The Family Paramyxoviridae includes the genera Morbillivirus, Paramyxovirus, and Pneumovirus.
Measles virus, a human pathogen, is in the genus Morbillivirus. It is an enveloped, single-stranded, non-segmented, negative-sense RNA virus. Its virions are pleomorphic (roughly spherical) in shape with a diameter of 300–500 nm. Parainfluenza and mumps viruses are within the genus Paramyxovirus, and the respiratory syncytial virus (RSV) and metapneumovirus are within the genus Pneumovirus. Two zoonotic and highly human pathogenic paramyxoviruses (Nipah virus and Hendra virus) were discovered in 1998 after outbreaks of severe encephalitis in Malaysia and Singapore. Their virions have similar morphologies and protein components.
Measles, also known as rubeola, is one of the five classic childhood exanthems, along with rubella, roseola, the fifth disease, and chickenpox. Historically, measles, a serious febrile illness was among the most common and unpleasant childhood viral infections, with potentially serious sequelae. Its incubation period usually lasts 7 to 13 days, and the prodrome starts with 2 to 4 days of high fever and “CCC and P” (cough, coryza, conjunctivitis, and photophobia). The disease is most contagious during this time. After 2 days of prodromal illness, the typical mucous membrane lesions known as Koplik spots appear. They appear mostly on the buccal mucosa across from the molars, but they may appear on other mucous membranes as well, including the conjunctivae and the vagina. The vesicular lesions, which last 24 to 48 hours, are usually small (1 to 2 mm) and are best described as grains of salt surrounded by a red halo, usually on the face and upper neck. They spread over about 3 days, eventually to the hands and feet. They usually lasts 5–6 days before fading.
Before 1960, more than 90% of the population younger than 20 years had experienced the rash, high fever, cough, conjunctivitis, and coryza of measles. Measles is still one of the most prominent infectious diseases (with >10 million clinical cases and nearly 120,000 deaths in 2012 worldwide in unvaccinated populations. The development of effective vaccine programs has made measles a rare disease in developed countries, but when children remain unvaccinated or do not receive their boosters, outbreaks of measles do occur even today. There is no specific treatment for measles.
Measles can spread readily when an infected person disseminates the virus via breathing, coughing and/or sneezing. The virus may remain viable in indoor air and on contaminated surfaces for up to two hours.
The recently recorded upsurge in measles cases has initiated an accelerated measles immunization program in several countries in an effort to stem the spread of the infection. In spite of the availability of a safe and effective vaccine, nearly 22 million children missed at least one dose of measles vaccine through routine immunization in 2022. In 2024, the first measles case was recorded in Toronto, ON, Canada. As of March 13, Public Health Ontario had confirmed at least eight cases of measles across the province. Similar increases in measles cases are being recorded in other parts of the country.
Apart from proper vaccination, maintaining good indoor air
quality can be an effective preventive measure against measles. CREM Co Labs
has the facilities for and experience in studying indoor air survival and
decontamination of viruses similar to the measles virus. CREM Co Labs has two separate
aerobiology facilities including two aerobiology chambers. We can assess air decontamination technologies
(air sanitizers and air purifiers) against all major classes of pathogens
including enveloped and non-enveloped viruses.
Further reading:
1) Medical Microbiology. (2021) Patrick R. Murray, Ken S. Rosenthal and
Michael A. Pfaller. Ninth Edition.
2) https://www.who.int/news-room/fact-sheets/detail/measles
3) Kondamudi NP, Waymack JR. Measles. [Updated 2023 Aug 12]. In:
StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; (2024 Jan) -. Available from: https://www.ncbi.nlm.nih.gov/books/NBK448068/
4) Carissa Wong : Measles outbreaks cause alarm: what
the data say. Nature, News explainer. 31 January 2024
5) Gastañaduy PA, Goodson JL, Panagiotakopoulos L, Rota
PA, Orenstein WA, Patel M. Measles in the 21st Century: Progress Toward
Achieving and Sustaining Elimination. J Infect Dis. 2021 Sep 30;224(12 Suppl
2):S420-S428. doi: 10.1093/infdis/jiaa793. PMID: 34590128; PMCID: PMC8482021.
6) https://www.cp24.com/news/second-case-of-measles-confirmed-in-toronto-1.6812011