EVALUATION OF THE NEUTRALIZING ABILITY OF 4 COMMERCIALLY AVAILABLE ANTIVENOMS AGAINST THE VENOM OF BOTHROPS-ASPER FROM COSTA-RICA

We studied the ability of four commercially available antivenoms to ne utralize several toxic and enzymatic activities of Bothrops asper (ter ciopelo) venom from Costa Rica. Experiments with preincubation of veno m and antivenom were carried out to test the neutralization of lethal, hemorrhagic, coagulant and indirect hemolytic activities. In addition , antibody titers against crude venom and myotoxin II purified from th is venom were determined by enzyme immunoassay (ELISA). Results indica te that polyvalent antivenom from Institute Clodomiro Picado (Costa Ri ca) has the highest neutralizing ability against lethal, coagulant and indirect hemolytic activities, whereas MYN polyvalent antivenom (Mexi co) has the highest neutralization against hemorrhagic activity. Antiv enom from Instituto Clodomiro Picado also has the highest antibody tit ers against crude B. asper venom and against myotoxin II. Antivenoms f rom Universidad Central de Venezuela (Venezuela), Vencofarma (Brazil) and MYN (Mexico) failed to neutralize the lethal effect of this venom. These results stress the need for rigorous quality control systems to evaluate the neutralizing ability of antivenoms in Central America.