What Are the Causes of Measles?

Measles is a contagious disease that poses significant harm to children. Complications such as otitis media, laryngotracheitis, pneumonia, and measles encephalitis may also arise. To prevent this disease, parents need to have a certain understanding of the causative factors of measles. What are the causes of measles? Let's take a look.

Measles virus belongs to the Paramyxoviridae family and is a single-stranded negative RNA virus. It has a diameter of approximately 100 to 250 nanometers and is encased in a capsid with a membrane containing hemagglutinin (HL), which has hemolytic activity. The measles virus has six structural proteins, and during the prodromal and rash stages, it can be isolated from nasal secretions, blood, and urine. The measles virus has only one serotype with stable antigenicity. It is not highly resistant and is sensitive to drying, sunlight, and high temperatures. UV light, peracetic acid, formaldehyde, lactic acid, and ether can all kill the measles virus, but it can survive for a long time in low temperatures.

1. Passive Immunization: Within 5 days of exposure to measles, immediate administration of immune serum globulin can prevent the onset of measles. However, this effect is not achieved if administered more than 6 days after exposure. Clinical manifestations may vary widely in those who receive immune serum globulin, with a longer incubation period and atypical symptoms and signs. Nevertheless, these individuals may still pose a potential risk of transmission to others. Passive immunization only lasts for 8 weeks, and subsequent active immunization measures should be taken.

2. Active Immunization: The use of attenuated live measles vaccine is an important measure for measles prevention, with an efficacy rate of up to 90%. Although 5% to 15% of vaccinated children may experience mild reactions such as fever, discomfort, and fatigue, a minority may develop a rash after fever, which does not lead to secondary bacterial infections or neurological complications. In China, the initial vaccination is recommended at 8 months of age. Early vaccination may neutralize the immune effect of the vaccine due to residual maternal antibodies in infants. Since the seropositive conversion rate after immunization is not 100% and the immune effect may weaken over time, a second dose of measles vaccine is recommended at 4 to 6 years or 11 to 12 years of age, and college-aged individuals should receive another measles immunization. If acute tuberculosis infection is present, measles vaccination should be administered along with tuberculosis treatment.

3. Control of Infectious Sources: Early detection and isolation are crucial. Generally, patients should be isolated for 5 days after the rash appears, and those with pneumonia should be isolated for up to 10 days. Susceptible individuals who have been in contact with measles patients should undergo a 3-week quarantine observation.

4. Cutting off Transmission Routes: Clothes of patients should be exposed to sunlight, and rooms previously occupied by patients should be ventilated and irradiated with ultraviolet light. During epidemic seasons, public awareness should be raised, and susceptible children should minimize their exposure to public places.