The Engaging Atlantans to Guide Effective Disease response (ENGAGED) Study
Who is sharing germs with who? It’s a simple question that we’re still trying to figure out. Emory CIDMATH researchers are stepping up to address this knowledge gap by studying how people interact to spread infectious diseases. Many infectious disease models assume people mix randomly like marbles in a bag. People, however, are much more complicated. “Human behavior is messy and changes all the time in response to a complex combination of forces,” notes Emory Assistant Professor of Epidemiology Dr. Kristin Nelson.
The timing, location, and duration of human interactions are key for understanding infectious disease transmission and how it varies by pathogen. For example, a passing interaction with someone who has measles may be enough for that disease to spread, whereas for other diseases like tuberculosis, one has to be near someone who has TB for an extended period of time.
To model infectious disease transmission in Georgia, we need to know how often we interact with each other. How many times do you sit next to strangers on a MARTA subway? During warmer times of year, are you more likely to meet friends on the Beltline or in a crowded restaurant indoors? And most important of all, how do you change these behaviors when you’re not feeling well?
To answer these questions and more, Dr. Nelson is spearheading a new study, the Engaging Atlantans to Guide Effective Disease response (ENGAGED) study, to understand contacts of individuals in Georgia. CIDMATH is partnering with Kaiser Permanente (KP) Georgia to enroll 650 participants, based in Atlanta and in northern Georgia, who have health insurance with KP to participate in the study over a six-month period. Assistant Research Professor and Co-Investigator Dr. Sharia Ahmed, and PhD candidate Pragati Prasad, PhD candidate Charlotte Doran, and Public Health Program Associate Machi Shiiba are additional team members.
For one day each month over the six-month period, CIDMATH investigators will send each participant a survey that will ask each participant different questions about who people have interacted with in the past day. A unique feature of CIDMATH’s partnership with KP Georgia is that the partnership facilitates integration of participants’ Electronic Health Records (EHR) into the study. When these records indicate that a participant is ill from a respiratory or gastrointestinal disease, a specific survey will be sent out to that participant asking about their recent contacts.
With these data, CIDMATH can reveal key insights on how Georgia residents interact over time and how the timing and duration of contacts change when people are sick and during different seasons. Importantly, this study can have a ripple effect to uplift other research at other institutions in and outside of the U.S., as researchers and practitioners can use this data to strengthen infectious disease transmission models. “If we can collect real-time data on these kinds of transmission networks or potential routes that a pathogen can take through a population, it allows us to target our interventions very effectively,” said Charlotte Doran.
For example, younger children and the elderly are most at risk for severe influenza complications. In a hypothetical influenza outbreak, knowing how people in these two subgroups interact with others could inform when, and for how long, is optimal to close daycares, instead of closing them at the first sign of illness. Or perhaps, influenza vaccine campaigns before the winter holidays could be targeted towards elderly people who are especially likely to interact with younger family members who may be more exposed to illness at school and in workplaces, where they spend most of their time.
Additionally, at a national level, influenza usually starts from the southeastern United States and spreads in waves from there to the rest of the country, and understanding how it is transmitting in and around Atlanta could give clues for how it may spread elsewhere. “Atlanta is super important for U.S.-specific epidemics because pretty much every respiratory disease starts in the southeast…Atlanta is pretty vital to understanding how severe diseases will be in the following year,” said Pragati Prasad.
With this understanding, we aim to build a future where we can more efficiently protect communities by identifying how germs are being transmitted between individuals.
“Akshay Deverakonda, the author of this article, is a recent MSPH Epidemiology graduate, concentrating in infectious disease epidemiology, in the Rollins School of Public Health Class of 2025.”