Jl. Molinari et al., IMMUNIZATION AGAINST PORCINE CYSTICERCOSIS IN AN ENDEMIC AREA IN MEXICO - A FIELD AND LABORATORY STUDY, The American journal of tropical medicine and hygiene, 49(4), 1993, pp. 502-512
Citations number
31
Categorie Soggetti
Public, Environmental & Occupation Heath","Tropical Medicine
An antigenic extract from Taenia solium metacestodes was evaluated for
immunogenicity in pig populations from a large area of endemic porcin
e cysticercosis in the State of Guerrero, Mexico. A total of 3,295 pig
s from 18 villages were immunized with a single dose of 250 mug of pro
tein administered intramuscularly. Systematic immunization was also pe
rformed on pigs (1,076 immunizations) from two of the villages with th
e highest percentages of cysticercosis. A year after immunization, por
cine cysticercosis decreased from 4.8% and 5.4% to 0%. Immunity agains
t the T. solium metacestode was estimated in vitro by measurements of
H-3-thymidine uptake and inhibition of leukocyte migration. Peripheral
blood lymphocytes from immunized cysticercotic (pigs that had cystice
rcosis prior to immunization), cysticercotic immunized (pigs that acqu
ired cysticercosis after immunization), and normal control pigs incorp
orated H-3-thymidine better than lymphocytes from cysticercotic pigs w
hen stimulated with concanavalin A. A significant inhibition in the le
ukocyte migration inhibition test was also found in leukocytes from im
munized cysticercotic pigs (P < 0.01). Histopathologic studies reveale
d granuloma formation surrounding the metacestodes of the immunized cy
sticercotic and cysticercotic immunized pigs. These metacestodes exhib
ited several stages of destruction. Large numbers of eosinophils were
frequently observed in a close association with the degeneration and d
estruction of parasites. Metacestodes in control cysticercotic pigs we
re intact and surrounded by a minor inflammatory reaction. Finally, th
e rate of in vitro evagination of scolices was high in metacestodes ob
tained from cysticercotic pigs and low or absent in those from immuniz
ed pigs (P < 0.01).