Topic: Malaria
Description
Malaria is caused by a parasite which is spread through the bite of particular types of mosquito. There are four types of malaria parasites. One type, called falciparum malaria, is dangerous because unless treated promptly it can cause severe illness and even death.
Australia was certified as being malaria free by the World Health Organisation (WHO) in 1981, however, there are several hundred imported cases of malaria recorded in Australia each year. Travellers to infected regions must take precautions to avoid mosquito bites, and usually anti-malarial drugs, to prevent malaria.
Malaria occurs in many countries but the regions of greatest risk to Australians include: the south-west Pacific (Solomon Islands, Papua New Guinea and Vanuatu), Asia (in particular parts of Thailand, Myanmar, Sabah, Vietnam and India) and Africa (with the East African countries posing a very high risk).
Visitors to resort areas (Bali, Phuket, and Pattaya) and major cities in South-east Asia (Hong Kong, Jakarta, Singapore, Kuala Lumpur, Penang, Bangkok and Chiangmai) do not routinely require anti-malaria drugs. However even short term visitors to Papua New Guinea and the Solomon Islands (including Port Moresby and Honiara) should take anti-malaria medications.
Symptoms
The most common symptoms of malaria are high fever, headache, backache, nausea, vomiting, and muscle and joint pains. In untreated people, malaria may persist for years.
The period between the bite of an infected mosquito and the appearance of symptoms may be as short as seven days, but sometimes people don’t become ill until eight to ten months after the bite.
Transmission
Malaria is not transmitted from person to person. Malaria is spread by the bite of particular types of mosquito and can only be spread in areas of Australia where these mosquitoes are found. Untreated people with malaria may be a source of mosquito infection for up to three years. Biting a person with malaria in their blood infects the mosquito. After a period of development inside the mosquito, malaria can be transmitted to another person when the same mosquito bites them. The mosquito is infected for life.
Treatment
There are several effective drugs for treating malaria, though treatment has become more complicated with the development of resistant malaria parasites. Early malaria can usually be easily treated whereas late, severe or complicated malaria can be a life-threatening medical emergency. Some types of malaria may reoccur, requiring additional treatment.
Prevention
Travellers visiting areas where malaria is common should take anti-malaria medication. There are a variety of anti-malaria drugs available. The choice varies according to the destination, duration of travel, and other personal factors. In some circumstances (eg. pregnancy and childhood) it is difficult to give advice on effective medication and if the risk is considered high, the best advice may be to stay home.
All anti-malaria medication must be taken as recommended. Do not stop the medication unless absolutely necessary. Most medication needs to be taken for four weeks after leaving the infected area. No anti-malaria drug is 100% effective. Therefore, malaria can still occur in people who take their medicine regularly.
It is also important to protect yourself from being bitten by mosquitoes.
- Avoid going outdoors between dusk and dawn in rural urban areas, and urban fringe areas.
- If outdoor after dusk, wear light coloured, long sleeved clothing and long trousers. Do not use perfumes or aftershave lotions as these fragrances attract mosquitoes.
- Sleep in properly screened rooms and use knockdown insect spray to kill any mosquitoes present in the room. Mosquito coils or vaporisers should be used at night.
- Use mosquito nets, check for holes and tuck the edges under the mattress before dusk. Nets can be impregnated with pyrethrinoid insecticide to enhance their protection.
- Use insect repellents containing up to 20% “DEET” on exposed skin, and garments, particularly at night. Repellents should not be used on children under six months of age and sparingly on children between six and 24 months of age.
If you become ill with fever within a year of travel to an infected region, it is important to inform your doctor of your travel and of the possibility of malaria.
Control
It is important that Australia remains malaria free. Mosquito eradication programs are the most effective way to control spread of disease.
Help and Assistance
For further information, please contact your local doctor, community health centre or nearest public health unit.
Footnotes
Heymann, D., ed. 2004. Control of Communicable Diseases Manual, 18th edition. Washington, DC: American Public Health Association.
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Last Updated: 12th October, 2009
Date Valid to: 30th June, 2010
