In the Literature

The attack rates and associated mortality during the 1918 influenza pandemic varied greatly among cities in the United States. The fact that cities, at a time when there was no effective vaccine or antiviral therapy, took greatly different social approaches in their attempts to control the outbreak has provided an opportunity for 2 groups of investigators to make correlations between those measures and outbreak severity in an attempt to estimate the potential efficacy of individual measures. These analyses concluded that among the most effective measures were those that created “social distancing,” such as closure of schools, churches, theaters, and other places of gathering. Simultaneous implementation of multiple measures was more effective than less aggressive approaches. As might be expected, efficacy was greater when multiple measures were instituted earlier in the pandemic than later and when they were continued for longer periods of time. Maintenance of restrictive measures for prolonged periods becomes difficult as the population begins to resist them after the initial shock of the effects of the pandemic. This proved to be problematic, because the 1918 epidemic tended to sweep through cities in waves, so that a new wave would hit the city after the initial large-scale social distancing measures had been lifted. Modern day urban populations in the United States are, by some estimates, less likely to be compliant with restrictions on lifestyle than were populations 90 years ago, making prolonged maintenance of similar measures likely to be more difficult. Furthermore, there have been vast social changes, including greater urbanization, as well as greater local and international mobility. On the other hand, antiviral drugs will be available for some individuals, and a vaccine may become available during a pandemic, although after a considerable delay. The Centers for Disease Control and Prevention’s recent Community Strategy for Pandemic Influenza Mitigation [1] indicates the need for a variety of protective measures. These include the isolation and treatment of all individuals with confirmed or probable pandemic influenza; the voluntary home quarantine of other household members; the dismissal of students from child care, schools, and school activities at all levels together; and maintenance of social distancing outside of those settings. Measures should also be taken to reduce contact between adults in both the community and the workplace with such tactics as cancellation of large public gatherings and alteration of workplace environments and schedules to decrease social density.