Eng. measles [ˈmi.zəlz], also known as morbilli, rubeola, red measles, and English measles, refers to ‘an acute, contagious viral disease, usually occurring in childhood and characterized by eruption of red spots on the skin, fever, and catarrhal symptoms. Also called rubeola’ (AHD). It is caused by the measles virus (MeV), which ‘is a single-stranded, negative-sense, enveloped (non-segmented) RNA virus of the genus Morbillivirus within the family Paramyxoviridae’ (WP). The virus causes
an infection of the respiratory system. Symptoms include fever, cough, runny nose, red eyes and a generalized, maculopapular, erythematous rash. The virus is highly contagious and is spread by coughing and sneezing via close personal contact or direct contact with secretions. (WP)
The word measles is the plural of Mid. Eng. measle, which is most likely a loanword from Middle Low German masele or Middle Dutch masel ‘pustule, spot on the skin’ (cf. Dutch mazelen ‘measles’ and Old High German masala ‘blood-blister’. These are words of Germanic origin, though the English spelling and pronunciation may have been influenced by Mid. Eng. mesel ‘leper’, an Old French loan ultimately from Lat. mĭsellus ‘wretch’, diminutive of mĭser ‘wretched, unfortunate, miserable, pitiable, lamentable, etc.’ (cf. Latin mĭserĭa ‘wretchedness, etc.’). The other English name for this disease, the medical term rubeola [ɹu.ˈbi.əl.ə], is a late 17th century New Latin word derived from the neuter plural of an unattested Lat. *rubeolus, diminutive of the Latin adjective rŭbĕus (also rŏbeus or rŏbus) ‘red, reddish’, because of the color of the red spots on the skin.
The word for measles in Spanish is sarampión, which has cognates in all the languages of the Iberian Peninsula and southern France. The source of this word is the dialectal Latin word sirimpiōnem (nom. sĭrĭmpĭo) ‘measles papule’ (the word papule is a 19th century loan from Latin păpŭla ‘pustule, pimple’, cf. Sp. pápula). According to Corominas, it is possible that the word was an alteration of an unattested *sinapionem, derived from Lat. sĭnāpi ‘mustard’, referring to the red blisters caused by the disease.
The word measles may refers to several diseases, such as black measles, also known as Rocky Mountain spotted fever or blue disease, ‘the most lethal and most frequently reported rickettsial illness in the United States’ (WP), in particular in the eastern US, produced by a bacterium Rickettsia rickettsii. The illness’ name in Spanish is Fiebre de las Montañas Rocosas, though it is also found in wooded areas of Central and South America.
The word measles can also refer to German measles, a different disease also known as rubella or three-day measles, which has similar but milder symptoms and is caused by the rubella virus. Rubella is known in Spanish as rubéola, rubeola, or sarampión alemán (note that in English, rubeola is another word for English measles, not German measles). The word rubella [ɹu.ˈbɛ.lə] is a late 19th century New Latin name for this disease, derived from the neuter plural form of the Latin adjective rŭbellus ‘reddish’ (fem. rŭbella), the diminutive of ruber ‘red’.