Objective: To determine the effectiveness of a screening programme to identify infants with sickle cell anaemia.
Setting: A metropolitan university hospital.
Method: 4845 (73.3%) newborn cord blood samples from 6271 infants born in the Thomas Jefferson University Hospital over a two year period were tested for the presence of haemoglobinopathies. The patient group comprised approximately 44% white Americans and 51% African Americans. Diagnoses of haemoglobinopathies were established by cellulose acetate (pH 8.6) and citrate agar (pH 6.2) electrophoresis, and thin layer isoelectric focusing.
Results: 17 African American infants were suspected of having sickle cell anaemia and their families were notified and called for retesting to confirm the diagnosis. Fourteen of these families responded; retesting confirmed the diagnosis of sickle cell anaemia in 12 (86%), and the remaining two (14%) had sickle cell trait. The other three families never responded and all efforts to reach them were unsuccessful so the diagnosis could not be confirmed. The infants for whom the diagnosis of sickle cell anaemia was confirmed were treated prophylactically with penicillin and enrolled in sickle cell programmes. Of 398 infants with an abnormal haemoglobin (Hb), 170 (3.5% of all infants tested) showed sickle trait, 63 (1.3%) showed Hb C trait, and 165 samples (3.4%) showed Hb Bart's. Letters of notification were sent to those families whose infants had sickle trait or Hb C trait. Thirty three (16%) families responded and asked for additional information, counselling, or testing of other family members. Three of these families (about 0.1% of all white subjects tested) were white subjects of Italian, English, and Polish ancestry, and all of their infants had sickle trait. Additional testing on other family members showed that one black parent had Hb SC disease that had not previously been diagnosed as the subject was asymptomatic.
Conclusions: A screening programme for newborns in a metropolitan hospital (a) was effective in identifying and treating infants with sickle cell anaemia with prophylactic penicillin, (b) was associated with difficulties in tracking infants and their families in about 30% of suspected cases of sickle cell disease, (c) found that sickle trait is not uncommon in white subjects, and (d) found that "silent" sickle cell disorders to occur among American black subjects.