The emergence of zoonotic and vector-borne pathogens can trigger significant changes in the infected host community. However, what seems like an abrupt emergence often occurs following a series of low probability events that must align to support pathogen amplification and subsequent disease outbreaks. While people frequently move pathogens around the globe, most introductions have little or no impact on local communities. Initial zoonotic spillover, followed by sustained human to human transmission remains a relatively rare sequence of events, even in settings where competent hosts and vectors commonly co-occur. Likewise, while there have been 5372 confirmed cases of travelers' Zika infection in U.S. states since 2015, subsequent ocal transmission (and 228 secondary infections) occurred in only two US counties. Predicting where and when introductions or spill-over events are likely to fuel locally sustained transmission is a current and urgent goal for disease ecology and public health.
Results/Conclusions
In this talk we synthesize evidence for abrupt ecological change (ACES) in vector-borne and zoonotic disease systems. We consider a generalized arboviral introduction and demonstrate how social and ecological conditions can facilitate or stabilize change at fine spatial scales. Weather, human behavior, and community ecology all influence the probability of ecological change, which is evidenced by sustained local transmission and shifts in human risk management. Finally, we discuss current opportunities and limitations in predicting where and when pathogen introductions become disease outbreaks.