Mansonella streptocerca (continued)
Figure 4-35. Life cycle of Mansonella streptocerca. (concluded)
ORGANISM 7: Onchocerca volvulus
GENERAL CHARACTERISTICS
COMMON NAME: Blinding filariasis, river blindness.
GEOGRAPHICAL DISTRIBUTION: Central and northern South America and Africa.
PATHOGENESIS: Cutaneous nodules, ocular lesions, pectoral pain, blindness.
HABITAT: Cutaneous and subcutaneous tissues.
VECTOR: Simulium species.
RESERVOIR HOST: None.
INFECTIVE FORM: Filariform larva.
MODE OF INFECTION: Inoculation.
PERIODICITY: None.
SPECIMEN OF CHOICE: Tissue biopsies.
SPECIMEN PROCESSING: Giemsa's or Hematoxylin/Eosin stains.
MICROFILARIA
SIZE: 220 to 260 mcm.
SHEATH: Absent.
TAIL: Blunt and slightly curved.
TERMINAL NUCLEI: Do not extend to the tip of the tail.
MD0842
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