It is a disease produced by a protozoan (parasite) Plasmodium, transmitted by the bite of the female mosquito (Anopheles).
There are four species of the genus Plasmodium:
- P. falciparum. (SEVERE MALARIA CAUSE)
- P. vivax.
- P. ovale.
- P. malariae
The infection begins when a female of the Anophleles mosquito, when it bites to feed, releases the sporozoites in the blood, which are found in the salivary glands of the mosquito, which move quickly to the liver, joining the hepatocytes (liver cells). , inside the liver cells, the parasites multiply (asexual reproduction) and break the cells, releasing merozoites.
The infections by P. vivax and P. ovale, do not multiply immediately, but remain latent, before beginning their reproduction (they are called hypnozoitos).
The merozoites, entering the bloodstream, invade the erythrocytes (red blood cells), which grow and multiply, break the red blood cell and release new merozoites, which invade new erythrocytes and repeat the cycle.
Some parasites become gametocytes (sexed forms), which are long-lived and not associated with disease, the mosquito when it bites and ingests blood, male and female gametocytes, fuse in the mosquito's intestine and form a zygote, that when it ripens, it originates an ookinete, it crosses the intestinal wall and becomes encyst. An oocyst is obtained that expands by asexual division, until it breaks and releases sporozoites, motiles that migrate to the salivary glands, waiting to be inoculated in the bite of another human being.
SYMPTOM.
-Headache
-Fever
-Chills and sweating, of night periods
-Abdominal pain
-Myalgia and arthralgia (muscle pain)
-Nausea, vomiting or diarrhea.
In species such as P. vivax, P.ovale and P. malariae, they produce a low parasitemia, mild anemia and in some cases, a palpable spleen (splenomegaly).
P.falciparum, with a high parasitaemia, produces severe anemia, splenomegaly, encephalopathies, renal failure, pulmonary edema and death.
SOME DIAGNOSTIC METHODS.
- The precoloration technique of Walker.
- Other, Romanowsky, Wright, Field or Leishman.
- ELISA techniques.
Additional exams:
- Hemogram.
- Erythrosedimentation.
- C-reactive protein.
TREATMENT:
Antimalarials.
Chloroquine
Amodiaquine
Mefloquine
Quinine
Primaquine
Malaria has been eradicated in some countries, but despite enormous efforts to control it, it has resurfaced in many parts of the tropics, due to increased resistance to treatment and inadequate control of the vector (mosquito), so that It is a problem, for tropical communities and for travelers.
If you plan to travel to endemic areas of malaria, you have to take into account the forms of prevention, such as the use of repellents, the use of mosquito nets and avoid the formation of mosquito breeding sites.