Malaria

Malaria is an infection spread through the bite of certain mosquitos that carry parasites. Symptoms include fever, chills, vomiting, headache and pain in muscles and joints. In some people Malaria can be a serious and life-threatening infection—especially in the elderly, infants and those with a weakened immune system.

The incidence of malaria is on the rise. Around 311 million new infections and 900,000 deaths occur worldwide every year.

Australia is free from Malaria, but it is occasionally present in the Torres Straight Islands. Usually Malaria is contracted from travelling in tropical and subtropical areas in Asia, Africa, Central and South America, the Pacific Islands and parts of the Middle East. Most Australian catch the disease in Papua New Guinea, East Timor and Indonesia.

What is Malaria?

Malaria is an infection of the liver and red blood cells caused by microscopic parasites. There are five types of parasites that cause malaria: Plasmodium ovale, P. malariae, P. knowlesi, P. vivax and P. falciparum.

Malaria parasites are spread through the bite of the female Anopheles mosquitoes—when she bites, the parasite is injected into your blood. When a mosquito bites a person with malaria, the mosquito may become infected and can then spread the disease. In rare cases, malaria can also be spread from person to person through blood transfusion, sharing injecting equipment, and from mother to foetus.

Symptoms of malaria

Symptoms include:

• Sudden fever
• Headache
• Chills
• Sweating
• Shivering
• Diarrhoea
• Nausea
• Vomiting
• Muscle and joint pain
• Anaemia and associated symptoms
• A general unwell feeling

The symptoms of malaria can sometimes present as a respiratory or gastrointestinal illness. Malaria caused by the Plasmodium falciparum parasite can be especially dangerous and lead to kidney failure, seizures, breathing difficulty and coma. The infection is sometimes fatal.

The symptoms usually develop 9-14 days after transmission and sometimes occur months later. In some people Malaria can re-occur months or years after exposure.

How to prevent malaria

If you are travelling to a malaria-affected area there are things you can do to reduce your risk.

Antimalarial drugs

Before travelling overseas visit your GP to discuss what options are available to you to avoid malaria. Depending on your itinerary and your medical history, you may be advised to take drugs to prevent malaria. Usually these drugs are taken several weeks before you travel, during and after. Unfortunately, these drugs are not 100% effective and you will need to take other measures to protect yourself from contracting malaria.

Mosquito bites

Mosquitoes not only carry malaria parasites but other infectious diseases too. To protect yourself against mosquito bites you can:

• Wear light-coloured, loose-fitting, long-sleeved shirts and pants
• Avoid perfumes, colognes and after-shave
• Take extra care at dawn, dusk and during the evening when mosquito bites are more prevalent
• Sleep in screened and air-conditioned rooms
• Use a bed net if where you are sleeping is exposed to the outdoors
• Avoid high risk areas if possible

Mosquito repellents

Products which repel mosquitoes can be applied to exposed skin, clothing and sprayed onto mosquito netting.

Mainstream products usually contain Diethyl Toluamide (DEET) or Picaridin. Unfortunately, these products may not be suitable for children under 12 months and there are people who prefer a more natural approach. Products which contain lemon eucalyptus, neem oil, cinnamon and citronella are effective alternatives, but they may need to be applied more frequently.

Wormwood

The Chinese medicinal plant Artemisia annua, otherwise known as wormwood, contains the antimalarial compound artemisinin.

In an open, randomized, controlled pilot trial, traditional tea preparations of wormwood in the treatment of uncomplicated malaria resulted in a quick resolution of parasitaemia and of clinical symptoms. After 7 days of medication, cure rates were on average 74% for the wormwood preparations compared with 91% for quinine. Even though the rates are higher in the quinone group, wormwood still offers a high recovery rates and is therefore suitable as a monotherapy for people who are unable to take traditional medicines or who don’t have access to them.

Zinc and vitamin A

Controlled trials of either vitamin A or zinc supplementation show that these nutrients can substantially reduce clinical malaria attacks. A deficiency in either of these nutrients, even if mild, can exacerbate malarial illness.

Zinc and vitamin A are protective against malaria because of their role in supporting a healthy immune system.

They can be easily supplemented in children and adults before, during and after travelling to increase resistance to infection.

The most definitive study to date of the effects of vitamin A on malaria was recently completed in Papua New Guinea. In this double-blind placebo-controlled trial, vitamin A supplementation reduced the frequency of P. falciparum episodes by 30% among preschool children. At the end of the study, geometric mean parasite density was 36% lower in the vitamin A group than in the placebo group, and the proportion of children with spleen enlargement was reduced by 11%.

A similar study on zinc supplementation reduced the frequency of health centre attendance due to P. falciparum malaria by 38%. Moreover, a 69% reduction was observed for malaria episodes accompanied by high levels of parasitemia, suggesting that zinc may preferentially protect against more severe malaria episodes.

Thiamine

Thiamine (Vitamin B1) deficiency is associated with greater risk of severe malaria and simple clinical malaria. Interestingly more recent research reveals that oxythiamine, a thiamine analog, inhibits proliferation of the malaria parasite Plasmodium falciparum—which may offer a new antimalarial drug target.

In naturopathy, vitamin B1 supplementation is often recommended as a natural defence against mosquito bites. The repellent effect is attributed to a foul odour, undetected by humans, which deters the female mosquito. The recommended dose to achieve this in adults is 100mg/day.

In summary

• Malaria is a disease transmitted by infected mosquitos in certain regions
• Implementing strategies to avoid mosquito bites and taking certain drugs and nutrients can help reduce your risk

References

1. https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/malaria
2. http://www.health.nsw.gov.au/Infectious/factsheets/Pages/malaria.aspx 
3. Geetha RV, Roy A. Essential oil repellents- A short review. Int J of Drug Develop. June 2014.http://www.ijddr.in/drug-development/essential-oil-repellents-a-short-review.php?aid=5498
4. Frances SP, et al. Comparative laboratory and field evaluation of repellent formulations containing deet and lemon eucalyptus oil against mosquitoes in Queensland, Australia. J Am Mosq Control Assoc. 2014 Mar;30(1):65-7 https://www.ncbi.nlm.nih.gov/pubmed/24772681
5. Mueller MS, et al. Randomized controlled trial of a traditional preparation of Artemisia annua L. (Annual Wormwood) in the treatment of malaria. Trans R Soc Trop Med Hyg. 2004 May;98(5):318-21 https://www.ncbi.nlm.nih.gov/pubmed/15109558
6. Chan XW, et al. Chemical and genetic validation of thiamine utilization as an antimalarial drug target. Nat Commun. 2013;4:2060 https://www.ncbi.nlm.nih.gov/pubmed/23804074