NR AVRC
AU Lupi,O.
TI Myiasis as a risk factor for prion diseases in humans
QU Journal of the European Academy of Dermatology and Venereology 2006 Oct; 20(9): 1037-45
PT journal article; review
AB Prion diseases are transmissible spongiform encephalopathies of humans and animals. The oral route is clearly associated with some prion diseases, according to the dissemination of bovine spongiform encephalopathy (BSE or mad cow disease) in cattle and kuru in humans. However, other prion diseases such as scrapie (in sheep) and chronic wasting disease (CWD) (in cervids) cannot be explained in this way and are probably more associated with a pattern of horizontal transmission in both domestic and wild animals. The skin and mucous membranes are a potential target for prion infections because keratinocytes and lymphocytes are susceptible to the abnormal infective isoform of the prion protein. Iatrogenic transmission of Creutzfeldt-Jakob disease (CJD) was also recognized after corneal transplants in humans and scrapie was successfully transmitted to mice after ocular instillation of infected brain tissue, confirming that these new routes could also be important in prion infections. Some ectoparasites have been proven to harbour prion rods in laboratory experiments. Prion rods were identified in both fly larvae and pupae; adult flies are also able to express prion proteins. The most common causes of myiasis in cattle and sheep, closely related animals with previous prion infections, are Hypoderma bovis and Oestrus ovis, respectively. Both species of flies present a life cycle very different from human myiasis, as they have a long contact with neurological structures, such as spinal canal and epidural fat, which are potentially rich in prion rods. Ophthalmomyiases in humans is commonly caused by both species of fly larvae worldwide, providing almost direct contact with the central nervous system (CNS). The high expression of the prion protein on the skin and mucosa and the severity of the inflammatory response to the larvae could readily increase the efficiency of transmission of prions in both animals and humans.
IN Die Maden der Großen Rinderdasselfliege (Hypoderma bovis) entwickeln sich im Fettgewebe von Brust- und Lendenwirbelsäule. Die Maden der Schafbremse (Oestrus ovis) wachsen in den Nasenschleimhäuten von Schafen heran. Der Autor meint, dass diese andere Dasselfliegen zur Verbreitung von TSE beitragen könnten, weil sie sich in engem Kontakt zu neuronalem Gewebe ihrer Wirte entwickeln. Dasselfliegen bevorzugen bestimmte Wirte, nehmen gelegentlich aber auch ganz andere Wirte an und könnten so eventuell Übertratungen über Speziesgenzen hinweg bewirken.
ZR 99
MH Animals; Humans; Myiasis/*complications; Prion Diseases/*etiology; Risk Factors
AD Department of Medical Clinics (Dermatology), Universidade Federal do Rio de Janeiro and Dermatology Section, Instituto de Dermatologia Prof. Rubem Azulay, Santa Casa da Misericordia do Rio de Janeiro, Rio de Janeiro/RJ, Brazil. omarlupi@globo.com
SP englisch
PO Niederlande