More than 20 people exposed to measles patient at Nemours Children's Hospital in Wilmington

WILMINGTON, Delaware (WPVI) -- Delaware health officials say they have identified between 20 and 30 people who were exposed to a measles patient late last month.

The state's Division of Public Health said Thursday the exposure happened at Nemours Children's Hospital in Wilmington between 6 a.m. and 12 p.m. on Dec. 29.

Officials say the measles patient was not showing symptoms at the time but was infectious.

Anyone who may have been exposed, and has symptoms, is asked to call the Office of Infectious Disease Epidemiology during regular business hours (302-744-4990) or the state's 24-hour reporting line at 1-888-295-5156 outside of normal business hours to coordinate testing, receive guidance, and limit any further exposures.

Those who are ill are urged to see immediate health care, but are also asked to notify healthcare providers that they - or their child - were exposed to measles.

Anyone who has not had both doses of the Measles, Mumps, and Rubella vaccine is urged to get them as soon as possible.

"The MMR vaccine is proven safe and effective at preventing measles having been administered for over five decades. Testing shows the vaccine to be 97% effective at preventing measles for those who have received two doses of the MMR vaccine and are not severely immunocompromised," health officials said.

MEASLES EXPOSURE IN PHILADELPHIA AND MONTGOMERY COUNTY

Officials in Philadelphia and Montgomery County, Pa. are also tracking incidents of measles exposure.

The exposures in Montgomery County happened at Holy Redeemer Pediatric Urgent Care in Meadowbrook and Jefferson Abington Hospital Emergency Department in Abington.

READ MORE: Officials warn of 2 possible measles exposure sites in Montgomery Co.

Meanwhile, Philadelphia officials have confirmed eight measles cases so far. City officials have said the cases are among unvaccinated residents.

READ MORE: 8 measles cases now identified, Philadelphia health officials say

MEASLES VACCINE INFO

The Division of Public Health released the following information about the vaccine:

-Children should get their first dose of vaccine between 12 and 15 months of age and their second dose between 4 and 6 years of age.

-If you have not received both doses by age 6, you should get your first or second dose as soon as possible.

-Infants 6-11 months who are traveling internationally should get an early dose of MMR.

-Vaccinations are available to both adults and children at many pharmacies, federally qualified health centers (FQHCs), and providers throughout Delaware and also at public health clinics for the uninsured or underinsured. Individuals should contact their preferred facility in advance to confirm supply and availability.

WHAT IS MEASLES?

Measles is a highly contagious, acute viral illness that begins with early symptoms of fever, cough, runny nose and pink eye, lasting two to four days before a rash appears.

The rash typically occurs three to five days after symptoms begin and usually appears on the face and spreads down the body.

Measles can cause severe health complications, including pneumonia, brain inflammation and death. The virus is transmitted by direct contact with infectious droplets or by airborne spread when an infected person breathes, coughs or sneezes.

The measles virus can remain infectious in the air and on surfaces for up to two hours after an infected person leaves an area.

Infected people are contagious from four days before the rash starts through four days after rash development. The incubation period for measles from exposure to fever is usually about 10 days (range, 7-12 days), and from exposure to rash onset is usually about 14 days (range, 7-21 days).

For more information on measles, visit 'Frequently Asked Questions' on the DPH website.