Pharmacy and Medicine

Malaria is an infectious disease caused by a parasite, Plasmodium, which infects red blood cells. Malaria is characterized by cycles of chills, fever, pain and sweating. Historical records suggest malaria has infected humans since the beginning of mankind. The name "mal 'aria" (meaning "bad air" in Italian) was first used in English in 1740 by H. Walpole when describing the disease. The term was shortened to "malaria" in the 20th century. C. Laveran in 1880 was the first to identify the parasites in human blood. In 1889, R. Ross discovered that mosquitoes transmitted malaria. Of the four species of malaria, the most serious type is Plasmodium falciparum malaria. It can be life-threatening. The other three species of malaria (P. vivax, P. malariae, and P. ovale) are generally less serious and are not life-threatening.

Symptoms:
The symptoms characteristic of malaria include flu-like illness with fever, chills, muscle aches, and headache. Some patients develop nausea, vomiting, cough, and diarrhea. Cycles of chills, fever, and sweating that repeat every one, two, or three days are typical. There can sometimes be vomiting, diarrhea, coughing, and yellowing (jaundice) of the skin and whites of the eyes due to destruction of red blood cells and liver cells.
People with severe P. falciparum malaria can develop bleeding problems, shock, liver or kidney failure, central nervous system problems, coma, and can die from the infection or its complications. Cerebral malaria (coma, or altered mental status or seizures) can occur with severe P. falciparum infection. It is lethal if not treated quickly; even with treatment, about 15%-20% die.

Uncomplicated Malaria:
The classical (but rarely observed) malaria attack lasts 6-10 hours. It consists of:
* a cold stage (sensation of cold, shivering)
* a hot stage (fever, headaches, vomiting; seizures in young children)
* and finally a sweating stage (sweats, return to normal temperature, tiredness)
Classically (but infrequently observed) the attacks occur every second day with the "tertian" parasites (P. falciparum, P. vivax, and P. ovale) and every third day with the "quartan" parasite (P. malariae).
More commonly, the patient presents with a combination of the following symptoms:
* Fever
* Chills
* Sweats
* Headaches
* Nausea and vomiting
* Body aches
* General malaise.
In countries where cases of malaria are infrequent, these symptoms may be attributed to influenza, a cold, or other common infections, especially if malaria is not suspected. Conversely, in countries where malaria is frequent, residents often recognize the symptoms as malaria and treat themselves without seeking diagnostic confirmation ("presumptive treatment").
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.
Diagnosis of malaria depends on the demonstration of parasites on a blood smear examined under a microscope. In P. falciparum malaria, additional laboratory findings may include mild anemia, mild decrease in blood platelets (thrombocytopenia), elevation of bilirubin, elevation of aminotransferases, albuminuria, and the presence of abnormal bodies in the urine (urinary "casts").
Severe Malaria:
Severe malaria occurs when P. falciparum infections are complicated by serious organ failures or abnormalities in the patient's blood or metabolism. The manifestations of severe malaria include:
* Cerebral malaria, with abnormal behavior, impairment of consciousness, seizures, coma, or other neurologic abnormalities
* Severe anemia due to hemolysis (destruction of the red blood cells)
* Hemoglobinuria (hemoglobin in the urine) due to hemolysis
* Pulmonary edema (fluid buildup in the lungs) or acute respiratory distress syndrome (ARDS), which may occur even after the parasite counts have decreased in response to treatment
* Abnormalities in blood coagulation and thrombocytopenia (decrease in blood platelets)
* Cardiovascular collapse and shock
Other manifestations that should raise concern are:
* Acute kidney failure
* Hyperparasitemia, where more than 5% of the red blood cells are infected by malaria parasites
* Metabolic acidosis (excessive acidity in the blood and tissue fluids), often in association with hypoglycemia
* Hypoglycemia (low blood glucose). Hypoglycaemia may also occur in pregnant women with uncomplicated malaria, or after treatment with quinine.
Severe malaria occurs most often in persons who have no immunity to malaria or whose immunity has decreased. These include all residents of areas with low or no malaria transmission, and young children and pregnant women in areas with high transmission.
In all areas, severe malaria is a medical emergency and should be treated urgently and aggressively.