Abstract. Dengue fever is becoming one of the major public health problems in the world and
its distribution has been premised on the migration of people from infected regions. This
study was carried out to determine the prevalence of dengue virus IgG antibody among the
patients with febrile conditions attending health facilities in Osogbo metropolis, Southwestern
Nigeria. The blood samples collected between July and September, 2014 were tested for
Plasmodium falciparum and the sera were subsequently subjected to Enzyme Linked
Immunosorbent Assay (ELISA) to detect the dengue virus IgG antibody. Of the hundred
consented participants screened, 77% were sero-positive for dengue virus IgG antibody while
41% were positive for P. falciparum. Thirty-three (33%) of the participants were positive for
both dengue virus IgG antibody and P. falciparum. No significant difference was found in the
prevalence of dengue virus IgG antibody and malaria among the participants (P>0.05). The
high prevalence of dengue virus IgG and malaria signifies the need by the government of
Osun State to sensitize residents and institute urgent measures to mitigate the resultant
effects of morbidity and mortality due to dengue fever and dengue hemorrhagic fever which
has hitherto appeared to be alien to the area.