Malaria

Definition:
Malaria is an acute and chronic parasitic disease transmitted by the bite of infected mosquitoes and it is confined mainly to tropical and subtropical areas.
This disease causes more disability and heavier economic burden than any parasitic disease.

Countries where malaria is endemic as of 2003 Malaria generally occurs in areas where environmental conditions allow parasite multiplication in the vector. Thus, malaria is usually restricted to tropical and subtropical areas (see map) and altitudes below 1,500 m. However, this distribution might be affected by climatic changes, especially global warming, and population movements. Both Plasmodium falciparum and P. malariae are encountered in all shaded areas of the map (with P. falciparum by far the most prevalent). Plasmodium vivax and P. ovale are traditionally thought to occupy complementary niches, with P. ovale predominating in Sub-Saharan Africa and P. vivax in the other areas; however these two species are not always distinguishable on the basis of morphologic characteristics alone; the use of molecular tools will help clarify their exact distribution.
Etiologic Agent:
Protozoa of genus plasmodia
1. The disease is caused by four species of protozoa:
a. Plasmodium falciparum (malignant tertian)
· This is considered as the most serious malarial infection because of the development of high parasitic densities in blood (RBC) with tendency to agglutinate and form into microemboli.
· This is most common in the Philippines.
b. Plasmodium vivax (Benign tertian)
· This is nonlife threatening except for the very young and the old.
· It is manifested by chills every 48 hours on the 3rd day onward especially if untreated.
c. Plasmodium malariae (Quartan)
· It is less frequently seen.
· This specie is nonlife threatening.
· Fever and chills usually occur every 72 hours usually on the 4th day after onset.
d. Plasmodium ovale is the rare type of protozoan species.
· This is rarely seen in the Philippines.
2. The primary vector of malaria is the female Anopheles mosquito which has the following characteristics:
a. It breeds in clear, flowing, and shaded streams usually in the mountains.
b. It is bigger in size than the ordinary mosquito.
c. It is brown in color.
d. It is a night-biting mosquito.
e. It usually does not bite a person in motion.
f. It assumes a 36º position when it alights on walls, trees, curtains, and the like.
Incubation period:
12 days for P. Falciparum
14 days for P. vivax and ovale
30 days for P. malariae
Period of Communicability:
Untreated or insufficiently treated patient may be the source of mosquito infection for more than three years in P. malariae, one to two years in P. vivax, and not more than one year on P. falciparum.
Mode of Transmission:
The disease is transmitted mechanically through the bite of an infected female anopheles mosquito
It can be transmitted parenterally through blood transfusion.
On rare occasions, it is transmitted from shared contaminated needles.
However, transplacental transmission of congenital malaria is a rare case.
Clinical Manifestations:
Paroxysms with shaking chills
Rapidly rising fever with severe headache
Profuse sweating
Myalgia, with feeling of well-being in between
Splenomegally, hepatomegally
Orthostatic hypotension
Paroxysms may last for 12 hours, then, maybe repeated daily or after a day or two.
In children:
Fever maybe continuous
Convulsions and gastrointestinal symptoms are prominent
Splenomegally
In cerebral malaria
Changes in sensorium, severe headache, and vomiting
Jacksonian or grand mal seizure may occur
Diagnostic Procedure:
Malarial smear – In this procedure, a film of blood is placed on a slide, stained, and examined microscopically.
Rapid diagnostic test (RDT) – This is a blood test for malaria that can be conducted outside the laboratory and in the field. It gives a result within 10 to 15 minutes. This is done to detect malarial parasite antigen in the blood.
Pathogenesis:
The parasite enters the mosquito’s stomach through the infected human blood obtained by biting or during blood meal.
The parasite undergoes sexual conjugation.
After 10 to 14 days, a number of young parasites are released which work their way into the salivary gland of the mosquito.
The organisms are carried in the saliva into the victim when the mosquito bites again.
The female alone plays the role of a vector and definitive host in conveying the disease from man to man (sexual propagation).
In humans, the organisms invade the RBC where they grow and undergo sexual schizogony.
Erythrocytic merozoites are produced leading to the rupture of RBC upon the release of the tiny organisms.
Young merozoites invade a new batch of RBC, to start another schizonic cycle.
Nursing Management:

Source:
www.nursingcrib.com