title: Immunosuppressive effect of Cryptosporidium baileyi infection on vaccination against Newcastle disease in chicks.
abstract: Hemagglutination-inhibition titers (log2) to Newcastle disease (ND) virus were chronologically observed in chicks, which were orally inoculated with 5 x 10(5) oocysts of Cryptosporidium baileyi at 2 days of age and subsequently vaccinated with inactivated ND virus at 4 and 21 days postinoculation. In general, the titers were considerably lower in the infected chicks than those in the uninfected control throughout the experimental period (p < 0.01), and rapid negative seroconversions were observed in the infected chicks. The titers reached a peak on weeks 2 and 4 post-booster-vaccination in the control and infected chicks, respectively. Thus, C. baileyi infection was shown to have an immunosuppressive effect on ND vaccination when the agent was given to 2-day-old chicks. It is suggested that C. baileyi infection in chicks may increase the host susceptibility to ND virus.
authors.affiliation: Bio-Safety Research Institute, Chonbuk National University, Chonju, Korea.
authors.forename: J K
authors.initials: JK
authors.lastname: Rhee
authors.forename: H C
authors.initials: HC
authors.lastname: Kim
authors.forename: S B
authors.initials: SB
authors.lastname: Lee
authors.forename: S Y
authors.initials: SY
authors.lastname: Yook
mesh_terms: D000818:Animals; D002645:Chickens; D003457:Cryptosporidiosis / Q000276:immunology*; D003458:Cryptosporidium / Q000276:immunology*; D006385:Hemagglutination Inhibition Tests; D007165:Immunosuppression Therapy; D008297:Male; D009521:Newcastle Disease / Q000276:immunology*; D009522:Newcastle disease virus / Q000276:immunology*; D014765:Viral Vaccines / Q000276:immunology*
chemical_list: D014765:Viral Vaccines