‘No longer bringing it home’: Hepatitis A in decline with routine vaccination for children
The greatest distributors of hepatitis A virus are children.
When they become infected with the virus, they do not get very sick — usually not sick enough to exhibit jaundice — but they produce a large amount of virus.
Children spread the virus among themselves and give it to adults. For almost 20 years, we have been routinely vaccinating children against HAV. Not only has HAV diminished among children, but because they are no longer bringing it home, the virus has also diminished among adults.
A surprising outbreak occurred a number of years ago among people experiencing homelessness, a challenging new population that often has mental health issues and that sometimes use drugs. It is also a population that may not have access to good sanitary facilities, so fecal-oral transmission through close contact can occur. In addition, people experiencing homelessness are not always ready to collaborate with public health departments.
This outbreak occurred in a less well-nourished population, and one that often has underlying illnesses, so the hospitalization rate was substantial. In various studies, it was over 10%, which is high for HAV. The outbreak was first recognized in California but soon cropped up in homeless populations in other parts of the country. There is more mobility among homeless persons than initially appreciated.
It was a big challenge. Public health officials first defined the problem under the leadership of the CDC. It then became the responsibility of state and local health departments to identify cases, provide medical care and — of equal and even greater importance, perhaps — vaccinate them.
This turned out to be challenging and, from the point of view of the health departments, required substantial resources. They had to pay for vaccines and provide a complete vaccination series, which requires two doses 6 to 18 months apart. This was frequently difficult to assure. If a person does not have a known address and you are unclear about their name, it is challenging to follow up with that second dose.
It was decided one dose was better than none, and I certainly agree with that. Health departments tried to get that first dose into as many people as possible. To a substantial degree, the effort was successful, but not completely, as you can imagine given the nature of the population. Nonetheless, HAV cases have come down in this high-risk population.
Continuing the use of HAV vaccine routinely in children and making it available to adults who fit all the risk categories remains critical even beyond this population. The HAV vaccine is so effective, safe and durable that, if we had the determination as a society to vaccinate everybody, we could eliminate this infection in the United States.
For more information:
William Schaffner, MD, is professor of preventive medicine in health policy and professor of medicine in the division of infectious diseases at Vanderbilt University School of Medicine. He can be reached at william.schaffner@vumc.org.
Collapse
Read more about