A total of 222 US measles cases have been reported this year in twelve jurisdictions: Alaska, California, Florida, Georgia, Kentucky, New Jersey, New Mexico, New York City, Pennsylvania, Rhode Island, Texas, and Washington.
Of these cases, 17% (38) have been hospitalised, with 93% (207) linked to three separate outbreaks. For comparison, 16 outbreaks were reported during the whole of 2024, with 69% of cases (198 of 285) being associated with outbreaks.
The American southwest has been hit hardest, where according to New Mexico health officials, an outbreak has resulted in the deaths of two unvaccinated individuals - the first US fatalities from the disease since 2015.
Texas has seen the biggest outbreak so far, with the Lone Star state identifying 198 cases as of 7th March, compared to 30 in neighbouring New Mexico. However, the recent spike does not appear to have been restricted geographically, with two unrelated cases recently confirmed in New York City according to the New York City health department.
In a recent statement, the New York State Department of Health said: ‘We are monitoring the situation very carefully. We have local health departments in each county that are prepared to investigate cases and distribute vaccines or other protective measures as needed. If there is a person with measles, we will quickly try to stop it from spreading.’ Details of the diagnosed individuals, including their age and vaccination status, have not been revealed, but officials are urging parents to make sure their children receive the MMR vaccine.
Measles is caused by the measles virus (Morbillivirus hominis). The basic reproductive rate (R0) of measles is commonly said to be 12-18, meaning a single infected individual can, on average, infect 12 to 18 others in a totally susceptible population. For context, R0 for COVID-19’s most contagious variant, Omicron, was only 1.90.
The re-emergence of preventable diseases coincides with the spread of misinformation about vaccines, and an associated decline in US vaccination rates.
US health secretary Robert F Kennedy Jr backtracked on his previous comments last week referring to the US measles outbreak as “not unusual”, saying on X that “ending the measles outbreak is a top priority for me”.
In a press release, Dr James McDonald, New York state health commissioner said: ‘As a pediatrician and the state’s doctor, I want to remind everyone that immunisation is safe and the best protection for your children against measles and other potentially deadly diseases.’
These recent outbreaks follow the White House’s announcement that it will immediately suspend all its aid programmes, including the dismantling of the United States Agency for International Development (USAID), which distributes overseas aid worth tens of billions of dollars every year.
Global health experts have expressed serious concerns over the decision, warning of the spread of disease, alongside delays to vaccine development and new treatments as a result of the cuts.