Malaria, which is Italian for bad air (3), is caused by parasitic protozoa of the genus Plasmodium (2). There are four etiologic agents of malaria and they include P. falciparum, P.vivax, P. malariae, and P. ovale (1). P. falciparum is the most important of these four because it is rapidly fatal and it is responsible for the majority of malaria related deaths (2). Malaria is carried by a couple of reservoirs, including animals and humans and its means of transmission is simply from the bite of a malaria-infected mosquito (1). It is usually an infected female Anopheles mosquito that bites its victim. The Plasmodium parasites are injected into the blood and make their way to the liver (4). Malaria usually occurs in the most tropical regions of the world. P. falciparum predominates in Africa, New Guinea and Haiti and it is said to be transmitted to humans through contact with birds.
Humans have had little contact with this parasite and have not had enough time to become adapted to it so this is a major reason for it virulence (12). Though P. falciparum is the most important species, P. vivax is the most common in Central America (2). This is the species that is causing all the problems with the major malaria outbreaks today. P. vivax are characterized by its developmental stages which can be seen in the peripheral blood film. Trophozoites are the first stage and are usually a few hours old already when they are seen under the microscope. The second stage is Gametocytes, when they are mature they are large and rounded and they fill the host cell. The third stage is Schizonts. Schizonts are large and contain Schuffner's dots (5).
There are many different tests for the identification of malaria. The identification of malaria primarily depends on the observation of the parasites in G-TS (6). Other techniques are based on fluorochromes like AO, DAPI-PI or BCP. Using these dyes reduces the time spent on reading the slides because the malaria parasites are recognized easier under the UV light (6). Another technique that has become more popular recently is the "dipstick" format. The dipstick tests detect plasmodial histidine rich protein-2 and parasite-specific lactate dehydrogenase. Both of these are present in the species P. falciparum. Some of these dipstick tests include ICT-Malaria Pf, OptiMALr and Kat-Quick kits. These tests have been reported to be very good, claiming sensitivities and specificities at almost 100%. The purpose of the dipstick tests is to speed up the diagnosing and enhancing the accuracy of diagnosing P. falciparum. Enzymatic immunoassays and immunofluorescence techniques can be used to detect antibodies to malaria (2).
As stated earlier malaria is Italian for bad air (3). It used to be thought that the disease came from bad air or gas from swamps. The malaria parasite was discovered in 1889 by Charles-Louis-Alphonse Laveran (13). Laveran was a parasitologist, a doctor, and a pathologist and in 1907 he received the Nobel Prize for Physiology or Medicine (13). Ronald Ross studied malaria in London in 1875 and went to Africa in 1899. While in Africa Ross found the species of mosquitoes that carry the deadly disease. He finally was able to demonstrate the life-cycle of the parasite in mosquitoes. In 1897 Ross was able to demonstrate that the mosquito was the vector of malaria (7). Distinguished authorities like Koch, Daniels and Bignami have confirmed Ross' research (3).
Signs and symptoms of malaria include fever and flu-like illness. This may include malaise, chills, headaches, diarrhea, and muscle aches. Malaria may also cause anemia, jaundice and loss of red blood cells (1). The chills, fever and sweating all occur in the first stage. Next the temperature rises and then falls. After this has occurred the person may fall asleep. Symptoms appear 10 to 16 days after the person has been bit by the infectious mosquito (8). P. vivax and P. ovale are the two types of malaria that can relapse (1). These symptoms of malaria recur at regular time periods (8). If a person becomes infected with the species P. falciparum, which is the deadliest species, and that person is not treated then these symptoms can lead to kidney failure, mental confusion, seizures, and even death (1).
The treatment of malaria can be taken care of in different ways. If someone thinks they may have been infected by malaria and cannot see a doctor right away there are self-treatments for them. First chloroquine should be taken and chloroquine prophylaxis should be started (9). Malaria can basically be treated with prescription drugs. Of course the type of prescription a person needs depends on the type of malaria they have. Drugs that are taken to treat malaria are called antimalarial drugs. Some of these drugs include Melfoquine, Doxycycline, Malarone, Chloroquine, and Hydroxychloroquine sulfate (1), (11). Travelers are encouraged to follow preventative measures for malaria. Some of these include taking any antimalarial drug to prevent malaria before leaving the country. Using bug repellent can help and wearing protective clothing like long pants and long sleeved shirts. Sleeping under a mosquito net if necessary is also preventing any mosquito bites (1). A new vaccine is under study for malaria. This new drug is called liver-stage antigen 3°Ø (LSA-3). When chimpanzees were immunized with LSA-3 their bodies produced antibodies to it. This then activates their immune system to get rid of the parasite (10).
Malaria is a very serious and deadly disease. Its recent outbreak has brought new attention to the disease. Hopefully with this new attention will come better prevention by everybody and new vaccinations from scientists. Until new and improved vaccinations come out everyone should do their part in controlling and preventing this disease.
References:
1. Traveler°Øs Health. 7/10/02. URL: www.cdc.gov/travel/malinfo.htm accessed on 11/25/02.
2. McConnell, Bill. Malaria, An On-Line Resource. 7/02. URL: www.rph.wa.gov/labs/haem/malaria/ assessed on 11/27/02.
3. Ronald Ross-Biography. 5/2/01. URL: www.nobel.se/medicine/laureates/1902/ross-bio.html assessed 12/2/02.
4. Parasitology-Malaria. 7/19/02. URL: www.lumc.nl/1040/research/malaria/back.html assessed on 12/5/02.
5. Characteristics of Plasmodium vivax. URL: www.btinternet.com/~ukneqas.parasitologyscheme/pvivax.htm assessed on 12/5/02.
6. Plasmodium vivax. URL: www.cdfound.to.it/HTML/pla4.htm assessed on 12/5/02.
7. Malaria Prevention°±. URL: www.malaria-prevention-info.com/malaria-preventions.html assessed on 12/6/02.
8. National Institutes of Health. Symptoms of Malaria. 11/11/02. URL: www.niaid.nih.gov/publications/malaria/symptoms.htm assessed on 12/4/02.
9. CCDR. Prevention of Malaria. 11/20/02. URL: www.hc-sc.gc.ca/hpb/lcdc/publicat/ccdr assessed on 12/6/02.
10. Nature. New Malaria Vaccine? URL: www.nature.com/nsu/001102/001102-4.html assessed on 12/4/02.
11. CDC. Prescription Drugs Preventing Malaria° 2/1/01. URL: www.cdc.gov/ncidod/dpd/parasites/malaria/factsht_malaria_drugs.htm assessed on 12/7/02.
12.Tortora, G. (2002). Microbial diseases of the cardiovascular and lymphatic systems. Microbiology an Introduction. 1, 644-655.
13. Encyclopedia Britannica. Laveran, Alphonse. (1997). URL: www.britannica.com/nobel/micro/340_84.html assessed 12/8/02