by Rachel Griess
We might not often consider it, but potentially deadly diseases are transmitted between animals and people, and this category of infectious pathogens - including rabies and West Nile virus - is center-stage as scientists worldwide work to improve knowledge at the interface of human, animal and environmental health.
These scientific efforts are part of the global One Health movement, and CSU is a leader with its longstanding expertise in infectious disease.
Francisco Olea-Popelka, a CSU veterinary epidemiologist, is an exemplar of One Health science as a researcher of zoonotic tuberculosis, meaning the forms of TB transmitted between animals and humans. In a sign of his expertise, Olea-Popelka recently became chair of the Zoonotic TB Sub-Section of the International Union against Tuberculosis and Lung Disease.
“I look forward to coordinating and leading international efforts to increase global awareness of zoonotic TB,” Olea-Popelka said. “We hope to provide a platform to combine efforts being carried out by researchers, physicians, veterinarians and public-health workers to prevent transmission of mycobacteria between humans, livestock and wildlife and to better treat human patients suffering from zoonotic TB.”
Lions, elephants, Cape buffalo, bovine, badgers, and goats are but a few of the creatures Olea-Popelka has studied in a quest to understand complex cross-infection patterns that different mycobacteria species, including the infectious Mycobacterium tuberculosis, can take while traveling through the environment, wildlife and domesticated animals to people.
The public-health threat posed by TB, which kills an estimated 1.5 million people worldwide every year, is the focus of World TB Day on March 24. To observe the day, CSU’s world-renowned TB research group, housed in the Mycobacteria Research Laboratories, will host about 100 visiting high-school students for hands-on laboratory activities.
In the United States, TB is not a leading health threat. But that is true only because of aggressive public-health measures that began in the early 1900s.
The disease slowed dramatically in this country with steps including testing of cattle for Mycobacterium bovis, the form of TB in cattle, and the pasteurization of milk, which protects people from TB passed through infected cattle.
The story is much different in the developing world: Between 2005 and 2008, bovine TB was reported in cattle populations in 128 out of 155 countries. Consuming unpasteurized dairy products and undercooked meat remains common in much of the developing world, and people often live and work alongside infected animals, Olea-Popelka said.
These patterns underscore the need to understand and track zoonotic TB.
“The work we do has a strong social component because zoonotic TB continues to affect people, especially underserved communities in developing countries,” Olea-Popelka said. “My interest lies in understanding the delicate and complex links between humans, domestic animals and wildlife in different environments and how these interactions impact the dynamics of a disease.”
Olea-Popelka’s work with TB began in Chile in 1998, when he assessed the risk of people contracting the disease by consuming unpasteurized dairy-goat products.
In 2000, he began ongoing research with the Irish Department of Agriculture and the University College Dublin to investigate epidemiological risks of TB in cattle and badgers in Ireland.
Since arriving at CSU in 2007, Olea-Popelka has expanded his global collaborations to improve diagnostic methods for TB in lions and Cape buffalo in southern Africa and elephants in North American facilities. He is a member of a new research team investigating transmission of zoonotic TB between cattle and humans in India, Kenya and Mexico, and between people and elephants in Zimbabwe and Zambia.
In aligning his work with One Health, Olea-Popelka said it is important to consider socioeconomic, cultural and political factors to fully understand zoonotic TB.
“There are tremendous opportunities for the human and veterinary fields to share and combine expertise,” Olea-Popelka said.