"These recommendations are intended for implementation when WHO [World Health Organization] has declared Phase 4 and/or 5 where there is a novel influenza virus circulating causing disease in humans, the disease spreads locally with small or large clusters, and there is evidence of limited or localized human to human transmission, but it has not yet spread to many parts of the world and a vaccine against this strain is not yet available. The objective is to contain or delay the spread before it becomes widespread. The duration of phase 4 and 5 are unknown, it may be as short as 1 day or as long as 1 month or more."
San Francisco Department of Public Health, Communicable Disease Control and Prevention Section. Posted here from Lessons Learned Information Sharing database (LLIS). Documents are for personal use only and copyright laws apply.
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