LB10. Changing Epidemiology of Hepatitis A Virus Infections–– United States, 2007─2017
Session: Oral Abstract Session: Late Breaker Oral Abstracts: Emerging Infections
Friday, October 5, 2018: 2:30 PM
Room: S 152-154
Background: Hepatitis A virus (HAV) is primarily spread fecal-orally and causes acute illness including fever, jaundice, and diarrhea. After introduction and widespread use of the hepatitis A vaccine in the United States, infection with HAV decreased and outbreaks typically associated with a common-source were uncommon.

Method: CDC receives reports of hepatitis A infections from states through the National Notifiable Disease Surveillance System (NNDSS) and/or directly to the viral hepatitis outbreak response team. We analyzed NNDSS hepatitis A data for 2007–2016, and a combination of NNDSS data and cases directly reported to the CDC hepatitis A outbreak response team during 2017; excluding 2017 NNDSS data from the four states that directly reported outbreaks to the outbreak response team to eliminate the potential for double-counting cases.

Result: During 2007─2011, a total of 10,619 hepatitis A cases were reported; 521 (5%) were associated with outbreaks. Of the 274 outbreak-associated cases for whom clinical data were reported, 102 (37%) were hospitalized and one (0.3%) died. Of the 407 outbreak-associated cases for whom risk exposure data were reported, 210 (52%) were associated with a common source. Comparatively, during 2012─2017, a total of 11,483 hepatitis A cases were reported; 2,323 (20%) were associated with outbreaks. Of the outbreak-associated cases for whom clinical data were reported, 1,306/2,162 (60%) were hospitalized and 43/2,178 (2%) died. Of the outbreak-associated cases for whom risk exposure data were reported, 379/2188 (17%) were associated with a common source.

Conclusion: In the United States, outbreaks of hepatitis A infections in the decade prior to 2017 were infrequent and typically associated with a common source. Reported cases associated with hepatitis A outbreaks are increasing, along with concurrent increases in hospitalizations and deaths among persons with outbreak-associated infections. Recent outbreaks indicate a decrease in cases associated with a common-source exposure. Decreasing the susceptible population through adherence to childhood vaccination recommendations and targeted vaccination of recommended at-risk groups can prevent future hepatitis A outbreaks of any transmission pattern.

Monique Foster, MD, MPH1, Megan Hofmeister, MD, MS, MPH1, Shaoman Yin, PhD, MSPH1 and Paul Weidle, PharmD MPH2, (1)Division of Viral Hepatitis, Centers for Disease Control and Prevention, Atlanta, GA, (2)Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, GA

Disclosures:

M. Foster, None

M. Hofmeister, None

S. Yin, None

P. Weidle, None

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