Unexplained fever in neonates may be associated with hepatitis B vaccine

Abstract

Aim - To investigate whether hepatitis B vaccination has increased the number of cases of unexplained neonatal fever. Method - The files of all infants born from 1 January 1991 to 31 December 1992, in whom a diagnosis of 'injected antibiotic' or 'disease of temperature regulation' was recorded, were reviewed. Those who had unexplained fever of 38°G or higher during the first three days of life were divided into two groups: infants who did not receive the hepatitis B vaccine (1991) and infants who did (1992). Results - In 1992 the incidence of unexplained fever in hepatitis B vaccinated neonates was significantly higher than in the 1991 group of pre-vaccination neonates (35 out of 5819 (0.6%) vs 14 out of 5010 neonates (0.28%) respectively, p=0.013). Conclusions - The increase in the number of cases of unexplained neonatal fever seems to be associated with the introduction of routine hepatitis B vaccination on the first day of life. The possibility that an excess number of neonates will undergo unnecessary procedures and treatment to diagnose unexplained fever justifies planning a controlled study to determine whether these preliminary findings point to a significant problem.