Ready or Not: Responding to Measles in the Postelimination Era Free

Jeffrey S. Duchin MD

Public Health - Seattle & King County and the University of Washington, Seattle

July 24, 2014

Responding to Measles in the Postelimination Era

TO THE EDITOR: Sammons provides a timely reminder of the importance of measles case recognition and management given ongoing outbreaks of measles internationally and repeated introductions of infectious measles cases into the US triggering outbreaks1. Several additional points deserve mention. Although as Sammons rightly points out that it is critical for clinicians to be able to promptly recognize classical clinical cases of measles based on symptoms, signs, and the travel and exposure history. It is also important to note that among persons with pre-existing immunity including previously vaccinated persons (particularly among health care workers) and in persons from measles endemic countries that have had prior measles infection, re-exposure to measles can lead to a modified clinical illness that may not be initially recognized as measles2. Obtaining specimens for measles RNA testing is especially important in these cases as interpretation of serological tests can be difficult.

Sammons also states that airborne precautions should be used for hospitalized measles cases, but that current guidelines do not specify whether a surgical mask or particulate respirator is indicted. Although the current (2007) guidance from the Healthcare Infection Control Practices Advisory Committee (HICPAC; Siegel JD, Rhinehart E, Jackson M, Chiarello L, and the Healthcare Infection Control Practices Advisory Committee, 2007 Guideline for Isolation Precautions: Preventing Transmission of Infectious Agents in Healthcare Settings http://www.cdc.gov/ncidod/dhqp/pdf/isolation2007.pdf) is agnostic on this point, more recent guidance from the Centers for Disease Control and Prevention are clear that irrespective of vaccination history, HCW entering the room of suspected and confirmed measles cases are recommended to use an N95 or similarly protective respirator 3. Assuring and documenting that all HCW have had two doses of MMR minimizes the risk of infection and facilitates efficient management of HCW exposed to measles cases.

And finally, in my experience, disproportionate significance is placed on the finding of Koplik spots in the assessment of potential measles cases. A report of Kpolik spots is understandably not very reliable given the general lack of familiarity of most practicing physicians with acute measles cases. More troubling is the tendency to erroneously interpret the absence of the pathognomic spots as evidence against acute measles infection.

Jeffrey S. Duchin, MD
Public Health - Seattle and King County and the University of Washington
Seattle, Washington

1 Sammons JS. Ann Int Med. 2014;161:145-146
2 Rota JS, et al. J Infect Dis. (2011) 204 (suppl 1): S559-S563 doi:10.1093/infdis/jir098
3 Shefer A, et al. Immunization of Health-Care Personnel. Recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR; November 25, 2011 /60(RR07);1-45 http://www.cdc.gov/mmwr/preview/mmwrhtml/rr6007a1.htm.).

Julia Shaklee Sammons, MD, MSCE

Children's Hospital of Philadelphia

September 8, 2014

Author's Response

I appreciate Dr. Duchin’s expansion on some of the nuances in measles recognition. It is true that clinical presentations may vary for those who have been previously vaccinated. Immunocompromised patients may also present with a modified clinical picture. In addition, I agree that the absence of Koplik spots should not exclude measles from the differential diagnosis of a patient who has other relevant clinical features and appropriate exposure history, particularly since the presence of Koplik spots is transient (2-3 days). Still, for providers who have never seen measles, the critical first step is awareness and the consideration of measles in returned travelers with febrile rash illness.
The importance of appropriate isolation and use of airborne precautions for suspected and confirmed cases of measles cannot be overemphasized. Dr. Duchin appropriately points out recent guidance from the Advisory Committee on Immunization Practices (ACIP)1 that includes a recommendation for use of an N-95 respirator or respirator with similar effectiveness in preventing airborne transmission, which will hopefully be incorporated in an updated version of current guidelines for isolation precautions.2
References
1. Shefer A, et al. Immunization of Health-Care Personnel. Recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR; November 25, 2011 /60(RR07);1-45 http://www.cdc.gov/mmwr/preview/mmwrhtml/rr6007a1.htm.).

2. Siegel JD, Rhinehart E, Jackson M, Chiarello L. 2007 Guideline for Isolation Precautions: Preventing Transmission of Infectious Agents in Health Care Settings. Am J Infect Control 2007;35:S65-164.