Viruses circulating in other parts of the world can put the Region at risk of outbreaks. The plan proposes actions

Washington, DC, September 27, 2017 (PAHO/WHO)- Ministers of health from the countries of the Americas approved a plan today to keep the Region free of measles, rubella, and congenital rubella syndrome (CRS), following the declaration of the end of endemic transmission of these diseases in recent years.

Measles was declared eliminated from the Americas in 2016, following the declaration of rubella and CRS elimination in 2015. The Region was the first in the world to have eliminated all three diseases, culminating a 22-year effort involving mass vaccination against measles, mumps, and rubella throughout the Americas.  

However, the highly contagious nature of the measles virus and the fact that both it and the rubella virus continue to circulate in the rest of the world mean that the Region is at risk of outbreaks.

"Achieving measles, rubella and CRS elimination was a hard-won battle," said Andres de Francisco, Director of the Family, Gender and Life Course Department of the Pan American Health Organization (PAHO), Regional Office for the Americas of the World Health Organization (WHO). "Maintaining elimination in an increasingly interconnected world will be an ongoing challenge in the coming years because countries are constantly in danger of importing and reintroducing the viruses, putting the progress they have made at risk."

The plan, which was approved during PAHO's 29th Sanitary Conference, incorporates the lessons learned from recent measles outbreaks in countries that had already eliminated the virus.

"The measles outbreaks in the post-elimination era taught us important lessons about the sustainability of elimination," said Cuauhtemoc Ruiz-Matus, chief of the Comprehensive Family Immunization program at PAHO/WHO. "When countries responded to their outbreaks quickly, they were able to reorient vaccination efforts and keep the virus from continuing to spread. The outbreaks have also helped countries to identify sizable gaps in vaccination coverage, which can be closed by strengthening routine immunization programs."

The plan lays out four strategic lines of action for countries to follow in order to sustain elimination. The actions center on maintaining population immunity through high vaccination coverage and strengthening surveillance systems to be able to quickly identify the measles and rubella viruses, especially in the face of other diseases with similar symptoms like zika and chikungunya: 

  • Guarantee universal access to measles and rubella vaccination services;
  • Strengthen the capacity of epidemiological surveillance systems for measles, rubella, and CRS;
  • Develop national operational capacity to maintain measles and rubella elimination; and
  • Establish standard mechanisms for rapid response to imported cases of measles, rubella, and CRS in order to prevent the reestablishment of endemic transmission in the Region.

Maintaining high vaccination coverage rates

The plan emphasizes that vaccination coverage rates in a population should be 95% or above in order to maintain elimination. In the last five years, regional coverage with the first dose of the MMR vaccine has ranged between 92% and 94%. However, regional and national vaccination coverage rates hide disparities at the local level. In 2015, only 49% of the children of the Americas lived in municipalities with vaccination coverage of 95% or higher.

Also during 2010-2015, regional coverage with the second dose of the MMR vaccine ranged between 70% and 83%. The population of susceptible children who have not received the second dose either as part of the regular health care routine or in a follow-up campaign continues to grow and transition into the adolescent and young adult age groups.

Achieving elimination

Before widespread measles vaccination began in 1980, measles caused 2.6 million deaths a year throughout the world, 12,000 of them in the Americas. One of the most contagious diseases known to humankind, measles primarily affects children and is transmitted by airborne droplets or via direct contact with secretions from the nose, mouth, and throat of infected individuals. Symptoms include high fever, generalized rash all over the body, stuffy nose, and reddened eyes. It can cause serious complications including blindness, encephalitis, severe diarrhea, ear infections and pneumonia, particularly in children with nutritional problems and in immunocompromised patients.

Rubella, also known as German measles, caused widespread outbreaks throughout the Americas before the introduction of the measles, mumps, and rubella (MMR) vaccine. Although the virus usually causes mild or asymptomatic infections in children and adults, when contracted by women early in pregnancy, it can cause miscarriage or CRS, a constellation of birth defects that often includes blindness, deafness, and congenital heart defects. Before mass-scale rubella vaccination, an estimated 16,000 to more than 20,000 children were born with CRS each year in Latin America and the Caribbean.

Although all six WHO Regions have committed to eliminate measles by 2020, and two have set an additional goal to eliminate rubella and CRS as well, progress has been slow. The Region of the Americas is the exception, as the only one to have eliminated both diseases.

Between 1994 and 2013, nearly 500 million people were vaccinated in catch-up campaigns (for children under 15), follow-up campaigns (typically for children 1 to 4 years old), and accelerated campaigns (usually for individuals 20 to 39 years old) as part of the strategy to eliminate measles and rubella. Accelerated campaigns to eliminate rubella, aimed at adolescents and young adults, also helped to consolidate the elimination of measles.

By the numbers:

  • More than 158,000 rubella cases were reported in 1997 alone in Latin America and the Caribbean.
  • Around 101,800 deaths were attributable to measles between 1971 and 1979 in the Americas.
  • A cost-effectiveness study on measles elimination in Latin America and the Caribbean has estimated that with vaccination, 3.2 million measles cases and 16,000 deaths will have been prevented in the Region between 2000 and 2020.

Links

Plan of Action for the Sustainability of Measles, Rubella, and Congenital Rubella Syndrome Elimination in the Americas 2018-2023
- Region of the Americas is declared free of measles 
- Americas region is declared the world's first to eliminate rubella
PAHO Immunization Program
- https://www.twitter.com/pahowho #GetVax #VaccinesWork #ByeByeMeasles