Evolving trends in hepatitis A epidemiology: Shifting patterns, emerging risks, and future strategies

Table 1 Clinical course and manifestations of hepatitis A virus infection

Phase	Approximate duration	Key clinical manifestations	Laboratory/virological findings
Incubation	2-6 weeks (mean 28 days)	Asymptomatic	HAV replication in liver; high virus in stool and blood; normal ALT
Prodromal (pre-icteric)	3-10 days	Fatigue, anorexia, nausea, low-grade fever, right upper quadrant discomfort, diarrhea in children	Rapid ALT/AST rise (> 1000 IU/L); HAV in stool; start of IgM anti-HAV appearance
Icteric phase	1-3 weeks	Jaundice, dark urine, pale stools, pruritus; fever and malaise subside	Peak ALT/AST; elevated bilirubin; IgM anti-HAV positive
Convalescent/recovery	Several weeks-months	Gradual improvement; residual fatigue	Enzyme levels normalize; IgM declines; IgG persists lifelong

ALT: Alanine aminotransferase; AST: Aspartate aminotransferase; HAV: Hepatitis A virus; Ig: Immunoglobulin.