BACKGROUND OF THE STUDY
Lonergan, Cline, Abbondazo (2001) defined sickle cell anaemia as a chronic, genetic and hemolytic disease peculiar to the negro race due to homozygous inheritance of abnormal haemoglobin and resulting in a variation in the structure of the globins. According to Claster and Vichinsky (2003), “Sickle Cell disease is an inherited blood disorder that affect the red blood cells”. People with sickle cell disease have red blood cells that contain mostly haemoglobin ‘S’, which is an abnormal type of haemoglobin. Sometimes, these red blood cells become sickle-shaped (crescent shaped) and have difficulty passing through small blood vessels.
Umeh (1996) explained further that when, sickle-shaped cells block small blood vessels, less blood can reach that part of the body. Tissue that does not receive a normal blood flow eventually becomes damaged because; the function of the normal red blood cell is to transport oxygen with the help o f haemoglobin. Claster (2004) disclosed that sickle cell trait (AS) is an inherited
condition in which both haemoglobin A and S are produced in the red blood cells, always more of A than S sickle cell trait is not a type of sickle cell disease, people with sickle cell trait are generally healthy.
As stated in Sarojini (1998), the sickle haemoglobin is inherited according to Mendelian laws as autosomal recessive character. The homozygous individual for sickle cell haemoglobin are designated as “SS” while the heterozygous individuals are designated as “AS” and are said to have the sickle cell trait or are carriers. Homozygous individual for normal haemoglobin are designated as “AA”.
According to Mendelian laws as cited in vermar (2004), if carriers (AS), marries each other they will probably produce a sickler (SS) in line with the Mendelian ratio 1(SS): 2(AS): 1(AA). In Umeh (2004), “for a person to become a sickler, he must inherit the gene for the sickle cell in a double recessive condition”. A person who inherits the recessive gene from both parents suffers from sickle cell anaemia. In this disease condition, the red blood cells contains less haemoglobin and therefore carry less volume of oxygen to the living cells and hence the loss of energy in the sufferers. The distorted shape of the red blood cells hiders free flow of blood in the vessels resulting in severe pain experienced by sufferers. Mak and Davies (2003), explained that the sickled cells are rapidly destroyed, the patient becomes anaemic, the bone marrow becomes over active in an attempt to build new red blood cells. This causes severe pains on the bones, severe anaemia causes the weakness of the heart; this could lead to heart failure. Umeh (1996), decleared that generally, there is a poor, physical development and the individual is usually very weak, life is miserable and where there is no proper medical attention the patient dies in his youthful age. According to styles and Wright (2005), the sickle cells also block the flow of blood through vessels resulting in lungs tissue damage (acute chest syndrome), pain episodes (arms, legs, chest and abdomen). It also causes damage to most organs including the spleen kidneys and liver. Damage to the spleen makes sickle cell disease patients especially young children easily overwhelmed by certain bacterial infections.