Comments
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. 967]
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. 1448] 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. 969] The stage of HBV infection can be determined using serological test results. See Table 3-3. [CDC Travel, p. 190] Myocarditis, pericarditis, pleural effusion, aplastic anemia, and encephalitis have been reported. [Cohen, 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. 310] The only vaccines that target sexually-transmitted diseases are hepatitis B and HPV. [Cecil, p. 1796] 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. 1446] "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 HBV DNA- and/or HBeAg-positive 6 weeks after the onset of symptoms are likely to develop chronic infection." [Cecil, p. 969] 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. 969]
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. 1455]
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