Measles: Brazil is at risk of returning the disease strongly, if children and adults are not immunized

Publicação: 14 de August de 2018

As of August 07, 1,100 cases of the disease were confirmed, 97% of them in Roraima and Amazonas, where the situation is described as an outbreak. Rio de Janeiro, São Paulo, Rio Grande do Sul, Rondônia, Pará, Amazonas and Roraima also recorded cases of the disease

Cases have multiplied since February. According to information from the Ministry of Health (MoH), the import-related outbreaks, have been proven by the genotype of the virus (D8), the same circulating in Venezuela

After two years of measles eradication, the virus has again affected the country. According to analyses by the Oswaldo Cruz Foundation (Fiocruz), the virus that circulates in northern Brazil matches the one affecting Venezuela, a country that faces since July 2017 an outbreak of the disease, with most cases arising in the State of Bolivar. The current economic and socio-political situation has led to an intense migratory movement that has contributed to the spread of the virus to other geographical areas.

This year in Brazil, over 1,069 cases were registered in the states of Amazonas (AM) and Roraima (RR) alone. According to the latest update released by the MoH, until August 7, 788 cases of measles had been confirmed in Amazonas and 5,058 remain under investigation. The State of Roraima has confirmed 281 cases of the disease and 111 are still under investigation. In addition to these two States, some isolated and import-related cases have been identified in the States of São Paulo (1), Rio de Janeiro (14); Rio Grande do Sul (13); Rondônia (1) and Pará (2). According to information from the Ministry, Brazil has five confirmed deaths and the state of Amazonas leads in number of cases.

The infectious disease physician at Clinical Research of Institute Evandro Chagas (IPEC/FIOCRUZ), Dr. Marília Santini de Oliveira links the return of already vaccine-eradicated diseases, such as measles, to a decrease in vaccination coverage. For her, the control of the outbreak depends on the efficiency of the response to the disease, which involves several factors, including training of health teams to quickly diagnose and notify cases, vaccination, in addition to availability, access and acceptance of the vaccine.

“The efficacy and safety of the vaccine, which were the arguments to eradicate measles in the past, remain high, as well as its impact on disease control, however, the continued circulation of the virus in some parts of the world requires vaccination coverage to stop new cases and outbreaks to occur. What changed in this equation was the decrease in vaccine coverage,” she points out.

Regarding the Brazilian expertise in controlling measles, the infectious disease expert points out that the knowledge about the prevention, detection and control of the disease is under the domain of managers responsible for these actions. She remembers that this knowledge was acquired in our region during the 22 years that led up to the obtaining of the certificate of elimination of the disease in the Americas, awarded by the World Health Organization, in 2016. “We know what to do, perhaps we must develop new ways of doing it, adapting health services, professional training and ways of communicating with the population that follow the technologies in a constant and rapid development and dissemination,” she says.

Reasons that diminish the effectiveness of the vaccination campaigns in Brazil

The resurgence of previously controlled vaccine-preventable diseases, such as measles, in the opinion of the infectious disease expert, is a result of an increase of the susceptible population, most likely due to a decrease in vaccination coverage. The factors leading to this decrease, however, are not so simple to determine and are probably several. Dr. Santini explains that some of these reasons may be related to the health system, as for example, location and working time at the health centers, hindering access to parents who work. Others are related to the acceptance of the vaccine by the population. “The decrease in the number of cases over the past 20 years has meant that most adults have never seen people with measles and do not believe in the need to vaccinate their children,” she notes.

The expert recognizes that to understand the factors involved in the decrease in the number of people vaccinated in the country it is necessary to perform a study including a large number of respondents, representing the different socio-demographic characteristics in Brazil. “As long as researches on the subject are not held, it is not possible to state with certainty which are the causes, although we can apply policies aiming to improve the situation based on the considered factors”, she adds.

Measles strike Yanomami Indians

The epidemic of measles struck Yanomami Indian tribes as well, both in Brazil and Venezuela. Until the day July 13, 67 cases of the disease were confirmed among Indians in the region, according to Indian Health Special Health District Yanomami and Iekuana (Dsei-Y). According to Rousseau de Jesus Oliveira, coordinator of Dsei-Y, the advance in the number of cases is worrisome and is directly related to the low vaccination among Venezuelan Indians. There are reports that many walk for days to cross the border and seek medical attention in Brazil.

Coordinator of Hutukara, David Kopenawa Yanomami said that 14 Indians have died in the border region as a result of the disease. But, according to information from the MoH, until June 11, only two cases had been confirmed among Brazilian Indians and 24 among Venezuelan Indians.

Dr. Santini points out that the way to control the disease and avoid major outbreaks is blocking vaccination (made in contrasting cases of measles) and adequate vaccination coverage of the general population. “If we are unable to do this, then we can expect the number of cases to increase,” she regrets.

Over 2 thousand cases of measles are recorded in the Americas

According to the Pan American Health Organization (PAHO), Brazil is the second country with most episodes of illness, second only to Venezuela.

Dr. Santini reiterates the importance of immunization, since it is practically certain that all non-immunized persons coming into contact with the pathogen will be infected, since the virus has a high infection competence, ease of transmission (respiratory tract) and a high rate of infectivity. The vaccination campaign began on August 6 throughout the country. Vaccination is the main and the best way to protect yourself against the disease. Immunization can be done at any age.