Dengue in infants: an overview

Abstract

Dengue virus (DV) infection causes either a benign syndrome, dengue fever, or a severe syndrome, dengue haemorrhagic fever/dengue shock syndrome (DHF/DSS), that is characterized by systemic capillary leakage, thrombocytopaenia and hypovolaemic shock. DHF/DSS occur mainly due to secondary infection by a heterotype DV infection in children and adults but in infants even primary infection by DV causes DHF/DSS. Clinical manifestations of DHF/DSS are more significantly associated with death in infants compared with older children. Vertical transmission of DV and anti-DV IgG has been well reported and is responsible for the pathogenesis of DV disease and its manifestations in infants. The complex pathogenesis of DHF/DSS during primary dengue in infants, with multiple age-related confounding factors, offers unique challenges to investigators. Dengue in infants is not often studied in detail due to practical limitations, but looking at the magnitude of DHF/DSS in infants and the unique opportunities this model provides, there is a need to focus on this problem. This paper reviews existing knowledge on this aspect of DV infection and the challenges it provides.

Figure 1

Role of ADE during DV infection of dendritic cells/macrophages that may determine whether it will lead to DF or DHF (based on Chaturvedi & Nagar, 2009).

Figure 2

Understanding the humoral immunopathogenesis of DHF/DSS during primary DV infection in infants.

Figure 3

Cytokines and transcription factors responsible for the generation of various subsets of CD4 T cells that may play roles in the pathogenesis of DHF.

Figure 4

Understanding the cellular immunopathogenesis of DHF/DSS during primary DV infection in infants. [Correction made on 23 April after online publication: Fig. 4 replaced with revised version.]