It’s a small world after all, at least for the hundreds of diseases known to be transmitted between humans and animals. Often, it takes both experts in a particular type of pathogen and researchers who compare the global pathogenic patterns of a number of species to thwart the spread of individual diseases. Salvatore Frasca Jr., professor in the Department of Pathobiology and Veterinary Science, is a mix of both.
Frasca conducts research characterizing pathogens in a broad swath of aquatic, mostly non-mammalian hosts, collaborating with a number of other researchers within and outside the University. Frasca also works in the state’s veterinary diagnostic laboratory, the Connecticut Veterinary Medical Diagnostic Laboratory, or CVMDL, which is housed in the Department of Pathobiology and Veterinary Science, and teaches undergraduate and graduate courses in pathobiology.
Throughout his research, collaboration, diagnostic service and teaching, Frasca has been a champion of a concept known in medicine as One Health, the idea that the health of humans, the health of animals and the health of the environment are all inextricably linked. Frasca calls the particular approach he promotes One Pathology. To Frasca, One Pathology means identifying, comparing and contrasting pathogenic patterns across species lines. One example: The features of certain fungal infections in cold-stunned sea turtles, Frasca says, look a lot like those in immunocompromised humans.
Frasca is a veterinary pathologist, with a BA in biology and society from Cornell University, a VMD (doctor of veterinary medicine) from the University of Pennsylvania, a PhD in pathobiology from UConn and board certification in veterinary anatomic pathology from the American College of Veterinary Pathologists. Frasca is impeccably qualified for his job, but he wasn’t always sure he would grow up to be an academic.
After receiving his bachelor’s, Frasca attended veterinary school to pursue what he thought would be a practical career as a veterinarian. He soon grew weary of the prospect of traditional veterinary practice, and began to work for Mystic Aquarium as an associate under the aquarium’s veterinarian, J. Lawrence Dunn. There, he and Dunn obtained the first grant to fund Mystic Aquarium’s internship program in aquatic animal medicine and soon after, Frasca was selected to be the first Mystic intern in aquatic animal medicine. Shortly after that, he connected with Herbert J. Van Kruiningen, a professor and pathologist in the Department of Pathobiology and Veterinary Science from 1966 to 2009. Frasca became a resident in veterinary anatomic pathology and PhD student in the Department’s graduate program, stayed on as a postdoctoral fellow and was hired as an assistant professor in 1999.
Frasca says that it was in the department that he found a passion for comparative pathology and the One Health, One Pathology, perspective. “It’s always been about, how can we compare pathology along species lines? How does human pathology compare to the pathology of different animals? Comparing and contrasting the pathologies is what we believe to be the height of insightful. That’s what drew me to this department and that’s what I hope (through my interests and my work) I continue to contribute to.”
Frasca’s most recent contribution was a study published with six other researchers in early July of this year that investigated a viral infection called phocine distemper virus (PDV) in harbor seals. They found that when harbor seal immune cells were exposed to a man-made chemical compound known as Aroclor 1260 ( produced largely from 1929 to 1979), they became more susceptible to PDV. Frasca’s recent study is just one among several that points out how humans can have a major impact on animals’ health. Another interesting connection Frasca mentions: PDV is a member of the same family of viruses, the morbilliviruses, as is the measles virus. Many morbilliviruses have been shown capable of spreading between different species, often with fatal consequences, and to have worldwide health impacts. It’s viruses like the morbilliviruses that Frasca believes to be highly relevant to a One Pathology approach.
Also highly relevant to One Pathology is the work veterinary pathologists do with emerging and zoonotic diseases, that is, those that are newly seen in populations and that get transmitted between different species. In Frasca’s case this has come as a pathologist working with international animal conservancy groups. Frasca says that veterinary pathologists can play an important role assisting in the treatment and management of rescued animals by helping to identify and characterize disease in captive populations. Frasca recounts an incident in 2007, when 105 Sulawesi tortoises were illegally captured and imported to the United States. The endangered tortoises, which live on the island of Sulawesi in the Indonesian archipelago, were confiscated by the US Fish and Wildlife Service when they arrived at Los Angeles International Airport. Frasca was part of the team of biologists and veterinarians that analyzed their pathology, discovering, among other things, a systemic infection from a new type of siadenovirus, a genus that had never before been seen in reptiles.
Captured animals often endure overcrowding, unsafe transportation and unhealthy storage, which can cause severe immune compromise and make them particularly susceptible to disease. In fact, captured animals are at risk for so many potential infections that it’s not always possible to narrow down where their disease came from. That’s the case with the Sulawesi siadenovirus. Frasca says it’s unclear whether this previously unrecognized virus came from a turtle species the tortoises were housed with, was a virus already native to the population, or was from another source entirely.
As a teacher, Frasca strives to instill the importance for One Pathology in his students. Frasca says that, more than ever, students are now choosing to pursue many different professions–dentists, medical practitioners, veterinarians, lab technicians, physician’s assistants, pathologist’s assistants–and he wants their pathobiological education to reflect this trend. That means providing a One Pathology perspective that can be relevant to any number of pathology and medical careers. Frasca says that if his students can make even one connection between an animal and human disease in their career, he will have been successful.
Frasca’s commitment to giving his students relevant and extensive education goes hand in with his enthusiasm for teaching. Take the capstone course of the department’s pathobiology major, Principles of Pathobiology. Students know the course as PVS 4300. But Frasca, who teaches the course, sees it differently: “I feel like I’m Steven Tyler going on tour. I get up for that course. It’s my gig.”
Frasca says that his research will continue in the direction of globally relevant infectious diseases. That means emerging zoonotic diseases, diseases that are high-risk to endangered populations of animals and diseases that affect immunocompromised animal and human hosts. While it’s society that ultimately determines whether a disease is globally relevant, it’s veterinary pathologists like Frasca who will continue to study them under an umbrella of One Health, and One Pathology, that enrich our understanding of both animal and human disease.
By Michael Clausen