Wastewater detection of emerging arbovirus infections: Case study of Dengue in the United States

Climate change and urbanization are increasing the distribution of insect vectors of infectious diseases. Dengue virus is an arbovirus that causes nearly 100 million symptomatic infections per year and is endemic in 124 countries, and the range of its mosquito vectors continues to increase. Surveillance of dengue virus infections is complicated by the fact that infections can be asymptomatic and symptoms may not be readily recognizable to clinicians. Here we show that wastewater monitoring can be used to detect dengue virus RNA to yield information about circulation of dengue infections in a community. We collected three samples of wastewater solids per week from three different wastewater treatment plants in Miami-Dade County, Florida where dengue infections have been locally acquired. Using molecular methods, we tested wastewater solids for RNA from the 4 dengue virus serotypes and consistently detected dengue virus 3 RNA at all three wastewater plants, and did not detect the other 3 serotypes. According to publicly available data on dengue infections, the vast majority of infections were caused by serotype 3. Wastewater detection of dengue virus RNA is possible with as few as 4.23 laboratory confirmed dengue cases per 1 million people, based on publicly available infection data.