 21:70–1.
2. http://www.cdc.gov/malaria/travelers/risk_assessment.html
3. Schlagenhauf P, Petersen E. Malaria chemoprophylaxis: strategies
for risk groups. Clin Microbiol Rev 2008; 21:466–72.
4. Steffen R., Heusser R., Mächler R. et al. Malaria chemoprophylaxis
among European tourists in tropical Africa: use, adverse reactions,
and efficacy. Bull World Health Organ 1990; 68: 313–22.
5. Beier JC, Killeen GF, Githure JI. Short report: entomologic inoculation rates and Plasmodium falciparum malaria prevalence in Africa.
Am J Trop Med Hyg 1999; 61: 109–13.
3
6. Voumard R, Berthod D, Rambaud-Althaus C et al. Recommendations
for malaria prevention in moderate to low risk areas: travellers’ choice
and risk perception. Malar J 2015; 14:139.
7. http://www.who.int/mediacentre/factsheets/fs094/en/
8. Muller JM, Simonet AL, Binois R et al. The respect of recommendations provided in an international travelers’ medical service: far from
the cup to the lips. J Travel Med 2013; 20:78–82.
9. Caillet-Gossot S, Laporte R, Noël G et al. Family compliance with
counseling for children traveling to the tropics. J Travel Med 2013;
20:171–6.
10. Haditsch M. “EST” vs. “stand-by treatment”. J Travel Med 1997;
4:207–8.