The presentation, management and prevention of crisis in sickle cell disease in Africa

Abstract

About 120 000 infants are born each year with sickle cell disease (SCD) in Africa. The majority have Hb SS, but Hb SC and Hb S β + thalassaemia are common in west Africa. The development of Plasmodium falciparum and P. malariae is partially inhibited in the Hb SS red cells, but malaria precipitates both haemolytic and infarctive crises, and is the commonest and most important cause of morbidity and mortality. The pneumococcus is likely to be the second major infectious cause of sickness and death. In one rural community, there were less than 2% of the expected number of subjects with SCD surviving beyond 5 years of age. Genetic factors improving prognosis include (1) the Senegal β chain haplotype, which is linked to a high level of Hb F, and (2) α + thalassaemia. Of environmental factors improving prognosis, the family is of first importance. The commonest age of presentation is 1–3 years. Children present with anaemic crises (malaria, splenic sequestration, folate deficiency, and possibly aplastic), infarctive crises (hand-foot syndrome, bone-pain, pulmonary and abdominal) or acute infections (malaria, pneumonia, septicaemia, meningitis, osteomyelitis). Tragically, many patients in central Africa have been infected by the human immunodeficiency virus (HIV) through blood transfusions; they present with generalised lymphadenopathy and other features of the acquired immunodeficiency syndrome (AIDS). The principles of management are (1) to ensure freedom from malaria, (2) to continue folic acid supplements, (3) to give blood transfusions only when anaemia endangers life, (4) to control pain, (5) to restore hydration, and (6) to prescribe broad spectrum antibiotics in large dosage and without delay, but only when there are definite indications, such as fever (>39°C), acute pulmonary disease, meningitis, and acute osteomyelitis. The advent of HIV and AIDS makes the control of SCD of even greater importance. Principles of control are (1) early diagnosis through appropriate laboratory techniques and selective screening, (2) education of parents, patients, health professionals and public, and (3) the maintenance of health at sickle cell clinics; measures must include antimalarial prophylaxis. SCD programmes should be integrated with primary health care and AIDS control programmes.