serologic diagnosis of hiv infection in infants and children is made especially difficult by the universal presence of maternal antibodies in blood during the first year of life , technical difficulties associated with the measurement of virus-specific igm antibodies ( except , perhaps , when the mother and , hence , the child have been very recently infected ) , and the weaker and more limited antibody reactivities revealed by western blot analysis .
C0021270
infants
C0008059
child