In June 1963 an outbreak of a dengue-like illness occurred in Jamaica. The only recorded dengue epidemic in Jamaica before that of 1963 had been in 1824, as mentioned in church records of causes of deaths.
Over 450 primary inoculations of serum from acutely ill patients and from mosquitoes associated with them were made in animals and in tissue-cell cultures. A possible isolation was made in one cell culture inoculated with material from Aedes aegypti mosquitoes, as evidenced by interference studies. Otherwise, no isolation was made, although inoculated suckling mice gave signs of disease of the central nervous system. The characterization of the epidemic as “dengue-like” was based upon the clinical course of patients and upon serologic findings.