Flying down south : preventing health problem

révention
en pratique médicale
INFECTIOUS DISEASES
Flying down south:
preventing potential health problems
The south has become such a popular holiday destination that the idea of travelling to these countries does not inspire health worries in the general
population. However, physicians should be concerned with prevention before patients take a trip south, and show good diagnostic judgement when
patients return, even when they travel to vacation destinations. Here are two key questions to ask your patients.
“So. Will you be going down south
for your holidays?”
During the time of year when people go south for
their holidays, patients should be asked this question
systematically.
Since most of them do not consider that a holiday
down south presents any danger to their health,
they will not automatically think to ask you about
preventive measures or to consult a travel clinic.
They need to be reminded that such holidays are not
without health risks.
“Hepatitis A looking for traveller to emigrate”
Every year, 100 to 200 Quebecers come back from
their holidays with hepatitis A. Most cases are
among travellers returning from a one- or two-week
holiday to Mexico or the Dominican Republic, in
adequate accommodations. Of course the risk is
higher for backpackers who go off to more remote
areas where conditions are marginal.
advice are usually sufficient. Determining if the trip
could have an effect on any underlying disease a
patient may have is also justified.
For trips to Africa or Asia, and for out-of-the-way
adventure holidays in Latin America, it might be
better to refer the patient to a travel clinic. This
type of trip can involve a range of vaccinations and
specific travel advice; in addition, all the vaccines
are available in these clinics.
“Have you travelled anywhere lately?”
Every year, Canadians die of malaria. How come?
The patient has a fever when he gets home? Think
malaria
Asking about recent trips is the key way to collect
information that will allow you to suspect malaria
in a person living in Quebec.
Malaria treatment must be started as quickly as
possible once the symptoms appear because irreversible, or even deadly, complications can develop
rapidly. Malaria should be considered for all feverish patients. Treatment can begin even if the
results from the blood smear are not immediately
available.
This disease is easy to treat, at least when it is
diagnosed within the first few hours. Therein lies
the problem. Deaths are generally due to delays that
are often cumulative: delay in consulting a physician,
delay in suspecting the disease and diagnosing it,
delay in treatment.
Geographical distribution of hepatitis A
”Vaccine looking to fly down south on someone’s
shoulder”
Hepatitis A vaccination is a good idea, even for
people going on hotel and beach holidays in the
south. It is recommended for any stay in a developing country where the disease is endemic (see map).
In America, these countries are: the Dominican
Republic, Haiti, Mexico, Cuba, and all the countries
of Central and South America. Vaccination is not
usually indicated for a trip to the other islands or
Florida.
With proper preparation, physicians can conduct
prevention interventions with most of their patients
going off on holidays to seaside resorts in the
south: hepatitis A vaccination and the usual general
March 2002
LEGEND
Regions where
hepatitis A is endemic
Guide d’intervention santé voyage, MSSS
1
Before heading south
Hepatitis A vaccination: a vaccine that is worth getting before leaving for Mexico,
the Dominican Republic, and anywhere in Latin America
Vaccines
Four interchangeable hepatitis A vaccines are currently available on the market.
Three vaccines are prepared from cultivated and
inactivated virus and using aluminium hydroxide as
adjuvant (potentiator), a standard, well-proven technology. Epaxal® also uses inactivated virus that is
coupled with virosomes or phospholipids, increasing
immunogenicity; this is a new technology.
Vaccination schedule
The vaccination schedule includes 2 doses. The minimum interval between doses varies from 6 to 12
months, depending on the product used. There is no
maximum interval: the 2nd dose can even be administered at the time of a subsequent trip. For more
information, consult the Quebec Immunisation
Protocol (PIQ) .
The first dose of vaccine protects against the disease
even if it is administered on the day of departure.
Although it takes about 10 days for immunity to
develop, the incubation period for hepatitis A varies
from 2 to 7 weeks. Therefore, the protection conferred
by the vaccine will be effective. After 2 doses of
vaccine, protection lasts several years. The specific
duration of this protection and the need for booster
shots after several years have not yet been determined.
The end of IG
Pregnancy and breast feeding
Costs
The safety of the vaccine for pregnant women has
not yet been established since it is not acceptable
to carry out the usual safety studies on pregnant
women. However, since the vaccine is made from inactivated (killed) virus, the risk to the foetus is thought
to be low. If a pregnant women is at risk for exposure
to hepatitis A, it is much more preferable that she
receive the vaccine. Breast feeding is not a contraindication, nor is it a contraindication to immunisation
with any other vaccine.
Each dose of vaccine costs about $43 for an adult
and $23 for a child, when vaccine is bought in bulk
directly from the manufacturer. Single doses bought
in a pharmacy are more expensive. These costs are
not usually covered by insurance programmes.
Hepatitis A vaccines
Vaccines
Havrix™ (GlaxoSmithKline)
Vaqta® (Merck)
AvaximTM (Aventis Pasteur)
Epaxal Berna®
Approved for
Paediatric formula
over 1 year of age
over 2 years of age
over 12 years of age
over 1 year of age
1-18 years
2-17 years
-
Immune globulin is hardly used anymore to prevent
hepatitis A among travellers. This decision was made
in light of the longer-term protection conferred by
the vaccine, the frequent problems in getting supplies of IG, and the difficulties in assessing the risk
of transmission of unknown infectious agents or
undetectable agents such as prions.
Combination A and B vaccine
GlaxoSmithKline also distributes Twinrix™, a combination hepatitis A and B vaccine. The vaccination
schedule for this vaccine is identical to the one for
hepatitis B vaccine: 3 injections, the first 2 given
one month apart, and the third given 5 months or
more after the second dose. The amount of hepatitis A viral antigen is lower in Twinrix™ vaccine; consequently, this product should be used only if 2
doses can be given before departure. Otherwise, it is
preferable to administer each vaccine separately.
Malaria prevention
Checking basic immunisation
A person’s immunisation status against
certain diseases should be checked if he or she
is planning to traveI.
Diphtheria-tetanus
Check basic immunisation and administer a
booster every 10 years. This precaution will
prevent having to receive a tetanus booster
shot in a developing country, should a slight
injury occur.
Poliomyelitis
Check basic immunisation; a booster can be
given, once only, 10 years or more after primary
vaccination. The booster dose should be given
because even though poliomyelitis caused by
the wild virus has been eliminated in the
Americas, a few countries still use live oral vaccine
(Sabin), whose use is linked with a small risk of
transmission of vaccine-associated poliomyelitis.
Measles, mumps, rubella
Check basic immunisation; measles control in
the rest of the Americas is similar to that in
Quebec. Verify that a person born in 1980 or
after has received 2 doses of measles vaccine.
If not, complete with MMR vaccine.
Hepatitis B
Ideally for everyone. Recommend strongly to
youth aged 18 and under (for whom the vaccine
is free), people who are single, and those who
have risk factors. Occasionally, risk factors
increase when travelling, with the sun, alcohol,
opportunities, permissiveness, etc.
Influenza
Depending upon personal risk factors.
Influenza is present all year round in the tropics.
2
If a trip is limited to a hotel and beach, there
is no risk of malaria except in Nicaragua, in
small Mexican seaside resorts south of Cancun
(Riviera Maya) and in Huatulco (Mexico). It is
always possible to check when there are new
travel destinations. There is also a risk of
malaria everywhere in Haiti. In these regions,
chloroquine is the preferred preventive medication. It is contraindicated for people with a
history of seizures.
When the risks of malaria are high, the best
preventive method is usually chemoprophylaxis.
Basic hygiene in tropical countries includes
taking precautions to prevent insect bites but
these measures are not effective enough to
replace chemoprophylaxis.
Prophylactic dosage for adults
250 mg chloroquine (Aralen®)
2 tablets a week. Begin 1 week before
travel, continue while in region and for
4 weeks after leaving the area.
Prévention en pratique médicale, March 2002
Fever on returning from a trip
Is it malaria?
When to suspect malaria
How to treat
Depending on clinical and lab data
Someone with malaria will often present flu-like symptoms: fever which is usually continuous, sometimes
accompanied by other non-specific symptoms. Malaria
should be suspected first in all feverish travellers.
Clinical and biological examinations do not reveal
much, but malaria is often accompanied by thrombocytopenia.
Plasmodium falciparum malaria normally occurs 1 to
4 weeks after exposure. P. vivax malaria can occur
much later; this infection is less serious and does
not usually endanger a person’s life.
Chloroquine is the preferred treatment for a patient
returning from a trip to a region where there are no
reports of resistance to chloroquine.
If the patient has travelled to a region where P. falciparum is chloroquine-resistant, quinine or quinidine can be used as initial treatment, and is usually
Geographical distribution of malaria and of chloroquine-resistant Plasmodium falciparum
Depending on the area visited
Cases of malaria diagnosed in Quebec are usually
among travellers returning from tropical Africa, the
Indian sub-continent (India, Pakistan, Bangladesh,
Sri Lanka), Haiti, Nicaragua, and Ecuador.
Although rare, malaria is also possible following
travel to a rural area in South-East Asia, China, or
other tropical countries in America (see map).
Depending on preventive medication used
If a traveller is not already taking medication to
prevent malaria, or if he or she is taking one that is
not effective, the risk of contracting malaria is much
higher than if taking effective medication (see Table).
Even so, it is important to verify whether the traveller
continued taking the medication during the prescribed
period following exposure. There is no prophylaxis
for the less serious P. vivax malaria (except atovaquone/proguanil or primaquine), which can occur
several months after the traveller has returned from
the trip.
LEGEND
Plasmodium falciparum
resistant to chloroquine
Chloroquine sensitive
malaria
Guide d’intervention santé voyage, MSSS
About 1000 cases of malaria are reported each year in
Canada. In 2000, 169 cases were reported in Quebec.
Deadly cases of malaria occur mostly among travellers
returning from tropical Africa.
Effectiveness of malaria chemoprophylaxis
by region of travel
Medication
Effectiveness
Mefloquine (Lariam®)
Effective everywhere except on the
Thailand-Myanmar (Burma) border
and the Thailand-Cambodia border
Atovaquone/proguanil (Malarone®)
Effective everywhere
Doxycycline
Effective everywhere
Primaquine
Effective everywhere
Chloroquine (Aralen®, Nivaquine® )
Effective only in Haiti, the
Dominican Republic and
Central America
Chloroquine/proguanil (Riamet®)
Pyrimethamine/dapsone (Maloprim®)
Pyrimethamine/sulfadoxine
(Fansidar®)
Not effective
Not effective
Not effective
How to confirm the diagnosis
A blood smear is required to confirm a diagnosis of
malaria. Thick blood smears are more sensitive; thin
smears are more specific and are used to identify
the species.
followed with another, more practical and better
tolerated anti-malarial drug once the patient has
improved. Atovaquone/proguanil is also very effective
and is better tolerated, but can only be taken orally.
When to treat
Treatment should start as soon as possible at onset
of symptoms, since irreversible and sometimes
deadly complications can appear abruptly. In most
cases, a patient with P. falciparum malaria has to be
hospitalised. If malaria is highly suspected, and
diagnostic testing is not available or a test result is
negative, treatment can start at once. Even a negative smear does exclude the diagnosis. If there is a
high index of suspicion, it may be preferable to keep
the patient in hospital and repeat diagnostic
testing 12 to 24 hours later. Treatment can also be
considered in the absence of a diagnosis.
Prévention en pratique médicale, March 2002
3
Adult dose for prophylaxis
250 mg per week, starting 1 week
before travel, during travel, and continuing for 4 weeks after returning
from malarious area.
1 tablet per day, starting 1 day before
travel, during travel, and continuing
for 7 days after returning from
malarious area.
100 mg per day, starting 1 day before
travel, during travel, and continuing
for 28 days after returning from
malarious area.
30 mg per day, starting the day before
travel, during travel, and continuing
for 4 days after returning from
malarious area.
500 mg per week, starting 1 week
before travel, during travel, and continuing for 4 weeks after returning
from malarious area.
Travel clinics
Travel Clinic - CLSC Pierrefonds
13800 Gouin Blvd. West
Pierrefonds, Quebec H8Z 3H6
Tel.: (514) 626-2572
General advice for travellers
• Only drink bottled or boiled water.
Clinique Santé-Voyage de Montréal
5855 Sherbrooke Street East
Montréal, Quebec H1N 1B6
Tel.: (514) 252-3890
• Wash and peel fruit before eating
them.
McGill University Centre for Tropical
Diseases
Montréal General Hospital
1650 Cedar Avenue, room D7-153
Montréal, Quebec H3G 1A4
Tel.: (514) 934-8049
• Only eat seafood, meat, and vegetables that have been well cooked.
Clinique Santé Voyage St-Luc
1001 Saint-Denis Street
Montréal, Quebec H2X 3H9
Tel.: (514) 890-8332
Clinique du voyageur
de l’Hôpital du Sacré-Coeur de Montréal
5400 Gouin Blvd. West
Montréal, Quebec H4J 1C5
Tel.: (514) 338-3169
Service de santé de l’Université de Montréal
2101, Édouard-Montpetit Blvd.
Montréal, Québec H3T 1J3
Tel.: (514) 343-6505
MédiClub Montréal - Travellers’ clinic
6100 du Boisé
Montréal, Quebec H3S 2W1
Tel.: (514) 739-5646, extension 221
Clinique Santé voyage Médisys
550 Sherbrooke Street West
Montréal, Quebec H3A 3C6
Tel.: (514) 845-1211
***
Travel clinic services are not free.
• Avoid eating bivalve mollucan shellfish (oysters, mussels, etc.); even in
the best conditions, they may not be
cooked enough or could have been
taken from contaminated waters.
ERRATUM
A twice-monthly column
on the Web
• Sexual protection is appropriate
everywhere. In fact, you should
probably include condoms in your
luggage just as you would your
swimsuit or toothbrush.
In the PPM on tuberculosis, the
telephone number for the TB clinic
at Hôpital Ste-Justine should have
been (514) 345-4931
extension 3900 or 3907.
révention
en pratique médicale
For more information
Guide d’intervention santé-voyage
Situation épidémiologique
et recommandations 1999
Includes the November 2001 update
Ministère de la Santé et des Services sociaux.
en pratique médicale
• Protect yourself against insect bites.
Use an insect repellent containing
DEET. Consider other measures such
as using an air conditioner.
• Vaccine manufacturers distribute
brochures with general advice for
travellers.
www.santepub-mtl.qc.ca
révention
• Protect yourself against the sun’s
harmful rays. Stay out of the sun
during the sunniest part of the day
and use a sunscreen lotion with a
sun protection factor of 15 or higher.
Available from the
Direction de la santé publique de Québec
[ (418) 666-7000 ] and as a pdf file on the
Ministère’s Web site at:
http://www.msss.gouv.qc.ca/preventioncontrole/
voyageurs/fs_voyageur.html
4
A publication of the Direction de la santé publique
de Montréal-Centre in collaboration with the
Association des médecins omnipraticiens de Montréal
as part of the Prévention en pratique médicale programme coordinated by Doctor Jean Cloutier.
This issue is produced by the Infectious Disease Unit.
Head of the Unit: Dr. John Carsley
Editor-in-chief: Dr. Monique Letellier
Editor: Blaise Lefebvre
Graphic design: Manon Girard
Translation: Sylvie Gauthier
Texts by: Dr. Guy Lonergan
Contributors:
Dr. Martin Champagne
Dr. David Dunn
1301 Sherbrooke Street East, Montréal, Quebec H2L 1M3
Telephone: (514) 528-2400, Fax: (514) 528-2452
http://www.santepub-mtl.qc.ca
Email: [email protected]
Legal deposit – 1st trimestre 2002
Bibliothèque nationale du Québec
Nationale Library of Canada
ISSN: 1481-3742
Agreement number: 40005583
Association
des Médecins
Omnipraticiens
de Montréal
Prévention en pratique médicale, March 2002