There
are less data -- some of it conflicting -- regarding genotype 4, which is being
seen with increasing frequency in Europe (though still uncommon in the U.S.).
As reported
in the July 2007 Journal of Viral Hepatitis, French researchers analyzed
epidemiological features and SVR rates in a retrospective study of 1532 genotype
4 patients, including 1056 infected in France, 227 immigrants infected in Egypt,
and 249 infected in sub-Saharan Africa.
• HCV subtypes 4a or 4d were
most common among patients infected in France, where the predominant route of
transmission was injection drug use.
•
Subtype 4a predominated (93%) among patients infected in Egypt, where transmission
was mostly related to parenteral treatment for schistosomiasis.
•
More than 7 different genotype 4 subtypes were found among patients infected in
sub-Saharan Africa, a group with no apparent single predominant route of infection.
•Liver
fibrosis was significantly less severe in genotype 4 patients infected in
France or Africa compared with those infected in Egypt.
•
However, SVR rates were higher in patients infected in Egypt, compared with those
infected in France or Africa (54.9%, 40.3%, and 32.4%, respectively; P < 0.05).
• Overall, better
treatment response was observed in patients infected with subtype 4a.
• In a multivariate analysis,
the 2 factors independently associated with SVR were infection in Egypt and absence
of severe fibrosis.
Conclusion
In
conclusion, the authors wrote, "the distribution of HCV-4 subtypes varies
with the geographical origin of transmission and affects the SVR following antiviral
treatment."
07/10/07
Reference D
Roulot, V Bourcier, V Grando, and others. Epidemiological characteristics and
response to peginterferon plus ribavirin treatment of hepatitis C virus genotype
4 infection. Journal of Viral Hepatitis 14(7): 460-467. July 2007.
