Taylor Kiyota And Hayley Dardick Malaria Malaria Parasite Taylor Kiyota And Hayley Dardick

General Characteristics Malaria is an infectious disease caused by protozoan parasites. In tropical and sub tropical parts of North and South American, Asia and Africa. Each year about 515,000,000 cases of malaria are reported. Between 1 and 3 million end up dying. 90% of deaths from malaria occur in Sub- Saharan Africa. Malaria is one of the most common infectious diseases. Poverty is usually associated with malaria and can cause it.

History Has infected people for over 50,000 years. References to malaria found beginning in 2700 B.C. in China. 1640’s- First effective treatment for malaria was introduced using the bark of the cinchona tree containing quinine. 1820- Quinine was extracted from bark by Pierre Joseph Pellertier and Joseph Bienaime Caventou. 1880- first significant advance made by Dr. Charles Louis Alphonse Laveran. He observed malaria parasites inside red blood cells, concluding for the first time protozoa was causing the disease. 1881- Carlos Finlay provided strong evidence that mosquitoes were transmitting the disease to humans. 1898- Sir Ronald Ross finally proved that malaria was transmitted from mosquitoes to humans. He received the 1902 Nobel Prize in Medicine. 1980’s- The liver form of the malaria parasite was first observed which explained why malaria could relapse.

The Parasite Behind Malaria Malaria is caused by protozoan parasites of the genus plasmodium. The group of human-pathogenic Plasmodium is called Malaria parasites. In humans malaria is caused by these plasmodium protists: P. falciparum, P. malariae, P. ovale, P vivax, and P. knowlesi. P. falciparum is the most common and is responsible for 80% of all cases and 90% of malaria related deaths.

Common Diseases Plasmodium pathogens cause malaria and malaria in pregnant women causes still births, infant mortality, and dangerously low birth weights

How Malaria is transmitted Only female Anopheles mosquitoes suck blood, therefore only they can pass on the disease. Malaria is also passed on through blood transfusions though that is a more rare occasion.

Malaria’s effects on the body Malaria causes fever and can appear as a flu-like illness (shaking, chills, headache, muscle aches and tiredness) Also can cause nausea, vomiting, and diarrhea. Because malaria decreases red blood cells, jaundice (skin and eyes turn yellow color) and anemia occur. Symptoms usually appear between 10 and 15 days after the mosquito bite. If not treated, malaria can be life-threatening by interfering with the blood supply to vital organs. Plasmodium falciparum (one malaria parasite), can cause kidney failure, seizures, mental confusion, coma, and death.

Common symptoms Common Symptoms: Fever Chills Sweats Headaches Nausea and vomiting Body aches General malaise.   Physical findings may include: Elevated temperature Perspiration Weakness Enlarged spleen. In P. falciparum malaria, additional findings may include: Mild jaundice Enlargement of the liver Increased respiratory rate.

Severe malaria When P. falciparum infections are complicated by serious organ failures or abnormalities in the patient's blood or metabolism. This can cause: abnormal behavior, impairment of consciousness, seizures, coma, or other neurologic abnormalities. Anemia due to hemolysis (destruction of the red blood cells) Fluid buildup in the lungs or acute respiratory distress syndrome (ARDS) Cardiovascular collapse and shock Acute kidney failure Hyperparasitemia, where more than 5% of the red blood cells are infected by malaria parasites Hypoglycemia (low blood glucose). Severe malaria occurs most often in persons who have no immunity to malaria or whose immunity has decreased. In all areas, severe malaria is a medical emergency and should be treated urgently and aggressively.

Reproduction of malaria Malaria parasites multiply within the infected red blood cells and liver cells of someone with the disease.  Sporozoites enter the bloodstream and migrate to the liver where they multiply and change into merozoites to infect the liver cells. They multiply asexually/asymptomatically for 6-15 days and produce 1000's of merozoites (This is the Exoerthrocytic stage)  Then they escape back into the bloodstream and infect red blood cells where they again multiply asexually and periodically break out to invade and infect other red blood cells. (This is the Erythrocytic stage)  Next, trophozoites develop for the feeding stage, then into schizonts for more reproduction and finally back into merozoites.  Sexual gametocytes are also produced- if they are picked up be mosquitoes then the life cycle continues when the mosquito transmits the parasites into another human.  Fertilization of the parasites also occurs in the mosquito's gut. New sporozoites develop and travel to mosquito's salivary gland.

Treatment There is currently nota vaccine for malaria. The effectiveness of antimalarial drugs differs with different species of the parasite and with different stages of the parasite's life cycle. The anti-malarial drugs interferes with the parasites life cycle. Anti-Malarial drugs include: chloroquine, mefloquine, primaquine, quinine, pyrimethamine-sulfadoxine (Fansidar), and doxycycline. Some plasmodium have developed resistance to certain medications and in some places in the world there are no affective treatments left.

Bibliography "Malaria." Wikipedia. 24 Jan. 2009<http://en.wikipedia.org/wiki/Malaria> "Malaria." Malaria. 25 Jan. 2009 <http://www.malaria.com>.