Measles, also known as Rubeola, is a highly contagious respiratory disease caused by the measles virus. It is characterized by a rash, fever, and upper respiratory symptoms. While vaccination has significantly reduced the incidence of measles, it remains a significant global health concern, especially in areas with low vaccination coverage. Understanding measles transmission, symptoms, complications, and prevention measures is crucial for public health.
Pathogen and Characteristics of the Measles Virus
Measles is caused by the Measles virus, a single-stranded negative-sense RNA virus that belongs to the Morbillivirus genus within the Paramyxoviridae family.
Key characteristics of the measles virus include:
- High contagiousness: Measles is one of the most contagious known viruses. One infected person can spread the virus to 9-18 susceptible individuals.
- Weak environmental resistance: The virus does not survive long outside the body but can remain infectious in the air or on surfaces for a short period.
After infection, the virus replicates in respiratory cells and spreads through the bloodstream, causing systemic symptoms and a characteristic rash.
Modes of Measles Transmission
Measles primarily spreads through:
- Airborne Transmission (Droplet and Aerosol Transmission)
The measles virus is primarily transmitted via airborne droplets and aerosols. When an infected person coughs, sneezes, or talks, tiny virus-laden particles can stay in the air for hours, potentially infecting others even after the infected person has left the room. - Direct Contact with Respiratory Secretions
Measles can spread through contact with nasal discharge, saliva, or other respiratory secretions. - Contact with Contaminated Surfaces
The virus can survive on surfaces for a short period. Although airborne transmission is the primary mode, indirect contact can still lead to infection.
Individuals are contagious from 4 days before the rash appears until 4 days after the rash shows. Patients typically show no symptoms during the incubation period, which complicates disease control.
Symptoms After Measles Infection
The incubation period for measles is generally 10-12 days (7-18 days possible). The disease progresses through several stages:
- Prodromal Stage (Catarrhal Stage) – Lasts 2-4 days:
- High fever (can exceed 40°C)
- Runny nose, nasal congestion
- Dry cough
- Conjunctivitis (red, watery eyes, light sensitivity)
- Koplik’s spots: Small, grayish-white spots with a red halo on the inside of the mouth, appearing 1-2 days before the rash, an early diagnostic sign.
- Eruptive Stage (Rash Stage) – 3-4 days after fever onset:
- Rash typically begins behind the ears and spreads to the face, neck, trunk, and limbs.
- The rash consists of red maculopapular lesions that blanch with pressure, and normal skin is visible between spots.
- Fever peaks, and systemic symptoms may worsen.
- Recovery Stage – 3-5 days after rash:
- The rash fades in the same order it appeared.
- Skin may show fine, flaky desquamation and discoloration.
Complications of Measles
Measles can lead to severe complications, especially in infants, young children, and malnourished individuals:
- Pneumonia: The most common and serious complication, which can lead to death.
- Otitis Media (Ear Infection): A common complication, often resulting in hearing impairment.
- Laryngitis and Pseudomembranous Croup: Can cause breathing difficulties.
- Diarrhea: Common in children, leading to dehydration.
- Encephalitis: Rare but life-threatening neurological complication, potentially causing permanent damage.
- Subacute Sclerosing Panencephalitis (SSPE): A fatal late complication that appears years after the infection and leads to progressive neurological deterioration.
- Worsening Malnutrition: Measles exacerbates existing malnutrition, consuming significant body energy.
Prevention of Measles
Prevention measures include:
- Measles Vaccination:
The MMR vaccine (Measles, Mumps, Rubella) is the most effective method to prevent measles.- First dose: 12-15 months old
- Second dose: 4-6 years old
High vaccination coverage is essential to control outbreaks.
- Patient Isolation:
Measles patients should be isolated to prevent transmission, ideally for 4 days after the rash appears. - Avoid Contact with Infected Individuals:
Susceptible, unvaccinated individuals should avoid close contact with infected persons. - Personal Hygiene:
Wash hands frequently and avoid touching the face with unwashed hands.
Treatment of Measles
There is no specific antiviral treatment for measles. Treatment focuses on supportive care:
- Rest and Hydration:
Adequate rest and plenty of fluids help the body recover. - Fever Management:
Fever-reducing medications like acetaminophen or ibuprofen can help manage fever and discomfort. - Eye Care:
Clean eye secretions with warm water and avoid strong light exposure to reduce irritation. - Skin Care:
Keep the skin clean to prevent secondary infections. - Vitamin A Supplementation:
In developing countries, vitamin A supplementation is recommended to reduce severity and complications, especially in children. - Complication Treatment:
If complications like pneumonia or ear infections occur, appropriate treatment (e.g., antibiotics for secondary bacterial infections) should be administered promptly.
Conclusion
Measles is a highly contagious disease that can lead to serious complications, including pneumonia, encephalitis, and death. Vaccination is the most effective means of prevention. Raising global vaccination rates is crucial to eliminating measles and protecting public health. If measles symptoms appear, seek medical attention immediately and follow isolation guidelines to prevent further spread.