Measles

Measles 

Definition

Measles is an infection caused by a virus, which causes an illness displaying a characteristic skin rash known as an exanthem. Measles is also sometimes called rubeola, 5-day measles, or hard measles.

Description

Measles infections appear all over the world. Prior to the current effective immunization program, large-scale measles outbreaks occurred on a two to three-year cycle, usually in the winter and spring. Smaller outbreaks occurred during the off-years. Babies up to about eight months of age are usually protected from contracting measles, due to immune cells they receive from their mothers in the uterus. Once someone has had measles infection, he or she can never get it again.

Causes and symptoms

Measles is caused by a type of virus called a paramyxovirus. It is an extremely contagious infection, spread through the tiny droplets that may spray into the air when an individual carrying the virus sneezes or coughs. About 85% of those people exposed to the virus will become infected with it. About 95% of those people infected with the virus will develop the illness called measles. Once someone is infected with the virus, it takes about 7-18 days before he or she actually becomes ill. The most contagious time period is the three to five days before symptoms begin through about four days after the characteristic measles rash has begun to appear.

The first signs of measles infection are fever, extremely runny nose, red, runny eyes, and a cough. A few days later, a rash appears in the mouth, particularly on the mucous membrane which lines the cheeks. This rash consists of tiny white dots (like grains of salt or sand) on a reddish bump. These are called Koplik's spots, and are unique to measles infection. The throat becomes red, swollen, and sore.

A couple of days after the appearance of the Koplik's spots, the measles rash begins. It appears in a characteristic progression, from the head, face, and neck, to the trunk, then abdomen, and next out along the arms and legs. The rash starts out as flat, red patches, but eventually develops some bumps. The rash may be somewhat itchy. When the rash begins to appear, the fever usually climbs higher, sometimes reaching as high as 105°F (40.5°C). There may be nausea, vomiting, diarrhea, and multiple swollen lymph nodes. The cough is usually more problematic at this point, and the patient feels awful. The rash usually lasts about five days. As it fades, it turns a brownish color, and eventually the affected skin becomes dry and flaky.

Many patients (about 5-15%) develop other complications. Bacterial infections, such as ear infections, sinus infections, and pneumonia are common, especially in children. Other viral infections may also strike the patient, including croup, bronchitis, laryngitis, or viral pneumonia. Inflammation of the liver, appendix, intestine, or lymph nodes within the abdomen may cause other complications. Rarely, inflammations of the heart or kidneys, a drop in platelet count (causing episodes of difficult-to-control bleeding), or reactivation of an old tuberculosis infection can occur.

An extremely serious complication of measles infection is swelling of the brain. Called encephalitis, this can occur up to several weeks after the basic measles symptoms have resolved. About one out of every thousand patients develops this complication, and about 10-15% of these patients die. Symptoms include fever, headache, sleepiness, seizures, and coma. Long-term problems following recovery from measles encephalitis may include seizures and mental retardation.

A very rare complication of measles can occur up to 10 years following the initial infection. Called subacute sclerosing panencephalitis, this is a slowly progressing, smoldering swelling and destruction of the entire brain. It is most common among people who had measles infection prior to the age of two years. Symptoms include changes in personality, decreased intelligence with accompanying school problems, decreased coordination, involuntary jerks and movements of the body. The disease progresses so that the individual becomes increasingly dependent, ultimately becoming bedridden and unaware of his or her surroundings. Blindness may develop, and the temperature may spike (rise rapidly) and fall unpredictably as the brain structures responsible for temperature regulation are affected. Death is inevitable.

Measles during pregnancy is a serious disease, leading to increased risk of a miscarriage or stillbirth. In addition, the mother's illness may progress to pneumonia.

Diagnosis

Measles infection is almost always diagnosed based on its characteristic symptoms, including Koplik's spots, and a rash which spreads from central body structures out towards the arms and legs. If there is any doubt as to the diagnosis, then a specimen of body fluids (mucus, urine) can be collected and combined with fluorescent-tagged measles virus antibodies. Antibodies are produced by the body's immune cells that can recognize and bind to markers (antigens) on the outside of specific organisms, in this case the measles virus. Once the fluorescent antibodies have attached themselves to the measles antigens in the specimen, the specimen can be viewed under a special microscope to verify the presence of measles virus.

Treatment

There are no treatments available to stop measles infection. Treatment is primarily aimed at helping the patient to be as comfortable as possible, and watching carefully so that antibiotics can be started promptly if a bacterial infection develops. Fever and discomfort can be treated with acetaminophen. Children with measles should never be given aspirin, as this has caused the fatal disease Reye's syndrome in the past. A cool-mist vaporizer may help decrease the cough. Patients should be given a lot of liquids to drink, in order to avoid dehydration from the fever.

Some studies have shown that children with measles encephalitis benefit from relatively large doses of vitamin A.

Alternative treatment

Botanical immune enhancement (with echinacea, for example) can assist the body in working through this viral infection. Homeopathic support also can be effective throughout the course of the illness. Some specific alternative treatments to soothe patients with measles include the Chinese herbs bupleurum (Bupleurum chinense) and peppermint (Mentha piperita), as well as a preparation made from empty cicada (Cryptotympana atrata) shells. The itchiness of the rash can be relieved with witch hazel (Hamamelis virginiana), chickweed (Stellaria media), or oatmeal baths. The eyes can be soothed with an eyewash made from the herb eyebright (Euphrasia officinalis). Practitioners of ayurvedic medicine recommend ginger or clove tea.

Prognosis

The prognosis for an otherwise healthy, well-nourished child who contracts measles is usually quite good. In developing countries, however, death rates may reach 15-25%. Adolescents and adults usually have a more difficult course. Women who contract the disease while pregnant may give birth to a baby with hearing impairment. Although only 1 in 1,000 patients with measles will develop encephalitis, 10-15% of those who do will die, and about another 25% will be left with permanent brain damage.

Prevention

Measles is a highly preventable infection. A very effective vaccine exists, made of live measles viruses which have been treated so that they cannot cause actual infection. The important markers on the viruses are intact, however, which causes an individual's immune system to react. Immune cells called antibodies are produced, which in the event of a future infection with measles virus will quickly recognize the organism, and kill it off. Measles vaccines are usually given at about 15 months of age; because prior to that age, the baby's immune system is not mature enough to initiate a reaction strong enough to insure long-term protection from the virus. A repeat injection should be given at about 10 or 11 years of age. Outbreaks on college campuses have occurred among unimmunized or incorrectly immunized students.

Measles vaccine should not be given to a pregnant woman, however, in spite of the seriousness of gestational measles. The reason for not giving this particular vaccine during pregnancy is the risk of transmitting measles to the unborn child.

Surprisingly, new cases of measles began being reported in some countries—including Great Britain—in 2001 because of parents' fears about vaccine safety. The combined vaccine for measles, mumps, and rubella (MMR) was claimed to cause autism or bowel disorders in some children. However, the World Health Organization (WHO) says there is no scientific merit to these claims. The United Nations expressed concern that unwarranted fear of the vaccine would begin spreading the disease in developing countries, and ultimately in developed countries as well. Parents in Britain began demanding the measles vaccine as a separate dose and scientists were exploring that option as an alternative to the combined MMR vaccine. Unfortunately, several children died during an outbreak of measles in Dublin because they had not received the vaccine. Child mortality due to measles is considered largely preventable, and making the MMR vaccine widely available in developing countries is part of WHO's strategy to reduce child mortality by two-thirds by the year 2015.

Key terms

Antibodies — Cells made by the immune system which have the ability to recognize foreign invaders (bacteria, viruses), and thus stimulate the immune system to kill them.

Antigens — Markers on the outside of such organisms as bacteria and viruses, which allow antibodies to recognize foreign invaders.

Encephalitis — Swelling, inflammation of the brain.

Exanthem (plural, exanthems or exanthemata) — A skin eruption regarded as a characteristic sign of such diseases as measles, German measles, and scarlet fever.

Koplik's spots — Tiny spots occurring inside the mouth, especially on the inside of the cheek. These spots consist of minuscule white dots (like grains of salt or sand) set onto a reddened bump. Unique to measles.

Resources

Books

Beers, Mark H., MD, and Robert Berkow, MD, editors. "Viral Infections: Measles." Section 19, Chapter 265. In The Merck Manual of Diagnosis and Therapy. Whitehouse Station, NJ: Merck Research Laboratories, 2004.

Periodicals

Chiba, M. E., M. Saito, N. Suzuki, et al. "Measles Infection in Pregnancy." Journal of Infection 47 (July 2003): 40-44.

Jones, G., R. W. Steketee, R. E. Black, et al. "How Many Child Deaths Can We Prevent This Year?" Lancet 362 (July 5, 2003): 65-71.

McBrien, J., J. Murphy, D. Gill, et al. "Measles Outbreak in Dublin, 2000." Pediatric Infectious Disease Journal 22 (July 2003): 580-584.

"Measles—United States, 2000. (From the Centers for Disease Control and Prevention)." Journal of the American Medical Association 287, no. 9 (March 6, 2002): 1105-1112.

Scott, L. A., and M. S. Stone. "Viral Exanthems." Dermatology Online Journal 9 (August 2003): 4.

Sur, D. K., D. H. Wallis, and T. X. O'Connell. "Vaccinations in Pregnancy." American Family Physician 68 (July 15, 2003): 299-304.

"WHO: Vaccine Fears Could Lead to Unnecessary Deaths." Medical Letter on the CDC & FDA March 17, 2002: 11.

Organizations

American Academy of Pediatrics (AAP). 141 Northwest Point Boulevard, Elk Grove Village, IL 60007. (847) 434-4000. http://www.aap.org.

Centers for Disease Control and Prevention. 1600 Clifton Rd., NE, Atlanta, GA 30333. (800) 311-3435, (404) 639-3311. http://www.cdc.gov.

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measles /mea·sles/ (mez´'lz) rubeola; a highly contagious viral infection, usually of childhood, involving primarily the respiratory tract and reticuloendothelial tissues, marked by an eruption of discrete, red papules, which become confluent, flatten, turn brown, and desquamate.

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atypical measles  a form of natural measles infection affecting those who previously received killed measles virus vaccine.

black measles  a severe form in which the eruption is very dark and petechial.

German measles  rubella.

hemorrhagic measles  black m.

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mea·sles (mzlz)

n.

1. 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.

2. Black measles.

3. Any of several other diseases, especially German measles, that cause similar but milder symptoms.

4. A disease of cattle and swine caused by tapeworm larvae.

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measles,

n viral disease characterized by the release of toxins that affect the central nervous system, red rash, fever, and white spots (Koplik's spots) on the tongue. Serious complications arising from measles include encephalitis, diarrhea, impaired vision, and pneumonia.

Measles.

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measles (mē´zlz),

n an infectious disease caused by a virus. There are two types: rubeola and rubella (German measles). Both have oral manifestations. See also spot, Koplik's.

measles, German,

n.pr See rubella.

measles, three-day,

n See rubella.

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measles

1. a highly contagious disease of humans characterized by a maculopapular skin rash and caused by a morbillivirus; called also rubeola.

2. a term used in veterinary science to identify animal diseases that have a speckled appearance thought to resemble the skin rash of measles in humans. The resemblance in most diseases is superficial and highly speculative.

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beef measles

see cysticercusbovis.

pork measles

see cysticercuscellulosae.

sheep measles

see cysticercusovis.

measles vaccine

a preparation containing attenuated human measles virus that is used to immunize dogs against canine distemper virus, based on the close antigenic relationship between the two viruses. It is only administered to young puppies, in which the persistence of maternal antibodies against canine distemper virus is likely to interfere with an immune response to canine distemper vaccine. It must always be followed by the administration of canine distemper vaccine by 4 months of age.