The Invasiveness of the Genus Sylvilagus in Massachusetts and the Resulting Increase in Human Allergen Sensitization to Rabbits
Monday, March 5, 2018
South Hall A2 (Convention Center)
Neal S Krishna, Vandana M. Krishna, MD FAAAAI, Ryan N Krishna, Sampath Krishna, PhD, MBA
RATIONALE: There has been a marked increase in the incidence of Eastern Cottontail rabbits (Sylvilagus floridanus) in Massachusetts. Patients in a community allergist’s office who were seen for rhinosinusitis symptoms had positive skin prick tests (SPT) to rabbit epithelia. Many reported encountering rabbits in their community without actual physical contact. We hypothesized that airborne exposure from rabbit proteins in close-quarters was likely causing sensitization. Rabbit species are difficult to control due to their high reproductive potential. In New England, due to their vigor and adaptability, S. floridanus has displaced S. transitionalis. Conservation measures are likely being applied (wrongly) to the invasive S. floridanus due their physical similarity with S. transitionalis.

METHODS: We reviewed 250 patient charts with positive SPT to rabbit epithelia. Patients were questioned on rabbit sightings around their neighborhood. Nearly all patients with positive rabbit skin test had noticed rabbits in their vicinity but denied physical contact.

RESULTS: The invasive S. floridanus outnumbers the native S. transitionalis. There is an increased incidence of positive SPT in children and adults. Cross-reactivity of rabbit epithelia to cats were considered and discarded as not all patients had SPT reactivity to cats, dogs, or rodents.

CONCLUSIONS: We hypothesize that the increasing level of positive SPT results is from airborne exposure to rabbit proteins from increasing S. floridanus population. Besides allergic rhinosinusitis symptoms, rabbits are also known to spread other vector-borne diseases such as the tularemia outbreak in Martha’s Vineyard in 2000. Identifying and controlling the rabbit populations are necessary to curtail further spread of such diseases.