Malaria is one of the major scourges of mankind in the developing world. It is estimated to affect more than 500 million people causing between one and three million deaths every year.
The protozoan Plasmodium species causes malaria due to infection. It is transmitted by the bite of die infected Anopheles mosquito. Four major species of Plasmodia are implicated in the causation of malaria in humans and these are Plasmodium Wax, Plasmodium Oval, Plasmodium Malariae and Plasmodium falciparum.
Among these species, it is Plasmodium Falciparum that is the most dangerous and that is responsible for most of the deaths resulting from malaria. Infection begins when the infected female Anopheles mosquito bites the human. The microscopic forms of the parasite are carried through the patient’s blood stream until they reach the liver.
There they invade the liver cells and begin to reproduce. The swollen liver cells actually burst discharging the merozoite forms of the parasite to circulation and this is when the symptoms of the infection start to become apparent. Once inside the bloodstream the merozoites invade the red blood cells and start to grow.
They consume and degrade the intracellular proteins inside the red cell, especially the hemoglobin, eventually causing the infected red cells to rupture.
The early symptoms of malaria are non-specific. The patient usually feels ill and has headache, fatigue, muscle pains and vague abdominal discomfort. These symptoms are followed by fever.
The fever in classical malaria is a sequence of paroxysms of fever spikes, chills and rigors with sweating occurring at regular intervals. Kidney failure is also seen sometimes in Falciparum Malaria.
Once the diagnosis of malaria has been made on the basis of a positive blood smear or strong clinical suspicion, then treatment should be started without delay. Chloroquine remains the mainstay in the treatment of malaria. The other drugs that are often used include Mefloquine, Tetracyclines, Primaquine, Pyrimethamine, Proguanil and Quinine.
Newer drugs like Habfantrine, Articulate and Qinghmsu are being used for cases of Chloroquine-resistant malaria. Except for the Falciparum malaria, patients who receive adequate treatment for the other forms, most often have an uneventful recovery. However, resistance to the conventional drugs is increasing and is a major cause for worry.
Cerebral malaria is a medical emergency and even with the best of treatment there is a substantial mortality rate. Use of suitable clothing, insect repellents, and bed nets etc. are recommended for preventing malaria. Widespread use of the bed nets and repellents has been shown to reduce the incidence if malaria.
Efforts are taken to reduce the population of mosquitoes in endemic areas. However, Chemoprophylaxis is often recommended for people who travel to malaria-endemic areas. Chloroquine is most often the drug of choice for hemoprophylaxis except in areas of known chloroquine-resistance here drugs like Mefloquine or Doxycycline are used.