Mansonella spp.

• Mansonella ozzardi, also known as New World filaria, is considered non-pathogenic
• Microfilariae of Mansonella ozzardi:

  • Have a rounded, blunt anterior end and measure approximately 220 um
  • The posterior end is short
  • Contain numerous nuclei that do not extend to the tip of the long, narrow, and tapered tail
  • Do not have a sheath
  • Found in blood and do not exhibit any periodicity
• Diagnosis of Mansonella ozzardi:

  • Microfilariae are recovered in the peripheral blood
  • Nonperiodic, meaning there is no known optimum time for collecting a blood sample
  • Giemsa staining is necessary to identify the characteristic microfilariae
• Mansonella perstans Common name: Perstans filaria

  • nonpathogenic
• Mansonella perstans Microfilariae:

  •      Measures about 200 um in length.

  •      It does not have a sheath and the body is filled with nuclei that extend all the way to the tip of the tail

  •      The anterior or tail end is rounded and blunt
• Mansonella perstans Adult:

  •      Resides in peritoneal and pleural cavities as well as the mesentery