EFFICACY OF ZANAMIVIR FOR CHEMOPROPHYLAXIS OF NURSING-HOME INFLUENZA OUTBREAKS

Despite vaccination, influenza remains a common cause of morbidity in nursing homes, Chemoprophylaxis of residents with currently available antivirals is not always effective and new agents effective against bo th influenza A and B are needed. In a randomized unblinded pilot study , we compared 14 day chemoprophylaxis with zanamivir; an antiviral whi ch inhibits influenza neuraminidase, to standard of care during sequen tial influenza A and influenza B outbreaks in a 735 bed nursing home. Influenza A outbreaks were declared on 6/14 epidemic units. Sixty-five volunteers on four epidemic units were randomized to zanamivir and on two epidemic units, 23 volunteers were randomized to rimantadine. Dur ing the 14 days of prophylaxis, only four new febrile respiratory illn esses were detected. One volunteer receiving rimantadine prophylaxis d eveloped laboratory-confirmed influenza. Influenza B outbreaks were de clared on 3/14 epidemic units. Thirty-Jive volunteers on two epidemic units were randomized to zanamivir and 18 volunteers on one epidemic u nit were randomized to no drug. During the 14 days of prophylaxis, onl y one new febrile respiratory illness was detected One volunteer rando mized to receive no drug developed laboratory-confirmed influenza. Zan amivir appears comparably effective to standard of care in preventing influenza-like illness and laboratory-confirmed influenza in nursing h omes, but requires further testing (C) 1998 Elsevier Science Ltd. All rights reserved.