Purpose of review: This review examines recent developments in human genetic susceptibility to enteropathogens that cause infectious diarrhea.
Recent findings: The affinity of specific norovirus genogroups to different histoblood group antigens (HBGAs) on secretor cells has been studied in different epidemiologic studies. HBGAs are also used as receptors by Vibrio cholerae with different degrees of affinity between biotypes. Polymorphisms in the CD14, lactoferrin and osteoprotegerin promoter genes were associated to diarrhea in travelers. Single nucleotide polymorphisms in the IL-8 genes are also associated to increased risk for enteroaggregative Escherichia coli and Clostridium difficile infection. IL-10 haplotypes were associated to enterotoxigenic E. coli associated diarrhea in exposed individuals. A family-based study showed a significant association of the LPLUNC1 gene and cholera. The major histocompatibility complex class II antigens are associated to different degrees of susceptibility and resistance to Salmonella, Cryptosporidium and Entamoeba infection.
Summary: Variants in genes that encode molecules that mediate attachment, pathogen recognition, inflammatory cytokine response, innate and acquired immunity are being identified as determinants of host genetic susceptibility to infectious diarrhea.