Measles

[[File:RougeoleDP.jpg|right|thumb|165px|Classic measles rash]]
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'''Measles''' ('''rubeoloa''', First Disease) is a highly contagious viral infection causing a classic rash. It was once endemic in the [[United States]], infecting 3-4 million people yearly and killing around five hundred.<ref name=CDC>[http://www.cdc.gov/measles/hcp/index.html Measles (Rubeola): For Healthcare Professionals] ''Centers for Disease Control''.</ref> The incidence of measles declined sharply after the introduction of the vaccine in the U.S. in 1963, and was declared "eliminated" (no longer endemic) in 2000. Cases still occurred but were imported and then spread briefly, being [[herd immunity|contained by a largely immune population]]. The elimination of measles in the U.S. has been put under threat since the mid- to late-1990s as vaccination rates dropped and cases rose.

==The disease==
Measles is caused by the measles [[virus]]. It is classically described by the clinical triad of cough, coryza (runny nose), and conjuntivitis (pink eye).<ref name=CDC/> These, along with fever, are the first signs of the disease, making it initially indistinguishable from the common cold. 

The classic red, bumpy rash appears on the body about 3-5 days after the cold symptoms, announcing itself as a case of measles rather than a cold. Unfortunately, the disease is contagious long before the rash appears.

Measles is one of the most contagious diseases known. It is often said that if a person with measles rides an elevator, a passenger can still catch it two hours later.

For most people, the cold symptoms and the rash resolve and all is well. Some people can go on to develop ear or lung infections or diarrhea, none of which is likely to be fatal. Still 0.1-0.2% will die from the lung or [[brain]] complications of measles (pneumonia or encephalitis, respectively).<ref>[http://www.cdc.gov/measles/about/complications.html Measles (Rubeola): Complications] ''Centers for Disease Control''.</ref> The disease has two main neurologic complications:

*Measles encephalitis is a swelling of the brain that occurs in about 0.1% measles victims and often leads to permanent brain damage.

*Rarer is subacute sclerosing panencephalitis (SSPE), a horrifying, fatal neurologic disease that can appear up to a decade after measles infection.

Complications of measles are most common in children under 5-years old, adults over 20, pregnant women, and people with immunity problems.

==Impact of vaccination==
[[File:Measles incidence-cdc.gif|right|A graph of incidences of measles incidences from the [[CDC]].]]
In the pre-vaccination era, most children caught measles. Despite increases in hygiene and medical techniques, rates of measles stayed effectively the same. In fact, anyone born before 1957 is presumed to have had the disease and to subsequently have lifetime immunity from reinfection.

When the first vaccine was licensed, measles basically disappeared from areas with widespread vaccination programs (measles is still endemic in some countries Asia and Africa with outbreaks around the world<ref name=cdc>[https://web.archive.org/web/20210830192205/https://www.cdc.gov/globalhealth/measles/data/global-measles-outbreaks.html Global Measles Outbreaks] (August 12, 2021) ''Centers for Disease Control and Prevention'' (archived from August 30, 2021).</ref>).

Based on a historical review of measles-infected vs. measles-vaccinated children, a 2015 analysis reported that it is likely that there is a long-term immuno-suppression caused by measles infection that increases the likelihood of fatality from other diseases.<ref name="erynbrown">[http://www.latimes.com/science/sciencenow/la-sci-sn-measles-long-term-effects-20150507-story.html Study points to years-long immune system woes from measles] by Eryn Brown (May 7, 2015) ''Los Angeles Times''.</ref><ref name="mina">[http://www.sciencemag.org/content/348/6235/694.short Long-term measles-induced immunomodulation increases overall childhood infectious disease mortality] by Michael J. Mina et al. ''Science'' 8 May 2015: Vol. 348 no. 6235 pp. 694-699. DOI: 10.1126/science.aaa3662</ref> The measles vaccine actually does prevent other unrelated diseases. That is because the measles virus targets immune cells and manages to erase much of the immune systems' "memory" for fighting diseases. A consequence of this is that the measles vaccine reduces overall death rates, not just from measles.<ref>[https://www.sciencenews.org/article/measles-immune-system-memory-infection Measles erases the immune system's memory: Beyond the rash, the infection makes it harder for the body to remember and attack other invaders] by Laura Sanders (6:00am, May 21, 2019) ''Science News''.</ref>

In highly contagious diseases such as measles, [[herd immunity]] (either from vaccination or prior exposure) needs to be at least 90-95% to prevent [[epidemic]]s.<ref>[http://theconversation.com/herd-immunity-and-measles-why-we-should-aim-for-100-vaccination-coverage-36868 Herd immunity and measles: why we should aim for 100% vaccination coverage] by Marcel Salathé (February 2, 2015 2.01am EST) ''The Conversation''.</ref> Unfortunately, the post-2001 numbers are rather worse, because of a loss of herd immunity following the rise of the [[anti-vaccination movement]].

==Wakefield Affair==
{{main|Andrew Wakefield}}

==North American Outbreak of 2014-2015==
{{cquote|It was only measles, doctor. No one worries about measles anymore.|||A baffled parent whose daughter died from measles in 1961 before widespread vaccination but when post-exposure immune globulin prophylaxis was available<ref>''Vaccine Nation: America's Changing Relationship with Immunization'' by Elena Conis (2015) The University of Chicago Press. ISBN 0226923762.</ref>{{rp|51,271}}}}
In 2014, there were 667 cases in the US, and in 2015 there were 189 cases.<ref name=cdc/> In 2025, following the pseudo-legitimation of antivaxerism with the appointment of [[Robert F. Kennedy Jr.]] as head of the US Department of Health and Human Services during the second [[Donald Trump]] administration, there have been 1130 confirmed measles cases in the US during the first-half of 2025.<ref>[https://web.archive.org/web/20250709204536/https://www.cdc.gov/measles/data-research/?CDC_AAref_Val=https://www.cdc.gov/measles/cases-outbreaks.html Measles Cases and Outbreaks] (July 9, 2025) ''Centers for Disease Control'' (archived from July 9, 2025).</ref>

==References==
{{reflist|2|80%}}

[[Category:Biology]]
[[Category:Disease]]
[[Category:Health care]]
[[Category:Medicine]]
[[Category:Viruses]]

Categories: Biology, Disease, Health care, Medicine, Viruses