Dengue virus replication in cultures of peripheral blood leukocytes during the course of dengue haemorrhagic fever.

A preliminary study was made of the ability of cultured human peripheral blood leukocytes (PBL) to support dengue 2 infection. Leukocyte donors, children hospitalized with primary (one case) or secondary dengue infections (12 cases), were studied during the acute and convalescent stages of illness. D2 virus replication occurred infrequently in PBL cultures obtained from children before the 10th day after onset of symptoms (2/23 samples), but frequently thereafter (8/13 samples). The absence of virus permissive cells during the acute stage of illness might be explained by several different mechanisms, including the possibility that permissive PBL are exhausted as the result of a severe dengue infection. An unexpected finding was the appearance of dengue hemagglutination-inhibition antibodies in cultures of PBL obtained from children during the acute stage of secondary dengue infections.