Significant incidents of hepatitis A outbreaks occurred through direct person-to-person transmission among drug users and homeless individuals during 2017, according to a report from the CDC.
“Outbreaks with direct HAV transmission among persons reporting drug use or homelessness signals a shift in HAV infection epidemiology in the United States, and vaccination of these populations at high risk can prevent future outbreaks,” Monique Foster, MD, from the division of Viral Hepatitis at the CDC, and colleagues wrote in the report.
During 2017, the CDC received 1,521 outbreak-associated HAV cases from California, Kentucky, Michigan and Utah. Local and state health departments investigations indicated that the reported infections were transmitted within-state and the outbreaks differed from other recent reports of transmission through contaminated food products.
Outcomes from the 2017 cases included 1,073 hospitalizations and 41 deaths. Forty-two patients had confirmed or probable hepatitis B coinfection and 341 had confirmed or probable hepatitis C coinfection.
The report also stated that 57% of the newly infected patients were drug users, homeless, or both, and 54% had an indication for the HAV vaccine, such as drug use or being men who have sex with men.
Of the 1,169 specimens from outbreak-associated cases sent to the CDC for additional testing, 1,054 had HAV confirmed by polymerase chain reaction and 1,014 tested positive for HAV genotype 1b. The strains circulating in California, Kentucky, and Utah were genetically different from those circulating in Michigan, according to the report.
“Increasing vaccination coverage among all at-risk groups recommended by ACIP to receive hepatitis A vaccine might halt ongoing outbreaks and prevent future large community outbreaks,” Foster and colleagues wrote. “CDC has recommended that local health jurisdictions experiencing HAV outbreaks among persons who report drug use or homelessness ensure procedures are in place for identifying these risk factors and that these groups are vaccinated against HAV infection. State and local health departments and CDC should be notified of any new suspected clusters of acute HAV infections.” – by Talitha Bennett
Disclosure: The authors report no relevant financial disclosures.