MALARIA PARASITE AND ITS EFFECT TO HUMAN HEALTH (A CASE STUDY OF UNIVERSITY OF NIGERIA TEACHING HOSPITAL (UNTH), ENUGU)

INTRODUCTION

1.1                        BACKGROUND INFORMATION

Malaria Parasite is regarded as one of the most serious health problems facing almost the whole world today.  It was noted that this parasitic disease is caused by species of poor tozoa called Plasmodium spp.  Within the compass of medical environment, malaria was known to be a parasitic disease that gets into human system through the pathogenic bite of an infected female anopheles mosquito, (Knudsen, 1992).

Malaria parasite was also found to be mostly infective to the children under 5 – 6 years and pregnant women, this is because this group of people usually build antibodies which do not prevent the endemic disease of the parasite, but tolerate the victim to a point where it is not consistently lethal (WHO 1986).  In the year 1880, AlphonsusLavaran first observed this parasite at it merizoit stage and was published in the B”Bullentine de Academic de Medicine pariss”.  Further findings on this malaria parasite was carried on by Italian doctors which includes Golgi Manson, baslianelli etc.  This people observed the mechanism of spreading and the life cycle of the parasite.  It was also estimated that 270 million new malaria infection occur worldwide along with 110 million cases of illness and 2 million deaths, where 25% of children’s’ death in Africa are attributed to malaria parasite (WHO, 1986).

Malaria parasite being a parasite, which falls into protozoa called sporazoa.  It means that they are spore formers; their life cycle involves an alternation of generation, one, which is sexual, and the other asexual method of reproduction.  The sexual and asexual generations in this parasite take place in two different hosts.  In the definite host, the parasite carries out the sexual part of the reproduction of which female anopheles mosquito is the host which the asexual part will be carried on in the intermediate host which is in the human blood system (Franklin and Wehrle, 1948).

According to Chees Brough (1987), this plasmodium spp, which is the causative agent of this malaria parasite are of four varieties species that attacks man.  They are:

a)       Plasmodium vivax, which causes tartian malaria, or vivax malaria

b)   Plasmodium malaria, the cause of quatain malaria also called malaria malariae

c)       Plasmodium oval that causes oval malaria and finally

d)   Plasmodium falciparum, which is the agent of malignant tartian malaria.

With skill and experience these organs and the differentiate disease they cause can be possibly differentiate from each other.

LIFE CYCLE                                                                                               

Among all the mosquitoes that suck blood, it is the female species that has the quality capable of sucking blood, the male mosquitoes are vegetarians, which mean plant feeders, and they feed on the plant juice, which they suck.  It is the female mosquito in the genus anopheles that bites man to suck blood, and in the process inject the malaria parasite in the body system.

Infectious mosquito contain in their salivary gland plasmodia, which occur in spindle-shaped form known as sporozoide.  Once a mosquito that is parasitise by this organism feeds on the host liver (intermediate host), it injects the sporozoites, these migrate to the host liver where in the parenchymal cells they multiply asexually.  This part of cycle is known as exoerythrocyticschizogony, exo-erythrocytic indicates that it takes place outside the red cell, “Schizogony” literally meaning splitting generation.  This malaria parasite leaves the liver cells, enter red blood cells, and begin the erythrocyticSchizogony phase.  While para-erythrocyticcycle continue in the parachymal cell of the liver.  The exceptions being plasmodium falaparum which do not undergo paraenythrocytic cycle.  In the red cell the malaria parasite grows in size making use of globin in haemoglobin as its source of protein as amino acid, the residual product collects as a pigment.

Then divisions of the protozoan nucleus occur.  At this point, the multinucleated organism inside a red cell is called Schizont or segmenter.  And a separate nucleus, which is surrounded by its own cytoplasm, is called a merocoite.  The number of the nuclear division and hence the number of merozoite formed varies from species toispecies and this factor is very useful for the identification of the type of species involved.  The red cells containing mature merozoite disintegrate, and merozoites thus released invade new red blood cells, becoming trophozoites and the cycle continues.

Because of the significant exception of the plasmodium falciparum for not undergoing para-erythrocytic cycle, different drugs and other control measure are used against this organism in erythrocytic and para-erythrocytic cycle, plasmodium falciparum being relatively easier to control than other species.  Mostly often but not all parasitised red blood cells give raise to merozoites.  Some plasmodia in red cells ultimately and differently develops either into two sexual forms viz:

The macrogamatocyte (female) or microgamtoclyte (male) or as the asexual form, which continues the cycle in the human system.

The gametocytes develop no further in man and will survive only when they are ingested by female anopueles mosquito.  Parenthentically, all the four species of malaria parasite mentioned above can be transmitted from one intermediate host to another by either transfusion of blood or congenitally.  The gametocytes ingested by a mosquito undergo further development, from each microgamatocyte, about a dozen or so mobile, flagella like microgametes are formed.  Then in the stomach of mosquito there occurs a union of the microgametes and macrogametes resulting in the formation of zygote, which proceeds to develop into an Ookinete.

This Ookinete is a worm like; it migrates to the stomach wall of the mosquito where it transforms to another form known as Oasyst.  Then within the Oosyst repeated nuclear divisions occur.  The mature Oosyst breaks with the release of thousands of sporozoites into the content mosquito.  Sporozoites now migrate to the salivary gland of the mosquito where they are ready again to be injected into the intermediate host (man) for another cycle.  The Cycle in the mosquito takes 1 to 3 weeks.  In man, the time from mosquito bite to first symptoms and thus the time for the pre-erythrocytic and erythrocytic cycle to occurs vary considerably.

The typical incubation periods in vivax, ovale malaria and palciparum malaria are on the order of 14 – 17, 10 – 14, 28, 8 – 10 days respectively.  This period occasionally may be much longer in vivax 16 – 12 mouths and malaria (years) disease condition.

1.2     STATEMENT OF PROBLEMS

A repeatedly report about malaria parasite infection has arise several years long ago and presently, causing regular fever, continuous chill, vomiting, headache, shortage of blood and other relative sickness, which forms the symptom of the infection.

The estimate of the incident of this parasite, according to WHO (1986) shows that about 270 million new malaria infection occurs worldwide with the accompaniment of 110 and 2 million case of illness and death respectively.  Where 25% of children’s’ death in Africa are attributed to malaria (WHO, 1986).

1.3     AIM AND OBJECTIVE OF THE STUDY

AIM

To determine malaria parasite in the blood cell and its effect to the human health.

THE SPECIFIC OBJECTIVE AR

1.   To identify varieties of Plasmodium spp., and the different stages of the parasite in the blood sample.

2.   To identify the effect of the parasite in the blood cell of an infected person.

3.   To proffer preventive measures to reduce the incidence of this and its mortality rate among children in the area where there is large infection of malaria parasite.

1.4     HYPOTHESIS

Hi                           -              Malaria parasite is high among children under 5 – 6 years

and pregnant women.

Ho              -        Malaria parasite is not high among children and pregnant

women.