Clinical and laboratory findings in dengue fever cases in Jamaica and the possible implications

ABSTRACT

Clinical and laboratory investigations of dengue fever cases in 1969 revealed no minor or major haemorrhagic phenomena, although the serological response of over two-thirds of confirmed cases was the 'secondary' type reaction, indicating reinfection. Dengue virus type 2 was the agent of infection whereas in 1968, when only 25 per cent cases showed a 'secondary' antibody response the infective agent was predominantly Dengue virus type 3. It is interesting to note that Dengue virus type 3 was also most likely responsible for the 1963 epidemic of Dengue-like illness. Now for the first time, there is indisputable evidence of the occurrence of a second dengue serotype (Dengue type 2) which most likely infected a large number of persons who had previously been infected, presumably, by Dengue type 3 - the latter being the only other type found in the island. It has been suggested that prior dengue virus infection sensitises some patients, who, on reinfection by a different dengue virus serotype, develop Dengue haemorrhagic fever and/or Dengue shock syndrome. These severe manifestations of dengue virus infections have been quite common in children of South-East Asia within the last two decades. Fortunately, these haemorrhagic phenomena have not occurred in Jamaica, although the basis for their occurrence seems to be present. It is important to note that reinfection by a different dengue virus serotype is a relatively recent feature of dengue disease in this country (AU)