Sustaining Transmission in Different Host Species: The Emblematic Case ofSarcoptes scabiei

Abstract

Some pathogens sustain transmission in multiple different host species, but how this epidemiologically important feat is achieved remains enigmatic. Sarcoptes scabiei is among the most host generalist and successful of mammalian parasites. We synthesize pathogen and host traits that mediate sustained transmission and present cases illustrating three transmission mechanisms (direct, indirect, and combined). The pathogen traits that explain the success of S. scabiei include immune response modulation, on-host movement capacity, off-host seeking behaviors, and environmental persistence. Sociality and host density appear to be key for hosts in which direct transmission dominates, whereas in solitary hosts, the use of shared environments is important for indirect transmission. In social den-using species, combined direct and indirect transmission appears likely. Empirical research rarely considers the mechanisms enabling S. scabiei to become endemic in host species—more often focusing on outbreaks. Our review may illuminate parasites’ adaptation strategies to sustain transmission through varied mechanisms across host species.

Sarcoptic Mange is an Emerging Threat to Biodiversity in the Qinling Mountains in China

“…Interestingly, prey-to-predator scabies transmission among wild animals has been proven (Francis et al, 2011). According to these reports, host susceptibility, host traits and adaptation strategies of scabies play key roles in cross-species transmission (Browne et al, 2022;Niedringhaus,Brown, & Sweeley et al, 2019).…”

Pathophysiological and Pharmaceutical Considerations for Enhancing the Control of Sarcoptes scabiei in Wombats Through Improved Transdermal Drug Delivery

“…Sarcoptic mange is the most impactful disease of the bare-nosed wombat ( Vombatus ursinus ). This fossorial marsupial has a largely solitary lifestyle, and exposure to S. scabiei is generally thought to occur via environmental transmission ( 6 ). Bare-nosed wombats shift burrows every 4–10 days and, thus, share burrows asynchronously ( 16 ).…”

“…100 million cases, remains among the 30 most prevalent infections of humans, and was recently recognized as a Neglected Tropical Disease by the World Health Organization ( 4 , 5 ). Evidence suggests that the global distribution of S. scabiei is associated with European colonialism (both people and their domestic animals), leading to numerous spill over and pathogen establishment events ( 3 , 6 , 7 ).…”

Characterising a sarcoptic mange epizootic in quenda (Isoodon fusciventer)

“…Whilst quenda also presented with disease in ventral areas of thin, soft skin, the posterior region was most consistently affected by sarcoptic mange. Direct contact between quenda can occur through mating and fighting and indirect contact can occur through rubbing or scratching on fomites, which are all activities that may result in S. scabiei contacting the posterior region of an animal ( Browne et al, 2022 ). Fomites may include rocks or tree trunks or the soil within dens or burrows that have been created by reservoir species such as foxes or rabbits, and have been established as a potential transmission source for S. scabiei in wombats ( Browne et al, 2021 ; Skerratt et al, 1998 ).…”

“…Adult quenda may be more susceptible to sarcoptic mange than pouched joeys and juveniles due to an increased risk of exposure to S. scabiei through contact with other quenda and fomites within their home range ( Browne et al 2022 ). Adults also have greater exposure to environmental stressors, which may result in compromised immunity and greater susceptibility to disease ( Bradley and Altizer, 2007 ).…”