Does Acute Hepatitis B Infection Cause Low-Grade Fever?

Acute hepatitis B virus (HBV) infection can indeed be associated with low-grade fever, though this symptom is neither universal nor specific to the condition. During the acute phase—typically occurring within 1–4 months after exposure—some individuals develop a constellation of nonspecific systemic symptoms, including mild fever (often sub-38°C), fatigue, anorexia, nausea, right upper quadrant abdominal discomfort, and myalgias. These manifestations reflect the host’s immune response to viral replication in hepatocytes rather than direct cytopathic effects of the virus itself.

Fever in acute HBV infection tends to be transient and self-limiting, resolving as the immune system begins to clear infected hepatocytes. It is important to note that up to 50% of adults with acute HBV remain asymptomatic, while others may present with jaundice or elevated serum transaminases without noticeable fever. When present, low-grade fever should be interpreted in context: its absence does not rule out infection, and its presence warrants evaluation for other potential causes—including co-infections, drug reactions, or alternative hepatic or systemic disorders.

Clinical assessment should include serologic testing for hepatitis B surface antigen (HBsAg), IgM anti-HBc, and alanine aminotransferase (ALT) levels to confirm acute infection. Management remains supportive; antiviral therapy is generally not indicated during uncomplicated acute HBV, as most immunocompetent adults achieve spontaneous viral clearance within six months.