The recent article by Belle and associates entitled “Epidemiological Investigation for Arboviruses in Jamaica, West Indies” includes a prominent statement that dengue type 4 was isolated from the sera of patients during epidemics in Jamaica in 1963 and 1968. This assertion is startling since dengue-4 has not otherwise been reported outside of Asia and the Western Pacific region. Whether or not dengue-4 has been or is present in the Caribbean is important in assessing the future risk of another major dengue epidemic.
The authors' evidence for the presence of dengue-4 virus was based on an earlier publication by Likar and associates. In this report, two viral antigen preparations derived from HeLa cells infected by virus in sera collected in 1963 from dengue patients reacted with both dengue types 3 and 4 antisera by complement fixation.This test, performed in the manner described, exhibits broad cross-reactions,