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Sickle Cell Anaemia: Prevention and Control By Dr. Murtala Muhammad Umar Contrary to common belief, genetically-determine diseases are not rare. Between 2 and 3% of all pregnancies result in the birth of a child with a condition that can be attributed to defective or absent gene. There are about 100 000 functional human genes which have been successfully mapped out recently. At conception human beings inherit two sets of genes from both parents and apart from identical twins, each individual has a unique genetic constitution. Sickle cell anaemia is one of the genetic diseases observed as far back as 1904 by Dr JB Herrics in the blood of an anaemic West Indian medical student. Haemoglobin (Hb) is an oxygen carrying molecule contain in the red blood cell. The normal Hb is H bA (adult Hb) which a child inherits from two normal parents. Hb A is able to efficiently transport oxygen to all body tissue. However, the inheritance of two abnormal Hb genes (Hb ss—sickle cell Haemoglobin) from both parents is what causes sickle cell anaemia. Some individuals inherit one normal and one abnormal Hb genes from either of the parents (Hb As) and are said to have sickle cell trait. A child whose both parents have the sickle cell trait has one in four chance of been born a sickler. This probability affects every pregnancy as all the offsprings could be sicklers, one or more, or known at all. The sickle cell trait occurs at an incidence of between 20% and 40% in the Black population of Africa. It has been reported that the prevalence rises from the time of birth until about 5 years of age, after which there is no further change. By 1982, it was estimated that in Nigeria alone, about 30 000 children are born each year with sickle cell disease. It is currently estimated that about 25% of adult Nigerians have the sickle cell trait and 1-3% have sickle cell anaemia. The normal red blood cells are round in shape and are able modify their shapes to negotiate even the smallest blood vessels in the body to supply oxygen. Sickle cell Hb also functions normally but in the absence of oxygen the red blood cell becomes initially reversible and later irrerversibly sickled. Unlike the normal red blood cells, the sickle cells have difficulty changing their shapes to pass through small blood vessels leading to reduce tissue oxygenation responsible for most of the signs and symptoms patients present with. Recurrent Pain especially from the bones and abdomen is a very common presentation that may warrant recurrent hospital admission. Painful, swollen hands and feet in a 6 months old child is usually the first presentation and must be taken serious by the parents. Factors such as infection, sudden temperature change, stress, pregnancy, low oxygen, etc could precipitate crisis (severe, unbearable pain). Anaemia (shortage of blood) is another fatal complication that sicklers suffer. It is mostly associated with yellowness of the eye. Anaemia occurs because the body system removes and destroys the sickle cells before reaching 120 days which is the average life span of normal red blood cells. Recurrent anaemia and pains combine to cause growth and developmental retardation.. Other complications worth mentioning include stroke, defective vision, priapism(sustained, painful penile erection), leg ulcers, poor wound healing, bone and joint deformities, end organ failure( e.g. kidney failure), pregnancy related complications, etc.There is virtually no body system that is speared by the disease. Ironically, people carrying the sickle cell trait resist malaria infection compared to those with normal Haemoglobin. Enuresis (bed wetting) which sickle cell anaemic patient suffer from may be shared by individuals with the trait who are otherwise normal.. Sickle cell anaemia is a disease with complications ranging from mild to life threatening ones with management consuming substantial part of the meager financial resources of the family. You can imagine the amount of money a family will spend if their child is to be admitted say an average of four times i n a year often requiring blood transfusion, fluid and expensive analgesics. The sorry state of it all is for the parents to lose the child before he or she attains productive age. The only solution left to us is to prevent this genetic disease as far as is humanly possible and minimize complications among those affected. The first step towards prevention is for each and every person to know his or her genotype. This can only be possible with health education and making screening centers accessible and available especially to the rural poor. But for the teaching/ specialist hospitals only few general hospitals in Nigeria have the facility to do Haemoglobin genotype at a cost that may be unaffordable to the masses. Sickle cell clubs available in the country can advocate for free screening by sourcing funds home and abroad. People are advice to go for pre marital counseling so that even if couples with the sickle cell trait insist on getting marriage their minds would have been prepared on what to anticipate. Prenatal diagnosis is now available in Lagos and allows the diagnosis of the disease as early as 3 months of pregnancy. The major dilemma is accepting to terminate the pregnancy for religious and cultural factors must come in to play. In a study by Kagu etal to find about awareness and acceptability of prenatal diagnosis of sickle cell among health workers in North Eastern Nigeria. Fifty three percent (187) of the respondents (out of 353) would not like to terminate pregnancy by abortion if prenatal diagnosis confirmed sickle cell anaemia (SCA) in first trimester with significantly more Christians saying no to abortion. In any case the pre natal diagnosis I think will still benefit the parents of the forthcoming sickler and who knows whether All mighty God can miraculously change the genotype or the diagnosis could be faulty. Finally if preventing the disease differ all measure the only option left is for the parents, health workers, governments and all stake holder concerns to cooperate together with the view to minimizing complications and possible rehabilitation Early diagnosis in a child with suspicious symptoms as mentioned above would ensure prompt treatment and evaluation. There a re special clinics for sicklers in most tertiary/secondary hospitals and parents can avail themselves of this opportunity. Because patients are prone to infections routine and other special immunizations are given to prevent infection. Blood tonics with the exception of the ones containing elemental iron and malarial prophylaxis are also routinely given in the clinic. Sickle cell patients with pregnancy are at risk of abortion, foetal growth retardation, abortion, low birth weight etc,complications, and are advice to book early and frequently visit antenatal clinic Sikclers should take adequate fluid to avoid dehydration which usually precipitate crisis. Good diet, warm and dry conditions help them stay healthy. Parents must make sure they visit the hospital once the child is sick instead of going to the chemist or self medication. Sickle cell anaemia has been responsible for high morbidity and mortality, in addition to decrease productivity in the black race. This is the time to sincerely act to reverse this trend so as to spear the lives pf millions of people affected directly or indirectly by the disease. God safe the black race
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