Introduction
Measles is an acute highly infectious disease of childhood caused by a specific virus of the group myxoviruses. It remains an important cause of death among young children globally, despite the availability of a safe and effective vaccine, in 2017 there were 110000 measles deaths globally, mostly among children under the age of five. Measles vaccination resulted in a 80% drop in measles deaths between 2000 and 2017 worldwide.
Epidemiological determinants
Agent and host factors: Measles is caused by an RNA paramyxovirus. The virus cannot survive outside the human body for any length of time but retains infectivity when stored at sub-zero temperature. Measles is highly infectious during the prodromal period and at the time of the eruption. Communicability declines rapidly after the appearance of the rash. Period of communicability is approximately 4 days before and 4 days after the appearance of the rash.
Measles affects virtually everyone in infancy or childhood (6 months to 3 years) of both the sexes in developing countries where environmental conditions are generally poor and older children usually over 5 years in developed countries. While looking at the nutrition status, measles tend to be very severe in the malnourished child, caring mortality up to 400 times higher than in well-nourished children having measles.
Environmental factor: The virus can spread in any season. In tropical zones, most cases of measles occur during the dry season whereas, in temperate climates, measles is a winter disease. In general, the less favorable the prevailing socio-economic conditions, the lower the average age at which children are attacked.
Transmission: Transmission occurs directly from person to person mainly by droplet infection and droplet nuclei. It is a highly contagious virus that lives in the nose and throat mucus of an infected person. It can spread to others through coughing and sneezing. Also, measles virus can live for up to two hours in an airspace where the infected person coughed or sneezed. If other people breathe the contaminated air or touch the infected surface, then touch their eyes, noses, or mouths, they can become infected.
Signs and symptoms of Measles are given below.
- High fever that begins about 10-12 days after exposure to the virus, and lasts 4 to 7 days.
- Cough
- Small white spots inside cheeks can develop in the initial stage.
- Runny nose (coryza)
- Red, watery eyes
- An eruption of rash usually on the face and upper neck after several days
No specific treatment exists for measles but routine measles vaccination for children, combined with mass immunization campaigns in countries with high case and death rate works well as a preventive method. Two doses of the vaccine are recommended to ensure immunity and prevent outbreaks, as about 15% of vaccinated children fail to develop immunity from the first dose. In 2017, 67% of children received the second dose of the measles vaccine.
Reference
- https://www.who.int/immunization/diseases/measles/en/
- https://www.who.int/news-room/fact-sheets/detail/measles
- https://www.health.gov.il/English/Topics/Pregnancy/Vaccination_of_infants/Pages/measles.aspx
- Lawrence, et.al (2006). Current medical diagnosis and medical treatment 45th Edition
- Park. Concept of Health and Disease. In: Park’s Textbook of PREVENTIVE AND SOCIAL MEDICINE. 23rd ed. India: Banarsidas Bhanot; 2015
- https://www.cdc.gov/measles/about/transmission.html
- https://www.cdc.gov/measles/about/signs-symptoms.html