As Measles Outbreak Persists, AAP Urges Clinicians to Ramp Up Infection Control Steps

Cases of measles have been reported in at least 6 US states, including Delaware, New Jersey, Georgia, Pennsylvania, Virginia, and Washington, according to a recent news release from the American Academy of Pediatrics (AAP).¹

The highly contagious disease is particularly dangerous in young children and is transmitted through contact with infectious droplets or when rendered airborne when an infected person breathes, coughs, or sneezes. After an infected person leaves an area, the US Centers for Disease Control and Prevention (CDC) estimates the virus can remain in the air for up to 2 hours.¹

Falling pediatric vaccination rates have left approximately 250 000 children at risk of vaccine preventable diseases, says the CDC. ©Rawpixel/shutterstock.com

“[These reports are] not really surprising given the decrease in vaccination rates that have been occurring since the pandemic,” said Tina Tan, MD, professor of pediatrics, Feinberg School of Medicine, Northwestern University; pediatric infectious diseases attending, Ann & Robert H Lurie Children's Hospital of Chicago, in an interview with Patient Care partner publication Contemporary Pediatrics.

“This is not new and demonstrates what is known, in that if vaccination rates do not stay at a level that is protective, outbreaks of vaccine preventable diseases will occur,” said Tan.

Characteristic signs and symptoms of the acute viral respiratory illness include a prodromal fever as high as 105° F, malaise, coryza, cough, and conjunctivitis, a pathognomonic enanthem on the buccal mucosa known as Koplik spots, followed by the recognizable maculopapular rash, according to the CDC.²

After exposure it can take up to 14 days for the rash to appear, typically first on the head, then spreading to the trunk and on to lower extremities. Individuals are considered contagious beginning 4 days before and until 4 days after appearance of the rash.²

As many as 9 out of 10 individuals who are susceptible and have close contact with an infected person will contract the disease, the CDC warns.² Infants and children aged younger than 5 years are at especially elevated risk for severe illness and complications from measles as are pregnant women and anyone who is immunocompromised.²

The US along with multiple other countries have seen vaccination rates fall below protective levels, observed Tan, in part a result of increased vaccine hesitancy attributed to the COVID-19 pandemic. “Measles and other vaccine preventable diseases need to be on the differential diagnoses of children presenting with signs and symptoms that may be associated with these diseases,” she cautioned.

Routine childhood immunization for the measles-mumps-rubella (MMR) vaccine is recommended at 12 to 15 months of age for the first dose, with the second coming at ages 4 through 6 years, or at least 28 days after first dose.²

Children aged 12 months through 12 years also are eligible for the MMR-varicella (MMRV) vaccine with doses administered at least 3 months apart.²

“Healthcare providers and health departments should not accept verbal reports of vaccination without written documentation as presumptive evidence of immunity,” the CDC states. Evidence of immunity for measles includes at least 1 of the following²:

• Written documentation of adequate vaccination:
  • ≥1 doses of a measles vaccine on or after the first birthday for preschool-aged children
  • 2 doses of a measles vaccine for school-aged children, including college students, health care personnel, and international travelers.
• Laboratory evidence of immunity
• Laboratory confirmation of measles
• Birth before 1957

A recent CDC study revealed that 93% of kindergartners were fully vaccinated against measles in the 2022 to 2023 school year, marking the third consecutive year that vaccination rates were below the “Healthy People 2030 target of 95%.”³ CDC officials estimate that currently there are approximately a quarter of a million kindergartners at risk.¹

A resurgence in measles and increasingly poor vaccination rates are raising concern in other western countries, according to the AAP news.¹ The UK issued warnings last week about regional increases in cases and estimated the number of unvaccinated at-risk children in the country at 3 million. The World Health Organization has reported a 45-fold increase in cases of measles in 2023 compared to 2022 for the European Region, ascribing the exponential rise to the fall off of measles vaccination coverage during the pandemic.¹

References:

1. Jenco M. Measles reported in multiple states; be prepared to take infection-control steps. AAP News. January 24, 2024. Accessed January 25, 2024. https://publications.aap.org/aapnews/news/27983/Measles-reported-in-multiple-states-be-prepared-to
2. Measles (Rubeloa). For healthcare providers. Centers for Disease Control and Prevention. Updated November 5, 2020. Accessed January 30, 2024. https://www.cdc.gov/measles/hcp/index.html
3. Halsey G. Exemption rate from school vaccination for kindergartners unprecedented in 2022-23: CDC Report. Patient Care. December 13, 2023. https://www.patientcareonline.com/view/exemption-rate-from-school-vaccination-for-kindergartners-unprecedented-in-2022-23-cdc-report