Malaria
...w.malaria.com). The life span of the plasmodium is spent in two hosts, the first being the insect vector (a female Anopheles mosquito; mouth parts of males cannot penetrate human skin) and the second being the human host. Humans contract the malaria parasite when the mosquito begins feeding. During this feeding the mosquito secretes sporozoite-bearing saliva beneath the epidermis of the human host; the sporozoites are then released into the bloodstream (Bogitsh 131). After one hour the sporozoites disappear from circulation, reemerging twenty-four to forty-eight hours later in the cells of the liver. Once in the liver the sporozoites periodically send out merozoites which can cause malaria symptoms to come back even after the patient seems to have recovered. After a malaria infected mosquito bites it can take anywhere from six to eight days to several months for the symptoms to develop, which is one of the reasons why it took scientists so long to see the correlation between mosquitoes and the disease. The initial symptoms of someone that has contracted malaria are nausea, fatigue, a slight rise in temperature, mild diarrhea and muscular pains; symptoms that are often mistaken for influenza or gastrointestinal infections. “The inflammatory reactions in the host are triggered by the rupturing of infected erythrocytes, which releases hemozoin and other malarial pigments, cellular debris, and parasite metabolic wastes into the circulatory system (Bogitsch 145).” As a result of the rupturing erythrocytes the body is eventually unable to recycle the iron that is bound in the insoluble hemozin and anemia develops. A symptom unique to the plasmodium falciparum is vascular obstruction. “The infected plasma membranes of the erythrocytes develop electron dense knobs by which they adhere to the endothelium of capillaries in visceral organs. Because of the infected plasma membranes the capillaries become obstructed and the affected organs become anoxic” (Bogitsh 146). There are currently very few processes of testing and diagnosing malaria. Because malaria infects the red blood cells the most common way of testing is through blood testing, in which the patient’s blood is smeared on to a glass slide and examined for parasites. Malaria can also be tested by means of an ultrasound which can reveal an enlarged spleen, a common sign of the disease. The first known and most common anti-malarial drug is quinine, an extract from the bark of a cinchona tree. Quinine destroys some stages of the parasite but also has many downsides. The drug is expensive and must be given in large does for long periods of time and as with most drugs quinine also has unpleasant side effects such as ringing of the ears, fever and allergic reactions. These problems led scientists to develop a new drug, chloroquine, a drug that is similar to quinine in structure, is also used to treat the disease and is a more common way of treatment because it is safer and less expensive. Both quinine and choloroquine treat malaria by preventing the invading parasite from sending out merozoites, which invade the red blood cells and cause the symptoms of the disease (Day 55). Because there are four different strains of malaria the drugs used to cure it have different effects on each strain. When malaria caused by the plasmodium falciparum or plasmodium malariae is treated with chloroquine the drug is enough to cure the disease, but for those caused by the other two strains it will only treat the initial attack. In today’s world of advanced medicine doctors often combine drugs to reduce the chances the malaria parasite will become resistant to a single medication. Newer treatments combine a combination of two drugs, chlorproguanil and dapsone, for patients that don’t have a severe form of malaria. There is also another new drug that has been developed called artesuante which is beneficial for people that travel. Artesuante comes in the form of a suppository and helps those who are vomiting repeatedly. Benefits of the drug are that it works quickly and can buy time for people that are in remote areas who must make a long trip to the hospital. Unfortunately there currently is no cure for malaria, but the good news is that malaria that is caused by milder parasites improves without treatment in ten to thirty days. Scientists are currently working on vaccines for the disease but are having many difficulties because the parasite goes through many stages, during which it keeps changing its identity making it harder to attack (Mueller). Yet another difficulty in finding a vaccine that works is that the same parasites from the same species, but from different geographical areas can be different enough that a vaccine that protects against one may not necessarily protect against another. While a concrete vaccine is not yet available there are experimental vaccines that target specific stages of development of the malaria parasite, but they do have limitations. While there currently is not a vaccine for malaria there are other ways of prevention that are useful in an area-wide or country-wide basis. The first of these methods is screening swellings to ...