Studying the Dermal Immune Environment in Progressive Canine Leishmaniosis and its Influence on Transmissibility
Canine Leishmaniosis (CanL) is a fatal disease in dogs. Additionally, Leishmania infantum, the causative agent, is zoonotic – capable of moving from infected dogs to humans through a sand fly vector. The skin of infected dogs is a significant deposit for L. infantum parasites and the site of interactions between the local immune response, the parasites, and feeding sand fly vectors. Understanding how progressive infection alters both the skin environment and transmission of Leishmania is critical to develop transmission-blocking interventions that prevent further infection of both dogs and humans.
In dogs infected with L. infantum, the systemic immune response plays a central role in the progression of clinical disease. These findings brought up questions about the dermal immune environment and the effects on transmissibility to feeding sand fly vectors. In this project, we investigate:
- When during disease progression, and by what inflammatory mechanisms, is Leishmania transmission to sand flies augmented?
- How do immune/inflammatory changes over the course of Leishmania infection modify the immune modulatory action of sand fly salivary proteins?
- Can manipulation of host skin inflammation alter host infectiousness to sand flies at different stages of disease?
The results of this work will provide valuable, foundational information on the sand fly-skin-parasite immune interface, an interaction that influences parasite transmission from skin to feeding sand flies. Additionally, this work will give valuable insight into how pro-inflammatory and anti-inflammatory signaling acts in skin after sand fly bites to impact both the skin immune environment and transmission to sand flies. Characterizing host factors that influence parasite transmission will enable identification of novel strategies to block L. infantum transmission from host skin to feeding sand flies.
Do pets put owners at risk for Lyme disease? Or do pets improve their owners tick prevention habits?
UW-Madison researchers have two online research studies on tick prevention now open to participants, including a new study specifically for pet owners.
The Tick App is an interactive mobile phone study where users can share their daily outdoor activities, explain tick prevention methods, and report tick encounters. Additionally, if users find a tick, they can submit a picture of the tick through the app for identification. Already this spring 69 Tick App users have reported tick encounters, and sent pictures s through the Tick App have. All of the ticks submitted so far have been adult black-legged ticks (Ixodes scapularis). These ticks are better known as deer ticks, and are responsible for many tick-borne diseases in Wisconsin, including Lyme disease. More than half of the ticks we’ve seen thus far came from a dog or cat, and about half of those were attached to a dog or cat, and the other half were crawling in the fur. These crawling ticks could go on to bite the pet or a household members.
In general, dog and cat owners are 1.5-2 times more likely to find a tick crawling on themselves than individuals who don’t have pets (Jones et al. 2018). People living with pets were also 1.5 times more likely to find a tick attached to themselves. This suggests that pet owners are at greater risk for tick-borne diseases. However, despite numerous studies, no link has been established between pet ownership and getting a tick-borne disease. This could be because we need more studies and information, or pet owners may be better at noticing ticks and preventing bites because they are carefully looking after their pets!
Researchers at UW-Madison have been using the Tick App to understand human and tick interactions since 2017. Over 50% of Tick App users thus far had pets, and they were more likely to use tick prevention methods. Because of that, this year the Tick App has launched an online spin-off study for pet owners to better understand the role of pets in tick prevention. Participants are asked to complete two, online 5 to 10-minute surveys: the first upon enrollment, and the second later this summer. Each survey asks about participants’ pets and veterinarian visits, and also asks participants to share their attitudes, knowledge, and behaviors around ticks. This information will help us determine whether acquiring a pet changes owners tick prevention habits.
To participate in this study, pet owners must be at least 18 years old, and own a dog or a cat. Pet owners can enroll for the pet study through http://bit.ly/PetsAndTicks. The Tick App can be downloaded in Google Play and the AppStore. Our website, www.thetickapp.org, provides flyers and more information for the app and the pet study. For questions about the pet study, please contact tickteam@wisc.edu, and for question about the Tick App please contact tickapp@wisc.edu.
