Ziekteverwekker
Malessezia are a group of yeast species that are often part of the normal skin fauna in a range of bird and animals species including humans. In healthy individuals, the yeast live from the oily substances on the surface of the skin without causing disease; this balance can be disturbed by, for example, another illness that challenges the immune system of the host animal, or changes to the condition of the skin (increased warmth or moisture), and can result in skin (dermatitis and ear (otitis) disease.
Gevoelige diersoorten
Whilst in recent years several new species of Malassezia have been identified that appear to show a degree of host species-specificity or host adaptation, the best characterised species are M. furfur and M. sympodialis which typically cause disease in humans, and M. pachydermatis that is found on the skin of a wide range of animal species.
There are very few reports of Malassezia-associated disease or identification or this organism in non-captive wildlife species. Malassezia spp. yeast were seen in the skin ulcer of a European badger submitted for post-mortem investigation at the DWHC in 2013.
Symptomen dieren
When yeast proliferate and invade deeper layers of the skin, the skin can become irritated. Whilst in extreme cases the whole body can be affected, typical sites for Malassezia dermatitis include folds in the skin (armpits, groins, between the digits), under the tail and in and around the ears. Affected skin may become reddened and flaky and may be covered with a smelly, greasy substance that mats the hair. The lesions can be itchy and in long-standing cases the skin can become pigmented and thickened.
Besmetting dieren
Malassezia is not thought to be contagious. Development of disease is typically the result of overgrowth of the resident yeast population and therefore reflects the health status and environment of individuals.
Symptomen mens
Malassezia can be associated with a range of skin conditions in humans including dandruff (flaky scalp) and seborrhoeic dermatitis.
In immune-compromised individuals, in particular premature babies, it may cause very serious systemic disease.
Besmetting mensen
As with other species, Malassezia skin disease tends to develop as a result of overgrowth of the yeast already present on an individuals skin.
It is not clear as to whether contact with infected animals poses a significant zoonotic threat to immune-compromised patients.
Sources
Morris, D. O., O’Shea, K., Shofer, F. S., & Rankin, S. (2005). Malassezia pachydermatis carriage in dog owners. Emerging infectious diseases, 11(1), 83.
Velegraki, A., Cafarchia, C., Gaitanis, G., Iatta, R., & Boekhout, T. (2015). Malassezia infections in humans and animals: pathophysiology, detection, and treatment. PLoS pathogens, 11(1), e1004523.
Zia, M., Mirhendi, H., & Toghyani, M. (2015). Detection and identification of Malassezia species in domestic animals and aquatic birds by PCR-RFLP. Iranian Journal of Veterinary Research, 16(1), 36.