Nearly as many cases of measles have been detected this year as in the whole of 2023, data shows.

Figures from the Centers for Disease Control and Prevention (CDC) show 41 cases were diagnosed in January and February compared to 58 in the whole of 2023. At this time last year, only three cases had been recorded.

Sixteen states have confirmed outbreaks so far — with Florida’s, linked to elementary schools, being the largest at ten cases.

The outbreaks have been attributed to falling measles vaccination rates for the third year in a row. 

The target is 95 percent, but last year it dipped to 93.1 percent, meaning hundreds of thousands of kindergarteners were not protected against the disease as they headed into schools.

The above map shows the states that have detected measles cases so far this year

Measles typically begins with cold-like symptoms, before causing a rash made up of small red spots, some of which can feel slightly raised. According to the NHS, it typically starts on the face and behind the ears before spreading further

Measles infections can be easily prevented with the two-dose MMR vaccine, which is more than 97 percent effective against infections with the disease.

The disease is one of the most infectious known to man and is spread via droplets in the air or contaminated surfaces, with nine in ten unvaccinated people exposed to the disease developing an infection.

Patients initially suffer symptoms including a runny nose and red and puffy eyes that are sensitive to light — but this can progress to a harsh cough and a rash that spreads from the face to the feet and is formed of flat red spots.

The CDC says about one in five people infected with measles are hospitalized while up to three out of every 1,000 patients die from the disease. One in a thousand also develop swelling in the brain.

Michigan was the latest state to record measles cases this year — after confirming infections in two adults who had recently traveled overseas.

Florida’s surgeon general Dr Joseph Ladapo drew criticism earlier last month after suggesting children who were exposed to measles in the state’s outbreak did not need to isolate at home.

Dr Robert Speth, a medical expert at South Florida’s Nova Southeastern University, told The Guardian: ‘His statements are more political than medical and that’s a horrible disservice to the citizens of Florida’.

‘He’s someone whose job is to protect public health, and he’s doing the exact opposite.’

The above graph shows the number of measles cases reported by year. There are about 100 cases reported in the US every year

The above shows the number of measles cases reported by week, revealing an uptick in recent weeks

The other states to report cases are: Arizona, California, Georgia, Indiana, Louisiana, Maryland, Minnesota, Missouri, New Jersey, New York, Ohio, Pennsylvania, Virginia and Washington.

Six of these states — Arizona, Georgia, Indiana, Louisiana, Michigan and Minnesota — did not report a single case of measles last year.

It is unclear what proportion of the cases are linked to international travel and how many patients have been infected in the US. 

Experts say measles comes into the US from overseas countries where vaccine coverage is limited, including Yemen, India and Russia.

Patients may then unwittingly spread it in their local areas before realizing they are infected.

Earlier this year, a child at the Children’s Hospital of Philadelphia was reportedly infected after they were placed into a bed next to a child who had measles before their condition was diagnosed. 

Before the Covid pandemic, America was recording around a hundred measles cases every year — mostly linked to international travel. 

The biggest outbreak was in 2019 when more than 1,274 cases were recorded — which was in part linked to parents holding ‘measles parties’ where they would expose unvaccinated children to the disease to get them immunity.

Cases have remained low since then, with the highest number recorded in 2022 when the US saw 121 cases of measles.

Measles was declared eliminated from the United States in 2000 but has continued to pop up in the country since.