The danger of the return of poliomyelitis | Drauzio Varella

Poliomyelitis, also known as infantile paralysis, is a serious disease, but it has been eradicated from Brazil. However, vaccination coverage against the disease has declined.

Since 2015, Brazil has faced declining vaccination coverage for all diseases for which vaccines exist. Among the reasons mentioned by the Brazilian Society of Vaccinations (SBIm), are the lack of information of health professionals on the vaccination schedule; lack of information on the population; little trust in government officials, institutions and health professionals; limited opening hours of health posts; disinformation; communication fails; and the growth of the anti-vaccination movement.

As a result, Brazil lost its certificate of eradication of measles, granted to the country in 2016 by the WHO, after the return to current cases of the disease. In the first two months of 2022 alone, more than 17,000 cases have been reported, revealing the risk of experiencing a disease outbreak.

See as well : Post-polio syndrome affects 75% of Brazilians who have had infantile paralysis

Vaccination coverage of another serious disease eradicated in the country, polio, popularly known as infantile paralysis, has decreased significantly. In 2015, Brazil vaccinated 98.3% of the target audience, a rate that fell to 84.2% in 2019 and 75.9% in 2020, according to the Institute for Public Health Policies (Ipes). According to the Ministry of Health, in 2021, coverage with the initial three doses of the vaccine was 67%; with booster doses, 52%.

“The scenario for vaccines in general, with a decline in vaccination coverage since 2015, as well as the decline in other disease prevention strategies, is starting to take effect: we already have outbreaks of measles in some areas,” explains the Dr. Bruno Ishigami, infectiologist doctor and student in Master of Public Health at Fiocruz.

Specialists have warned of the threat of experiencing a similar situation with other diseases already under control, such as diphtheria and the rubellaor eradicated, such as poliomyelitis.

The African continent, which had also eradicated poliomyelitis, returned to current cases of the disease earlier this year, in Malawi. The country has experienced an outbreak of the disease, which recently hit Mozambique. The cases serve as a warning to Brazil.

“With low vaccination coverage in a country where basic sanitation is precarious, we in Brazil have the perfect scenario for polio to spread, since it is a faecal-oral transmission disease. There is a real risk that we will see the re-emergence of diseases that we were able to eradicate or control,” adds Dr. Ishigami.

Since polio vaccination requires three initial doses followed by booster doses, many parents end up skipping the vaccination due to lack of information and logistical difficulties. Therefore, a decrease in compliance between the first dose and the others is common, in vaccines that require more than one dose.

Moreover, the vaccination campaigns, according to several consulted experts and the SBIm itself, have not been well communicated, which leads parents to miss the vaccination dates.

“We must instruct the health authorities to carry out prevention campaigns, which distribute vaccines and encourage people to get vaccinated. We are able to improve our vaccination coverage,” concludes the infectiologist.

Polio

Poliomyelitis is a contagious disease caused by a virus called poliovirus which has three serotypes (1, 2 and 3) and is transmitted by the oral-faecal route (contact of the mouth with contaminated faeces) or oro-oral, through expelled droplets. talking, coughing or sneezing.

In general, it may or may not cause infantile paralysis and usually affects children under 4 years of age, although it can also affect adults.

See as well : Testimony of a person who had poliomyelitis

Most infections cause few or no symptoms, similar to a respiratory infection such as reproach. However, about 1% of patients may develop the paralytic form of the disease when the virus reaches the neurons motors and can leave permanent scars.

In addition, the disease can cause post-polio syndrome, a neurological disorder that affects infected people about 15 years after being infected with the virus. The condition is not caused by the reactivation of the virus, but by the wear and tear resulting from the excessive use of motor neurons close to those destroyed by the poliovirus.

History of Poliomyelitis in Brazil

Poliomyelitis was recorded in Brazil as early as the end of the 19th century. In the following century, several outbreaks and epidemics of the disease marked the country’s history, attracting the attention of public opinion in the 1950s, when cases broke out in several cities. At that time, the image of children suffering from severe infantile paralysis was common, some needing the famous “steel lung”, a structure of cylindrical tubes where the child was kept lying down with only the head out, subjected to the action of a vacuum pump. .which decreased and increased the air pressure to inhale and exhale through the lungs who could not breathe due to muscle weakness caused by the disease.

From the 1960s, efforts were made to control the disease, with mass vaccination using the Sabin vaccine. In the 1970s, the country adopted a nationally coordinated strategy to combat poliomyelitis, instituting the National Polio Control Plan, abandoned in 1974 after health workers concluded that routine vaccination was not not enough to control the disease.

It was not until 1980 that the government reestablished strategic action to fight poliomyelitis, instituting the first mass vaccination campaign.

In 1989, what would be the last case of the disease caused by the wild virus in the country was notified, in the town of Souza, in Paraíba (PB). In 1994, the country received Wild Poliovirus Free Area certification from the Pan American Health Organization (PAHO).

vaccines

There are two vaccines to prevent the disease:

— VIP (inactivated injectable vaccine, also called Salk): It is applied in the routine vaccination of children, at 2, 4 and 6 months, with boosters between 15 and 18 months and between 4 and 5 years. In the public network, doses from the age of 1 are made with OPV.

— OPV (oral attenuated vaccine, also known as Sabin): In the infant vaccination routine of the Basic Health Units, it is applied as a booster at 15 months and 4 years old and in vaccination campaigns for children from 1 to 4 years old. This vaccine is adopted by the SUS because, in addition to being easier to administer (two drops are enough orally), it is eliminated in the stool, thus protecting other vulnerable unvaccinated people, especially in regions where the basic sanitation system is precarious.

Consulting: Brazilian Vaccination Society (SBIm) and Oswaldo Cruz Foundation (Fiocruz)

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