Written by Joy Stephens
United Nations recognizes as worldwide health issue
In a document dated December 18, 2008, the United Nations passed a resolution that recognizes sickle-cell anemia as a public health issue worldwide and named June 19 Sickle Cell Disease World Day.
Discovered almost one hundred years ago, sickle-cell anemia, an inherited blood disorder, has been described as the world’s foremost genetic disease. There are well over a million documented cases globally and many more unreported. While concentrated in African countries north of the Zambesi River, the disease is also found in North America, the Caribbean, South and Central America, the Indian sub-continent, Middle East and countries surrounding the Mediterranean.
Sickle cell anemia also commonly referred to as sickle cell disease, affects the red blood cells.
From a booklet published by St. Jude Children’s Research Hospital, Memphis, TN, people with the disease have red blood cells containing mostly hemoglobin S while normal blood contains hemoglobin A. The problem arises when the hemoglobin S red blood cells changes shape adopting a sickle or crescent form, making it difficult for the blood to flow through small blood vessels and therefore limiting the supply of oxygen.
According to information on the Sickle Cell Foundation Nigeria web site, 37 million people in that country carry the trait. Exhibiting no symptoms, these carriers are protected from malaria and are more likely to survive the acute illness, especially among children. When two carriers procreate, they have a one in four chance of having a child with the disease, a one in two chance of having a child with the trait and a one in four chance of having a child with normal hemoglobin A.
Symptoms can appear in infants as young as 4 months old and vary in intensity and occurrences. Sudden pain is commonly seen. This occurs when the normally ‘doughnut shaped’ red blood cells change shape and block regular flow of blood through small blood vessels. As parts of the body are deprived of oxygen rich blood they require, the heart, brain and other organs can be damaged. Other symptoms include fatigue, shortness of breath, dizziness, headache, pale skin, chest pain and coldness in the hands and feet.
Complications of the disease include hand-foot syndrome, a painful swelling of the hands and feet. This is usually the first sign that an infant has the disease. A condition called splenic crises occurs when the spleen becomes damaged trying to filter out the sickle cells. This leads to an increased susceptibility to infections. Acute chest syndrome occurs when sickle cells are trapped in the lungs. Pulmonary arterial hypertension means that small blood vessels in the lungs are damaged. Other symptoms include delayed growth and puberty, strokes, eye problems, priapism (unwanted and painful erections in males), gallstones, ulcers on the legs and rare but serious multiple organ failure.
Treatments focus on managing the complications of the disease. Children, up to the age of 5, are given antibiotics provided they have been able to keep their spleen. Hydroxyurea, a drug taken daily, helps reduce the number of pain crisis and acute chest syndrome attacks. Blood transfusions can be given to combat worsening anemia and to prevent strokes or pneumonia. Research is underway to uncover other ways to treat the disease. This includes gene therapy, bone marrow transplants and new drugs. There is no widely available and safe cure for the disease.
In the U.S. the average life span is in the mid-40s. One in 10 African Americans carry the trait, one in every 500 babies are born with the disease and approximately 70,000 are affected.
According to Dr Isaac Odame of the Hospital for Sick Children in Toronto, statistics for Canada must be estimated as Ontario is the only province that does universal newborn screening. Using demographic data, there are approximately 3,500 sickle cell patients with 100 new cases each year. Among African Canadians, one in every 400 babies born will have the disease while one in 10 individuals will be carriers.
Blood tests and genetic counseling are available to determine carrier status and options for reproduction.