Social and Economic Impact of Plasmodium Falciporum

PLASMODIUM FALCIPARUM (MALARIA)
INTRODUCTION
The genus of protozoa (unicellular eukaryotes) Plasmodium includes chromalveolate - protists of
the phylum - Apicomplexa, order - Haemosporida, family - Plasmodidae. Their members of the
genus are obligate parasites of vertebrate hosts; Plasmodium spp. includes Plasmodium
falciparum, Plasmodium knowlesi, Plasmodium malariae, Plasmodium vivax, and the two
closely related species Plasmodium ovale curtisi and Plasmodium ovale wallikeri, which are
genetically different. In typical human hosts, each of these six parasites causes an acute febrile
illness of varying severity and duration known as malaria.
Malaria is a global infectious disease that continues to be one of the leading causes of morbidity
and mortality in developing countries. The most severe and fatal malaria is caused mainly by
Plasmodium falciparum. Female mosquitoes of the genus Anopheles exclusively transmit
Plasmodium falciparum, feed on blood for egg production and these blood meals link humans
and host mosquitoes in the parasite's life cycle. "The successful development of the malaria
parasite in the mosquito (from the "gametocyte" stage to the "sporozoite" stage) depends on
several factors" (CDC, 2019). Of the approximately 430 species of Anopheles, only 3040
transmit malaria in nature.
Anopheles mosquitoes' life cycle is of four stages: egg, larva, pupa, and adult. The first three
stages are aquatic, depending on the species and the ambient temperature. The female Anopheles
mosquito that bites can transmit malaria. Male mosquitoes cannot transmit malaria or other
diseases; they do not bite and. Adult female mosquitoes are generally short-lived, with only a
tiny fraction living long enough (more than ten days in tropical regions) to transmit malaria.
Unlike the human host, the mosquito host does not suffer markedly from the presence of the
parasites.
Malaria is caused by Plasmodium falciparum (also known as malignant or falciparum malaria).
However, drugs are available for treatment, it is responsible for more than 90% of global malaria
mortality, and therefore it remains a significant threat to global public health. Malaria is endemic
in more than 90 countries and affects around 40% of the world's population. P. falciparum is

prevalent in the WHO African region, accounting for 99.7% of malaria cases; it is also
widespread in Southeast Asia, the eastern Mediterranean, and the western Pacific.
The groups most affected by malaria in high transmission areas are children under five years of
age, whose deaths account for 67% of deaths from malaria globally. In low transmission areas,
all age groups are at risk due to low immunity. Its management and prognosis depend on the
knowledge of a possible diagnosis, early detection, and timely effective treatment.
LIFE CYCLE OF PLASMODIUM FALCIPARUM
The malaria pathogen is transmitted to the human host when an infected female Anopheles
mosquito ingests blood, and at the same time, passes a small number of sporozoites contained in
its salivary glands into human skin.
In humans, the agile sporozoite enters the bloodstream, allowing it to reach the liver and thus
escape host immunity or drainage through the lymphatic system. Once the sporozoites have
reached the hepatic sinusoids, they cross the sinusoidal barrier and invade the hepatocytes, in
which they build a parasitophorous vacuole and differentiate in the first round of asexual
replication; The parasites grow and multiply for two to several days, first in the liver cells and
then in red blood cells. Once in the bloodstream, the merozoites rapidly invade circulating red
blood cells (RBCs), initiating the repeated cycle of asexual replication. The parasite goes through
the ring and trophozoite stages for 48 hours before finally replicating in the schizont stage
(schizogony) in 8 to 32 daughter merozoites. At this point, the parasitized erythrocytes (pRBCs)
breakthrough and release merozoites into the circulation, initiating another round of asexual
replication. During each cycle, a small subset of parasites deviate from asexual reproduction and
instead produce sexual offspring that separate the following process into male and female sexual
forms known as gametocytes. Male and female gametocytes re-enter the peripheral circulation
(although evidence suggests that the bone marrow is the primary site of gametocyte maturation),
becoming competent for mosquito infection. Mature gametocytes can circulate in human blood
for several days, maximizing their chances of transmitting to mosquitoes. A female Anopheles
mosquito ingests gametocytes as she feeds on an infected human.

In the mosquito's stomach, fertilization of a macrogamete by a microgamete results in the
formation of a zygote, which undergoes meiosis and becomes an invasive mobile ookinete that
traverses the epithelial layer of the midgut wall to form an oocyst. When the oocyst wall bursts,
it penetrates the hemolymph to enter the salivary gland. From there, the sporozoites reach the
mosquito's salivary glands and invade the gland, where they remain until they are transmitted to
a new human host.
When the Anopheles mosquito ingests blood in human, anticoagulant saliva is injected along
with the sporozoites that travel to the liver in the blood, thus continuing the life cycle of malaria.
Parasites in the blood stage are responsible for the clinical manifestations of the disease. Thus,
the infected mosquito transmits the disease from one person to another (as a "vector"), while
infected people transmit the parasite to the mosquito. Unlike the human host, the vector mosquito
does not suffer from the presence of parasites.
TRANSMISSION OF MALARIA (Plasmodium falciparum)
Malaria transmission depends on the vector, the human host, and the environment. When an
infected female Anopheles mosquito bites a human, a small amount of blood is drawn, so the
sporozoites (microscopic malaria parasites) enter the peripheral bloodstream and are taken up by
the hepatocytes, where they form a pre-erythrocyte asexual (liver stage) in the liver go through
schizonts up to 2 weeks before the start of the sanguine stage.
Within red blood cells, the merozoite develops through the process of erythrocytic schizogony
into an erythrocytic schizont (blood-stage) or a spherical or banana-shaped mononuclear
gametocyte. The time required for erythrocyte schizogony, which determines the time between
the release of successive generations of merozoites, is responsible for the classic periodicity of
fever in malaria. However, the clinical symptoms are mainly due to the asexual stages of the
parasite's multiplication in human blood. The time between infection with the pathogenic
parasite and the appearance of malaria symptoms is called malaria incubation. The infected
person may feel normal for 7 to 14 days when infected with P. falciparum because it has a
shorter incubation period.

Because malaria is found in the red blood cells of an infected person, malaria can rarely be
transmitted through organ transplants, blood transfusions, or sharing blood-contaminated needles
or syringes, and malaria can also be transmitted from mother to fetus before or during delivery.
The ability of the human body to prevent the invasion of malaria pathogens is an essential factor
in the transmission of malaria and depends on climatic conditions; Mosquito survival is based on
precipitation patterns, temperature, and humidity. Transmission is most intense where the
mosquito has a longer life (so that the parasite has time to complete its development in the
mosquito).
Where does malaria transmission occur?
For Plasmodium falciparum (malaria) transmission to occur, conditions must be such that all
three components of the malaria life cycle are present:
 Anopheles mosquitoes, which can feed on humans, and in which the parasites spend half
their cycle life of "guest without the host."
 People can complete it. Anopheles mosquitoes can bite that and in which the parasites, as
"vortex hosts," can complete half their life cycle
 Malaria parasites.
Malaria occurs worldwide but is rare in the United States. It is common in developing countries
and areas with warm temperatures and high humidity, including Africa, Central, and South
America, the Dominican Republic, Haiti and other regions of the Caribbean, Eastern -Europe,
South Asia, and some regions in Oceania.
In many malaria-endemic countries, P. falciparum (malaria) transmission does not occur in all
parts of the country. Transmission does not occur even within tropical and subtropical areas; at
very great heights; during the colder seasons in some regions; in deserts (no oases), and in some
countries where transmission has been interrupted by successful control/elimination programs.
The disease is still widespread in the tropics and subtropics and the warmer regions closer to the
equator. In these areas, malaria transmission can be endemic and predictable every year, or an

epidemic, which occurs sporadically if conditions are right. Endemic malaria transmission can
occur year-round or seasonally. In some regions of Africa, 90 to 100 percent of children under
five years old have a constant stream of malaria parasites in their blood. Since naturally acquired
immunity develops with increased exposure, malaria is more common in children in endemic
areas. On the other hand, naturally obtained immunity falls between epidemics, and malaria
affects all age groups in outbreaks.
The highest transmission is found in Africa, sub-Sahara, and parts of Oceania such as Papua
New Guinea. This parasite is widespread in many countries in sub-Saharan Africa. The WHO
African Region continues to bear a disproportionate share of the global malaria challenges. The
region, in 2019 was home to 94% of all malaria cases and deaths; about half of all malaria deaths
worldwide occurred in 6 countries: Nigeria (23%), the Democratic Republic of the Congo (11%),
the United Republic of Tanzania (5%), Burkina Faso (4%), Mozambique (4%) and Niger (4ch).
Economic development and public health efforts have eradicated malaria in many temperate
areas, such as Western Europe and the United States. However, most of these areas are home to
Anopheles mosquitoes that can transmit P. falciparum (malaria), and reintroducing the disease is
a constant threat.
Who is most likely to be infected by P. falciparum (malaria) and the
circumstances under which they may be infected?
According to the World's latest Malaria Report, released on November 30, 2020, there were 229
million malaria cases in 2019, compared with 228 million patients in 2018. The estimated
number of deaths from malaria in 2019 was 409,000, compared to 411,000 deaths in the year.
2018 4,444 people prone to mosquito bites infected with P. falciparum are at increased risk of
dying from malaria. People at high risk of infection with P. falciparum include:
 A human who has little or no immunity to P. falciparum (malaria).
 Young children are more likely to become very sick and die.
 Travelers from malaria-free regions with little or no immunity are very vulnerable to areas
with high P. falciparum (malaria) infection rates.

 Pregnant women with low immunity and HIV-infected pregnant women are at high risk of
severe anemia and impaired fetal development.
 In rural and riverine areas with limited access to health care services, people are at high risk
for malaria infection.
An estimated 90% of deaths due to malaria occur in Africa south of the Sahara, with most
children of five years and below in 2019; they accounted for 67% (274 000) of all malaria deaths
worldwide. Malaria infection results in high rates of miscarriage and causes over 10% of
maternal deaths, soaring to a 50% rate in cases of the severe disease annually. An estimated
200,000 infants die annually due to infection during pregnancy. Biological traits (innate and
acquired) and behavioral traits can affect an individual's risk of malaria and the ecology of
malaria as a whole on a larger scale.
HUMAN FACTORS AND PLASMODIUM FALCIPARUM (MALARIA)
TRANSMISSION
Genetic Factors
Biological properties that exist from birth can be protected from certain types of malaria. Two
genetic factors are epidemiologically important, both of which are associated with human
erythrocytes. Individuals with the sickle cell trait (a heterozygote of the abnormal hemoglobin
gene HbS) enjoy physical benefits because they are relatively protected from Plasmodium
falciparum. Because P. falciparum malaria has long been one of the leading causes of death in
Africa, and the sickle cell trait is now more common in Africans and people of African descent
than in other populations. In general, hemoglobin-related disorders and other hemoglobin
disorders such as hemoglobin C, thalassemia, and G6PD deficiency are more common in
endemic malaria areas. They are thought to protect against malaria disease.
Acquired Immunity
Acquired immunity has a significant impact on the impact of malaria on individuals and
communities. After repeated malaria attacks, a person can partially develop defensive immunity.