Double blind study of placebo and ribavirin as prophylaxis in cases of contact with varicella in children.

Abstract

The aim of this study was to determine whether or not ribavirin provides protection against varicella in those who come in contact with the virus. In a double blind placebo study, ribavirin (20 mg/kg/day, p.o.) or placebo was administered to children who had contact with varicella. Treatment was administered to 61 children (Group 1) within the first 3 days of contact, 45 of them were immunocompetent and 16 were immunodepressed. Treatment was given to 54 children on the 7th day after contact (Group 2); 48 of them were immunocompetent and 6 immunodepressed. In group 1, 11 (50%) of the immunocompetent treated with ribavirin developed chicken pox while 11 (50%) were asymptomatic. For seroconversion, there was no significant difference (p=0.586). In group 2, we did not find varicella in immunocompetent patients receiving ribavirin (0/24), for placebo there were 2 (2/24) cases of varicella. Varicella was not observed in immunodepressed patients in Group 2. A difference was not observed with the administration of ribavirin at day 3 or 7 versus placebo to prevent development of varicella. This study may have implications for the public health efforts in the prophylaxis of chicken pox.