History of
Malaria
Dear Reader,
I observed a lot of people were suffered from Malaria at least once in their
lifetime. So, here I would like to share the almost information(I believe)
about malaria and its consequences for the sake of educating the people.
Protozoan
parasite caused the Malaria disease. Plasmodium genus transmitted through the
female anopheles mosquitoes. In 1880, Alphones Laveran discovered the Malaria
parasite in the infected person. William Maccullum invented the sexual stages
of mosquitoes reproduction in human blood. Dr. Ronald Ross was a military
doctor, who did his research extensively on malaria for 16 years (1881-1897).
Malaria disease is known from almost 5th century B.C. Malaria which derived
from Italian which means bad
air. So it was believed that bad air caused to malaria. Manson hypothesis
is that mosquitoes transmit malaria. Sir Ronald Ross confirmed that mosquitoes
are main sources to malaria.
Life cycle of plasmodium:
* In the infective stage the sporozoites(it is an asexual mode of
reproduction stage of malaria parasite) are entered into the human body. They attack liver cells.
* Sporozoites are
increased through an asexual mode of reproduction. This leads to the production
single nucleate merozoites. These merozoites attack red blood cell. Merozoites
which attack another new red blood cell.
* This entire process
occur repeatedly this leads to the malaria disease. Some young merozoites
develop into a male and female gamete.
* Malarial parasites life
mainly depends on two hosts. The primary host is the mosquito, the Secondary host is
the man. The parasite
develops in man through an asexual mode of reproduction. This phase of the life
cycle of the parasite is known as an Asexual
cycle.
* The phase of a life
cycle in the mosquito is called sexual cycle. For the survival of the female
mosquitoes they depend on man blood and male mosquitoes depend on plant juices.
Asexual reproduction in
men:
When female anopheles mosquito bites the parasite enter into our body. This
phase of life is known as Sporozoites.
These sporozoites enter into the liver cell after half an hour. Slowly they
acquire totally liver cell and they feed on the contents of the liver cell.
This phase is called crypto-schizont
phase. Daughter cells are
produced by asexual mode of reproduction by schizont. They are called Crypto-Merozoites.
Merozoites are broken the liver cell and enter into the blood. Among some
merozoites are attack the new cells. They are produced in a large number of
merozoites and they are enter into the red blood cells. All these changes take
place in the liver cells. Hence it is called pre-erythrocytic
cycle. This entire process occurs in 7 to 17 days and parasite enter into
the blood. But phase completed the parasite enter into the red blood cells.
After entering into the red blood cells parasite feed on the content of the red
blood cells. So their body size grows. They are completely developed, occupy
the inner space of the red blood cells. They are called Schizont. 6 to 24
merozoites are produced by the division of the schizont. Red blood cells are
ruptured by merozoites and released into the blood. Merozoites are again
attacked the new red blood cells. So their number increased. This is the stage
of the Erythrocytic cycle. This process takes place in red blood cells. Hence
it is called Erythrocytic cycle. The break of the red blood cells and enter
into the blood is linked with cold and fever. It is treated as malarial fever.
After few generations, some of the merozoites develop into gametocytes in the
red blood cells. They are two kinds…
1. Macro gametocytes
2. Micro gametocytes
Gametocytes further
development takes place in the mosquito.
Life cycle in mosquito:
Mosquito sucks the blood gametocytes enter into its digestive system. Their
further development takes place when they migrate into the walls of the
digestive system. Macro gametocytes develop into macrogamete which is equal to
unfertilized egg. Micro gametocytes give to microgamete which is equal to
sperms.
Fusion of egg and sperms resulting this zygote is formed. Zygotes travel to the
outer layer of the wall. It develops in size and divided into a large number of
sporozoites.
The sporozoites travel towards the salivary glands of mosquito. When infected
mosquito bites sporozoites are released into the human body along with mosquito
saliva. Inculcation period varies for different species of plasmodium. Malaria
begins with a sensation of extremely cold. Patients want to be covered with
heavy blankets. Human body
temperature raised for 106oF. This stage may be seen for a
period of 2 to 4 hours. Severe headache
and body pains are common
during this period.
Next stage is releasing sweat. This process occurs 2-3 days when merozoites are
ruptured the red blood cells. If parasite enters into the children body it
blocks the capillaries, which are supplying blood to the brain.
Quinine is used to treat malaria. But parasite is developed resistance to Quinine.
That’s why new drugs were invented to control malaria. To control malaria the
best way is controlling mosquito population and using mosquito nets. Before the
invention of the life cycle of the malaria parasite, malariologist could not
explain how the malaria parasite transmits from one person to another.
Italian malariologist concluded that mosquitoes were helped to transmit the
malaria disease. Ronal Ross discovered that plasmodium rectum caused to avian
malaria in birds. In the human being also malaria spread through mosquitoes.
Ronald Ross believed that malaria is not caused by mosquitoes and thought it is
an intestinal infection. Monson and Ross showed blood slides containing malaria
parasite. Incompletely understanding of life cycle in humans, nobody knows how
the parasite grows in first 10 days. The stage of a life cycle in humans
malaria parasite to complete time taken nearly 70 years. To understanding human
malaria before this malariologist commonly formed in birds, mammals ad
reptiles.
After a few centuries various discoveries concerning the malaria parasite and
their transmission. Alphonse Laveran observed first that parasites are present
in the blood of malaria patient in 1980. Finally, Ronald Ross discovered the life
cycle of the malaria parasite in man and female anopheles mosquito and he got
the noble prize in the year 1902 for this invention.
On 20th August, 1897, Ross found clear outlines about 12mm diameter cells. Each
cell containing a type of cell, black pigment. He draws rough sketches in his
notebooks. Finally, Ross discovered the route map of malaria. Infected patient
blood to mosquito stomach to salivary glands to infect a healthy person. So on
20th August we
celebrate world malaria day.
I am feeling very happy to share my knowledge with you. Feel free to give any
comments, suggestions.
Thank You.
