Pediculus humanus and Phthirus pubis

1
Pediculus humanus and Phthirus pubis

• body and pubic crab lice

2

• Lice are cosmopolitan parasites of humans,
  occurring in all areas of the world and in all
  socio-economic classes.  The body louse will
  serve as the vector for epidemic typhus (caused
  by Rickettsia prowazekii), trench fever (caused
  by Rochalimaea quintana, a rickettsia), and
  relapsing fever (caused by a spirochete, Borrelia
  recurrentis).  Severe epidemics of these diseases
  have occurred throughout history, particularly
  during wars.

3

• Lice are spread from human to human most often by
  direct contact or contact with contaminated
  clothing, etc.  Body lice are restricted most
  often to the human body and head (some
  authorities believe the head louse is a separate
  species).  Crab lice are most often restricted to
  the pubic region, but may spread to the armpits,
  facial hair (beard, etc.), eyebrows, and
  eyelashes.  Infestations with lice are not a
  serious problem (as long as the lice are not
  infected with a disease), but they can cause a
  number of uncomfortable symptoms, including skin
  irritations and intense itching.

4

• Pediculus humanus, the human body louse
  (approximate length 2 mm).

5

• A crab louse attached to a hair. 

6

• A "nit" or egg of Pediculus humanus.