Editing Hepatitis C (section)

=== Chronic infection ===
About 70% of those exposed to the virus develop a chronic infection.<ref name=whofactsheet/> This is defined as the presence of detectable viral replication for at least six months. Though most experience minimal or no symptoms during the initial few decades of a chronic infection,<ref name=Book2011 /> chronic {{nowrap|hepatitis C}} can be associated with fatigue<ref name=ID2010 /> and mild cognitive problems.<ref>{{cite journal | vauthors = Forton DM, Allsop JM, Cox IJ, Hamilton G, Wesnes K, Thomas HC, Taylor-Robinson SD | title = A review of cognitive impairment and cerebral metabolite abnormalities in patients with hepatitis C infection | journal = AIDS | volume = 19 | issue = Suppl 3 | pages = S53-63 | date = October 2005 | pmid = 16251829 | doi = 10.1097/01.aids.0000192071.72948.77 | doi-access = free }}</ref> After several years, chronic infection may cause [[cirrhosis]] or [[liver cancer]].<ref name=NEJM2011 /> The liver enzymes measured from blood samples are normal in 7–53%.<ref name=Nicot2011 /> (Elevated levels indicate the virus or other disease is damaging liver cells). Late relapses after apparent cure have been reported, but these can be difficult to distinguish from reinfection.<ref name=Nicot2011 />

[[Steatohepatitis|Fatty changes to the liver]] occur in about half of those infected and are usually present before cirrhosis develops.<ref name="El-Zayadi2008" /><ref>{{cite journal | vauthors = Paradis V, Bedossa P | title = Definition and natural history of metabolic steatosis: histology and cellular aspects | journal = Diabetes & Metabolism | volume = 34 | issue = 6 Pt 2 | pages = 638–42 | date = December 2008 | pmid = 19195624 | doi = 10.1016/S1262-3636(08)74598-1 }}</ref> Usually (80% of the time) this change affects less than a third of the liver.<ref name="El-Zayadi2008">{{cite journal | vauthors = El-Zayadi AR | title = Hepatic steatosis: a benign disease or a silent killer | journal = World Journal of Gastroenterology | volume = 14 | issue = 26 | pages = 4120–6 | date = July 2008 | pmid = 18636654 | pmc = 2725370 | doi = 10.3748/wjg.14.4120 | doi-access = free }}</ref> Worldwide hepatitis C is the cause of 27% of cirrhosis cases and 25% of hepatocellular carcinoma.<ref name=World2007>{{cite journal | vauthors = Alter MJ | title = Epidemiology of hepatitis C virus infection | journal = World Journal of Gastroenterology | volume = 13 | issue = 17 | pages = 2436–41 | date = May 2007 | pmid = 17552026 | pmc = 4146761 | doi = 10.3748/wjg.v13.i17.2436 | doi-broken-date = 2024-11-14 | doi-access = free }}</ref> About 10–30% of those infected develop cirrhosis over 30 years.<ref name=NEJM2011 /><ref name=AFP2010 /> Cirrhosis is more common in those also infected with [[hepatitis B]], [[schistosoma]], or HIV, in [[alcoholic]]s, and in those of male sex.<ref name=AFP2010 /> In those with hepatitis C, excess alcohol increases the risk of developing cirrhosis 5-fold.<ref>{{cite journal | vauthors = Mueller S, Millonig G, Seitz HK | title = Alcoholic liver disease and hepatitis C: a frequently underestimated combination | journal = World Journal of Gastroenterology | volume = 15 | issue = 28 | pages = 3462–71 | date = July 2009 | pmid = 19630099 | pmc = 2715970 | doi = 10.3748/wjg.15.3462 | doi-access = free }}</ref> Those who develop cirrhosis have a 20-fold greater risk of [[hepatocellular carcinoma]]. This transformation occurs at a rate of 1–3% per year.<ref name=NEJM2011 /><ref name=AFP2010 /> Being infected with hepatitis B in addition to hepatitis C increases this risk further.<ref>{{cite journal | vauthors = Fattovich G, Stroffolini T, Zagni I, Donato F | title = Hepatocellular carcinoma in cirrhosis: incidence and risk factors | journal = Gastroenterology | volume = 127 | issue = 5 Suppl 1 | pages = S35-50 | date = November 2004 | pmid = 15508101 | doi = 10.1053/j.gastro.2004.09.014 | doi-access = free }}</ref>

Liver cirrhosis may lead to [[portal hypertension]], [[ascites]] (accumulation of fluid in the abdomen), [[coagulopathy|easy bruising or bleeding]], varices (enlarged veins, especially in the stomach and esophagus), [[jaundice]], and a syndrome of cognitive impairment known as [[hepatic encephalopathy]].<ref name=Tah2009 /> Ascites occurs at some stage in more than half of those who have a chronic infection.<ref name=Zaltron2012>{{cite journal | vauthors = Zaltron S, Spinetti A, Biasi L, Baiguera C, Castelli F | title = Chronic HCV infection: epidemiological and clinical relevance | journal = BMC Infectious Diseases | volume = 12 | pages = S2 | year = 2012 | issue = Suppl 2 | pmid = 23173556 | pmc = 3495628 | doi = 10.1186/1471-2334-12-S2-S2 | doi-access = free }}</ref>