Hepatitis B: Sexual Contacts-Reply

My colleagues and I find the data of Drs Peterkin and Crawford to be of interest. However, there are several differences in the design of the two studies that probably explain the disparate results. Perhaps the most important of these is the fact that their analysis was retrospective and did not allow for administration of HBIg within a defined period. It is generally accepted that immunoglobulin preparations provide passive-active immunity only if given relatively soon after exposure.¹ In our study, index cases of hepatitis were usually identified within two weeks after the onset of illness. Furthermore, the "preinjection interval" (the time between the onset of symptoms in the index case and the administration of immunoglobulin) was generally less than three weeks. The negative effect of longer exposure periods is well illustrated by the case of a seronegative spouse who was given 5 mL of HBIg when we initially failed