Hepatitis A is no longer primarily a travel and food-related infection, as most infections from 2016 to 2020 were related to drug use or homelessness, according to the CDC.
56% of people infected with hepatitis A in the US used drugs (injected or not), 14% were homeless, and 12% were recently incarcerated in data from 33 states for the period from August 2016 and December 2020.
Coinfections with hepatitis B were seen in 5.2% of reported cases, and 30.3% were coinfected with hepatitis C, as reported by Megan Hofmeister, MD, MS, MPH, CDC Division of Viral Hepatitis, and his colleagues in Weekly Morbidity and Mortality Report.
“These outbreaks mark a change in the epidemiology of hepatitis A in the United States,” the CDC researchers wrote.
Hepatitis A data for the previous 15-year period from 2000 to 2015 it showed drug use associated with infection in 3.5% of cases. The incidence was reported more frequently in the Hispanic population.
“Previously, international travel and exposure to foodborne outbreaks were the most frequently reported risk factors,” Hofmeister and colleagues wrote. “Prior to the introduction of hepatitis A vaccines, … transmission was largely due to spread from asymptomatically infected children, and hepatitis A disproportionately affected racial and ethnic minority populations.”
In the 2016-2020 analysis, cases occurred predominantly among men, white people, and adults ages 30 to 49.
Retrospective data included 37,553 outbreak-related cases reported during that five-year period. By contrast, reported cases of hepatitis A were lower in the earlier period, with 1,398 cases reported in 2011 and 1,390 in 2015, for example.
Of all cases in 2016-2020, 61.4% of people were hospitalized and 380 deaths were attributed to hepatitis A. That was an increase from the 42% hospitalized in Data from 2016 exclusively from the National System for Surveillance of Compulsory Notifiable Diseases. Hofmeister’s group noted that the older age of the patients and the corresponding higher likelihood of comorbidities (including co-infection with hepatitis B or C) could be responsible for the higher rates of hospitalization.
Recent initiatives have helped reduce the numbers since the outbreak it was declared in 2016. The outbreak remains active in 13 states, while 24 states have officially declared their outbreaks over.
“Increased hepatitis A vaccination coverage, particularly through the implementation of successful non-traditional vaccination strategies among disproportionately affected populations, is needed to continue progress in halting current outbreaks and preventing disease.” similar outbreaks in the future,” the researchers wrote.
From 2016 through mid-September 2022, there have been 44,650 cases, 27,250 hospitalizations, and 415 deaths attributed to hepatitis A.
The CDC’s Advisory Committee on Immunization Practices recommended vaccination of the homeless in 2019, when the outbreak was at its height. The CDC has warned that overcoming stigma and mistrust and addressing vaccine hesitancy are important to improving vaccination. Ongoing initiatives since 2017 that have been contributing to infection control include satellite programs and non-traditional vaccination and staffing strategies in correctional facilities, vaccination and substance use treatment centers, as well as syringe service programs and shelters. for homeless people.
Data limitations included that risk factors were self-reported and subject to recall bias, lack of systematic ethnicity determination, and variations in how hepatitis A-related deaths are classified between states. Also, since surveillance for hepatitis A is passive in the US, cases may be underestimated, the researchers noted. In addition, a substantial proportion of data was missing.
Investigators had nothing to disclose.