Recently identified factors predisposing children to infectious diseases.

PURPOSE OF REVIEW: To identify articles published between January 2006 and January 2008 that have significantly enhanced our understanding of why some children are prone to severe or recurrent infectious diseases.

RECENT FINDINGS: Significant inroads into the genetic basis of immune disorders leading to severe and recurrent infections in children have been made over the last few years. We now understand the specific susceptibility to herpes simplex virus encephalitis, the underlying cause of hyper IgE and Hermansky-Pudlak type 2 syndromes, as well as further explanations for the genotypic/phenotypic variations in severe combined immunodeficiency, common variable immunodeficiency and congenital neutropenia syndromes. Virulence factors for Staphylococcus aureus and Plasmodium falciparum have also been identified, and disease pathophysiology of respiratory syncytial virus related bronchiolitis and of acute pyelonephritis are better understood.

SUMMARY: Progress in this area continues to be rapid. Clinicians now have the knowledge and techniques to explain why many children develop infectious diseases.