What is Measles?
Measles is an acute viral respiratory illness with at least a 90% secondary infection rate in susceptible domestic contacts. It is usually thought of as a childhood illness but affects all ages. It runs with prodromal fever, cough, coryza, conjunctivitis, and the pathognomonic enanthem (Koplik spots), followed by an erythematous maculopapular rash on the third to the seventh day. Infection confers lifelong immunity.
Pathophysiology
In temperate areas, incidence peaks in late winter and spring. Transmission is by respiratory droplets, which stay active and contagious airborne or on surfaces for up to 2 hours. Initial infection and replication occur in tracheal and bronchial epithelial cells. After 2-4 days the virus infects local lymphatic tissue, likely carried by pulmonary macrophages. After amplification in regional lymph nodes, a mostly cell-associated viremia spreads the virus to multiple organs before the rash appears. Measles also causes generalized immunosuppression, with decreases in delayed-type hypersensitivity, interleukin (IL)-12 production, and antigen-specific lymphoproliferative responses that persist for weeks to months after acute infection.
Statistics and Incidences
The practice of giving 2 doses of live-attenuated measles vaccine to prevent school outbreaks dates to the vaccine's first licensure in 1963, and the immunization program cut reported incidence by more than 99%. From 1989 to 1991 a major resurgence hit unvaccinated preschoolers, causing 55,000 cases and 130 deaths and prompting the second-dose recommendation that effectively eliminated endemic US transmission. By 1997-1999 incidence reached a historic low (< 0.5 cases per million persons). From 1997 to 2004 reported incidence ran as low as 37-116 cases per year, and from 2000 through 2007 an average of 63 cases were reported annually to the CDC.
In 2004, 34 cases were reported; after that all-time low, annual incidence climbed, with most cases tied directly or indirectly to international travel. In 2005, 66 cases were reported to the CDC, of which 34 were linked to a single Indiana outbreak from an unvaccinated 17-year-old American traveling in Romania. In 2006, 49 confirmed cases were reported. From January to June 2008, 131 cases were reported, and at least 47% of those 131 infections were in school-aged children whose parents declined vaccination.
From January 1 to May 20, 2011, 118 cases were reported, the highest for that period since 1996. Of these, 105 (89%) were import-associated and the source of the remaining 13 could not be determined; 105 (89%) of the 118 were unvaccinated, and 24 (20%) were persons 12 months to 19 years of age whose parents claimed a religious or personal exemption. About half of the 118 cases, 58 or 49%, came from 9 outbreaks. The largest involved 21 persons in Minnesota, where MMR safety concerns left many children unvaccinated, and at least 7 infants too young for MMR were infected. From January 1 to May 23, 2014, 288 confirmed cases were reported, exceeding the prior annual high (220 cases in 2011) since measles was declared eliminated in the United States in 2000.
Measles remains a major global cause of vaccine-preventable death. The WHO and CDC estimated about 10.3 million cases worldwide in 2023, a 20 percent rise from 2022, with roughly 107,500 deaths, most of them in children younger than 5 (CDC). Falling immunization coverage drives these surges, and measles is still a leading infectious cause of childhood blindness in low-coverage regions. Earlier figures of 30 million cases and about 1 million deaths a year reflect the pre-expansion-program era and no longer describe the current burden. In 1998, cases per 100,000 total population reported to the WHO were 1.6 in the Americas, 8.2 in Europe, 11.1 in the Eastern Mediterranean, 4.2 in South East Asia, 5.0 in the Western Pacific, and 61.7 in Africa. In 2006 only 187 confirmed cases were reported in the Western Hemisphere (mainly Venezuela, Mexico, and the United States). Between 2000 and 2008, worldwide cases reported to the WHO and UNICEF fell 67% (from 852,937 to 278,358).
Of the 66 US cases in 2005, 7 (10.6%) were infants, 4 (6.1%) were children aged 1-4 years, 33 (50%) were persons aged 5-19 years, 7 (10.6%) were adults aged 20-34 years, and 15 (22.7%) were adults older than 35 years. Among the 118 US patients reported between January 1 and May 20, 2011, ages ranged from 3 months to 68 years.
Causes
The cause is the measles virus, a single-stranded, negative-sense enveloped RNA virus of the genus Morbillivirus, family Paramyxoviridae. Humans are the natural hosts; no animal reservoirs are known. It spreads by coughing and sneezing through close personal contact or direct contact with secretions. Children with immunodeficiency from HIV or AIDS, leukemia, alkylating agents, or corticosteroid therapy can contract measles regardless of immunization status. Travel to or contact with travelers from endemic areas is a risk, as is loss of passive antibody before the age of routine immunization.
Clinical Manifestations
Incubation runs 7 to 14 days (average 10-12 days). The first sign is usually high fever (often >104°F [40°C]) lasting 4-7 days. The prodrome brings malaise, fever, anorexia, and the classic triad of conjunctivitis, cough, and coryza (the "3 Cs"). The exanthem appears 2-4 days after the prodrome starts and lasts 3-5 days, usually 1-2 days after Koplik spots; mild pruritus may occur. On average the rash develops about 14 days after exposure, starting on the face and upper neck and spreading to the extremities. Koplik spots are small spots seen inside the cheeks during this early stage.
Assessment and Diagnostic Findings
The diagnosis is usually clinical, but lab confirmation is needed for public health and outbreak control. The measles virus sandwich-capture IgM antibody assay, available through many local health departments and the CDC, is the quickest way to confirm acute measles; labs can also confirm by showing more than a 4-fold rise in IgG between acute and convalescent sera, though relying on rising IgG titers alone delays treatment. Throat and nasal swabs can go on viral transport medium or a culturette to isolate the virus, and urine can be sent in a sterile container for viral culture. Reverse-transcription PCR is highly sensitive for measles virus RNA in blood, throat, nasopharyngeal, or urine specimens and, where available, confirms the diagnosis quickly. If bacterial pneumonia is suspected, do chest radiography, though frequent measles pneumonia even in uncomplicated cases limits its predictive value for bacterial bronchopneumonia.
Medical Management
Treatment is supportive. Keep the child well hydrated and replace fluids lost to diarrhea or emesis. Consider vitamin A supplementation, especially in children and those with signs of vitamin A deficiency. Hospitalize for complications (bacterial superinfection, pneumonia, dehydration, croup). Treat secondary infections such as otitis media or bacterial pneumonia with antibiotics, and admit patients with severe complicating infections such as encephalomyelitis for observation and antibiotics as appropriate. Postexposure prophylaxis in susceptible exposed individuals is measles virus vaccine or human immunoglobulin (Ig).
Pharmacologic Therapy
Medications include vitamin A, antivirals (ribavirin), measles virus vaccine, and human immunoglobulin (Ig). Vitamin A in children with measles in developing countries markedly reduces morbidity and mortality, so two doses given 24 hours apart are recommended, with a third age-specific dose 2 to 4 weeks later for children with signs of vitamin A deficiency. Measles virus is susceptible to ribavirin in vitro; ribavirin (IV or aerosolized) has been used in severely affected and immunocompromised adults with acute measles or SSPE (IV plus intrathecal high-dose interferon alfa), but no controlled trials exist, it is not FDA approved for this use, and it should be considered experimental. The live MMR vaccine induces active immunity against measles, mumps, and rubella. Human Ig prevents or modifies measles in susceptible individuals if given within 6 days of exposure.
Nursing Management
Nursing Assessment
Examine the child for findings of measles, assess the patient's or family's knowledge of the disease, and assess the family's hygiene practices for preventing spread.
Nursing Diagnosis
Major diagnoses are impaired social interaction related to isolation from friends, risk for impaired skin integrity related to raking pruritus, high risk of infection related to host and infectious agents, and acute pain related to skin lesions and irritated mucous membranes.
Nursing Care Planning and Goals
Skin stays clean, dry, and intact; mucous membranes stay moist and discomfort stays within the patient's tolerable range; the patient understands the purpose of isolation, cooperates, and stays free of distress.
Nursing Interventions
Isolation: place the patient on isolation precautions to limit community transmission, and isolate immediately when early catarrhal symptoms appear. Skin care: measles causes extreme pruritus, so keep nails short, use long pants and sleeves to prevent scratching, keep skin moist with provider-recommended lotions, and avoid sunlight and heat. Eye care: treat conjunctivitis with warm saline when removing secretions, discourage rubbing, and protect the eyes from strong light. Hydration: encourage oral fluids, using oral rehydration solution. Temperature control: give antipyretics as ordered for a temperature greater than 100.4 Fahrenheit unless the provider directs otherwise, and remind parents not to give aspirin because of Reye's syndrome risk.
Evaluation
Skin became clean, dry, and intact; mucous membranes stayed moist with discomfort within the patient's tolerable range; the patient understood the purpose of isolation, cooperated, and stayed free of distress.
Documentation Guidelines
Document individual findings including contributing factors, interactions, the nature of social exchanges, and specifics of behavior; cultural and religious beliefs and expectations; the plan of care and teaching plan; responses to interventions, teaching, and actions; attainment or progress toward the desired outcome; and long-term needs.
Frequently Asked Questions
What are the "3 Cs" of measles? Cough, coryza (runny nose), and conjunctivitis. They appear in the prodrome alongside high fever, before the rash. Koplik spots inside the cheeks are pathognomonic and show up a day or two before the rash.
How contagious is measles? Extremely. It has at least a 90 percent secondary attack rate among susceptible household contacts, and the virus stays airborne or on surfaces for up to 2 hours after an infected person leaves. This is why airborne isolation goes up the moment measles is suspected.
When does the rash appear and how does it spread? The maculopapular rash starts 2 to 4 days after the prodrome, about 14 days after exposure on average. It begins on the face and upper neck and spreads downward to the trunk and extremities, then fades in the same order.
Is there a specific treatment for measles? Care is supportive: hydration, fever control, and rest. The WHO and CDC recommend vitamin A for children with measles, given as two doses 24 hours apart, because it lowers morbidity and mortality. Antibiotics treat bacterial complications like otitis media or pneumonia, not the virus itself.
Why should you not give aspirin? Aspirin in children with a viral illness like measles raises the risk of Reye's syndrome. Use acetaminophen or ibuprofen for fever instead, per the provider's orders.
Can measles be prevented? Yes. Two doses of the live MMR vaccine confer durable immunity, and the program cut US incidence by more than 99 percent and eliminated endemic transmission in 2000 (CDC). Most current US cases trace to international travel and unvaccinated communities.