Perhaps we are becoming complacent about an ancient and entrenched killer disease in tropical countries – malaria. Perhaps it is being overshadowed with the news of Ebola and the continuing problem of AIDS, and recent fears about antibiotic-resitant TB entering Australia, and other more sensational stories.
One of the tragedies of the strict controls necessary to control Ebola infection in north-west Africa is that it is taking beds and hospitals and staff away from the normal medical needs of those countries, such as for malaria and childbirth.
While the news headlines scream that the current Ebola epidemic has killed thousands, malaria is quietly killing almost a million (a thousand times a thousand) every year, mostly children. It infects hundreds of millions more – many of whom continue to have bouts of fever on and off for the rest of their lives, even after surviving the first severe infection. Some of these people may become carriers, enabling mosquitoes who bite them to spread the disease further.
Although scientific and medical researchers have indeed been trying to eradicate this scourge for centuries, there has only ever been partial success. Now, after many dead-ends and partial solutions, some recent research developments provide some hope.
Brief history of malaria
Malaria is an ancient disease. It has a very complicated biology, which makes it difficult to treat and more difficult to eradicate.
The name comes from two Latin words meaning "bad air". The ancient Romans knew that this disease was contracted in swampy, humid areas that smelt bad. They did not know that the smell had nothing to do with the disease. It was not until the 1880s that the means of transmission were discovered, leading eventually to the Nobel Prize for medical researcher Ronald Ross in 1902.
It was probably one of the fevers mentioned in both Old and New Testaments, as it is known to be endemic in the Fertile Cresent of North Africa, and has been found in 40% of Egyptian mummies studied. It was also reported in ancient China. In fact, one of the modern drugs used to control malaria (arteminsin) is derived from the Chinese traditional medicine from the sweet wormwood tree. A modified form of this medicine is now always administered as part of a multi-drug regime, to minimise any resistance to the drugs.
Malaria has killed European pioneers in many parts of the world. Just a few examples include: Dutch settlers and visiting sailors in former Batavia (now Indonesia); workers building the Suez Canal; Victorian explorers in Africa; the first settlers in New Orleans (American Indians sensibly never actually camped there, they only met on high ground briefly, to trade). It has also killed more soldiers than have ever died in battle: it possibly killed Alexander The Great; and it was endemic in early America, killing many English troops fighting there. It has been reported: "one of the first military expenditures of the American Continental Congress, around 1775, was for $300 to buy quinine to protect General Washington's troops".
During WWII, American and Australian troops who were sent to "the Islands" to fight the Japanese invasion were supplied with Atabrine as a chemoprophylactic against malaria. It is an anti-parasitic drug, a modification of natural quinine. Unfortunately, it made their skin very yellow which was a bit of a shock to their wives and girlfriends when they returned home.
Simplified biology
Malaria is caused by a single-celled parasite a protozoan named Plasmidium, which is neither a bacterium nor a virus. This parasite has two hosts (mosquito and human) and it changes its form several times as it completes these two separate life cycles. This multifaceted complexity has made it difficult for medical researchers to find a "cure" or vaccine to eliminate it completely.
Let us start our description with the mosquito. A female of one of several Anopholes species takes a blood meal from a human who is already infected with the parasite in his or her blood. Mosquitoes need this protein meal in order to breed. The parasite gets from the blood into the mosquito's stomach and undergoes some changes, then migrates to the salivary glands over about two weeks. When this same mosquito bites another human, some of the parasites enter the blood with a drop of saliva that is injected with the bite.
Now things get complicated. The parasites first go into the liver where they grow and multiply, then after that they infect red blood cells where they change form and multiply again until they break the blood cell open, and the daughter cells of the parasite infect more blood cells. This takes about two weeks, and it is at that time that the symptoms of malaria occur (fever, fatigue, vomiting and headaches).
Some individuals are immune, or partially immune, due to their genetics. For example, traits such as sickle cell anemia are thought to protect individuals against malaria, although they produce other medical problems. In countries where malaria is endemic, there is partial "herd immunity" due to exposure of many people to the parasite all their lives enabling their natural immune system to fight off the bug – but this immunity decreases during pregnancy, leaving mothers and young babies particularly vulnerable to malaria. Poor nutrition and the energy demands of growing children also reduce immunity.
Two recent Australian advances provide hope
Jeremiah 33 verses 2-3 (ESV) says "Thus says the Lord who made the earth, the Lord who formed it to establish it – the Lord is his name: 'Call to me and I will answer you, and will tell you great and hidden things that you have not known'"
A team of scientists at Deakin University, Victoria have found there is only one protein secreted by the protozoan parasites that enables them to stick to the red blood cells, and move through the membrane. If the production of this one protein can be blocked, that will pave the way for new, targetted medications that may be able to prevent infection.
Another group of researchers at the Walter and Eliza Hall Institute in Melbourne have found that an antibiotic that is already known and used, blocks proteins necessary for the survival of the malaria parasite right at the ribosome, the site of protein synthesis within the cell. They are collaborating with chemists at the Institute to make modifications of this antibiotic that will hopefully be more effective for this particular task.
In the meantime, prevention is better than cure
For those living in malaria-prone areas, the most recent cheap, preventative measure is to sleep under insecticide-impregnated mosquito nets. This protects the most vulnerable, particularly children, but it will only work if they actually sleep under the nets on a hot, humid night – all night long. Some spraying of the inside of houses is still undertaken too, the benefits being deemed to outweigh some long-term environmental consequences.
Travellers to areas where malaria is endemic should take the advice of their medical practitioner. Particular prophylactic medications are advised for different areas, due to varying resistance of different strains of either mosquitoes or the parasite. People are also always advised to wear long sleeves and pants, and use good quality insect repellent at night.
If a traveller does become ill, it is reassuring to remember that even with the medication available so far available, most cases can be effectively treated if picked up early, and usually the patient recovers completely.
Dr Mark Tronson is a Baptist minister (retired) who served as the Australian cricket team chaplain for 17 years (2000 ret) and established Life After Cricket in 2001. He was recognised by the Olympic Ministry Medal in 2009 presented by Carl Lewis Olympian of the Century. He mentors young writers and has written 24 books, and enjoys writing. He is married to Delma, with four adult children and grand-children.
Mark Tronson's archive of articles can be viewed at http://www.pressserviceinternational.org/mark-tronson.html