TRAVEL VACCINES AND MALARIA
Abstract
A brief guide to travel vaccines and malaria prevention
Planning what you need before you travel: Before leaving New Zealand to travel abroad it is important to find out what travel vaccinations or malaria prevention is necessary well in advance. Many vaccines take time to become fully effective and some must be given in a series over days or weeks. For this reason it is ideal to arrange an appointment with your doctor or practice nurse at least 4-6 weeks before your departure date.
There are several websites that are useful for planning what vaccinations are recommended for travel within any particular country as well as what malaria prevention (if any) is needed. Examples of some useful websites are included at the end of this article.
What vaccines are most often recommended?
a) Routine vaccinations
Before travelling abroad is a good time to ensure whether your routine immunisations are up-to-date, and if they are not then ensure that you do arrange to get any necessary vaccines and boosters.
Tetanus, Diptheria, Pertussis, Measles, Mumps, Rubella & Poliomyelitis
Your vaccination history for these diseases should be reviewed and any necessary boosters arranged.
Seasonal influenza vaccine
Influenza vaccination is recommended for children, pregnant women, older people and anyone suffering from chronic lung, heart or kidney disease or any immune problems. Remember that seasonal flu’ patterns are opposite in the southern and northern hemispheres (i.e. when it is summer in New Zealand, it is winter in Europe). Unfortunately it can be difficult to source seasonal influenza vaccine in New Zealand outside of the months of March-September, so as an alternative your doctor may discuss the use of influenza anti-viral medication if you get exposed to a case of probable flu’.
Pneumococcal vaccine
Pneumococcal vaccination is recommended for older people and anyone suffering from chronic lung, heart or kidney disease, sickle cell disease or any immune problems as well as for people who do not have a spleen.
b) Commonly required travel related vaccines
Hepatitis A
Hepatitis A is a virus that is transmitted mainly through contaminated water and food. If a person becomes infected with hepatitis A they can become feverish, develop abdominal pain and liver upset (usually making their eyes and skin turn yellow in colour or ‘jaundiced’). Prevention includes good personal hygiene (e.g. washing your hands well after visiting the toilet), drinking only from a safe water supply, eating only well cooked foods and peeling your own fruits, as well as vaccination.
Hepatitis A vaccination is recommended for travel to most developing countries. It can be obtained as a single vaccine (known as havarix) or in combination with typhoid (known as hepatyrix). If you boost a hepatitis A vaccine within the first 6-12 months, the immunity is then thought to last for approx. 20 years or more.
A combination Hepatitis A and Hepatitis B vaccine is also available (known as twinrix).
Hepatitis B
In contrast to Hepatitis A, Hepatitis B virus is transmitted through sex, infected blood and blood products or via items in contact with infected blood (e.g. razor blades, tattoo needles and needles used for injecting drugs intravenously). If a person becomes infected with hepatitis B they can become unwell (often for several months) and severe liver damage can result.
Hepatitis B vaccination is recommended for most countries but especially if you will have close contact with the local population (e.g. through sexual relations, those working in health care fields, aid workers, teachers, missionaries).
Hepatitis B vaccination involves 3 vaccines spaced over several months.
Typhoid fever
This is an infection of the intestines caused by a bacteria transmitted through contaminated food and water in areas with poor sanitary conditions. If a person contracts typhoid they will commonly have headache, fever and abdominal pain.
Prevention includes good personal hygiene, drinking only from a safe water supply, eating only well cooked foods and peeling your own fruits, as well as vaccination.
Typhoid vaccination can be obtained as a single vaccine or in combination with Hepatitis A (hepatyrix).
Vaccination is recommended ideally 10 days prior to travel, and generally a booster is required after 3 years if you are again travelling to a country that recommended typhoid vaccination.
Cholera
Cholera is a water-borne illness that causes severe diarrhoea and dehydration.
Dukoral is an oral vaccine available to help prevent cholera and travellers’ diarrhoea caused by certain toxin-producing E.Coli (a type of bacteria). This vaccine is given in 2 doses 1-6 weeks apart (except children aged 2-6 years should receive 3 doses). At present it is not recommended for children under 2 years.
c) Less commonly required vaccines
These vaccines may not be so frequently needed by travellers to the majority of countries but may be a recommendation depending on which countries you are visiting.
Yellow fever
Yellow fever is a viral infection transmitted by mosquitos in many countries in Africa and South America.
A yellow fever vaccination certificate is required for travellers coming from a country with high risk of yellow fever transmission.
Vaccination is recommended at least 10 days prior to travel, and generally a booster is required 10 years after course completion. It is usually necessary to visit a travel health specialist to obtain Yellow fever vaccination as it is not routinely stocked or ordered in by most general practices.
Japanese Encephalitis
This is a viral infection transmitted by mosquitos in Asia and Southeast Asia. Prevention includes insect-bite prevention measures (e.g. DEET insect repellent to exposed skin, applying permethrin to bed-net, clothing and gear).
Vaccination is recommended for people travelling extensively in rural areas or if they will be living where mosquitos may be living/breeding (e.g. near irrigated land).
Rabies
Rabies is a viral infection transmitted through the saliva of infected animal bites. If bitten by a rabid animal, the infection can affect the brain and spinal cord and can be fatal. The kinds of animals that are sometimes infected with rabies are dogs, monkeys, cats and other mammals.
A series of 3 injections are advised for people planning an extended stay or on working assignments in rural or remote areas particularly in Africa, Asia, Central and South America. The vaccinations are recommended 1 month prior to travel, and generally a booster is required 1-2 years after course completion if travelling again to a country where rabies is prevalent.
It is important to understand that the pre-exposure vaccinations only provide some initial protection. If a vaccinated person gets bitten by an animal which potentially could have rabies then they still require 2 additional post-exposure injections urgently.
Someone who has not been vaccinated, if bitten by a animal which is suspected of potentially having rabies, will require 5 injections in addition to rabies immune globulin. The problem is that in many underdeveloped countries rabies immune globulin is in extremely short supply and sometimes may not even be available.
Malaria prevention – should I be taking tablets for this?
Malaria is a serious and sometimes fatal disease transmitted by mosquito bites. Malaria prevention consists of mosquito bite avoidance and taking malaria prophylaxis (medicine to help reduce your chances of contracting the disease if you are bitten).
Mosquito bite avoidance involves trying not to be outside at dawn and from dusk onwards, covering up with light clothing especially around the ankles/feet area, sleeping under insecticide-impregnated mosquito nets, spraying indoors with an insecticide as well as applying a topical insecticide to your skin when outside. Insecticides containing a chemical known as DEET are often recommended and can be bought at pharmacies.
It is important to note that there are other mosquito-transmitted diseases such as Dengue fever and chikungunya that can be acquired from mosquito bites during daylight hours, which is why mosquito bite avoidance is so necessary.
The choice of malaria prevention medication most often depends on which particular country you are going to visit and whether any resistance against a particular chemical has developed in that region.
Chloroquine
· Taken once weekly
· Started 1-2 weeks prior to travel, during and for 4 weeks afterwards
· Safe in pregnancy
· Cannot be used in areas where there is chloroquine resistance (many parts of Asia and Africa)
Malarone
· Taken once daily
· Started 1-2 days prior to travel, during and for 7 days afterwards
· Well tolerated (side effects are uncommon)
· Can be more expensive than some other options
· Not to be taken in pregnancy
Doxycycline
· Taken once daily
· Started 1-2 days prior to travel, during and for 4 weeks later
· Can cause skin sensitivity to strong sunlight in some people
· Inexpensive
· Not to be taken in pregnancy
Mefloquine
· Taken once weekly
· Safe in pregnancy
· Started 2 weeks prior to travel, during and for 4 weeks later
· Should not be used in patients with seizures disorders or certain psychiatric disorders
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Useful websites
These websites contain information about what vaccines and malaria prevention is needed in different parts of the world:
· http://www.traveldoctor.co.uk/tables.htm
Another website that has useful information on what outbreaks are occurring around the world is: http://www.safetravel.govt.nz