If there is anything scientists are certain of when it comes to bats and their supposed role in causing human disease, it is that they still have a lot to learn.
Aside from well-established things like rabies virus, SARS coronavirus (the virus that causes severe acute respiratory syndrome) and Marburg virus (an extremely dangerous but rare hemorrhagic fever pathogen), bats appear to carry a plethora of other germs with unclear effects, if any, on human health.
And even some commonly believed bat paradigms may be incorrect. For example, some speculate that bats play a role in the transmission of Ebola simply because Ebola and Marburg are related pathogens. But scientific evidence to support such speculation is scant, at best.
A lack of evidence that bats are key reservoirs of human disease has not prevented their vilification or efforts to exterminate bat colonies where threats are presumed to lurk.
“The fact is that they provide important ecosystem services – insect control, pollination and seed dispersal, to name a few – and we want them around,” says Tony Goldberg, a University of Wisconsin-Madison epidemiologist and virus hunter. “But bats are also increasingly acknowledged as hosts of medically significant viruses. I have mixed feelings about that.”
To better understand the dynamics of bats and potential threats to human health, Goldberg and his colleagues explored the relationship of an African forest bat, a novel virus and a parasite. Their work, described in a report published July 13 in Nature Scientific Reports, identifies all three players as potentially new species, at least at the molecular level as determined by their genetic sequences.
Many viral pathogens often have more than one or two hosts or intermediate hosts needed to complete their life cycles. The role of bat parasites in maintaining chains of viral infection is little studied, and the new Wisconsin study serves up some intriguing insights into how viruses co-opt parasites to help do the dirty work of disease transmission.
The parasite in the current study is an eyeless, wingless fly, technically an ectoparasite. It depends on the bat to be both its eyes and wings. And it plays host to a virus, as the current study shows. For the virus, the fly plays the role of chauffeur. “From a virus’s perspective, an ectoparasite is like Uber. It’s a great way to get around – from animal to animal – at minimal expense and effort,” Goldberg explains.
The bat in the study belongs to the megabat suborder. It is a fruit bat and was trapped, tested and released by Goldberg’s colleague and study co-author Robert Kityo of Uganda’s Makerere University in Kampala.
The bat fly, according to the new study, was infected with a newly discovered rhabdovirus dubbed Kanyawara virus, a distant relative of the rabies virus. “These things were chock-full of the virus,” says Goldberg, a professor of pathobiological sciences at UW-Madison’s School of Veterinary Medicine. That said, he adds that “we don’t know if this virus is transmitted beyond the ectoparasite. We couldn’t find it in the bat. Maybe it is an insect virus.”
However, it is well known that ectoparasites transmit disease, says the Wisconsin epidemiologist, noting that things like ticks and fleas harbor important pathogens like typhus, bubonic plague, Lyme disease and Rocky Mountain spotted fever.
“Bat flies bite people if given the chance,” Goldberg says of the parasite, which he described as “shockingly large, leggy and fast – a parasite from hell.”
The report published this week notes that rare cases of human infection with bat-associated viruses remain enigmatic. The study cites the 1969 case of a British dockworker bitten by an unknown insect while unloading peanuts from Nigeria, and who was subsequently infected by Le Dantec virus, a relative of the virus Goldberg and his colleagues found in abundance in the bat flies they sampled. “Was the dockworker bitten by a bat fly? We’ll never know.”
The subtext of the research, according to Goldberg, is Ebola and the ecology of disease. Scientists are beginning to understand that serious pathogens like Ebola and SARS don’t come out of nowhere. They are already lurking in the environment, and the leap from an animal to a human can be just a matter of time and an organism’s ability to shift from one host to another.
“The big picture relevance of the research is that if we’re going to understand the diversity of viruses in the world, we need to look in unusual places,” Goldberg says. “We have a lot to learn about the basic distribution of species on the planet.”
By Terry Devitt, UW-Madison/ July 13, 2017
It’s no accident that researchers at the University of Wisconsin-Madison have taken a lead role addressing the Zika virus epidemic gripping the Americas. Many of them were already at work fighting viruses and mosquito-borne diseases in Central and South America.
David O’Connor, a pathology professor, first learned of babies born with severe birth defects from his HIV research collaborators in Brazil. Jorge Osorio, professor of pathobiological sciences, and Matt Aliota, a research scientist, were first to identify Zika virus circulating in Colombia.
Adding expertise in obstetrics, virology, radiology and public health from UW-Madison’s rare breadth of scientific expertise, the researchers are now working to screen mosquitoes for the ability to carry Zika virus and infect humans, and to use a harmless bacterium to block mosquito transmission of the virus. They are studying Zika infection in monkeys to describe the progression of infection and its dire consequences in pregnancy. And they’re sharing their findings with public health officials and scientists around the world to speed our path to the best vaccines, treatments and strategies to arrest Zika’s spread.
GHI provided core funding for a biosafety level 3 insect laboratory in the Robert P. Hanson Laboratories of the School of Veterinary Medicine that is essential to the Zika work. “Even though Zika had not yet emerged, GHI was aware of the threat of mosquito-borne viruses, due to related viruses such as dengue and chikungunya,” says GHI Associate Director of Research Tony Goldberg. “No one predicted the emergence of Zika virus in particular, but GHI predicted the need for state-of-the-art research facilities for new arthropod-borne diseases. Thanks to the research environment at UW-Madison and the contributions of campus units like GHI and the School of Veterinary Medicine, we were ready.”
GHI also helped fund a Colombian researcher working with the School of Veterinary Medicine.
UW-Madison/ July 28. 2016
A version of this story appeared first on the International Division website.
Global health was well represented when the International Division and the Institute for Regional and International Studies (IRIS) awarded incubator grants to six interdisciplinary research projects that blend place-based scientific inquiry with international expertise.
These projects focus on Africa, South Asia, Eurasia, and Latin America, in fields as diverse as public health, child development, civil engineering, climate science, archaeology, genetics, virology, and environmental studies.
Offered this year for the first time, the grants are aimed at bringing together faculty in STEM fields who are conducting place-based research abroad with experts from regional and area studies centers within IRIS.
“These grants are based on the idea that scientific inquiry will improve through collaboration with regional experts, while area specialists will benefit from working with colleagues in the physical, biological, and quantitative social sciences.”— Richard Keller, associate dean of the International Division.
Funding for these awards, of up to $50,000 each, comes from the Andrew W. Mellon Foundation and other International Division funds.
The six projects were selected by a committee of senior faculty from a range of disciplines from among proposals submitted by 18 teams of faculty and academic staff from across the UW–Madison campus. The proposals covered all continents except Antarctica.
The selected projects, with principal investigators and brief descriptions, are:
The 2013-15 Ebola Outbreak and Child Development: Measuring the Impact among Child Survivors and Peers, and Identifying Opportunities for Care (Maureen Durkin, Population Health Sciences; Claire Wendland, Anthropology. Both are members of the Global Health Institute (GHI) Advisory)
The Ebola epidemic of 2013-15 was the worst in recorded history, with repercussions likely for generations. Children especially are vulnerable to the effects of disaster and trauma, but the nature of these effects in the aftermath of the Ebola outbreak is unclear. The researchers intend to address the impacts of the epidemic on child development and wellbeing in Sierra Leone by generating knowledge that can be used to guide plans for clinical and community intervention. They intend to use the grant to gather preliminary information that will enable to them to pursue larger funding opportunities.
Exploring Miletus: Archaeology & Science at the Interface of Europe, Asia, and Africa (William Aylward, Classics; Caitlin Pepperell, Medical Microbiology and Immunology)
This project combines methodologies in archaeology, molecular biology and genetics to gain insight into historical human populations, specifically examining diet, demography and infectious disease. Miletus, an ancient city on the Aegean coast of southwestern Turkey, represents over 4,500 years of human settlement at the intersection of three continents. With the newly-opened ancient DNA (aDNA) and mass-spectrometry facilities in the UW–Madison Biotechnology Center (UWBC), as well as the expertise of the Molecular Archaeology Group, the researchers are able to recover preserved biomolecules, including DNA, proteins, and lipids, to reconstruct historical human environments.
Connecting Landscapes in the Greater Guadalajara Socio-Ecological Ecosystem: An International Studies Action Research Partnership for Sustainability (Constance Flanagan, School of Human Ecology; Paul Zedler, Nelson Institute for Environmental Studies)
The researchers have proposed an interdisciplinary partnership between UW–Madison and the University Guadalajara (UDG) to focus on environmental sustainability. This project will include planning joint activities with the new, interactive UDG-affiliated Museo de Ciencias Ambiental (MCA), and an action research effort to implement UW–Madison’s Earth Partnership Program (EP) in conjunction with MCA and in collaboration with the surrounding community.
Mapping Hot Spots: ‘One Health’ and the History of Infectious Disease Research in Uganda (Neil Kodesh, History; Tony Goldberg, School of Veterinary Medicine; Josh Garoon, Community and Environmental Sociology. Goldberg is a GHI associate director, )
This project aims to inaugurate an interdisciplinary program that bridges the biological sciences and history to address a variety of questions about certain countries and regions that have emerged as epicenters of poor health and “hot spots” for infectious diseases. The researchers intend to use the seed funding to establish a novel collaborative infrastructure at UW–Madison for exploring how science, history, and culture intersect in Sub-Saharan Africa to establish and perpetuate modern concepts of health, disease, and their ecological linkages.
This project – a partnership between UW–Madison and municipal leaders in Bahir Dar, Ethiopia – aims to bring design and planning knowledge of transportation systems to this rapidly growing regional capital. The goal is to increase the capacity for accommodating urban growth and mobility, while preserving safety and quality of life. The participants are seeking to position Bahir Dar as a leader for smart, healthy urbanization within the region and throughout Africa.
Poles apart? An Interdisciplinary Approach to Studying Climate Vulnerability in the Himalayas (Stephen Young, Geography; Tristan L’Ecuyer, Atmospheric and Oceanic Sciences; Anne Sophie Daloz, Atmospheric and Oceanic Sciences)
The main objective of this project is to examine the impact of climate change on the behavior of farmers in the Himalayas, while also attempting to understand the impact that migrant youth from the region have on household vulnerability. According to many reports, climate change will induce major transformations in the landscape over the next few decades. These biophysical changes will clearly interact with socio-economic processes that include changing rural livelihoods and land use strategies.
By Kerry G. Hill/ April 8, 2016
The Global Health Institute (GHI) will award up to $375,000 in Seed Grant funding to University of Wisconsin-Madison faculty and staff who are launching new global health research projects.
The Institute also will make almost $100,000 in awards to fund graduate research in global health, visiting scholars and global health travel grants.
The application deadline for all grants is 5 p.m. Monday, Jan. 12. Seed Grant applicants must also submit a letter of intent by 5 p.m. Monday, Dec. 1.