乌鸦传媒

The ongoing 2019 measles epidemic threatens a number of highly vulnerable patient populations, as measles has the potential for serious complications, researchers argued.

Growing numbers of measles outbreaks in the U.S., as well as abroad, threaten children, pregnant women, as well as cancer patients and patients living with HIV, according to Anthony Fauci, MD, director of the National Institute of Allergy and Infectious Diseases (NIAID), and colleagues.

Writing in a Perspective in the , the researchers noted that measles has historically been a disease of children, especially those under age 5, and others "with poor nutritional status, particularly if they have a vitamin A deficiency."

But thanks to vaccination programs, these "seasonal epidemics" in young children no longer exist, Fauci and colleagues wrote. However, the sporadic cases seen in adults may be particularly dangerous to certain populations: immunosuppressed people, for example, may have atypical presentations as well as severe complications such as giant-cell pneumonia and measles inclusion-body encephalitis.

Not surprisingly, measles can lead to serious complications, and even death, in people with HIV infection. But Fauci and colleagues also listed several other patient populations where higher rates of complications and deaths have been reported, including:

• Cancer patients
• People with solid organ transplants
• People receiving high-dose glucocorticoids
• People receiving immunomodulatory therapy for rheumatologic disease

Far from a "trivial disease," Fauci and colleagues enumerated some of the most common complications of measles infection. While pneumonia is the leading cause of measles-related deaths, they said, other complications include keratoconjunctivitis, which may lead to blindness in vitamin A-deficient populations, otitis media, and "secondary infections related to measles-induced immunosuppression."

Measles can also have severe neurological complications and "long-term neurologic sequelae" for patients who survive these complications, they said.

Fauci and colleagues described the danger of nosocomial transmission of measles, citing a 2015 measles outbreak in Shanghai, where a single child with measles in a pediatric oncology clinic infected 23 other children, half of whom ended up with severe complications, and a case fatality rate of 21%.

While the U.S. has had 555 cases of measles in 20 states confirmed this year through April 11, the authors also noted recent measles epidemics around the world, citing a 31% increase in the number of measles cases from 2016 through 2017. Indeed, measles is a global problem -- from the >100,000 cases and 1,205 deaths in Madagascar to the tripling of cases in Europe in 2018 versus 2017. The authors also noted that measles is now endemic in Venezuela (where it had previously been eliminated) and likely in a number of European countries, where transmission has been interrupted.

"The recent upsurge in U.S. measles cases, including the worrisome number seen thus far in 2019 represents an alarming step backwards," Fauci and colleagues wrote. "If this trend is not reversed, measles may rebound in full force in both the United States and other countries and regions where it had been previously eliminated."

"Promoting measles vaccination is a societal responsibility," they concluded.

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