Discover - USA (2020-01 & 2020-02)

56 DISCOVERMAGAZINE.COM

KAT

ER

YN

A^ K

ON

/SH

UT

TE

RS

TO

CK

i

In February, an international

traveler carrying the measles virus

passed through Boston’s busy South

Station bus terminal. Once discovered,

the Boston Public Health Commission

urged anyone in the person’s path who

was unvaccinated — other travelers, local

residents, bus drivers, station employees

— to see their doctors.

“Measles is the most contagious virus

we know about,” says H. Cody Meissner,

chief of pediatric infectious diseases at

Floating Hospital for Children at Tufts

Medical Center in Boston. “Hundreds of

people could have been exposed.”

A cough or sneeze from an infected

individual can spray particles of the virus

— each one only about 5 microns, barely

smaller than a human red blood cell —

that can remain infectious and airborne

for up to two hours. Measles easily infects

around 9 in 10 unvaccinated people who

breathe contaminated air or touch an

infected surface. “The germs that cause

these diseases ... are plentiful — they’re

just waiting until they find someone who

is not immune,” says Meissner.

The Boston incident happened in

the midst of the largest measles out-

break in the U.S. since 1992. Successful

vaccination campaigns had led to the

domestic elimination of the disease by

2000.

But in 2019, roughly 1,250 cases had

been confirmed in 31 states by October

— over three times the number of cases

reported in 2018 (372). The outbreaks

have been mostly concentrated in New

York, New Jersey, Washington state and

California, with the majority of cases,

more than 700, occurring in New York

City. Over 400 more occurred elsewhere

in the state, primarily in cloistered

Orthodox Jewish communities.

“It’s really a bunch of small outbreaks,”

says Tom Clark, deputy director for

the Centers for Disease Control and

Prevention’s Division of Viral Diseases.

“Most of them are under control after a

handful of cases.” That’s because most

people are vaccinated, says Clark.

“[But] sometimes, close-knit com-

munities are under-vaccinated by

choice, often because of parents’ con-

cerns about the safety of vaccines or a

lack of concern about the seriousness of

the diseases vaccines protect against,”

says Clark.

While most people fully recover,

roughly 1 in 5 cases leads to serious

complications that can include miscar-

riages, severe diarrhea, ear infections,

pneumonia and encephalitis, an infec-

tion triggering brain swelling that can

result in a vegetative state or even death.

A small but growing number of people

Measles Returns

BY LINDA MARSA