On Friday, Colorado health officials confirmed the state’s fifth incidence of measles for the year, marking a significant concern as this latest case involved an adult who had received the MMR vaccine (measles, mumps, and rubella). The individual, residing in Denver, had recently traveled to the Mexican state of Chihuahua, which is currently experiencing an outbreak of measles.
Two other confirmed cases in Colorado—a baby in Denver and a resident of Pueblo—are also linked to travel in Chihuahua. In an effort to manage potential exposure, the Colorado Department of Public Health and Environment (CDPHE) has identified a specific location where individuals may have come into contact with the virus. It is advised that anyone who visited the Kaiser Permanente urgent care clinic located at 8383 W. Alameda Ave. in Lakewood between 10:30 a.m. and 1 p.m. on Saturday, April 19, should closely monitor for symptoms for the next 21 days and consider refraining from public gatherings.
If you suspect you may be infected with measles, it is crucial to contact your healthcare provider before visiting their office or an emergency clinic. This precaution will help ensure that the staff can prepare for your arrival without risking exposure to other patients.
This case is particularly noteworthy as it involves a person with verified proof of vaccination, which raises questions about breakthrough infections. According to Dr. Ned Calonge, the chief medical officer at CDPHE, such occurrences, while unusual, are not entirely unexpected. The MMR vaccine is highly effective, with two doses providing approximately 97% effectiveness against infection, while a single dose offers about 93% effectiveness. Statistically, this means that roughly three out of every 100 vaccinated individuals exposed to the virus may still contract the disease.
Fortunately, when breakthrough infections do occur, they tend to be milder, as was the case with the recent Colorado patient, who is reportedly feeling well. Dr. Calonge noted that individuals who have been vaccinated and develop measles are generally less contagious than those who are unvaccinated.
Dr. Calonge clarified that the emergence of a breakthrough infection does not indicate a dangerous mutation of the virus or an increased ability to evade the immune system. Instead, he pointed out that a small number of individuals may not respond adequately to the MMR vaccine, or their immunity may diminish over time.
In light of the recent cases, health officials have expressed optimism about the public health system’s ability to respond to measles infections. However, some earlier instances highlighted delays in reporting suspected cases. These delays prompted the CDPHE to remind clinics and laboratories of the importance of promptly notifying the state about potential measles cases.
In this latest case, nearly a week elapsed from the time the individual visited the clinic to when the public was informed of the confirmed measles case. Dr. Calonge explained that while the clinic reported the case to CDPHE immediately, the delay in public notification was due to uncertainties regarding the vaccination status and the likelihood of a positive test result for measles.
Regardless of these challenges, Dr. Calonge emphasized that anyone tested for measles should maintain isolation until their test results are confirmed.
