Measles: Why Be Cautious?

Measles is an infectious disease that, despite advances in prevention, continues to pose a significant threat to global public health.

Understanding the nature of this disease, its causes, symptoms, potential complications, and prevention strategies is crucial to protect ourselves and our loved ones. Let’s examine in detail why it’s important to pay attention to measles.

What is Measles?

Measles is an acute exanthematous infectious disease caused by an RNA virus belonging to the Morbillivirus genus of the Paramyxoviridae family. It is a highly contagious disease that exclusively affects humans, having no other natural hosts.

Before the introduction of the vaccine in the 1960s, measles was responsible for cyclical epidemics every two to three years, causing about 2.6 million deaths annually worldwide.

Thanks to vaccination campaigns, the incidence of measles has decreased significantly worldwide. However, the disease remains a major cause of morbidity and mortality, especially in developing countries. In 2022, it is estimated that measles caused the death of 136,200 people, mainly children under five years of age.

The World Health Organization (WHO) has set measles elimination targets in all six of its regions. This goal requires very high levels of immunity in the population. To date, only the Region of the Americas has achieved elimination in 2016, but unfortunately, endemic transmission has subsequently been re-established.

What Causes Measles?

Measles is caused by a highly contagious virus. Its transmissibility is exceptionally high, with a basic reproduction number between 12 and 18.

This means that in a completely susceptible population, one infected person can infect 12 to 18 others. In fact, 90% of non-immune people exposed to an infected individual contract the disease.

Transmission occurs primarily through nasal and pharyngeal secretions and respiratory droplets that spread in the air when an infected person coughs or sneezes. The measles virus is remarkably resistant in the environment, remaining infectious in the air and on contaminated surfaces for up to two hours after emission.

In temperate climate countries, measles tends to peak in incidence towards the end of winter and early spring. The contagious period extends from four days before to four days after the appearance of the characteristic rash, making controlling the spread particularly challenging.

What Are the Symptoms of Measles?

Measles symptoms appear after an incubation period ranging from 7 to 18 days, with an average of 10-12 days. The progression of the disease can be divided into several phases:

1. Prodromal phase: The first symptoms are similar to those of a common cold. They include cough, rhinitis (runny nose), and conjunctivitis. These are accompanied by general malaise and fever that progressively increases, potentially reaching 39-40.5°C.
2. Exanthematic phase: After 2-4 days from the onset of symptoms, the characteristic skin rash (exanthem) appears. It begins on the face and neck and then spreads, over 2-3 days, to the rest of the body. The rash persists for 3-7 days and then disappears following the order of onset, sometimes ending with slight desquamation that may go unnoticed.
3. Koplik’s spots: A pathognomonic sign of measles, present in 60-70% of cases. These are bluish-white lesions, slightly raised, 2-3 mm in diameter, appearing on the buccal mucosa, usually opposite the first molar. They generally appear one day before the skin rash and persist for 2-3 days.

Other common symptoms include photophobia, sore throat, headache, abdominal pain, and mild generalized lymphadenopathy. Fever usually persists for 2-3 days after the appearance of the rash, while cough can last up to 10 days.

It’s important to note that in some people, especially those with pre-existing partial immunity, measles can manifest in milder forms, making clinical diagnosis more difficult.

What Are the Complications of Measles?

Although most people recover from measles within 2-3 weeks, the disease can have a severe course and lead to serious, sometimes fatal complications. Complications can affect up to 30% of cases, with even higher percentages in developing countries.

Groups at highest risk of complications are:

• Children under 5 years of age
• Adults over 20 years of age
• Pregnant women
• People with immune deficiency

The most serious complications include:

1. Pneumonia: Can complicate 1-6% of cases and is one of the main causes of death associated with measles.
2. Acute encephalitis: Occurs in about 0.1% of cases (1 in 1000) and can lead to permanent neurological damage in 20-30% of complicated cases.
3. Subacute sclerosing panencephalitis (SSPE): A rare but serious long-term complication that manifests on average 7 years after primary infection. SSPE is a degenerative disease of the central nervous system characterized by deterioration of mental faculties and seizures. It occurs at a frequency of 4-11 cases per 100,000 measles cases, with a higher incidence (18/100,000) when primary infection was acquired before 5 years of age.

Other complications include otitis media, laryngotracheobronchitis, diarrhea, dehydration, keratitis, thrombocytopenia, and febrile seizures. In developing countries, measles associated with vitamin A deficiency is one of the main causes of acquired blindness in children.

The lethality of measles varies significantly between developed and developing countries. In industrialized countries, the mortality rate is 0.05-0.1%, while in underdeveloped countries it can reach up to 6% of cases.

Are There Treatments?

Currently, there is no specific antiviral treatment for measles. Therapy is mainly supportive and aims to alleviate symptoms and prevent complications. Therapeutic measures generally include:

1. Fever and pain management: Drugs such as paracetamol or ibuprofen are used to reduce fever and relieve discomfort.
2. Hydration: It’s crucial to ensure adequate fluid intake to prevent dehydration, especially in the presence of high fever.
3. Rest: Rest is important to allow the body to fight the infection.
4. Antibiotics: May be prescribed in case of secondary bacterial complications, such as pneumonia or otitis.
5. Vitamin A supplementation: The World Health Organization recommends administering high doses of oral vitamin A to infected children, especially in developing countries. This intervention has been shown to reduce complications, particularly vision problems and blindness, as well as mortality. However, in Italy and other industrialized countries, the routine use of vitamin A in measles patients without malnutrition is currently not recommended due to lack of supporting data.

In case of severe complications, such as encephalitis or severe pneumonia, hospitalization may be necessary for intensive treatment.

How Is Measles Prevented?

Measles prevention is primarily based on vaccination, which represents the most effective method to control the spread of the disease. The measles vaccine has been available for about 60 years and is characterized by high efficacy, low cost, and an excellent safety profile.

The vaccine is a live attenuated preparation and is generally administered in combination with vaccines against rubella and mumps (MMR vaccine) or with the addition of the vaccine against chickenpox (MMRV).

In Italy, the vaccination schedule includes two doses:

• First dose: administered at 12 months of age
• Second dose: administered at 5 years of age

This vaccination schedule offers protection to over 90% of vaccinated individuals. It’s important to note that in children under 12 months of age, the efficacy of the vaccine may be reduced due to the presence of maternal antibodies. However, in particular situations such as epidemics, the vaccine can be administered from six months of age.

As with all vaccines, there are some contraindications:

• Severe allergic reaction to a previous dose or to one of the vaccine components
• Immune deficiency (being a live attenuated vaccine)
• Pregnancy

It’s important to emphasize that exposure to measles is not a contraindication to vaccination. On the contrary, the vaccine can be effective as post-exposure prophylaxis if administered within 72 hours of contact with a measles case.

For subjects who cannot be vaccinated (e.g., children under 6 months, susceptible pregnant women, and immunocompromised patients), immunoglobulins can be used as post-exposure prophylaxis up to six days after contact.

Widespread vaccination not only protects vaccinated individuals but also contributes to herd immunity, indirectly protecting those who cannot be vaccinated.

We’re with you.

At Parentalife, we are committed to supporting parents in their journey of raising and caring for their children. Through our detailed guides, educational programs, and personalized consultations, we offer reliable and up-to-date information on crucial topics.

SOURCES

Kondamudi NP, Waymack JR. Measles. [Aggiornato 2023 Ago 12]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Gen-. Disponibile qui: https://www.ncbi.nlm.nih.gov/books/NBK448068/