After two epidemics, death revives alert for yellow fever in Minas

Larissa Figueiredo*

The death of a man from yellow fever in the region on the border between the states of Minas Gerais and São Paulo rekindled the alert among health authorities regarding the risk of the disease. The victim was 50 years old, lived in Águas de Lindoia (SP), had no record of vaccination against the disease and presented two positive tests for the virus. The likely site of infection remains under investigation, as the man visited a forested area in the Minas Gerais municipality of Monte Sião, in the south of the state, around 15 days before the onset of symptoms.

Faced with the fatal case of the disease – which caused epidemics in Minas Gerais with 340 deaths between 2016 and 2018 – the Ministry of Health issued, on Sunday, a warning to intensify health surveillance and immunization actions in areas with active transmission of the virus. In addition to this fatal case, three diagnoses were confirmed in Brazil in the last six months, according to the folder, two of them resulting in deaths. The health mobilization aims to speed up the communication of suspected cases to prevent new outbreaks, especially considering that the disease has a high fatality rate.

Still amid the consequences of the worst dengue epidemic in history, the alert brings back memories of the critical years faced in Minas Gerais in the face of yellow fever. In the 2016/2017 season, 475 cases of the wild type of the disease were confirmed in the state. Of the total, 162 patients did not survive – a fatality rate of 34.1%. The situation was already considered the most serious since 1980, but the situation was even worse in the following period. Between July 2017 and June 2018, there were 527 confirmed cases, with 178 deaths. The fatality rate decreased slightly compared to the previous period, but remained high, at 33.5%.

Contacted by the State of Minas, the State Department of Health stated in a note that, since the notification of the most recent death, on April 12, it has been investigating the case. Meetings were held to address the matter with health authorities from the ministry and São Paulo, according to the ministry, and guidance was made available to health professionals and managers on the situation, through technical documents and meetings of the Emergency Monitoring Committee.

Also according to state Health, a webinar was held yesterday to discuss the issue of arboviruses in the state, which includes yellow fever, with the participation of the Minas Gerais Association of Municipalities and the Council of Municipal Health Departments of Minas Gerais (Cosems). Epidemiological surveillance, control of transmitting insects and vaccination actions were also intensified in the affected region of Monte Sião, mainly in rural locations, to expand coverage against yellow fever in people not yet immunized.

The secretariat maintains that the municipality of Monte Sião, as well as the territory of the Regional Health Unit of Pouso Alegre, where it is located, has no recent record of deaths of monkeys infected with the yellow fever virus – a situation that serves as a warning of the risk of human cases. Data from the Vaccination Panel of the National Calendar of the Ministry of Health indicate that vaccination coverage for yellow fever in children under 1 year of age, from January to March 2024, is 89.41%.

Characteristics of the virus

In Brazil, the disease cycle is currently wild, with transmission through mosquitoes of the genera Haemagogus and Sabethes. The last cases of urban yellow fever were recorded in the country in 1942, and all cases confirmed since then are attributed to the transmission cycle in forest or rural areas.

The disease is endemic in the Amazon region, but, from time to time, it emerges in the extra-Amazon region. The pattern is seasonal, with most cases occurring between December and May. Outbreaks occur when the virus encounters favorable conditions for transmission, such as high temperatures, low vaccination coverage and high density of vectors (mosquitoes) and hosts (monkeys and humans).

From 2014 onwards, the virus re-emerged in the Central-West region of the country, spreading in the following years to other regions. Between 2014 and 2023, 2,304 cases of yellow fever were recorded in humans, 790 of which resulted in deaths in Brazil. In Minas, the worst period occurred between 2016 and 2018.

Among the Ministry of Health’s recommendations are the alert for surveillance and immunization teams to intensify actions in the affected areas, with expansion to neighboring municipalities; notification of the illness or death of monkeys; and attention to symptoms of mild and moderate fever in unvaccinated people.

Appeal for vaccination

Regarding vaccination, the recommendations are that the strategy of actively searching for unvaccinated people in alert regions be used. According to the Secretary of Health and Environmental Surveillance of the Ministry of Health (SVSA/MS), Ethel Maciel, vaccination, available in the Unified Health System (SUS), is extremely important for combating the disease.

“Yellow fever is a disease that is easily preventable with the vaccine. And it is available on SUS for all ages. Anti-vaccine lying campaigns have not only harmed (immunization against) Covid. Yellow fever vaccination coverage is below recommended levels. That is why it is important for the entire population to be up to date with their vaccinations”, informs Ethel.

Last Friday, the Ministry of Health made 150,000 extra doses of the yellow fever vaccine available for the state of São Paulo. A recommendation was also made for free access to the vaccine in health units, without the need for prior scheduling.

* Interns under the supervision of editor Roney Garcia