The
Treatment of Malaria in the Third World
Introduction
The
history of malaria dates back to before the history of humanity. This is
because it is an ancient disease which evolved before the evolution of humans. The
disease, which is widespread as well as potentially fatal is infectious and has
affected humanity for most of human history. Human malaria is argued to have
its origin in Africa and coevolving along with non-human primates and its host,
mosquitoes. The initial evidence of the parasites responsible for the disease
was revealed in preserved mosquitoes from the Palaeogene era which are estimated to be 30 million
years old. Human beings may have for the first time infected with Plasmodium
falciparum from primates, particularly gorillas. According to Packard
(2007) approximately 100 centuries ago, the disease began having a major effect
on the survival of humans which corresponded with the beginning of agricultural
practices, (Neolithic revolution), a result was natural selection for thalassaemias,
sickle-cell disorder, ovalocytosis, elliptocytosis, glucose-6-phosphate
dehydrogenase deficiency and loss of the Duffy antigen and Gerbich antigen on
the erythrocytes due to fact that the disorders of the blood present a
selective benefit against infection of malaria (Shah 2010).
According
to Snow et al (2005), malaria is a disease caused by a parasite and is
responsible for the demise of at least one million individuals per year, 90
percent of the deaths occurring sub-Saharan
Africa. Deaths from malaria in the third world mostly affect children under the
age of five. Regardless of the efforts to prevent and treat malaria in the
third world, the burden of the disease is still significantly high. The
treatment and prevention of malaria has been studied in medicine and science
for centuries, and following the identification of the parasite causing the
disease, focus has been on its biology. The studies are still on given that
there is still no effective vaccine for the disease has been produced. While
some efforts have been put in the third world with the help of the
international community, the disease continues to be elusive given that some
older anti-malarial medications lose their effectiveness because of the
parasite developing resistance to the drugs.
The
causes of malaria
Parasites
that cause malaria in humans are from the genus Plasmodium, phylum
Apicomplexa. In humans there are five species of Plasmodium which infect
and are transmitted by human beings: P. falciparum, P. ovale,
P. malariae, P. vivax and P. knowlesi. The severe cases of malaria are mostly
caused by P. falciparum. The type of malaria caused by P. ovale,
P. vivax and P. malariae,
is normally of milder form and are not as fatal as those caused by P. falciparum.
Among the people infected by the parasite, P. falciparum is the
mainly the common species recognized (~75 percent), then P. vivax
(~20 percent). P. falciparum is also responsible for most deaths
from malaria (Owusu-Ofori, Parry and Bates 2010). Proportionally of P. vivax
is more widespread in countries outside of Africa. Documented cases of
infections with various species of Plasmodium originating from higher apes have been identified; nevertheless with
the exemption of P. knowlesi, which is a zoonotic species, prevalent in Southeast Asia,
causing the disease in macaques. However, it can cause serious infections in
human beings (Mueller, Zimmerman and Reeder, 2007).
The
disease is common in tropical areas due to the fact that these regions receive
significant amount of rainfall, constantly with high humidity as well as high
temperatures, together with stagnant waters. These are the breeding grounds for
mosquito larvae where they readily mature, providing them with such an environment
conducive for their continued breeding (Owusu-Ofori, Parry and Bates 2010).
The
classic hosts for the parasite that causes the disease are the Anopheles
female mosquitoes. The mosquitoes play the role of the transmission vectors to
human beings and other vertebrates as the secondary hosts. The parasite is
ingested by young Anopheles female mosquitoes once they feed on infected
vertebrate carriers. The salivary glands of the mosquitoes that have been
infected with the parasite carry Plasmodium sporozoites. According to
Mueller, Zimmerman and Reeder (2007) the mosquito is infected once it consumes
a blood meal from a vertebrate which is infected. Following ingestion, the
gametocytes of the parasite are taken up in blood where they are again differentiate
into female or male gametes and then combine in the gut of the mosquito. An ookinete
is produced which the lining of the gut producing an oocyst in the wall of the gut.
On rupturing of the oocyst, sporozoites are released that move through the body
of the mosquito to the salivary glands. It is from the salivary glands that
they are capable of infecting a human host. When the mosquito is feeding on the
blood of a human host, the sporozoites along side the saliva of the mosquito
are injected into the skin (Snow et al 2005).
The
treatment of malaria
The
treatment of the disease is normally on the basis of the seriousness of the
disease. The experience and assessment of the physician determines whether a
person is given medications, injections or admitted in the hospital for more
specialized treatment. For uncomplicated or mild malaria, treatment can involve
oral drugs. The most effective treatment for malaria caused by P. falciparum
is the administration of artemisinins together with other anti-malarials (referred
to as artemisinin-combination therapy). This treatment procedure is carried out
in reducing the risk of artemisinin resistance. The other ant-malarials use in the
combination includes amodiaquine, mefloquine, lumefantrine, or
sulfadoxine/pyrimethamine. There is another recommended combination which is
piperaquine and dihydroartemisinin (Sarkar et al. 2009).
Severe
cases of malaria necessitate the parenteral administration of anti-malarial medications.
Up to the mid 2000, the most commonly used strategy for treating severe cases
of malaria was quinine. However, treatment using artesunate has been revealed
to be more effective compared to quinine in both adults and children. Treatment
of such cases if malaria also necessitates supportive strategies which are
effectively carried out in critical care units, such as managing high fevers
(hyperpyrexia) as well as the successive seizures which may come as a result, supervision
for hypoglycemia, respiratory depression, and hypokalemia. Those infected with P. ovale,
P. vivax,
or P. malariae are
normally given treatment on an out-patient basis. Infection with P. vivax
requires treatment both of blood stages (using ACT or Chloroquine) and
primaquine to clear liver forms (Sarkar et al. 2009).
Prevention
of malaria
Hartjes
(2011) argues that transmission of malaria basically happens between dusk and
dawn. There are various methods which are use in preventing the transmission of
the disease and all of them basically involve prevention of the parasite being
injected into the body by a mosquito.
Some of the methods which are used in the prevention of malaria include
mosquito eradication, medications, and the prevention of bites. Staines and
Krishna (2012) posits that the presence of the disease in a region necessitates
a blend of high mosquito population density, high human population density, and
high rates of transmission from mosquitoes to humans as well as from humans to
mosquitoes. In case any of these elements is decreased significantly, there
will be eventual disappearance of the parasite from the region. This was the
case in Europe, North America, Europe and most regions in the Middle East. Nevertheless,
unless there is complete elimination of the parasite from the entire world,
re-establishment could occur in case of reversion of conditions to a blend
which supports the reproduction of the parasite. Due to the increase migration
and travelling, there are various cases of imported malaria in many countries
(Pates and Curtis 2005).
However,
researchers and medical experts have argued that in the long run, prevention of
the disease might end up being more cost-effective in the third world compared
to its treatment. Nevertheless, the capital costs necessary for prevention are
still too much for the poor in the third world countries. There is still a wide
gap between the cost of control (that is maintaining low endemicity) and eradication
projects between nations (Carmichael, 2010). For instance in China, where the
government in the year 2010 pronounced a strategy for pursuing eradication of
the disease in the provinces in the country, the necessary cost is a minor
percentage of public spending on health. On the other hand, the same kind of
project in a country like Tanzania would require an approximated one-fifth of
the public spending on health (Hartjes 2011).
Staines and Krishna (2012) suggest that some of the specific methods of preventing malaria include vector control, indoor residual spraying, mosquito nets, and medications. Vector control involves eradication of the diseases by eliminating mosquitoes. Efforts such as drainage of wetland breeding grounds as well as effective sanitation play a major role in vector control. Use of pesticide DDT as well as other methods of eliminating mosquitoes was successful in prevention of the disease in some countries like Egypt and Brazil. Another method of vector control resulting from the use of genetic technology is genetic manipulation of malaria mosquitoes. This is the introduction of foreign DNA into the genome of the mosquito to make it more resistance or increase its lifespan. Indoor residual spraying (IRS) involves the spraying insecticides on the walls of the house from the inside. This kills mosquitoes resting on the walls after feeding. DDT is one of the common pesticides. Sleeping under treated mosquito nets keep the mosquitoes away from humans. Thus, they cannot not feed and infect them with the parasite. Drugs such as Chloroquine are used, but due to resistance others such as, mefloquine (Lariam), doxycycline, or the mixture of proguanil hydrochloride (Malarone) and atovaquone are used in preventing infection (Carmichael, 2010).
Conclusion
Malaria
is a potentially fatal disease which is caused by a parasite transmitted by
female anopheles mosquitoes. Malaria has a very long history probably preceding
human evolution. The disease is common and one of the main causes of death in
the third world, especially the sub-Saharan Africa. The diseases cause more
deaths in these regions that in other parts of the world particularly in
children below the age of five. Malaria can be prevented with effective means
although the cost of prevention is high for these regions. Treatment is also
possible although some of the drugs have become resistance. Therefore, there
are calls for the international community to put more efforts in helping in the
fight against malaria in the third world, being one of the reasons behind the
failure to eradiate poverty.
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