Severe infections in sickle cell disease: clinical features and preventionin children

Sickle-cell disease (SCD) is associated with frequent and often severe Infe ctions as a result of immune function impairment and functional asplenia. A lso, infection can trigger a vasoocclusive crisis. Pneumonococcal bacteremi a and meningitis due to S. pneumoniae are often lethal and justify the peni cillin prophylaxis, which has provided a dramatic decrease in early mortali ty bacterial pneumonia is common in patients younger than four years, with most cases being due to S. pneumoniae, H. influenzae, Mycoplasma pneumoniae , Chlamydia pneumoniae. Acute chest syndrome is both a difficult differenti al diagnosis and a common concomitant of bacterial pneumonia, because they are often intricated. Osteomyelitis is generally due to Salmonella, most of ten S. enteritidis. Multiple foci are common and treatment is difficult, wi th some patients developing chronic osteomyelitis with sequestration. Osteo myelitis is less frequent in developed countries and must been differentiat ed with bone infarction by use of bone scintigraphy. Parvovirus B19 infecti on causes acute erythroblastopenias. Malaria does not result in cerebral ma laria, but can lead to severe anaemia or vasoocclusive crisis, and should t herefore be effectively prevented. Antimicrobials are generally selected fo r efficacy against pneumococci (septicemia, meningitis), Salmonella (osteom yelitis, meningitis), and M. pneumoniae (pneumonia). Prophylactic therapy i s of paramount importance and relies on long-term or lifelong penicillin th erapy started at three months of age and on closely-spaced immunizations, m ost notably against peumococci, hepatitis B virus, S. typhi and H. influenz ae. Resistant pneumococcal strains have not been reported to cause prophyla ctic treatment failures., New conjugated pneumococcal vaccines are effectiv e in protecting very young infants and should therefore be used in sickle c ell patients. (C) 2001 Editions scientifiques et medicales Elsevier SAS.