Hepatitis A

Organism, Causative Agent, or Etiologic Agent
Hepatitis A is caused by infections with the hepatitis A virus (HAV). HAV is a picornavirus with humans as the only natural host.

HAV is transmitted from person-to-person through the fecal-oral route. Outbreaks due to HAV have been linked to contaminated water, food contaminated by infected persons where the food was not properly cooked or handles after cooking, raw or undercooked mollusks harvested from contaminated waters, and contaminated produce.

Groups at increased risk for hepatitis A or its complications include:

  • International travelers (particularly high-risk itineraries like travel to rural areas in high-risk countries) 
  • Recent international adoptees from HAV endemic countries
  • Men who have sex with men
  • Users of illegal drugs

Symptoms (Clinical Illness)
HAV is indistinguishable from other forms of acute viral hepatitis without lab testing. The illness typically has an abrupt onset of fever, malaise, anorexia, nausea, abdominal discomfort, jaundice, and dark urine. 

Incubation Period
Average of 28-30 days (range 15-50 days).

HAV is most infectious 2 weeks before illness to 1 week after onset of jaundice.

Prevention and Vaccination
The best way to prevent hepatitis A is through vaccination with the hepatitis A vaccine. Practicing good hand hygiene plays an important role in preventing the spread of hepatitis A which includes washing hands after using the bathroom, changing diapers, and before preparing or eating food.

School Exclusion Policy
Food-handlers and school children should be kept out of work or school for 7 days after the onset of symptoms.
25 Tex. Admin. Code §97.7.  

Recent Texas Trends
Current finalized data are available through 2020. Hepatitis A case counts, and incidence rates have declined in Texas up through 2018 in response to vaccine availability and childhood immunization requirements. The steepest declines occurred in counties that have historically experienced the highest incidence rates and that implemented vaccine requirements soon after ACIP recommendations for targeted immunization. Hepatitis A vaccination was required for childcare enrollees starting in 1999 and for K - grade 1 starting in school year 2010-2011. In 2018, 88 cases of hepatitis A were reported in Texas, the lowest total count so far. In 2019 that count rose to 160 cases and in 2020 rose to 223 cases, largely due to an outbreak. 
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