2017 Volume 43 Issue 12 Pages 701-705
There are few reports on post-exposure prophylaxis (PEP) of oseltamivir for preventive efficacy of secondary infection of influenza. Especially, there is no report on medical institutions with many elderly people. Our aim was to verify the preventive efficacy of secondary infection of influenza by post-exposure prophylaxis of oseltamivir in medical institutions with many elderly people. We retrospectively investigated the secondary infection rate of roommates administered oseltamivir prophylactically for 5 days (PEP group) and that of roommates who were not administered oseltamivir (non-PEP group). The observation period was set as up to 10 days from influenza diagnosis.
There were 121 index cases of influenza, 550 roommates. We compared 441 cases of the PEP group with 95 cases of the non-PEP group. The median age was 72[57-84] in the PEP group and 73[53-83] in the non-PEP group. The secondary infection to the roommates was 0.7％ (3/441) in the PEP group and 9.5％ (9/95) in the non-PEP group (Protective efficacy 92％; 95％ confidence interval, 72.1-97.9; P < 0.001), and the secondary infection to the roommates who could be observed for 10 days was 1.2％ (3/242) in the PEP group and 14.5％ (9/62) in the non-PEP group (Protective efficacy 92％; 95％ confidence interval, 69.4-97.6; P < 0.001).
This study suggests that in medical institutions with many elderly people, oseltamivir 5-day prophylactic administration to roommates of influenza patients might be useful for preventing secondary infection.
