ABSTRACT
BACKGROUND: Neurocysticercosis (NCC) is the infection of the human central nervous system (CNS) by Taenia solium larvae that cause significant neurological morbidity. Studies on NCC pathophysiology, host-parasite interactions or therapeutic agents are limited by the lack of suitable animal models. We have previously reported that carotid injection of activated T. solium oncospheres directs parasites into the CNS and consistently reproduces NCC. This study assessed the minimal dose required to consistently obtain NCC by intracarotid oncosphere injection and compared antigen and antibody response profiles by dose-group. METHODS/PRINCIPAL FINDINGS: Three groups of pigs were infected with either 2500 (n = 10), 5000 (n = 11), or 10000 (n = 10) oncospheres. Two pigs died during the study. Necropsy exam at day 150 post-infection (PI) demonstrated viable NCC in 21/29 pigs (72.4%), with higher NCC rates with increasing oncosphere doses (4/9 [44.4%], 9/11 [81.8%] and 8/9 [88.9%] for 2500, 5000, and 10000 oncospheres respectively, P for trend = 0.035). CNS cyst burden was also higher in pigs with increasing doses (P for trend = 0.008). Viable and degenerated muscle cysticerci were also found in all pigs, with degenerated cysticerci more frequent in the 2500 oncosphere dose-group. All pigs were positive for circulating parasite antigens on ELISA (Ag-ELISA) from day 14 PI; circulating antigens markedly increased at day 30 PI and remained high with plateau levels in pigs infected with either 5000 or 10000 oncospheres, but not in pigs infected with 2500 oncospheres. Specific antibodies appeared at day 30 PI and were not different between dose-groups. CONCLUSION/SIGNIFICANCE: Intracarotid injection of 5000 or more oncospheres produces high NCC rates in pigs with CNS cyst burdens like those usually found in human NCC, making this model appropriate for studies on the pathogenesis of NCC and the effects of antiparasitic treatment.
Subject(s)
Central Nervous System Cysts , Neurocysticercosis , Swine Diseases , Taenia solium , Animals , Cysticercus , Neurocysticercosis/drug therapy , Swine , Swine Diseases/parasitologyABSTRACT
The efficacy of two locally produced oxfendazole (OFZ) formulations against cysticercosis at 22,5% and 10%, versus a commercial formulation (Synanthic 9,06%) was evaluated in twenty-two naturally infected pigs that received a single oral dose of 30 mg/kg. Pigs were sacrificed at eight weeks post-treatment to evaluate the cysts found in their carcasses, and to determine the cysticidal efficacy, which was defined as the proportion of degenerated cysts over total cysts. Only degenerated cysts were found in muscle, heart, and tongue of pigs treated with OFZ in all groups, which shows an efficacy of 100%. Viable and degenerated cysts were found in brains, being the efficacy lower in all groups (65% [commercial OFZ], 47% [local OFZ 22.5%] and 31% [local OFZ 10%], p = 0.355). Locally produced OFZ formulations were similarly effective to the commercial formulation and may provide a practical alternative for the treatment of porcine cysticercosis.
Se evaluó la eficacia de dos formulaciones de oxfendazol (OFZ) contra cisticercosis producidas localmente, al 22,5% y 10% en comparación con una formulación comercial (Synanthic 9,06%) en 22 cerdos naturalmente infectados, que recibieron una dosis oral de 30 mg/kg. Los cerdos fueron sacrificados a las ocho semanas postratamiento para evaluar quistes en en sus carcasas, y se determinó la eficacia cisticida a través de la proporción de quistes degenerados sobre el total. Solo se encontraron quistes degenerados en la musculatura, corazón y lengua de los cerdos tratados con OFZ en todos los grupos, lo cual muestra una eficacia del 100%. En los cerebros se encontraron quistes viables y degenerados, con una eficacia menor en todos los grupos (65% [OFZ comercial], 47% [OFZ local 22,5%] y 31% [OFZ local 10%], p = 0,355. Las formulaciones de OFZ producidas localmente fueron igual de efectivas que la formulación comercial y pueden proporcionar una alternativa para el tratamiento de la cisticercosis porcina.