Photo by Scott Wallace/World Bank
How diseases jump from animals to humans is
the focus of a new grant by Fogarty to Duke
University for study in Tanzania, where livestock
By Jeff Gray
Diseases that can jump from animals to humans - called zoonoses - are a global health concern. They are a particular problem in Tanzania, where many people live in close proximity to livestock. To address this, Fogarty and NIH - in partnership with the National Science Foundation - recently awarded Duke University $1.7 million to support groundbreaking research in the East African country.
The four-year grant from the Ecology of Infectious Diseases initiative will help establish an innovative surveillance project in northern Tanzania designed to track three diseases that can be transmitted among a wide range of host species. Dr. John Crump, the principal investigator, will bring together medical, social, veterinary and ecological scientists in order to carry out a large-scale study of the impact of three bacterial zoonoses: leptospirosis, Q fever and brucellosis.
These diseases account for more hospital admissions for fever than malaria, resulting in deaths in some cases. Reproductive problems and loss of milk production caused by the three bacteria also have major effects on livestock production in the region, where many rural households rely on domesticated animals for food security, income and social capital.
Coxiella burnetii, the heat-resistant bacterium that causes Q fever, is particularly virulent and can take an airborne form transmittable to humans. Diagnostic tests for the three diseases are often unavailable in resource-poor areas, increasing the likelihood of misdiagnosis and improper medical treatment of patients.
“In northern Tanzania, malaria was the clinical diagnosis for over 60 percent of inpatients with fever, and Q fever, leptospirosis, and brucellosis were never diagnosed clinically nor specially treated,” said Crump. “Misdiagnosis of these infections as malaria and consequent lack of specific therapy increases the risk of complications and death.”
Crump’s team will focus on three different environments where human, livestock and wildlife interactions occur: pastoral areas where livestock are raised, agropastoral areas where both crops and livestock exist and peri-urban areas that are immediately adjacent to cities or suburbs. A novel combination of research methods and approaches will be used, including human illness surveillance, analysis of hospital records, household surveys, social behavioral studies and linked human-animal epidemiological studies. The resulting data can also be used in potential control strategies such as animal vaccination.
“This study will help build desperately needed diagnostic capacity in a neglected area of disease research in Tanzania,” said Dr. Christine Jessup, Fogarty’s program officer for the Ecology of Infectious Diseases initiative. “By bringing together such diverse disciplines, the program stands a much greater chance of yielding more effective interventions and agricultural practices.”
The Ecology of Infectious Diseases program, a joint NIH-NSF initiative, supports interdisciplinary efforts to understand the underlying ecological and biological relationships between the emergence and transmission of infectious diseases and manmade environmental change such as habitat alteration, biological invasion, climate change and pollution