Malaria, Essay Example

A few years ago a British student visited Botswana for his gap year where he met this girl who later became his girlfriend. He had carried his anti-malaria tablets as advised by his doctor that he used to take once every day. He took these drugs religiously because he had been told that they would protect him from malaria while he was in Botswana.  The girl became sick and tests showed that she was suffering from malaria. It was on a Sunday when the only health center that operated in the area was a dispensary and had ran out of drugs. After testing for malaria she just had to go home to wait for Monday so that she could buy the prescribed drugs from the local pharmacy.

The boyfriend could not stand seeing the girl so sick so decided to give his anti-malaria tablets. The girl took them and remarkable improvement could be noticed the next day. He decided to have her more drugs until she had fully recovered because the drugs were proving to work better than the local drugs. The drugs reduced and the boy had to do without them because he couldn’t find these drugs anywhere in the country. When he got back home he started falling sick and since he did not disclose to anyone that he had not taken his anti-malaria tabs for quite sometime while in Africa, the doctors didn’t give the right treatment. He eventually died because malaria had been in his system for quite a long time.

In Africa alone, malaria is a disease that is estimated to kill a million people per annum.  The most common time of getting malaria is when the climate is at its warmer or wetter months in that area. Widespread resistance has been developing to the original anti-malarial and the newer alternatives developed to replace them.   The development of artemisinin derived drugs, with their higher efficacy, in combination with other longer acting drugs  appears to be the way forward to combat malaria, provided the economic and logistical obstacles of changing many poor counties health policies can be overcome.

Caused by protozoa of the genus plasmodium, malaria has four species that infect humans, P.falciparum, P.malariae, P.vivax and P.ovale, causing an estimated 247 million malaria cases worldwide (in 2006), with over 90% of those caused by just one species, P.falciparum. The WHO currently classifies 109 countries and territories as malaria endemic, with an estimated 3.3 billion people living in areas with moderate transmission risk and 1.2 billion people (about one fifth of the global population) living in areas at high risk for malaria transmission. The human host of the plasmodium parasite is initially infected when a female Anopheles mosquito takes its blood meal, the parasite entering the host when the mosquito injects saliva with anticoagulant and antiplatelet properties.

The human host is infected with sporozoites.  The sporozoites are motile and can quickly enter the systemic circulation, ultimately ending their journey by invading the host’s hepatocytes. This process takes only minutes from the introduction of the parasite to the human host.  Once the sporozoites are within the hepatocytes, they are almost invisible to the host’s immune system and therefore safe from any immune response. The human host is asymptomatic during the liver stage of the parasite’s development.  After approximately six days, each sporozoite will yield many thousands of merozoites.  These then escape the hepatocytes, killing it in the process, and enter the circulation.

Once in the blood, merozoites invade erythrocytes and begin developing down one of two possible paths.  In one path, merozoites develop through the ring, trophozoite and schizont stages until the schizont eventually ruptures, killing the erythrocyte and releasing more merozoites into the circulation which are free to perpetuate the cycle.  The other path includes the first intraerythrocytic stage, the ring stage, but the merozoites then develop into gametocytes rather than trophozoites.  The gametocyte is the brief stage when the parasite is in a diploid state.  Gametocytes are non-pathogenic and infectious to the Anopheles mosquito.  Therefore, when another female Anopheles mosquito takes a blood meal the gametocytes are ingested and can begin the mosquito stage of the life cycle. The two main mechanisms by which malaria can cause morbidity and death are severe anaemia and cerebral malaria. Proposed mechanisms include microvascular blood flow obstruction, inducing hypoxia, the same mechanism that is responsible for sequestration of trophozoites and complications arising from this.

An alternative mechanism involves a malarial toxin.  Once released, the toxin would stimulate macrophages to release TNF-? and other cytokines resulting in the production of nitric oxide (NO).  High levels of NO diffusing across the blood-brain barrier could produce the reduced state of consciousness seen in cerebral malaria. The 2006 recommendations from the WHO for the treatment of uncomplicated falciparum malaria – defined by the WHO as “symptomatic malaria without signs of severity or evidence of vital organ dysfunction”

Just like any other disease, malaria can be prevented and cured. Malaria and anti-malaria tablets and Cipla Medpro(2008) state that besides personal protection measures like sleeping under a net, putting on protective clothing and using mosquito repellants, there is anti-malarial medication that comes in different types.  These types are prescribed depending on the area one is visiting and the health history of the person. A traveler needs to take the tablets before they leave their respective area and after going back home. If he develops influenza-like symptoms or fever-like illness, he should therefore be tested for malaria if he goes home from an area that is prone to malaria. It’s therefore good to take precaution before it’s too late.

Works Cited

Cipra Medpro. 2008. Retrieved on July 20, 2009 from <http:/ /www.cipramedpro.co.za/afaq.php>.

Malaria and anti-malaria tablets. 2009. July 20, 2009 <http:/ /www.home.intekom.com/../Mararia.htm>.

WHO Global Malaria Programme. 2009. Retrieved on July 20, 2009 from http:/ /www.who.int/malaria/pages/performance/antimalarialmedicines.html.