1897: Malarial parasite - The book of science

Malarial parasite
Life cycle
A bad thing happens
Commentary

Charles Louis Alphonse Laveran, Patrick Manson, Ronald Ross parasitology

Malarial parasite

Ronald Ross found the eggs of the parasite
in the stomach wall of a specific species of mosquito
and showed that they got there by feeding on the blood
of a man with malaria.
Alphonse Laveran had already, in 1880,
discovered the malarial parasite,
and Patrick Manson had suggested, in 1894,
that malaria was transmitted by mosquitoes.

Life cycle

A female mosquito of the species Anopheles,
to get protein to produce her eggs,
sucks human blood.
To reduce clotting and constriction of your blood vessels,
the mosquito injects her saliva,
infected with sporozoites, beneath your skin,
from where the sporozoites migrate into your bloodstream.
The sporozoites collect in your liver
where they invade cells and set up homes,
transform into a rounded form,
and mature into schizonts containing many merozoites.
Merosomes bud off the infected liver cells
and these lodge in capillaries of the lungs
where they disintegrate, releasing thousands of merozoites,
which invade red blood cells.
In red blood cells, the merozoites
transform into ring-shaped and trophozoite forms
and they divide several times into new merozoites
that escape and invade other red blood cells.
Some merozoites get into your bone marrow,
change into male or female gametocytes,
then freely circulate in your blood,
which the female mosquito sucks up.
In the mosquito’s midgut,
the gametocytes change into gametes,
fertilize each oher, become diploid zygotes,
and transform into invasive ookinetes that escape the gut.
Outside the gut, they invade cells and set up homes
where they divide and produce thousands of sporozoites.
The sporozoites migrate to the salivary glands
from where they are injected into their next host.

A bad thing happens

Mosquitoes suck
as if there were good and bad.
You do not like the parasite
and neither does the mosquito.
It is unfortunate that humans
make such good hosts for this worm.

Ronald Ross studied malaria at a hospital in Calcutta India from 1882 to 1899. In 1897, he contracted malaria, was transferred to a medical school in Secunderabad, and there he discovered the plasmodium parasite in Anopheles mosquitoes.