Quantifying the relationship between arboviral infection prevalence and human mobility patterns among participants of the Communities Organized to Prevent Arboviruses cohort (COPA) in southern Puerto Rico

Abstract

Human movement is increasingly being recognized as a major driver of arbovirus risk and dissemination. The Communities Organized to Prevent Arboviruses (COPA) study is a cohort in southern Puerto Rico to measure arboviral prevalence, evaluate interventions, and collect mobility data. To quantify the relationship between arboviral prevalence and human mobility patterns, we fit multilevel logistic regression models to estimate odds ratios for mobility-related predictors of positive chikungunya IgG or Zika IgM test results collected from COPA, assuming mobility data does not change substantially from year to year. From May 8, 2018–June 8, 2019, 39% of the 1,845 active participants during the study period had a positive arboviral seroprevalence result. Most (74%) participants reported spending five or more weekly hours outside of their home. A 1% increase in weekly hours spent outside the home was associated with a 4% (95% confidence interval (CI): 2–7%) decrease in the odds of testing positive for arbovirus. After adjusting for age and whether a person had air conditioning (AC) at home, any time spent in a work location was protective against arbovirus infection (32% decrease, CI: 9–49%). In fact, there was a general decreased prevalence for individuals who visited locations that were inside and had AC or screens, regardless of the type of location (32% decrease, CI: 12–47%). In this population, the protective characteristics of locations visited appear to be the most important driver of the relationship between mobility and arboviral prevalence. This relationship indicates that not all mobility is the same, with elements like screens and AC providing protection in some locations. These findings highlight the general importance of AC and screens, which are known to be protective against mosquitoes and mosquito-transmitted diseases.

Author summary

We characterized the relationship between arboviral infection prevalence and human mobility patterns among 1,845 participants in the Communities Organized to Prevent Arboviruses (COPA) study in Ponce, Puerto Rico. Among participants, 39% had a positive arboviral seroprevalence result. The majority (74%) reported spending 5 or more weekly hours outside of their home of residence. In general, more time spent outside the home was associated with decreased arboviral infection prevalence in this population. Arboviral prevalence was associated with the types of locations participants visited regularly, and characteristics of those locations. Work and locations with air conditioning (AC) or screens were protective for arboviral prevalence. Different from other studies, in this population, the characteristics of locations visited appear to be the most important drivers of the relationship between mobility and arboviral prevalence. This relationship indicates that not all mobility is the same, with elements like screens and AC providing protection in some locations. Previous studies have shown that household AC and screens are important factors in determining arboviral risk; however, results from this study further highlight their importance in non-residential locations where people visit. These findings support the use of screens and AC in all locations in areas at risk for arbovirus transmission.