[The molecular epidemiology of hepatitis A in The Netherlands; the usefulness of typing isolated viral strains]. / Moleculaire epidemiologie van hepatitis A in Nederland; het nut van het typeren van geïsoleerde virusstammen.

OBJECTIVE: To investigate the epidemiological links between several outbreaks of hepatitis A in The Netherlands (2001-2004). DESIGN: Descriptive. METHOD: Blood samples taken in connection with reports of hepatitis A to municipal health centres from 2001-2004, were typed by determining the nucleotide sequence of the VP3-VP1 and the VP1-P2A regions of the genome of the hepatitis A virus (HAV). Genetic distances were represented graphically by means of a phylogenetic tree. RESULTS: The study into the spread of various subtypes of HAV showed a clear link between the HAV-(sub)genotype and risk of transmission: in men that have sex with men only genotype 1A occurred, in travellers to African countries genotype 1B was predominantly seen. CONCLUSION: A database containing various viral strains from people with hepatitis A in The Netherlands could, if kept up to date, be used as an aid in confirming the classical way of tracing sources as well as for the evaluation of preventative measures.