Organism, Causative Agent, or Etiologic Agent
Hepatitis B virus (HBV) is a member of the family Picornaviridae. There are many types of viral hepatitis, each designated by a letter (A, B, C, etc).
HBV is transmitted through activities that involve percutaneous (i.e., puncture through the skin) or mucosal contact with infectious blood or body fluids (e.g., semen, saliva), including
- Sex with an infected partner
- Injection drug use that involves sharing needles, syringes, or drug-preparation equipment
- Being born to an infected mother
- Contact with blood or open sores of an infected person
- Needle sticks or sharp instrument exposures
Sharing items such as razors or toothbrushes with an infected person
HBV is not spread through food or water, sharing eating utensils, breastfeeding, hugging, kissing, hand holding, coughing, or sneezing.
The presence of signs and symptoms varies by age. Most children under age 5 years and newly infected immunosuppressed adults are asymptomatic; whereas 30%–50% of persons aged ≥5 years have initial signs and symptoms. When present, signs and symptoms can include
- Loss of appetite
- Abdominal pain
- Dark urine
- Clay-colored bowel movements
- Joint pain
- Jaundice (yellow-ish skin or eyes)
There are two stages to hepatitis B: acute and chronic. At the time of infection with hepatitis B, people are considered to have acute hepatitis B. After that, their hepatitis B will resolve, making them immune to further infection or they will become chronically infected, meaning they can infect other people and may continue to have other symptoms or compliations. After acute infection, about 90% of infants and 30% of children under 5 years will become chronically infected compared to about 5% of adults.
Persons with chronic HBV infection might be asymptomatic, have no evidence of liver disease, or have a spectrum of disease ranging from chronic hepatitis to cirrhosis or hepatocellular carcinoma (a type of liver cancer).
To prevent infection, Texas recommends the vaccination of all children at birth. Vaccination is currently required for school entry in Texas. Adults that are at high risk for infection can also be immunized. Among others, this includes health care workers and people who use drugs or have unsafe sexual practices. In addition to vaccination, practicing safe sex and not sharing needles or other instruments that might be exposed to bodily fluids can reduce the risk of spreading hepatitis B.
Pregnant women are routinely screened during prenatal care and at birth to ensure that hepatitis B is not passed to their baby. If a woman has hepatitis B, her baby will receive preventive medication at birth to help prevent infection.
School Exclusion Policy
Children with acute or chronic hepatitis B do not need to be excluded from school or childcare. Rules for exclusion of sick children from school and childcare are outlined in the Texas Administrative Code, specifically Rule 97.7 for schools and Rule 746.3603 for childcare.
Recent Texas Trends
The introduction of a safe and effective vaccine and the further implementation of that vaccine into school requirements helped to combat the increase of acute hepatitis B in Texas. Since 1991, Texas experienced a steady decline in the incidence of the disease. Reported incidence for acute hepatitis B in 2010 was 394. This represents a decrease of 85% in comparison to reported incidence in 1991. This overall decline was greatest among children and adolescent groups under the age of 18 years. Adults ages 18 and older have consistently made up the majority of hepatitis B cases in Texas. Only acute hepatitis B is reportable in Texas.