Sickle-cell disease (SCD) is associated with frequent and often severe
infections as a result of immune function impairment and functional asplenia. Also,
infection can trigger a vasoocclusive crisis. Pneumonococcal
bacteremia and
meningitis due to S. pneumoniae are often lethal and justify the
penicillin prophylaxis, which has provided a dramatic decrease in early mortality
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 differential diagnosis and a common concomitant of
bacterial pneumonia, because they are often intricated.
Osteomyelitis is generally due to Salmonella, most often S. enteritidis. Multiple foci are common and treatment is difficult, with some patients developing chronic
osteomyelitis with sequestration.
Osteomyelitis is less frequent in developed countries and must been differentiated with bone
infarction by use of bone scintigraphy.
Parvovirus B19 infection causes acute erythroblastopenias.
Malaria does not result in
cerebral malaria, but can lead to severe anaemia or vasoocclusive crisis, and should therefore be effectively prevented. Antimicrobials are generally selected for efficacy against pneumococci (
septicemia,
meningitis), Salmonella (
osteomyelitis,
meningitis), and M. pneumoniae (
pneumonia). Prophylactic
therapy is of paramount importance and relies on long-term or lifelong
penicillin therapy started at three months of age and no closely-spaced immunizations, most notably against peumococci, hepatitis B virus, S. typhi and H. influenzae. Resistant pneumococcal strains have not been reported to cause prophylactic treatment failures. New conjugated
pneumococcal vaccines are effective in protecting very young infants and should therefore be used in sickle cell patients.