Hepatitis B

CASES/YEAR

1,025,000 (US); 400,000,000 (Global)

CATEGORY

Sexually-Transmitted

AGENT TYPE

Viruses

OTHER NAMES

Serum hepatitis; Hepatitis D (Related Infection);

ACUITY

Acute-Moderate

INCUBATION

90 days (60-150 days); [CDC Travel]

INITIAL SYMPTOMS

Pre-icteric: fatigue, nausea, and right upper quadrant pain; 10-20% of patients have serum-sickness like symptoms (fever, rash, hives, and arthralgias); Icteric: jaundice & weight loss; hepatosplenomegaly may develop. [Cecil, p. 959]

PRECAUTIONS

Standard. "See specific recommendations for care of patients in hemodialysis centers." [CDC 2007 Guideline for Isolation Precautions] "All persons who are HBsAg-positive are potentially infectious. . . . The infectivity of chronically infected individuals varies from high (HBeAg-positive, HBV-DNA above 100,000 copies /mL) to modest (anti-HBe-positive)." [CCDM, p. 260]

COMMENTS

FINDINGS
Less than 10% of children and about 30-50% of adults develop jaundice after infection. Severity ranges from no symptoms to fatal infections. Presenting symptoms in some cases include abdominal discomfort, arthralgias, and rash. Fever may be absent. The hepatitis B antigen (HBsAg) first becomes detectable as early as several weeks before onset of symptoms; it persists in the serum of patients with chronic infection. [CCDM, p. 257-8] Other common symptoms are loss of appetite, dark urine, and light-colored stools. Symptoms occurring in less than 30% of patients include headache, myalgia, arthralgia, diarrhea, and constipation. Less than 1% of adult patients develop fulminant hepatitis with bleeding diathesis (GI bleeding) and coma. [ID, p. 761, 770] Hypersplenism with thrombocytopenia and leukopenia can occur in chronic cases. [PPID, p. 1557] Rare complications are pancreatitis, myocarditis, pneumonia, aplastic anemia, transverse myelitis, and peripheral neuropathy. Terminal symptoms of fulminant hepatitis include coma, gastrointestinal bleeding, sepsis, and renal failure. [Harrison ID, p. 862-3] The stage of HBV infection can be determined using serological test results. See Table 4-3. [CDC Travel, p. 190] Myocarditis, pericarditis, pleural effusion, aplastic anemia, and encephalitis have been reported. [Cohen, 3rd Ed, p. 411]

EPIDEMIOLOGY:
Chronic hepatitis B infection rates vary from highly endemic (>8% HBsAg prevalence) to intermediate (2% to 7%) to low. "Where endemicity is low (HBsAg prevalence <2%), most infections occur in young adults, especially through sexual contact and injection drug use." Any parenteral or mucosal exposure can transmit infection from a patient's blood. Fecal-oral transmission has not been documented. Patients with chronic infection have increased risk for cirrhosis and liver cancer. [CCDM, p. 258-9] "Among U.S. patients for whom a risk factor can be ascertained, most hepatitis B virus infections are transmitted sexually." [Harrison ID, p. 318] The only vaccines that target sexually-transmitted diseases are hepatitis B and HPV. [Cecil, p. 1841] In high-prevalence areas, most infections are perinatal and the rate of progression to chronic infection is about 90% compared to low-prevalence areas where most infections occur in adolescents or adults (1% progression to chronic infection). [PPID, p. 1556] "HCP and trainees in certain populations at high risk for chronic hepatitis B (e.g., those born in countries with high and intermediate endemicity) should be tested for HBsAg and anti-HBc/anti-HBs to determine infection status." [ACIP, 2011] "Patients who remain positive for HBV DNA or HBeAg 6 weeks after the onset of symptoms are likely to develop chronic infection." [Cecil, p. 962] Immunodeficiency increases risk for chronic infection. [CCDM, p. 257]

VACCINATION:
Post-vaccination testing is not recommended except for high-risk groups (infants of positive mothers, healthcare workers, dialysis patients, and sexual partners of HBV carriers). About 3-10% of vaccinated subjects are "non-responders"; they should be revaccinated. Up to two thirds of vaccinated subjects lose their anti-HBs antibodies after 10-15 years; if at risk, they should receive a booster. [Cecil, p. 962]

POST-EXPOSURE PROPHYLAXIS:
Non-immunized workers exposed to blood from an HBsAg-positive source should receive HBIG, and the vaccine series should be started. [CCDM, p. 264] For unvaccinated workers exposed to HBV-infected blood from a needlestick or cut, the estimated risk is 6-30% depending upon the hepatitis B e antigen (HBeAg) status of the source patient. [www.nccc.ucsf.edu/hiv_clinical_resources/pep_guidelines] Consider postexposure prophylaxis "after HCP experience any percutaneous, ocular, mucous-membrane or nonintact skin exposure to blood or body fluid in the workplace. . . . Vaccinated HCP with documented immunity (anti-HBs concentrations of > or =10 mIU/mL) require no postexposure prophylaxis, serologic testing, or additional vaccination." [ACIP, 2011]

HEPATITIS D:
Hepatitis D virus (HDV) requires the presence of hepatitis B (HBV) for transmission. The incubation period is about 2-8 weeks. HDV is found only in patients who are positive for HBsAg. Studies in Europe and the USA have shown that 1/4 to 1/2 of fulminant hepatitis cases are caused by concurrent infection with HBV and HDV. Diagnosis is made by detecting anti-HDV by EIA. Rising IgM indicates ongoing replication. The most sensitive test for HDV viremia is reverse transcription PCR. [CCDM, p. 268-70] Clinical courses are similar for hepatitis B and D, but hepatitis D is more severe in regard to end-stage liver disease, cirrhosis, and risk of hepatocellular cancer. [PPID, p. 1565]

DIAGNOSTIC

Specific antigens and antibodies: HbcAb IgM positive early before HBsAg/sAb; Evidence of acute hepatitis by AST/ALT liver enzymes elevated in range of several 100 to several 1000 IU/L; [5MCC-2020]

SCOPE

Global; Endemic areas (carrier rates of >10%) include Asia & sub-Saharan Africa; A chronic progressive disorder in high-prevalence areas; [PPID, p. 1556]

SIGNS & SYMPTOMS

• >arthralgia
• >fatigue, weakness
• >fever
• >myalgia
• G abdominal pain
• G blood in stool
• G hepatomegaly
• G jaundice
• G liver function test, abnormal
• G nausea, vomiting
• H anemia
• H eosinophilia
• H leukopenia
• H lymphadenopathy
• H splenomegaly
• H thrombocytopenia
• N confusion, delirium
• N headache
• S papules or plaques
• S petechiae and ecchymoses
• S rash (exanthem)
• S urticaria
• X pleural effusions
• *acute renal failure
• *arthritis
• *bleeding tendency
• *cancer
• *cirrhosis
• *encephalitis
• *erythema nodosum
• *glomerulonephritis
• *hepatitis
• *myocarditis
• *pancreatitis
• *pericarditis
• *peripheral neuropathy
• *pneumonia
• *sepsis
• *stupor, coma
• *weight loss

ANTIMICROBIC

Yes

VACCINE

Yes

ENTRY

Needle (Includes Drug Abuse), Scalpel or Transfusion, Skin or Mucous Membranes (Includes Conjunctiva), Sexual Contact

SOURCE

Person-to-Person

RESERVOIR

Human

RISK FACTORS

• AIDS patients
• Care for patients (bloodborne pathogen)
• Fail to complete immunizations
• Handle needles or surgical instruments
• Have a blood transfusion
• Injection drug users
• Travel to endemic area
• Work in a medical or research lab

TREATMENT

"No treatments attenuate acute viral hepatitis." [Merck Manual, p. 225] Antiviral therapy is recommended in patients with severe acute hepatitis B. [Cecil, p. 962] "There are several antiviral medications for people with chronic HBV infection." [CDC Travel]

DRUG LINK

CDC - Viral Hepatitis

REFERENCES FOR CASES/YEAR

1. (US) MMWR 2011: 2,903; Cases/year of hepatitis B decreased from 66,232 before vaccine to 18,800 in 2012. [Harrison ID, p. 49t] Estimated 850,000 to 2.2 million carriers in the US; 1800 die each year from liver cirrhosis and cancer. [PPID, p. 1947]
2. (Global) 600,000 die every year; [Fact sheets from WHO 2013] There are >350-400 million carriers of HBsAg in the world. [Harrison ID, p. 886] 250 million people are infected chronically; [PPID, p. 1548]