What is measles? Introduction
Measles is a highly contagious disease caused by the measles virus. It is one of the most contagious viruses of all human viruses causing widespread morbidity and mortality worldwide.
Measles is a notifiable disease in the United States, United Kingdom, Australia, and many other European countries.
Although considered mainly an illness of children, it can affect people of all ages. Once infected, your body will build up a lifelong immunity to the virus after you’ve had it.
The measles virus primarily infects the respiratory tract and then spreads to other parts of the body including the liver, skin, central nervous system, and the spleen.
Initial symptoms typically include high fever, cough with a running nose, and the classical body rash. It can cause serious complications even in healthy children and can even be fatal, especially in children below the age of 5 years old.
The hallmark skin rash all over the body of measles is caused when the virus spreads to the skin and causes inflammation of the capillaries in the skin.
Treatment is mainly supportive. Some may use broad-spectrum anti-viral drugs, and antibiotics may be used in case of super-added bacterial infection.
Epidemiology
Worldwide
Measles outbreaks occur worldwide. It is still considered a major cause of childhood morbidity and mortality despite an effective and safe vaccine being available. Children below 2 years of age in developing countries are the major group affected.
In 2013, the WHO estimated 145,700 deaths due to measles, globally.
In 2014, 451,756 suspected cases were registered worldwide.
According to the World Health Organization (WHO), in 2022, there were more than 9 million people infected with the measles virus and 136,000 deaths worldwide.
It is still a widespread and fatal disease in developing countries because of improper and nonaggressive vaccination measures.
Unvaccinated and malnourished individuals and those in whom immunity is compromised are highly susceptible to developing measles, its complications, and even death.
Measles kills more children, especially those who have not taken the vaccine. Getting vaccinated is the best way to protect yourself against this disease.
The measles vaccine was made first available in 1963. An improved version of the vaccine was created in 1968 and has been in use since.
All countries offer the measles vaccine in their immunization schedule. It has prevented many infections and deaths. For example, between 2000 and 2022, the vaccine prevented as many as 57 million deaths.
United States
In the United States, although measles was declared eliminated in 2000, its outbreaks (five or more cases) have occurred.
From January to May 2014, 288 confirmed cases were reported to the CDC, and most of those infected were unvaccinated or under-vaccinated individuals
The largest outbreak occurred in 2019, primarily among non-vaccinated people. 1274 cases were reported in 31 states of the United States. That is the highest number of cases since 1992.
Cases continue to occur in the country caused by the virus brought into the country by travelers from abroad. Unvaccinated individuals are specially infected.
Due to high vaccination rates, measles has not been widespread in the United States for about two decades. Those cases that occurred originated outside the country and infected those who were not vaccinated.
Due to an aggressive vaccination program resulting in high vaccination rates, it has been effectively contained in the United States for about two decades. Cases that were detected, originated outside the country and affected unvaccinated individuals.
Almost all cases in the US were those who traveled internally or came into close contact with those who traveled internationally.
Fatality rates
Measles kills more children than any other infectious viral disease that can be prevented with vaccines. The infection causes suppression of the immune system of the body, which subsequently leads to severe health complications, that can cause death, especially among young children.
Before the vaccine was introduced in 1963, major epidemics occurred every two to three years and caused an estimated 2.6 million deaths each year worldwide.
In 2022, despite the availability of an effective, safe, and cost-effective vaccine, about 136,000 people out of the 9 million infected, died from measles. They were mostly children below the age of five years.
Aggressive immunization programs by WHO, respective countries, and some international partners successfully prevented an estimated 57 million deaths between 2000–2022. Because of successful vaccination, the death rate declined from 761,000 in 2000 to 136,000 in 2022 worldwide.
- Generally, about 3 in 1,000 children infected with measles will succumb to the disease.
- Due to poor healthcare facilities and high malnutrition rates in developing countries, the fatality rate can be as high as 28%.
- In those with compromised immunity such as due to AIDS, the fatality rate is about 30%.
- Before the measles vaccine was introduced in 1963, 400-500 deaths occurred in the United States every year.
Measles Virus – Can it be eradicated?
The virus is a single-stranded RNA virus and is a member of the genus Morbillivirus within the family Paramyxoviridae. Other names of measles include morbilli, rubeola, red measles, and English measles
Humans are the only natural hosts of the measles virus. It is not known to affect other animals. And, since humans are the only reservoir for the measles virus, it can theoretically be eradicated from the world.
Measles meets the following criteria for a disease that can be eradicated:
- No animal or any other environmental reservoir except humans
- Precise diagnostic tests are available.
- A highly effective, safe, and cost-effective vaccine against this virus
- Successful measles eradication programs have been carried out in many large geographical areas.
