Prevention and management of infection in children with sickle cell anaemia.

Sickle cell anaemia (SCA) predisposes a child to infections for various reasons, including increased bone marrow turnover, poor perfusion and functional asplenia leading to decreased opsonisation of polysaccharide encapsulated organisms. Bacteria and viruses that most frequently cause serious infections in children with sickle cell disease are Streptococcus pneumoniae, Haemophilus influenzae type b, Salmonella spp., Escherichia coli, Staphylococcus aureus, Mycoplasma pneumoniae, Chlamydia pneumoniae, parvovirus B19 and hepatitis A, B and C viruses. Penicillin prophylaxis has decreased the incidence of infection-related morbidity and mortality significantly in children with SCA. Children <3 years of age are administered oral penicillin 125mg twice daily, and the dose is increased to 250mg twice daily for the >3 to 5 year age group. Adherence to the penicillin prophylactic regimen is recommended for children with SCA who are >5 years of age. For children with SCA who have recurrent invasive pneumococcal infections, an effort is made to keep the child on penicillin prophylaxis indefinitely. The administration of various childhood vaccines has also made an appreciable impact on the overall morbidity and mortality associated with infection in children with SCA. The administration of the heptavalent conjugate pneumococcal vaccine (PCV7) has provided control of invasive pneumococcal infections, and the prophylactic use of the H. influenzae type b conjugate vaccine has reduced the incidence of septicaemia and meningitis caused by this organism. Other vaccines used prophylactically in children with SCA include hepatitis A and B, and vaccines against influenza and varicella viruses. The immediate administration of intravenous antibacterials, after appropriate blood and urine cultures, is of great importance in the treatment of the febrile child with SCA. Ceftriaxone and cefotaxime have been recommended for the treatment of septic episodes in SCA associated with S. pneumoniae, Haemophilus and Salmonella spp. Infection with Yersinia enterocolitica may be treated with cefotaxime or an aminoglycoside. The prevalence of Helicobacter pylori infection in SCA is unknown. Effective therapies include metronidazole, tetracycline or amoxicillin. Parvovirus infections require supportive care and specific antiviral therapy is not indicated. The judicious use of antimicrobials is encouraged in view of the worldwide emergence of multidrug-resistant strains. The long term sequelae associated with infections in children with SCA can be decreased with the implementation of immunisation programmes and effective and prompt treatment with appropriate antibacterials.