Mexico's Disease Hot-Spots Identified
Data from nine cities in Mexico confirms that identifying dengue fever “hot spots” can provide a predictive map for future outbreaks of Zika and chikungunya, the Aedes aegypti mosquito spreads viral diseases.
The journal Lancet Planetary Health published the research encompassing data for 2008 through 2020 from Acapulco, Merida, Veracruz, Cancun, Tapachula, Villahermosa, Campeche, Iguala and Coatzacoalcos.
The results found a 6% overlap of hot spots for dengue and Zika and a 53% overlap for dengue and chikungunya cases.
Led by Gonzalo Vazquez-Prokopec, associate professor in Emory University’s Department of Environmental Sciences, this new study provides a risk-stratification method to more effectively guide the control of diseases spread by Aedes aegypti.
“Our results can help public health officials to do targeted, proactive interventions for emerging Aedes-borne diseases,” Prof. Vazquez-Prokopec stated in a press release issued on July 7, 2021. “We’re providing them with statistical frameworks in the form of maps to guide their actions.”
This new work builds on a previous study of the spatial-temporal overlap of the three diseases, focused on Merida, a city of one million located in the Yucatan Peninsula. That study showed that nearly half of Merida’s dengue cases from 2008 to 2015 were clustered in 27 percent of the city. In addition, these dengue hot spots contained 75 percent of the first chikungunya cases reported during the outbreak of that disease in 2015 and 100 percent of the first Zika cases reported during the Zika outbreak of 2016.
Mosquito control efforts generally involve outdoor spraying that covers broad swaths of a city.
However, Vazquez-Prokopec is currently leading a consortium in a randomized clinical trial in Merida to test targeted indoor residual spraying as an intervention against Aedes-borne diseases. The five-year trial, launched in 2020, is funded by a $6.5 million grant from the US National Institutes of Health.