How do humans, animals and the environments they live in affect the emergence of infectious diseases such as leptospirosis and babesiosis? With two new grants totaling over $4 million researchers at the Yale School of Public Health are hoping to better understand how ecology drives the transmission of infectious diseases both here in Connecticut and in urban slum communities in Brazil.
The National Institutes of Health and National Science Foundation, as part of their Ecology and Evolution of Infectious Disease (EEID) Program, have awarded two of 12 grants this year to scientists in the Department of Epidemiology of Microbial Diseases.
A $2 million grant will fund the study “Eco-epidemiology of Leptospirosis in the Urban Slums of Brazil” and $2.1 million was awarded to the study “Babesiosis Emergence in the United States”.
“Yale is a leading institution in the field of eco-epidemiology,” says Albert Ko, MD, chair of the Yale School of Public Health Department of Epidemiology of Microbial Diseases. “Some of the pioneering work in this field was performed by Professor Durland Fish at Yale and focused on the emergence of Lyme disease and West Nile virus in the US.” Eco-epidemiology aims to identify the broader ecological determinants of human health and determine how more environmentally sound public health responses can be made against infectious disease threats.
Ko, principal investigator of the study in Brazil, describes leptospirosis as a neglected disease since it disproportionally affects the poorest segments of the world’s population. Leptospirosis is transmitted by rats and causes large epidemics in slum communities. The limited understanding of how the bacterial pathogen is maintained in the rat population and the slum environment and transmitted to humans has been a major barrier to developing effective interventions.
The multi-disciplinary team of researchers that will implement the study in the city of Salvador, Brazil include Jamie Childs, a YSPH zoonotic disease expert; Adalgisa Caccone, a population geneticist in the Yale Department of Ecology and Evolutionary Biology; Michael Begon, an ecologist from the University of Liverpool; Peter Diggle, a spatial statistician from Lancaster University; Mitermayer Reis, a clinical researcher from the Oswaldo Cruz Foundation-Brazilian Ministry of Health; and Ko.
The newly funded study on babesiosis, meanwhile, is led by Maria Diuk-Wasser, PhD, Assistant Professor in the Department of Epidemiology of Microbial Diseases. The study seeks to understand why babesiosis is emerging now, about 30 years later than Lyme disease, and whether the Lyme epidemic is actually facilitating the spread of babesiosis. Both diseases are spread by the same tick species. Her research team will conduct ecological surveys of hosts, ticks and pathogens on Block Island, where babesiosis has been present for decades and on the Connecticut mainland, where it has only recently emerged.
In collaboration with YSPH researchers Durland Fish, PhD, and Peter Krause, MD, the study will also examine how the babesiosis pathogen is acquired by humans, ticks and wildlife hosts.