What to Know About Measles to Be Safe

Measles is a high­ly con­ta­gious viral dis­ease. With 9 out of 10 sus­cep­ti­ble peo­ple exposed to measles devel­op­ing the dis­ease, measles is con­sid­ered one of the most con­ta­gious diseases.

The Unit­ed States has seen an increase in measles cas­es this year (2024). Below are con­tribut­ing fac­tors to the increase in measles cases:

• Trav­el­ers to the Unit­ed States
• Peo­ple return­ing from trav­el to oth­er countries
• Spread­ing of the dis­ease to per­sons who have not received a full vac­ci­na­tion series, including:
  • Unvac­ci­nat­ed individuals 
  • Those under one year old who are too young to receive the stan­dard vaccine 

How Measles is Spread

Measles is spread through res­pi­ra­to­ry droplets, which enter the air through cough­ing or sneez­ing and can remain in the air and live on sur­faces for two hours. While symp­toms of measles may not appear for 8 – 12 days after expo­sure to the virus, those infect­ed are con­ta­gious for about four days pri­or to the onset of the rash and for about four days after the onset of the rash. 

Symp­toms of Measles

Measles caus­es high fevers, up to 104 – 105 degrees Fahren­heit, that may last for sev­er­al days. Fol­low­ing a fever, those infect­ed with measles can expect to expe­ri­ence a run­ny nose, a cough, and con­junc­tivi­tis (red, watery eyes). One may also devel­op oral lesions (Koplick spots) — white-gray cir­cles on the inside of the cheeks — when infect­ed with measles. A few days after the start of the fever, a rash will devel­op. The rash presents with flat pink/​red spots that start near the hair­line as well as on the face and then spread down­ward through the body.

The infec­tion can also cause pneu­mo­nia, which can be severe. His­tor­i­cal­ly, about 10 – 15% of patients need to be admit­ted to the hos­pi­tal due to the sever­i­ty of symp­toms, but that rate is high­er — at about 50% — in the 2024 out­break. The infec­tion can also cause encephali­tis (brain infec­tion), in about 1/1000 cas­es, of which 80 – 85% will have per­ma­nent brain dam­age. The over­all death rate for acute measles infec­tion is 1 – 3 out of 1,000.

Treat­ment of Measles & The Measles Vaccine

There is no spe­cif­ic treat­ment for measles. For­tu­nate­ly, there is a high­ly effec­tive vac­cine to pre­vent measles. The measles vac­cine is part of the MMR (Measles, Mumps, Rubel­la) vac­cine that is usu­al­ly giv­en at 12 months old and 4 – 5 years old. 

• First Dose: The first dose is about 93% effec­tive at pre­vent­ing the dis­ease, with an increase to 97% effec­tive­ness after the sec­ond dose. The first dose can be giv­en to infants as young as 6 months old for trav­el to inter­na­tion­al areas at high­er risk. Note that trav­el dos­es are not count­ed in the stan­dard series, and anoth­er dose, con­sid­ered the first dose, is still required after 12 months old. 
• Sec­ond Dose: The sec­ond dose can be giv­en as ear­ly as 28 days after the first dose. 

If your child is too young to get a vac­cine, the risk of measles expo­sure is still gen­er­al­ly low in a high­ly vac­ci­nat­ed pop­u­la­tion. It is always a good idea to prac­tice good hand wash­ing with soap and water or hand sanitizer.

In the event of a local out­break, lim­it your infant’s expo­sure to crowds, oth­er chil­dren, and any­one with res­pi­ra­to­ry (cold) symp­toms. For adults, any­one born before 1957 is con­sid­ered immune to measles and does not require a vac­cine at this time, except in rare med­ical cir­cum­stances. Any­one who has had a two-dose series of the vac­cine is also con­sid­ered immune. 

If you are con­cerned that you or your child has measles or has been exposed to measles, con­tact your doctor’s office for more information.

Addi­tion­al Measles Resources

Healthy​Chil​dren​.org, the Amer­i­can Acad­e­my of Pedi­atrics web­site for par­ents, has excel­lent arti­cles on measles. Addi­tion­al infor­ma­tion is also avail­able from the Cen­ters for Dis­ease Con­trol and Prevention.