Acute Hepatitis C

Acute hepatitis C is infection with hepatitis C virus (HCV), an RNA flavivirus, within the first 6 months after exposure.

• Transmission: unsafe injections and medical procedures, injection drug use, transfusion of unscreened blood, needlestick injury, sexual transmission (men who have sex with men and HIV positive), perinatal (about 5 percent).
• Incubation is 2 to 12 weeks (average 7).
• About 70 to 80 percent progress to chronic infection; spontaneous clearance occurs in 20 to 30 percent, more often with jaundice, female sex and favourable host genetics.

Most infections are asymptomatic; 20 to 30 percent have jaundice, malaise, anorexia, nausea, dark urine and right upper quadrant pain.

• Fulminant hepatic failure is very rare.
• Differential diagnosis: acute hepatitis A, B, D and E, cytomegalovirus, Epstein-Barr virus, drug-induced liver injury, alcoholic hepatitis, autoimmune hepatitis, leptospirosis, malaria, yellow fever, biliary obstruction.
• Complications: chronic hepatitis C, cirrhosis, hepatocellular carcinoma, cryoglobulinaemic vasculitis, glomerulonephritis, porphyria cutanea tarda, lichen planus, and HBV reactivation if coinfected.

HCV RNA by PCR is positive within 1 to 2 weeks of exposure; anti-HCV antibody may be negative for 6 to 8 weeks (window period) and then seroconverts.

• ALT often 10 times the upper limit of normal, bilirubin raised; INR, albumin, full blood count.
• Test for HIV, hepatitis B surface antigen and core antibody, hepatitis A IgG.
• Repeat HCV RNA at 12 and 24 weeks to determine spontaneous clearance.
• After needlestick: baseline anti-HCV, ALT, then HCV RNA at 3 to 6 weeks and anti-HCV at 6 months.

Supportive: rest, hydration, no alcohol, avoid hepatotoxic drugs, paracetamol up to 2 g daily.

Pharmacological

• Direct-acting antivirals may be started at once and cure above 95 percent. Options: sofosbuvir 400 mg plus velpatasvir 100 mg once daily for 12 weeks; glecaprevir 300 mg plus pibrentasvir 120 mg once daily for 8 weeks; sofosbuvir 400 mg plus daclatasvir 60 mg once daily for 12 weeks (reduce daclatasvir to 30 mg with strong CYP3A inducers or 90 mg with efavirenz).
• Alternative strategy where monitoring is reliable: wait 12 weeks for spontaneous clearance, then treat if HCV RNA persists.
• Pregnant women: defer treatment until after delivery.
• Check hepatitis B status before treatment and monitor if HBsAg positive (reactivation).

Special groups

• HIV coinfection: sofosbuvir 400 mg plus velpatasvir 100 mg once daily for 12 weeks, checking drug interactions with antiretroviral therapy (efavirenz lowers velpatasvir levels and is avoided).
• People who inject drugs: treat without waiting for abstinence; harm reduction (needle exchange, opioid substitution).
• Healthcare worker exposure: no post-exposure prophylaxis; early treatment on seroconversion.

Red flags: encephalopathy, INR above 1.5, jaundice persisting over 8 weeks.

Follow-up: HCV RNA 12 weeks after completing treatment (cure confirmed by undetectable RNA); counsel on reinfection risk.