A new study has identified the 25 US counties which are most at risk of measles outbreaks, due to low vaccination rates and a high volume of international travel.
The analysis was done by researchers at The University of Texas at Austin and Johns Hopkins University and considered the areas volumes of international travel from foreign countries with large measles outbreaks and the prevalence of nonmedical exemptions from childhood vaccination.
The increase in measles outbreaks
• January 2019, there have been more than 700 confirmed measles cases in 22 states in the US;
• This is almost double the figures last year; and
• It is the highest number of measles outbreaks reported since the virus was eradicated in the US in 2000.
The study’s lead author, Sahotra Sarkar, a philosophy and integrative biology professor at UT Austin and an expert on public health, explained: “For measles, most experts believe that there will be one to two deaths per 1,000 cases, most likely infants. We are set to see over 1,000 cases in the U.S. in 2019. So, for the first time since the 1980s, we may expect infant deaths from measles in the U.S.”
Sarkar added: “We have long known that vaccine avoidance is a critical public health issue in the U.S. and Europe. Our results show how travel from regions elsewhere compounds this risk.”
Public health policy recommendations
Lauren Gardner, an associate professor of civil engineering at Johns Hopkins and a UT Austin engineering alumna, commented: “Critically, we recommend that public health officials and policymakers prioritize monitoring the counties we identify to be at high risk that have not yet reported cases, especially those that lie adjacent to counties with ongoing outbreaks and those that house large international airports.”
Lower vaccination rates
Sarkar concluded: “The vaccine avoidance problem is not limited to measles. Pertussis – whooping cough – is another disease making a comeback because of dropping vaccination rates, and we predict serious outbreaks in the U.S. in the near future. Policymakers must focus on centres of vaccination refusal as well as regions with a lot of passenger inflow from affected countries worldwide if there are even small local pockets of unvaccinated people.”