MALARIA - A SILENT KILLER

MALARIA: ETYMOLOGY.

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Over 3,000 species of mosquitoes are in existence throughout the world. These little pests are considered the most deadly animals in the world and contribute to close to a million deaths per year. This is due to the diseases transmitted by their bite. Although, not all mosquitoes suck blood. Many species of mosquitoes suck blood and transmit diseases in the process, such diseases include, Yellow fever, West Nile virus, Malaria et.c.
MALARIA: CAUSES
Malaria parasite belongs to the genus Plasmodium (phylum: Apicomplexa). In humans, malaria is caused by five different species of plasmodium and this include:
1.Plasmodium vivax 2. Plasmodium ovale 3. Plasmodium malariae 4. Plasmodium falciparum 5. Plasmodium knowlesi.
Although, most deaths are caused by Plasmodium falciparum (as it is regarded as the deadliest of them all) because P. vivax, P. ovale, P. malariae, P. knowlesi all causes a milder form of malaria.
LIFECYCLE OF THE MALARIA PARASITE

Malaria infection develops via two phases: 1. Exoerythrocytic phase (involves liver) 2. Erythrocytic phase (involves Red blood cells)
The infected mosquito pierces the skin transmitting a sporozoite(motile infected form). The sprozoites travels through the blood vessels to the liver cells(hepatocytes) where it reproduces asexually- a process known as SCHIZOGONY for a period of 8 – 30 days producing thousands of merozoites which invades the red blood cells and initiates a series of asexual multiplication(schizogony) that produces 8 – 24 new infective merozoites at which point the cells burst and the infective cycle begins anew.
Other merozoites develop into immature gametocytes- macrogametocytes and microgametocytes, which when a fertilized mosquito bites a person are taken up with the blood and mature in the mosquito gut. The macrogametocyte matures into a macrogamete and the microgametocyte matures into eight microgametes through three divisions in a process known as EXFLAGELLATION. Then the macrogamete fuses with one out of the eight microgametes and they form an OOKINETE- a ciliated, diploid, elongated, fertilized, motile zygote. Ookinetes develop into new sporozoites that migrates to the insects salivary glands ready to infect a new vertebrate host.
DID YOU KNOW??? Only female mosquitoes feed on blood; male mosquitoes feed on plant nectar and do not transmit the disease. Females of the mosquito genus Anopheles prefer to feed at night, they usually start searching for a meal at dusk and will continue throughout the night until taking a meal.
SIGNS AND SYMPTOMS
Signs and symptoms of malaria begins 8 – 25 days following infection, however it may take longer for those who have taken antimalarial medication as prevention. One major symptom of malaria is PAROXYSM- a cyclical occurrence of sudden coldness followed by shivering and then fever and sweating, occurring every two days (tertian malaria) in P. vivax and P. ovale infections and every three days (quartan malaria) for P. malariae. P. falciparum infection can cause recurrent malaria for every 36 – 48 hours. Other symptoms include: Fever, tiredness, headaches and vomiting. In severe cases, it can cause yellow skin, seizures, coma and even death. In children, under the age of five often, malaria causes ANEMIA – which is the decrease in red blood cells in the blood or the lowered ability of the blood to carry oxygen.
PREVENTION AND TREATMENT
Methods used to prevent malaria include medications, prevention of bites, mosquito elimination. Malaria is treated with antimalarial medications, the one used depends on the type and severity of the disease. The most effective treatment for P. falciparum infection is the use of Artemisinins in combination with other antimalarials known as Artemisinin-combination therapy (ACT).