Measles Cases on the Rise: The Importance of Speedy Identification

Recent Measles Cases in the United States

The Centers for Disease Control and Prevention (CDC) declared measles eliminated in the United States in the year 2000, primarily due to successful vaccination programs. However, measles is making a comeback in a time when many practicing primary care physicians and pediatricians have not seen the disease firsthand.

As of April 11, 18 states have reported 121 cases of measles in 2024 (CDC), including 7 outbreaks.

The Importance of Early Measles Identification

The timely identification and management of measles cases is crucial as it allows for prompt isolation of the infected individual, reducing the risk of further community transmission.

Early diagnosis also enables healthcare providers to initiate appropriate supportive care and monitor for potential complications. Additionally, identifying measles early facilitates contact tracing efforts, helping to contain outbreaks and protect vulnerable populations.

What is Measles?

Measles, also known as rubeola, is a highly contagious infection of the respiratory system that is caused by a virus within the Paramyxoviridae family.

Measles is more common in developing countries as most people in industrialized nations are vaccinated. However, local outbreaks in communities with clusters of unvaccinated individuals still occur in the United States.

How Measles is Spread

Measles is transmitted via respiratory droplets and can remain viable and transmissible for up to 2 hours in an airspace after an infected person leaves an area. The incubation period after the measles virus enters the upper respiratory mucosa is about 10 days (range 7-21 days), with a rash typically appearing about 14 days after an exposure.

Infected individuals are considered contagious from about 4 days prior to the appearance of the rash through about 4 days after its appearance.

What to Look For in Measles

The symptoms of measles generally begin between 7 and 14 days after the person was infected. Remember the three C’s of measles:

• cough
• coryza
• conjunctivitis

A prodrome characterized by fever, coryza (nasal congestion), cough, and conjunctivitis occurs for about 3-4 days followed by the onset of the rash and will increase in severity until the rash reaches its peak.

The rash of measles consists of small, red macules and papules first appearing behind the ears and at the forehead then moves downward toward the feet to cover the body. In darker skin colors, the redness may be harder to see, or it may appear purple or darker than surrounding skin.

Sometimes red papules with blue-white centers appear inside the mouth, called Koplik spots. Koplik spots may develop 2-3 days after symptoms begin and prior to the generalized cutaneous eruption.

Mimickers of Measles

Keep in mind the following diseases when examining a patient with measles-like signs and symptoms:

• infectious mononucleosis
• erythema infectiosum
• roseola
• rubella
• enteroviral infection
• Kawasaki disease
• Rocky Mountain spotted fever
• exanthematous drug eruption

Measles Management and Treatment

Treatment is supportive and focused on relieving common symptoms and providing nutritional support, such as vitamin A supplementation.

Measles Prevention

Measles can be prevented with the MMR vaccine, and doctors across the country encourage everyone who can to get the vaccine. The CDC says two doses of the MMR vaccine are about 97% effective at preventing measles; one dose is about 93% effective.

Public Health Information

VisualDx offers valuable resources to equip you with the knowledge to quickly rule measles in or out and educate your patients:

• Handbook-length peer-reviewed disease information
• 81 medical images across a variety of ages, skin tones and disease stages
• Shareable handouts written with the patient in mind in both English and Spanish
• Public Health Page with disease information available to all website visitors
• Webinar recording: Spotting Measles

 Further Information

You can learn more from public health resources including CDC, Mayo Clinic, and your state health department.

Updated April 16, 2024