Malaria is one of the most important public health problems in terms of morbidity and mortality, causing more than 200 million cases and 655.000 deaths every year. A statistical record from the world health organization indicates that about 106 countries in the world are at risk of transmission of the infection. One may avidly ask, “What is malaria?” malaria is an infective disease caused by protozoan parasite, Plasmodium, through the bite of an infected female Anopheles mosquito. Malaria infection in humans is caused by five Plasmodium parasites, viz Plasmodium vivax, P.falciparum, P.malariae, P.ovale and P. knowelesi. The current distribution of malaria with respect to the causative parasite elaboratively indicates that P. falciparum is the major cause of malaria in Africa.
Malaria occurs primarily in tropical and some subtropical regions of Africa, Central and South America, Asia, and Oceania. In areas where malaria occurs, there is tremendous variation in the intensity of transmission and risk of infection. For example, over 90 percent of clinical malaria infections and deaths occur in sub-Saharan Africa. Malaria is one of the insidious diseases the sub-Saharan African countries are battling with. In the year 2010 for instance, Africa recorded 81% of malaria cases in the world, 91% of which resulted in death. When bitten by an infected Anopheles mosquito, in the cost of feeding, sporozoites are injected into the bloodstream. These sporozoites are carried in circulation to infect liver cells. They undergo asexual reproduction, producing schizonts. In 6 to 14 days or even more, the schizonts rupture to release merozoites into the bloodstream.
These merozoites invade red blood cells and undergo a second phase of asexual reproduction, developing into, trophozoites, and finally blood stage schizonts. The schizonts rupture, destroying the red blood cell and releasing more merozoites into the bloodstream, starting another cycle of asexual development and multiplication. This erythrocytic cycle will continue until the infected individual is successfully treated, mounts an immune response that clears the infection or dies. During blood meal. Sexual reproduction however occurs in the mosquito. Sporozoites are formed, which migrate to the salivary glands, making the mosquito infective to humans.
It is important to know that the overall level of immunity to malaria is highest in areas where malaria transmission is most intense, such as Africa. The first exposure to malaria occurs very early in childhood, and with repeated exposures, the likelihood of severe illness or death lessens or declines. In Africa, where the majority of malaria-associated deaths occur, the highest mortality rates occur in children less than 5 years old. In areas with very high levels of transmission, severe malaria tends to manifest itself more frequently as anaemia because more red blood cells are destroyed and so only few are available to bind oxygen. The illness in these areas tend to be more frequent in all age groups. Displaced populations migrating from areas of little or no malaria transmission to areas with heightened degree of transmission are therefore at greatest risk of severe illness and death due to a lack of acquired immunity from infancy. Until these population themselves acquire a protective level of immunity to malaria, these populations will probably require a much more intensive intervention effort to achieve and maintain low rates of morbidity and mortality. Also, malaria has an important effect in the way of chronic or repeated infections, including anemia and poor pregnancy outcome. Acute malaria in pregnant women who have no immunity poses maternal and fetal fatality if not adequately treated. In Semi immune pregnant women, however, malaria parasites preferentially sequester in the placenta, with minimal increase in overt clinical disease. Malaria during pregnancy is a cause of both maternal anemia and low birth weight, accounting for as much as 35 percent of preventable low birth weight in malarious areas.
Coming down to our beloved country Ghana, about 27 million are at risk of malaria infection. This has come about as a result of poor environmental sanitation, poor drainage systems and failure to clear bushes among others, which tend to serve as breeding places for mosquitoes, consequently inclining the level of malaria cases in the country. In spite of this, the government of Ghana in collaboration with the world health organization have put mechanisms in place to incarcerate this “human enemy” called malaria. However these measures put in place have not been adequate in preventing, treating, controlling and eliminating of malaria. Sharing of mosquito nets, introduction of malarial drugs, introduction of national health insurance scheme (NHIS) for free health care accessibility are some programmes initiated to debilitate malaria. Without forgetting, manufacturing of insecticides, mosquito repellents and coils are also introduced to fight against malaria.
To avert and to thwart the action of Plasmodium parasite, as a means of treating malaria, drugs were introduced to attack and kill the parasite within the system of the affected person. Quinine and chloroquine are outstanding examples of anti-malarial drugs used as treatment policy. However, in early 2004, there was a change of treatment drug due to certain modification of the parasite which enables it to resist chloroquine. Currently, The Food and Drug Administration has approved the drug Krintafel (tafenoquine) for the treatment of malaria following a Priority Review this past Friday, 26th April 2019. The drug, developed by GSK Pharmaceuticals and Medicines for Malaria Venture, is a single dose medication designed for people who've had malaria before. It prevents the relapse of malaria caused by Plasmodium vivax (P.vivax). Unlike its cousin Plasmodium falciparum, which is responsible for approximately 75% of the cases, following the initial infection in the blood, P. vivax can go into a dormant stage in the liver, where most anti-malaria medications cannot reach it.
Currently, patients with P.vivax require a 10 day treatment with the drug Primaquine to eradicate those dormant liver parasites. Many patients, much to the frustration of doctors, do not complete all 10 days of treatment, leading to the survival of the parasite and the recurrence of malaria.
Krintafel, approved this past Friday, eradicates dormant P.vivax parasites after one dose. Drug resistance is not limited to chloroquine. In some areas of Southeast Asia, the situation is deteriorating to the point where few effective therapies exist. Chloroquine was abandoned as first-line therapy for malaria in Thailand in 1972 in preference to sulfadoxine/pyrimethamine. Currently, multidrug-resistant malaria in Thailand is being treated with a combination of an artemisinin derivative and mefloquine; efficacy of this combination has remained high. To date, no confirmed cases of resistance to the artemisinin drugs have been reported. However, in 2004, there was a change in treatment policy to artemisinin combination therapies (ACTs) in Ghana, i.e. artesunate-amodiaquine, for treatment of uncomplicated malaria. This treatment policy has since been revised twice, in 2007 and 2009, to include other ACTs, namely artemeter-lumefantrine and dihydroartemisinin-piperaquine.
Reports of decreasing sensitivity in vitro in some areas, as well as a number of case reports of potential treatment failures, raise concern that this class of antimalarial drug is not “immune” to the development of resistance. In many areas where population displacement occurs, national treatment policies of the host and source countries may not necessarily reflect the drug resistance patterns of a given region or population. In many cases this is due to a lack of current efficacy data, a lack of funds for implementation of a new policy, and a variety of other concerns. It is therefore no surprise that after the introduction of this intervention, the problem still persisted. To tackle this problem, various stakeholders must be brought together with a research team to locate and furnished all remote areas lacking health centers with one and a well-trained experienced health care provider, as far as human life is concern.
Moreover, as part of the control and prevention programmes, NHIS was introduced to provide a ‘free’ healthcare to the people. The introduction of the national insurance cover was an initiative to encourage persons to take advantage of it and go to the health center to access basic health care. This however turned out to be a fiasco when the funding body, government, delayed in the payment of claims which has led to many health centers running at a loss, hence refusing to offer health care to persons on the service. Some health facilities too offer just diagnostic services to patients and ask them ( patients) to purchase the drugs on their own.
Malaria is still considered a global health problem and a major killer. Morbidity and mortality burden of malaria could be reduced strengthening prevention, improving malaria diagnosis, using correct therapies based on artemisinin combination and adopting strategies aimed at preventing drug resistance. Real malaria incidence is difficult to obtain. However, it is possible to make reliable estimates thanks to the data supplied by Ministries of Health of different countries and to accurate prevalence studies. Determination of real incidence of malaria and determination of the real Plasmodium species distribution are two different issues that could help expert in the eradication of malaria, the real and unique goal in the fight against malaria.
Akpetey, Bright Kwaku
Physician Assistant Student
University of Cape Coast
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