Posted August 23, 2019. Past health advisories and alerts are archived for historical purposes and are not maintained or updated.
Since our last Health Alert on this topic (sent June 6), an additional six cases of acute hepatitis A virus (HAV) infection have been reported in people experiencing homelessness, for a total of nine cases in Spokane residents. Additional cases have been identified in other counties. The locally acquired cases had jaundice onsets of May 24 to July 14. All cases have a history of homelessness and drug use during their incubation periods. No common link has been established. SRHD continues to target outreach and immunizations towards persons living homeless and entities serving persons living homeless.
Widespread HAV outbreaks have been reported across the country since 2016, largely in the same populations. A significant percentage of the 22,500 reported cases have resulted in hospitalizations (59% of cases) and at least 221 deaths, representing the vulnerability of these populations.
The primary means of HAV transmission in the United States is typically person-to-person through the fecal-oral route (i.e., ingestion of something that has been contaminated with the feces of an infected person). Symptoms include fever, fatigue, loss of appetite, nausea, vomiting, abdominal pain, dark urine, clay-colored bowel movements, joint pain, and jaundice. Although rare, atypical extra-hepatic manifestations include rash, pancreatitis, renal disease, arthritis, and anemia. Severe infections can result in cholestatic hepatitis, relapsing hepatitis, and fulminant hepatitis leading to death. Average incubation of HAV is 28 days, but illness can occur up to 50 days after exposure. An HAV-infected person can be viremic up to six weeks through their clinical course and excrete virus in stool for up to two weeks prior to becoming symptomatic, making identifying exposures particularly difficult. Illness from HAV is typically acute and self-limited; however, when this disease affects populations with already poor health (e.g., HBV and HCV infections, chronic liver disease), infection can lead to serious outcomes, including death. Eighty-nine percent of local cases in this outbreak have been hospitalized, which is a significantly higher percentage than the national average of 59% for recent outbreaks in other communities across the country.
The best way to prevent HAV infection is through vaccination with the HAV vaccine. The immunogenicity of one dose of HAV vaccine is 94-100%. The second dose helps ensure lifetime immunity. The number and timing of the doses depends on the type of vaccine administered. Vaccines containing HAV antigen that are currently licensed in the United States are the single-antigen vaccines HAVRIX® (manufactured by GlaxoSmithKline, Rixensart, Belgium) and VAQTA® (manufactured by Merck & Co., Inc., Whitehouse Station, New Jersey) and the combination vaccine TWINRIX® (containing both HAV and HBV antigens; manufactured by GlaxoSmithKline). All are inactivated vaccines. GamaSTAN S/D (Grifols Therapeutics, Inc., Research Triangle Park, North Carolina) immune globulin (IG) for intramuscular administration is the only IG product approved for HAV prophylaxis. The efficacy of IG or vaccine when administered greater than two weeks after exposure has not been established.
HAV is a disease of poor sanitation conditions therefore practicing good hand hygiene—including thoroughly washing hands with warm water and soap after using the bathroom, changing diapers, and before preparing or eating food—plays an important role in preventing the spread of HAV in all segments of the community.
For more information: https://www.cdc.gov/hepatitis/outbreaks/2017March-HepatitisA.htm
NEW Free continuing education activity available from CDC’s MMWR and Medscape -- Recommendations of the Advisory Committee on Immunization Practices for Use of Hepatitis A Vaccine for Persons Experiencing Homelessness.