Travel related diseases

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Malaria

What is Malaria?

It is caused by a parasite which is transmitted by the bite of mosquitoes. The time between the infective bite and the appearance of symptoms varies between 7-30 days. Some may have longer periods up to months or even longer. Symptoms of malaria include intermittent fever, chills, sweating, headache, tiredness, poor appetite and muscle pain. In typical cases, the fever comes, then subsides for 1-3 days and then comes again in a cyclical pattern. Complications include anaemia, liver and kidney failure, seizures, mental confusion, coma, and death if the disease is not treated promptly.

How does it spread?

Malaria is spread by the bite of an infective female Anopheline mosquito. The parasite enters the human body while the mosquito is sucking blood.

How can you prevent it?

Avoiding the bite of mosquito is the first line and the best defence against contracting malaria. You can take the following precautions in preventing mosquito bites:

  • Wear long-sleeved shirts and trousers

  • Rest in air-conditioned or well-screened rooms;

  • Use aerosol insecticide indoor and use bed nets if sleeping areas are not air-conditioned or screened.

  • Use insect repellents containing DEET on exposed skin and clothings. For details about the use of insect repellents, please refer to Frequently Asked Questions.

  • If travelling in endemic rural areas, carry a portable bed net and apply permethrin on it as well as to clothes.

There is no vaccine against malaria though development of malaria vaccine is underway. If you travel to areas where malaria is common, consult your doctor beforehand for preventive measures and obtain anti-malarial drugs for prophylaxis if necessary. The commonly used drugs include chloroquine, proguanil, mefloquine, doxycycline and malarone. The choices are based on the particular destinations you are going to visit, the risks as determined by your travelling behaviour and your previous health status. They should only be taken after consulting a doctor. If you decide to take such medication you should start it before the trip, continue throughout the trip and after leaving the malarious area according to the instruction of the doctor.

During your visit abroad or after coming back to Hong Kong, if you have symptoms of malaria, seek medical advice immediately and inform the doctor of the places you have visited. Urgent blood tests may be performed and prompt treatment is vital.

How is it treated?

There are effective drugs against malaria but early diagnosis and prompt treatment are crucial. The doctor would prescribe a course of anti-malarial drugs with other supportive measures. The patient should complete the whole course of medication to ensure clearance of the malaria parasites. Malaria parasites resistant to some anti-malarial drugs has been reported in some parts of the world e.g. Cambodia. Travellers should inform doctors of their itinerary so that appropriate medication can be prescribed.

Where is it found?

Malaria is found in tropical and subtropical areas of the world.

Malaria, 2015

Specific information on malaria risk for each country can be found at the World Health Organization website at http://www.who.int/ith [Country list].

 

 

Last revision date: 4 February 2016