Detection of dengue virus neutralizing antibodies in bats from Costa Rica and Ecuador.

Neutralizing antibodies for dengue virus serotypes 1 and 2 and serotypes 2 and 3 were detected in 1998 in 12 of 53 (22.6%) and 3 of 10 (30.0%) bats sampled in Costa Rica and Ecuador, respectively. Dengue is a consistent health problem in the two Costa Rican communities in which bats were sampled. The high percentage of bats with neutralizing antibodies to dengue virus in these two Costa Rican communities suggests that bats may become infected with dengue virus. This appears to be the case in Costa Rica and Ecuador.