Delays in Global Disease Outbreak Responses: Lessons from H1N1, Ebola, and Zika

Abstract

In global disease outbreaks, there are significant time delays between the source of an outbreak and collective action. Some delay is necessary, but recent delays have been extended by insufficient surveillance capacity and time-consuming efforts to mobilize action. Three public health emergencies of international concern (PHEICs)-H1N1, Ebola, and Zika-allow us to identify and compare sources of delays and consider seven hypotheses about what influences the length of delays. These hypotheses can then motivate further research that empirically tests them. The three PHEICs suggest that deferred global mobilization is a greater source of delay than is poor surveillance capacity. These case study outbreaks support hypotheses that we see quicker responses for novel diseases when outbreaks do not coincide with holidays and when US citizens are infected. They do not support hypotheses that we see quicker responses for more severe outbreaks or those that threaten larger numbers of people. Better understanding the reason for delays can help target policy interventions and identify the kind of global institutional changes needed to reduce the spread and severity of future PHEICs.

FIGURE 1—

Delays From Index Case to Outbreak Detection to PHEIC Declaration Note. PHEIC = public health emergencies of international concern. The H1N1 outbreak began March 15, 2009, was detected March 18, 2009, and was declared a PHEIC April 25, 2009. The West African Ebola outbreak began December 26, 2013, was detected March 22, 2014, and was declared a PHEIC August 8, 2014. For the Zika outbreak, the main concern was microcephaly rather than Zika virus infections; thus we consider this outbreak to have begun October 22, 2015, when the rise in microcephaly cases was first identified, and we consider the outbreak detected November 28, 2015, once there was strong evidence of a link between the virus and the microcephaly cases. The Zika outbreak was declared a PHEIC February 1, 2016.