Measles, also known as rubeola, not to be confused with rubella, is a disease caused by a virus of the genus Morbillivirus. Measles was long considered a normal childhood disease, but the virus can cause severe complications in otherwise healthy children and adults, including sometimes-fatal encephalitis, pneumonia and diarrhea. Only 37 measles cases were reported in the United States in 2004. But a few cases are still imported from countries with lower vaccination rates and the disease occurs domestically as well. Most developed countries routinely vaccinate children against measles but the virus still killed 500,000 people, mostly children, around the world in 2003, according to the World Health Organization.
An increase in imported cases has led to increased
reports of measles disease in the United States.
Amish in Ohio
The measles outbreak that struck an Amish community in 2014 illustrates the ongoing threat the infection presents -- and the importance of routine vaccination. The outbreak, which ultimately infected 383 people in Ohio, was the largest the United States had seen in over 20 years. It was almost entirely limited to an Amish community, and most who fell ill had never been vaccinated against measles.
Vaccines are crucial and necessary, but they do have a small risk which does not outweigh the benefits.
Vaccine. 2015. Risk of febrile seizure after measles-mumps-rubella-varicella vaccine: A systematic review and meta-analysis. We searched PubMed, Embase, BIOSIS Previews, Scopus, Web of Science, Cochrane Library and other databases through 12 December 2014. A total of thirty-nine studies were included. First MMRV vaccine dose in children aged 10-24 months was associated with an elevated risk of seizure or febrile seizure.
Two types of measles
Measles is best known for causing a rash in childhood, but measles can affect other parts of the body and sometimes occurs in adults. Vaccination has significantly reduced the number of cases in the United Statesr.
There are two types of measles, each caused by a different virus. Although both produce a rash and fever, they are really different diseases:
1. The rubeola virus causes "red measles," also known as "hard measles." Although most people recover without problems, rubeola can lead to pneumonia or inflammation of the brain (encephalitis).
2. The rubella virus causes "German measles," also known as "three-day measles." This is usually a milder disease than red measles. However, this virus can cause significant birth defects if an infected pregnant woman passes the virus to her unborn child.
History of Measles in USA
Before such vaccination was introduced in the United States in the mid-1960s, more than half a million cases of measles were reported each year. By the mid-1970s, fewer than 50,000 cases were being reported annually in the United States, but a severe outbreak in Los Angeles in 1977 led to compulsory immunization of schoolchildren. A second dose of measles vaccine was introduced in 1989. In March 2000, it was announced that measles was no longer endemic in the USA. However, a 2005 measles outbreak occurred in Indiana when a 17-year-old girl who was incubating measles returned to Indiana from Romania, the outbreak ultimately involved at least 34 persons, 1 of whom had life-threatening illness.
From January to July 2008, a total of 131 measles cases were reported to the U.S. Centers for Disease Control and Prevention, the highest number seen during the same 7-month period since 1996.
A total of 137 U.S. measles cases were reported in
the United States 2008. Most of these cases were imported or associated
with importations from other countries.
Measles is an acute infectious disease that can affect persons of all ages but is most severe in young infants and adults. Person-to-person transmission occurs through direct contact or droplet spread. Infected persons can infect others during the prodromal period before the characteristic rash appears, creating ample opportunity for people who are incubating the disease to travel from a country where the virus is circulating.
In the United States, measles vaccine is delivered in combination with mumps and rubella vaccines. Although the two-dose strategy ensures that a high proportion of those who are vaccinated will be immune to measles (seroconversion after two doses of vaccine is estimated to be 98 percent), the conversion rate is lower for mumps (approximately 88 percent). Thus, the proportion of persons in a U.S. community who are susceptible to mumps is greater than the proportion who are susceptible to measles, and outbreaks, when they occur, will be larger.
Vaccine. Feb 9 2014. The effect of early measles vaccination on thymic size. A randomized study from Guinea-Bissau. In low-income countries early measles vaccine (MV) is associated with reduced child mortality which cannot be explained by prevention of measles. A large thymus gland in infancy is also associated with reduced mortality. We hypothesized that early MV is associated with increased thymic size. Within a randomized trial providing MV at age 4.5 and 9 months or MV only at age 9 months, thymic size was assessed by ultrasound at age 4.5 months, before randomization to early MV or no early MV, and 4 weeks later. Among 656 children, there was no effect of early MV on thymic size. In a post hoc analysis early MV was associated with a negative effect in healthy children but a positive effect in ill children. In conclusion, early MV at age 4.5 months had no overall effect on thymus size 4 weeks later.
Two measles-containing vaccines are safe, according to a new 12-year study published in 2015. The research included children between the ages of 12 to 23 months. Some youngsters received the combination measles-mumps-rubella-varicella (MMRV) vaccine. Others were given separately administered measles-mumps-rubella and varicella (MMR + V) vaccines, but they received both vaccines on the same day.
Risk of vaccination
J Cancer. 2014 Jan 5. Does the Measles Virus Contribute to Carcinogenesis? - A Review. An association between the measles virus and classical Hodgkin lymphoma has previously been suggested by us. This has been refuted by two European groups. A reevaluation of the arguments held against our thesis was carried out and further evidence for a relationship between the measles virus and additional solid tumors has been presented. We have suggested a molecular mechanism to support a possible contribution of the virus to carcinogenesis in classical Hodgkin lymphoma.
Spread of Measles
Measles is spread through respiration (contact with fluids from an infected person's nose and mouth, either directly or through aerosol transmission), and is highly contagious - 90% of people without immunity sharing a house with an infected person will catch it. Airborne precautions should be taken for all suspected cases of measles. The incubation period usually lasts for 10-12 days (during which there are no symptoms). Infected people remain contagious from the appearance of the first symptoms until 3-5 days after the rash appears.
High vaccination coverage rates and the administration of a second dose of measles vaccine have resulted in a significant decline in the incidence of measles and neurologic diseases due to measles in many countries. However, intermittent outbreaks of measles still occur even in countries with excellent vaccination coverage, suggesting the existence of high rates of measles virus introduction from endemic regions and/or waning of vaccine-induced immunity.
Worldwide measles deaths dropped 48 percent in six years as immunization efforts reached more children in sub-Saharan Africa. The World Health Organization (WHO) and U.N. Children's Fund (UNICEF) said the fall in deaths to 454,000 in 2004 from 871,000 in 1999 was "an outstanding public health success story". A safe, cheap and effective measles vaccine has been available since the 1960s, but the highly infectious disease is still a major killer of children in developing countries. About 410,000 children under the age of 5 died from measles in 2004, many from complications related to severe diarrhea and pneumonia, the U.N. agencies said in a joint statement.
During the first three months of 2009, large outbreaks of measles have been reported in Burkina Faso, France, Iraq, Switzerland, and Vietnam.
Measles deaths drop
January 2007 - Deaths from measles have fallen by 60 percent worldwide since 1999 in what experts described on Friday as an historic victory for global health. Accelerated control measures including an increase in routine measles immunizations and a campaign to reach marginalized children in the 45 worst hit countries has pushed deaths down from an estimated 873,000 in 1999 to around 345,000 in 2005. The biggest fall has been in Africa where the number of children dying from measles fell 75 percent to 126,000.
Measles in Boston
The city reported the first outbreak of measles in seven years after four people in a downtown office tower were diagnosed with the highly infectious disease. The Boston Public Health Commission opened a second emergency health clinic in May 2006 at the 60-story John Hancock Tower after it became known that hundreds of workers may be at risk of developing measles. The four who were diagnosed with the disease all worked at Investors Bank & Trust, a financial services firm. Three of the workers caught the disease from a contract worker who recently traveled from India.