HCV genotype 4 in Belgium: three distinct patterns among patients from European and African origin

Considered uncommon in western countries some years ago, hepatitis C virus of genotype 4 is now spreading in some areas of Europe. This is assumed to be due to immigration from a region of high prevalence for this genotype and to propagation among drug users. In the south of Belgium, genotype 4 currently accounts for 10% of hepatitis C virus patients and its prevalence is increasing with time.

To better define the genotype 4 carriers' characteristics.

In a database comprising 1726 viraemic hepatitis C virus patients, the files of 85 genotype 4 carriers were reviewed.

Beside the African (58%) and European drug user (15%) subgroups classically described, a third subgroup consisting of European nondrug users (26%) was identified as peculiar: these patients were older, had been mostly contaminated sporadically, presented a great diversity of subtypes, and were mainly of Italian origin. In this subgroup, contamination was supposed to be ancient, having occurred probably in Italy before immigration into Belgium. By contrast, European drug users were infected with only two subtypes (4c/4d and 4), an observation in favour of recent spread. Africans had a great diversity of subtypes, were young, and were mostly contaminated sporadically in their home countries. Despite their epidemiological differences, the clinical management, and in particular the rates of eligibility for treatment, were similar for these three groups.

Three different patterns of genotype 4 carriers were observed, corresponding to three different spreading profiles. They did not induce, however, different clinical management.