Epidemiology of measles

Epidemiology of Measles

Measles, also known as rubeola, is a highly contagious viral disease that affects primarily children but can also occur in adults. The Epidemiology of measles has been a subject of study since the disease was first identified. This article aims to provide a comprehensive overview of the epidemiological aspects of measles, including its incidence, distribution, and the factors influencing its spread.

Incidence and Distribution

Measles is a global health concern, with cases reported from nearly every part of the world. Prior to the introduction of the measles vaccine in 1963, major epidemics occurred approximately every 2-3 years, and the disease was responsible for millions of deaths annually. The widespread use of the vaccine has led to a significant decrease in the number of measles cases worldwide. However, the disease remains endemic in many countries, particularly in parts of Africa and Asia where vaccination coverage is low.

In recent years, there has been a resurgence of measles in regions previously close to elimination, including Europe and North America. This resurgence has been attributed to declines in vaccine coverage, leading to gaps in herd immunity. The World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC) provide updates on the current incidence and distribution of measles globally.

Transmission

Measles is caused by the measles virus, a paramyxovirus of the genus Morbillivirus. It is transmitted from person to person primarily through respiratory droplets when an infected person coughs or sneezes. The virus can live for up to two hours in the air or on surfaces where the infected person coughed or sneezed. Individuals are contagious from four days before to four days after the rash appears.

Risk Factors

Unvaccinated individuals are at the highest risk of contracting measles. Other risk factors include international travel to areas with ongoing measles outbreaks, being immunocompromised, and living in crowded conditions. Children under the age of five and adults over the age of 20 are more likely to suffer from measles complications.

Complications

Measles can lead to serious health complications, particularly in children under the age of 5 and adults over the age of 20. Complications include pneumonia, encephalitis (inflammation of the brain), and subacute sclerosing panencephalitis (SSPE), a rare but fatal degenerative disease of the central nervous system. Pregnant women who contract measles are at risk of premature delivery, miscarriage, and low-birth-weight infants.

Prevention

The most effective way to prevent measles is through vaccination. The measles vaccine is often administered in combination with mumps and rubella vaccines (MMR). Two doses of the MMR vaccine are about 97% effective at preventing measles. Efforts to increase vaccine coverage are crucial to controlling the spread of measles and preventing outbreaks.

Global Health Initiatives

Several global health initiatives aim to reduce the incidence of measles. The Measles & Rubella Initiative, a partnership between the American Red Cross, the United Nations Foundation, the CDC, UNICEF, and the WHO, is committed to ensuring that no child dies from measles or is born with congenital rubella syndrome. The Global Vaccine Action Plan (GVAP) is another initiative that seeks to prevent millions of deaths by 2020 through more equitable access to existing vaccines for people in all communities.

Conclusion

The epidemiology of measles highlights the importance of vaccination in controlling the spread of the disease. Despite significant progress in reducing global measles incidence, the disease remains a public health challenge in many parts of the world. Continued efforts to improve vaccine coverage and surveillance are essential to achieve measles elimination worldwide.

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