Guidelines for Malaria Prevention in Travellers from
the UK
Malaria is a preventable, life-threatening disease transmitted
by the bite of the female anopheline mosquito. While the disease is
not endemic in the UK, approximately 2000 cases of malaria occur
every year in travellers returning to the UK from malaria-endemic
countries.
Malaria is predominantly a disease affecting Africa, South and
Central America, Asia and the Middle East. The heaviest burden is
in Africa, where around 90% of approximately one million deaths
from malaria worldwide occur each year.
The Advisory Committee on Malaria Prevention for UK Travellers
(ACMP) has produced guidelines of essential information on malaria
prevention for healthcare workers who advise travellers, entitled:
Guidelines for Malaria Prevention in Travellers from the United
Kingdom for 2003. The guideline consists of eight sections:
| Section 1: |
purpose and scope of
guidelines |
| Section 2: |
summary recommendations |
| Section 3: |
issues considered in producing guidelines
on chemoprophylaxis for malaria |
| Section 4: |
advising travellers |
| Section 5: |
detailed recommendations |
| Section 6: |
recommendations by area |
| Section 7: |
surveillance |
| Section 8: |
future prospects |
1. Purpose and scope of guidelines
These guidelines on malaria prevention are designed to aid
healthcare workers who advise travellers, particularly those who
will be overseas for less than a year. The present (to May 2003)
revision is the responsibility of the Health Protection Agency
Advisory Committee on Malaria Prevention for UK Travellers (ACMP;
membership given at the end of the full guidelines).
The full guidelines are in three parts. The first part is a summary
that emphasises modifications to the advice given in the recent
guidelines, published in 1997 and 2001. As oversimplified lists of
recommendations by country can be misleading, the second part
(sections 3-4 in the full guidelines) discusses the issues
addressed in formulating the guidelines. The second part also
addresses the healthcare worker’s consultation with prospective
travellers. In concept and practice, chemoprophylaxis lies
somewhere between vaccinations (for which people expect governments
to lay down schedules) and treatment of ill people (which is
determined by individual clinical need and choice).
The risks of malaria need to be balanced against the risks of the
preventive measures, on the basis of the data available. Travellers
may ask for an explanation of these risks and doctors and practice
nurses need to be well informed and able to present this
information to travellers. Doctors, practice nurses and pharmacists
are asked to read this section to ensure that due attention is paid
to the traveller’s history and destination.
The third part (sections 5-8 in the full guidelines) gives specific
recommendations for travellers to named destinations and some
details of individual drugs. Fuller information on some drugs now
less used was given in early versions of the
guidelines.
These guidelines reflect a broad range of expert professional
opinion. Data are inadequate for unequivocal views to be given on
several issues, but all available evidence has been taken into
consideration. There is often a range of acceptable options, but to
meet the requests of general practitioners the guidelines aim to
give one recommended option and state the alternatives, suggesting
when and how different regimens can be used to good effect.
However, there are now several options for effective prophylaxis of
highly chloroquine-resistant falciparum malaria, and the choice
between them will depend on details of the journey and individual
preferences. The choice should involve adviser and traveller, with
the aim of improved compliance.
Authorisation to market drugs for use in the UK is the
responsibility of the Medicines and Healthcare products Regulatory
Agency (MHRA), advised by the Committee on Safety of Medicines, not
of the ACMP. The guidelines should therefore be read as a
supplement to and not as a substitute for the relevant summaries of
product characteristics (SPCs or ‘data sheets’).
The second part (sections 3-4 in the full guidelines) of these
guidelines may also be of use to prospective travellers who wish to
read about the options themselves. All readers are recommended to
read part three (sections 5-8 in the full guidelines) in its
entirety to get a balanced picture.
2. Summary recommendations
Four steps remain essential to prevent damage to health due to
malaria in UK travellers:
• Awareness: know about the risk of malaria
• Bites by mosquitoes: prevent or avoid
• Compliance with appropriate Chemoprophylaxis
• Diagnose breakthrough malaria swiftly and obtain treatment
promptly
Recent guidelines give greater emphasis to the importance of
balancing the risk of malaria and the risk of adverse reactions to
antimalarials. This depends upon:
• place to be visited
• duration of the visit
• degree of exposure
• level of drug resistance
• type of traveller
All these factors affect the risk of malaria. Whereas most adverse
reactions to antimalarials occur within the first few doses, the
cumulative risk of contracting malaria is roughly proportional to
the length of stay in a malarious area. The longer the stay,
therefore, the more important it is to use a regimen with a high
protective efficacy.
It is more important to take an effective antimalarial regimen
regularly than to agonise too much over which one to take. When two
choices are finely balanced the wrong course of action is to take
neither. In travellers who develop fever or a flu-like illness
within three months after possible exposure to malaria the need for
prompt medical attention cannot be overemphasised. It is also
desirable to keep a sense of proportion between malaria and other
health problems related to travel and to remember that malaria is
both relatively preventable, and treatable if diagnosed early. At
present, between 0.5% and 1% of falciparum cases in the UK die of
the disease.
The range of antimalarials for protection against highly
chloroquine-resistant malaria is expanding. In addition to the
highly effective mefloquine which has a weekly regimen, doxycycline
is now licensed for malaria prevention. Atovaquone/proguanil
(Malarone), now licensed for prophylaxis, is increasingly being
considered, especially for brief visits to highly malarious areas.
In the case of mefloquine, increased awareness of distressing
adverse neuropsychiatric reactions indicates caution in its use,
but it remains of great value where there is intense exposure to
malaria that is highly resistant to chloroquine.
It is important to observe contraindications to the use of specific
antimalarials, and especially not to give mefloquine to people with
a history of epilepsy or psychiatric illness, including depression.
Chloroquine is relatively contraindicated in people who have had
fits or who have psoriasis. Doxycycline is being used more often
for those unable to take these drugs and going to high-risk areas,
but it does carry a small risk of photosensitisation.
The preferred chemoprophylaxis for the few areas without
chloroquine resistance is chloroquine. Those unable to take
chloroquine should take proguanil. For areas such as South Asia
(the Indian subcontinent), with low or moderate levels of
transmission of falciparum malaria that is slightly or moderately
resistant to chloroquine, the preferred chemoprophylaxis is at
present proguanil plus chloroquine.
Chemoprophylaxis is not recommended for places where there is a
very low risk of acquiring highly multidrug-resistant malaria as
the risk of adverse effects exceeds the risk of contracting the
disease, but travellers are urged to maintain a high degree of
awareness and seek immediate diagnosis and treatment of any febrile
illness.
In areas with a high or very high risk of malaria that is strongly
chloroquine resistant the frequency of adverse reactions to
chemoprophylaxis has to be balanced against the risk of severe
malarial illness and of death from falciparum malaria. The overall
prevalence of adverse reactions, and of discontinuing
chemoprophylaxis because of them, is comparable between regimens.
Recent data indicate a significant frequency of subjective
distressing neuropsychiatric adverse effects with mefloquine, but
the results of different studies vary considerably. In the absence
of recognised contraindications it is impossible to predict which
individuals will suffer from these side effects.
On the other hand, mefloquine continues to have a substantially
greater protective efficacy in East Africa, for example, than
proguanil plus chloroquine. Therefore, for most of Africa,
proguanil plus chloroquine is not recommended unless neither
mefloquine, nor doxycycline, nor atovaquone/proguanil, can be
taken.
Full recommendations by country and person are set out in part
three (sections 5-8 in the full guidelines). Alternative regimens
are usually given for travellers unable for any reason to take a
recommended regimen.
Sources of advice on malaria prevention for
travellers
The information below gives sources of advice for doctors and
practice nurses who need more detailed advice for specific problems
than this paper provides.
HPA Malaria Reference Laboratory (MRL) (at London School of Hygiene
and Tropical Medicine): 020 7636 3924
National Travel Health Network and Centre (NaTHNaC): 020 7380
9234
Glasgow, SCIEH for Travax users only, 2-4pm: 0141 300 1130
Birmingham Heartlands Hospital (Infectious Disease Unit): 0121 424
0357
Liverpool School of Tropical Medicine: 0151 708 9393
Oxford: 01865 225 214
London, Northwick Park Hospital: 020 8869 2831
Hospital for Tropical Diseases Treatment only (ask for the medical
officer on duty, Patrick Manson Unit): 020 7387 9300
Recorded advice for travellers from the HPA Malaria Reference
Laboratory is available on 09065 508 908 (calls charged at 100p per
minute).