Sir.—Anderson et al, in a recent article in the Journal (129:1389,1975), stated that the high hepatitis B infection rates in their study were most probably related to (1) maternal-fetal transfusion at the time of delivery, (2) fetal ingestion of maternal blood during the passage through the birth canal, or (3) fetal exposure to maternal blood during delivery through dermatological lesions.
Stevens et al,1 in a very similar article, reported a high transmission rate of hepatitis B infection to infants from mothers who were asymptomatic carriers. This article prompted Smith and Hindman,2 in a letter to the editor, to question whether breast feeding was a causative factor in this transmission. Beasley3 replied that the frequency of antigenemia was similar among breast- and formula-fed infants.
I have the following questions concerning the study of Anderson and co-workers:
What was the incidence of antigenemia in infants who were breast-and bottle-fed?