Mosquito control is still our primary line of defense against many of the dangerous diseases that the insects transmit via their bites. Especially for new diseases, against which we may have no vaccines or effective medications, limiting the risk of infection can be critical in avoiding large scale outbreaks. Mosquito control is mostly handled by dedicated vector-control agencies on local and regional levels, responding to monitored mosquito populations, disease surveillance in both mosquitos and humans, and public demand for action to control mosquito populations. These agencies do not traditionally work to coordinate their responses and, as a result, may risk making inefficient, or even ineffective, decisions about when and how to control mosquito populations to minimize risks to human health.

Our work used mathematical models to explore the implications of having these independent and uncoordinated decisions made by local and regional mosquito control agencies on health risks to human populations from Zika Virus. We worked to discover how much human health risk could be affected by strategic coordination in mosquito control across a regional landscape. We considered how these risks were influenced by mosquito ecology, human movement patterns, public demand for mosquito control in response to perceived risks of infection, costs and delays involved in trying to coordinate control efforts across agencies, and types of surveillance employed to monitor risk. We worked to communicate our findings not only to the academic community, but directly to local and state vector control agencies/decision makers.

Based on our work, we were able to make some very concrete and actionable recommendations about the nature of mosquito-borne disease control. We found that commuting patterns for people living near urban centers can drastically alter whether or not it is effective to work to coordinate mosquito control across neighborhoods. We found that there are cases in which mosquito ecology and human movement can actually make it least effective to target control in the most travel-connected areas. We found that different biting rates and disease transmission risks from each bite (which are disease-specific) change which mosquito life stage (larva vs. adult) should be targeted for control efforts to accomplish the best reduction in human health risks. Critically, we found that many of the control strategies used led to very different outcomes depending on what type of risk was being monitored to inform control actions (e.g. mosquito populations, human disease cases, etc.).

While we initially worked just to understand how the scientific factors of mosquito ecology, human behavior and health, and mosquito control efforts would result in different outbreak dynamics, we also considered how economic and efficiency costs might constrain the options available for coordination among control agencies to ensure that our results were useful to real-world practitioners. From this perspective, we learned that when it is easy or inexpensive to use highly sensitive and accurate surveillance methods for adult mosquito population monitoring, then there is very little to be gained by incurring the further costs of coordination of control efforts. However, when it is either expensive or inaccurate to monitor mosquito populations, or else when control decisions are based on epidemiological surveillance in either the mosquitoes or the humans, then it becomes very important (and cost effective) to communicate and coordinate control actions among agencies.

While our work focused specifically on the mosquitoes that transmit Zika-virus, and on the types of human behavior and movement patterns in regions under risk from Zika, the models we built and published during this project can be used to help support increased efficacy of vector control for any vector-borne disease. This strengthens our understanding of how to prevent the transmission of disease and promote human health and safety.

Last Modified: 12/29/2018
Modified by: Nina H Fefferman