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Malaria is transmitted to human beings by a female mosquito known as anopheles mosquito. Studies reveal that not all anopheles mosquitoes have the virus that causes malaria. For an individual to be infected with malaria, he/she must be bitten by an anopheles mosquito, which is infected by the malaria-causing virus. Once such an infected mosquito bites an individual, it injects the malaria parasite into the individual’s blood stream. “The malaria parasite then travels through the bloodstream to the liver and eventually infects the red blood cells” (What is Malaria?) The malaria-causing parasite is usually present in the saliva of the mosquito. Therefore, when a mosquito bites a person, it injects a small amount of its saliva, which contains the malaria parasite. Malaria is not directly transmitted from one person to another. Transmission is only through the anopheles mosquito. However, there are a few cases of transmission of malaria from one person to another through blood transfusion and sharing of contaminated needles and other sharp objects, especially among the drug addicts (What is Malaria?).
There are usually four different types of malaria. These are vivax, ovale, falciparum malaria, and malariae. Among the four types of malaria, falciparum malaria is the most serious type (What is Malaria?) It usually leads to death if not treated during its early stages. The other types are not very serious, but they can also lead to death if they are incubated in the body for a long period without any treatment (What is Malaria?)
Where in the world is malaria found?
Malaria disease is more common in the Sub-Saharan region of Africa, South America, Asia, and a few parts of North America (Malaria - Causes, Symptoms and Treatment). In North America, few cases of malaria have been reported, but it has been found that, they have been transmitted to the patients through blood transfusion and sharing of infected needles and other sharp objects among the drug addicts. According to WHO report, approximately 3.3 billion people around the world (almost half of the world’s population), are currently infected with malaria (Malaria - Causes, Symptoms and Treatment). Every year, more than 250 million cases of malaria are reported in the world, of which, almost one million cases succumb to death.
High prevalence rates of malaria are commonly observed in the under-developed countries and in some of the developing countries of Africa and Asian continents. According to the World Water Organization, high prevalence rates of malaria are observed in these regions because they are forest fringe zones (Disease Fact Sheet: Malaria). Malaria disease is closely associated with availability of water: specifically, swamp waters. The development of the malaria-causing mosquito varies in different water-ecological zones. Usually, its development starts from the larval stage, which adapts well in water-ecological zones that are shaded (minimal sunlight), with little or no vegetation, blackish, stagnant and flowing slowly (Disease Fact Sheet: Malaria).
According to the World Water Organization, due to the current global changes in climate, the altitude limits for development of malaria seems to have increased, hence, the frequent cases of malaria in the highlands of East Africa and Madagascar (Disease Fact Sheet: Malaria). In Asia, specifically East Asia, high prevalence rates of malaria are common due the nature of agricultural activities, which takes place in this region. East Asia depends much on irrigation in production of food commodities. Therefore, the region has many irrigation systems and reservoirs, which provide favorable environment for development of mosquitoes.
In 2001, the prevalence rate of malaria in the world was as follows; 90 percent in the Sub-Saharan region of Africa, 7.5 percent in Brazil, Vietnam, Sri Lanka, India, Colombia, and Solomon Islands, and the remaining 2.5% distributed across North America, Europe, and Australia (Disease Fact Sheet: Malaria). (See appendix 1 for areas affected with malaria)
Who tend to be infected with Malaria?
Infection with malaria is common among children below the age of five years, and among pregnant women (World Health Organization). Children below the age of five years are commonly infected with malaria due to the inability of their body immune systems to fight the malaria-causing parasite/virus. The red blood cells are responsible for protecting the body against infections, which are introduced into the body by viruses and bacteria. Usually, the red blood cells are not fully developed in children below the age of five years. Therefore, when an anopheles mosquito infected with malaria-causing parasite bites a child, his/her body is unable to provide enough red blood cells, which provide the body with immunity against infection. In pregnant women, malaria-causing parasite is able to develop quickly because; the red blood cells are usually distributed between the mother and the unborn child. However, cases of malaria are also reported among children above the age of five years and among adult men and women. In Sub-Saharan Africa, cases of more than one infection with malaria per individual have been reported among the populations. Many individuals in this region suffer bouts of malaria in their lifetime.
The incubation time of malaria is between 7 and 21 days. Usually, once a mosquito bites a person, he/she can stay up to 21 days without showing any symptoms of malaria infection (Disease Fact Sheet: Malaria). The incubation period varies with the condition of individual’s immunity system. An individual with a strong immunity system: is less infected with other disease-causing elements, is likely to have a longer incubation period than an individual with weaker body immunity. However, according to the World Health Organization, if an individual has taken an inadequate dose of malaria prevention medication, he/she might incubate malaria for a period longer than 21 days: the range can exceed 10 months (World Health Organization). Moreover, the incubation period of malaria also depends on the type of malaria parasite. Some malaria parasites take much longer period to cause symptoms while others take much less time to cause symptoms (World Health Organization).
Sign and symptoms
Common symptoms of malaria are fever, headache, vomiting, anemia, diarrhea, muscle aches, yellowing of the skin and eyes, and coughing (Center for Disease Control). Usually, the first sign of malaria is occurrence of sudden coldness in the body. The occurrence may be cyclical, ranging between 30 minutes and one hour (Center for Disease Control). This is immediately followed by rigor. Rigor is a situation whereby an individual develops feelings of stiffness or inflexibility of the body muscles, especially the lower limbs muscles (Center for Disease Control). This may then be followed by fever: high body temperatures accompanied by sweating. This may last between four to six hours (Center for Disease Control).
In cases of infection with vivax or ovale types of malaria, signs of fever may occur after every two days if the infected person does not seek treatment after the first occurrence. On the other hand, fever occurrences are observed after every three days in cases of infection with malariae malaria (Center for Disease Control). However, fever occurrences are recurrent in cases of falciparum malaria. The occurrences range between 36 and 38 hours (Center for Disease Control). During fever occurrences, the infected person may experience cyclical headaches, and vomiting. If treatment is not provided after these signs have been observed, then yellowing of the skin and the eyes maybe observed (Center for Disease Control). Anemia in adults and abnormal posturing in children may then follow this. However, both signs maybe exhibited either in a child or in an adult concurrently. If malaria is not treated at this stage, it may result into destruction of the brain, leading to cerebral malaria. If untreated, these symptoms results into death or coma (Center for Disease Control).
There are several drugs, which can be administered to a malaria patient. Chloroquine is the most effective medicine where the malaria-causing parasite is still sensitive: has not yet developed resistance to drugs (World Health Organization). Chloroquine is usually administered to first time patients of malaria, and those who have not taken any other malaria medications. However, due to resistance of malaria-causing parasite to chloroquine, medical researchers have discovered other malaria medicines, which are more effective than chloroquine. These are mefloquine, doxycycline, and a combination of proguanil hydrochloride and atovaquone (World Health Organization). According to WHO, the combination of proguanil hydrochloride and atovaquone, and doxycycline are the best malaria drugs for building body tolerance against the malaria-causing parasite. On the other hand, mefloquine is effective in severe cases of malaria: cerebral malaria (World Health Organization).
Since the prophylactic effects of the afore-mentioned drugs do not start immediately after the intake of the drugs, physicians recommend that people visiting malaria-prone areas should take one or two weeks before they start their journey. Physicians also recommend that if the signs and symptoms of malaria do not disappear, a few days after finishing the dose of the prescribed drug, an individual should take a different type of malaria drugs (Malaria - Causes, Symptoms and Treatment).