Volume 36, Issue 1
  • ISSN: 0002-9637
  • E-ISSN: 1476-1645



The course of infection with in gerbils was studied after oral inoculation with either cysts isolated from humans or cultured trophozoites. Primary infections occurred in 87% of exposed gerbils; cyst release peaked during the second and third weeks post-infection; cysts and trophozoites were observed for up to 49 and 87 days post-infection, respectively. Gerbils were refractory to challenge infection with infective human source cysts at 5 months post-infection. Overall, 50% of animals given subcutaneous injections of hydrocortisone acetate, during or following the late stages of their primary infection, showed recrudescence of infection as evidenced by passage of cysts; percentages showing recrudescence were: 80% at 50 days post-infection, 55% at 70 days post-infection, 27% at 7 months post-infection, and 50% (2 of 4) in gerbils challenged unsuccessfully at 5 months post-infection and subsequently injected with hydrocortisone acetate at 7 months post-infection. Both infected animals and uninfected controls injected with hydrocortisone acetate were immunocompromised as evidenced by significantly reduced plaque forming cell responses to sheep red blood cells. We conclude that infections with in gerbils can last longer than standard examinations for cysts would indicate, and that long-term immunity to this organism can be nonsterile.


Article metrics loading...

The graphs shown below represent data from March 2017
Loading full text...

Full text loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error