The Measles outbreak in Texas and New Mexico has reached nearly 300 cases, with doctors warning that the disease can bring deadly, long-term complications for young children who become infected.

The Lone Star State has had 259 cases since just before the weekend while 35 have been reported in New Mexico in the current outbreak, according to the states’ health departments.

With measles cases reported in 13 other states, doctors fear a once-rare neurological condition caused by measles infections may become more widespread and claim lives in the near future.

The measles outbreak in Texas and New Mexico have reached nearly 300 cases, with 13 others states reporting infections. stock.adobe.com

Subacute sclerosing panencephalitis (SSPE), also known as Dawson disease, is a rare form of progressive brain inflammation caused by a persistent infection with the measles virus, according to the National Institutes of Health (NIH).

The condition typically develops seven to 10 years after the initial measles infection, with no known cure. SSPE cases are almost always fatal, according to health officials.

The condition is also more common among toddlers who are infected with measles, Adam Ratner, a pediatric infectious disease specialist in New York City, told NPR.

“It turns out that in some age groups, especially in kids under about age 2, it’s much more common than we thought,” Ratner warned.

Officials are urging parents to get their child vaccinated to avoid the serious, long-term complications caused by a measles infection. Getty Images

While the US usually sees only four to five cases of SSPE per year, the NIH warned that the number is likely to go up given the spike in measles cases and America’s unvaccinated population.

Generally, around four to 11 cases per 100,000 cases of measles result in SSPE, according to the NIH. SSPE is more common in children less than five years old.

Measles has also been known to trigger immune amnesia, a condition that causes people to lose the antibodies they’ve developed over the years, taking away their natural defenses against viruses and bacteria.

There are 259 measles cases in Texas alone, with many of the cases located in unvaccinated pockets of the Lone Star State. Getty Images

Those who develop immune amnesia are therefore forced to contend with the illnesses they had already developed antibodies against.

The measles vaccine was notably touted as the key source for eliminating the high rate of infection deaths among children around the world when it was introduced in the 1960s as it protected them from immune amnesia.

Measles was declared eliminated in the US in 2000, but cases have been on the rise in recent years as vaccine skepticism has become more prevalent.

Last week, New Mexico confirmed this year’s second fatality, in an unvaccinated adult. That comes after an unvaccinated child died in February.