       Document 0234
 DOCN  M9640234
 TI    Cryptosporidium parvum: intensity of infection and oocyst excretion
       patterns in healthy volunteers.
 DT    9604
 AU    Chappell CL; Okhuysen PC; Sterling CR; DuPont HL; Center for Infectious
       Diseases, University of Texas School of; Public Health, Houston 77030,
       USA.
 SO    J Infect Dis. 1996 Jan;173(1):232-6. Unique Identifier : AIDSLINE
       MED/96132487
 AB    Data about human Cryptosporidium parvum infection have originated from
       travelers, community and day care center outbreaks, and persons infected
       with the human immunodeficiency virus. In addition, experimental
       infection in 29 antibody-negative, healthy, adult volunteers generated
       information on the dose-infection response of C. parvum (Iowa strain).
       In that report, low inocula were sufficient to cause infection in 18 and
       illness in 7 persons. To further define the duration and intensity of
       infection in this population, oocyst shedding patterns were investigated
       in the 18 subjects infected with C. parvum. Oocyst quantitation revealed
       that volunteers with diarrheal illness (n = 7) excreted more oocysts
       over the course of the infection than did volunteers without diarrhea (n
       = 11; P < .05). Symptomatic subjects were more likely to shed oocysts on
       consecutive days. Further, a statistical nonsignificant inverse trend
       (r2 = .330, P = .136) was seen between challenge dose and total excreted
       oocysts. This paradox may relate to receptor saturation or a toxic
       effect on cells, parasites, or both afforded by a high inoculum.
 DE    Animal  Cryptosporidiosis/*PARASITOLOGY/TRANSMISSION  Cryptosporidium
       parvum/ISOLATION & PURIF/*PATHOGENICITY  Diarrhea/PARASITOLOGY  Disease
       Susceptibility  Feces/PARASITOLOGY  Human  Parasite Egg Count  Support,
       Non-U.S. Gov't  Support, U.S. Gov't, Non-P.H.S.  Support, U.S. Gov't,
       P.H.S.  Travel  JOURNAL ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).

