Scabies  This is caused by mites of the Sarcoptes family  Each mammalian species has its own species of mite, but these mites may reside temporally on an animal or human that is not its typical host. Side-note: Notoedres cati, the causative agent of head scabies in cats, occasionally causes a transient dermatitis in humans.

Scabies in Humans  Sarcoptes scabiei is the species-specific agent which affects humans.  Clinical symptoms result from the 2-3 cm long tunnels the mite burrows in the skin. They include: Intense itching of the hands, elbows, axilla or torso.  Outbreaks of human scabies usually occur in nursing homes among the old, debilitated and the immunocompromised.

Scabies in Humans  Disease caused by mites of animal origin is usually less severe, much more rare.  Despite the tendency during an outbreak of scabies to blame animal contact for the infection. Disease caused by animal species are unable of sustaining an epidemic in humans. The more mild symptoms caused by species which affect animals may be due to the inability of the mite to reproduce in a heterologous host.

Transmission of Scabies  The mite is transmitted by intimate contact and by contaminated objects.  Possible vehicles include clothing of man, towels, bedclothes, animal bedding, and horse blankets.  Various Sarcoptes spp. have been transmitted to man from horses, dogs, cattle, sheep, goats, pigs, camels, and zoo animals.  Prevention and control of zoonotic scabies is based upon treating affected animals with Lindane or some other effective compound.  But... Most scabies is strictly of human origin.

Lice A part of our culture. Going through something “with a fine-toothed comb” “Nit picking”

Lice: Dispelling the Myths  People associate all ectoparasites with animals, and are eager to blame animals when humans become infested by lice!! Head lice are not vectors for more serious diseases.  In reality, the three types of human lice (body, pubic and head) are very specifically adapted to people, and animals do not play a role in their epidemiology. Studies have shown that the family dog or cat is not important in perpetuating the infestation or transmission of lice to humans.  Often the occurrence of an outbreak of head lice represents an convenient excuse for people to dispose of unwanted pets.

Lice in Humans  Infestations of head lice are the most common type of lice infestation in the USA. Head lice are most common in children (adults rarely infested). Human children are by far the most important reservoir and source of infestation.  Human pubic lice are spread by sexual contact.  Body lice are very rare in the USA.

Cutaneous Anthrax  Industrial Setting Contact with imported wool, goat hairs, skins, other animal products. Bongo drums from Haiti – goat skins.  Agricultural setting Midwestern floods bring up spores to cause sporadic cases. People infected from direct contact with infected live animals.

Cutaneus Anthrax (continued)  No man-to-man transmission  Most U.S. cases are cutaneous anthrax  Painless puritic vesicle progresses to black eschar.  If spores inhaled – inhalation anthrax.

Ocular larval migrans – retinal lesion from migration