University of São Paulo: Analysis of increasing monkeypox cases points to lack of coordinated control measures

The number of new cases of monkeypox virus disease has been increasing by 40% each week in the states of Minas Gerais, Rio de Janeiro and São Paulo, reaching an 80% growth in Goiás and the Federal District. The number is estimated in a preliminary study carried out by Rede Análise, with the participation of the Faculdade de Saúde Pública (FSP) at USP, which used official data updated until August 22, when Brazil had 3,896 total reported cases, the first of which was on June 9. . The research suggests that the growth in the number of cases is associated with the lack of control over the transmission of the disease. For this reason, the researchers recommend massive, coordinated testing, contact tracing and isolation of confirmed cases. Research is described in preprint, previous version of a scientific article, not yet reviewed or evaluated by other scientists, published on the medXriv website.

“ Monkeypox is a zoonotic viral infection, meaning it can spread from animals to humans and also between humans. However, the vast majority of cases seem to be transmitted by direct contact with the skin lesions”, says Professor Fredi Alexander Diaz-Quijano, from FSP, one of those responsible for the research , to Jornal da USP . “The virus can cause a series of signs, some people have mild symptoms, others can develop more serious diseases, and pregnant women, children and people with compromised immune systems are at risk for complications.”

The professor points out that the most common symptoms of monkeypox include fever, headache, muscle aches, back pain, weakness, swollen lymph nodes, followed or accompanied by a skin rash, which can last for two to three weeks. “The rash can affect the face, palms, soles of the feet, groin, genital or anal regions,” he notes. “The number of wounds can range from one to several thousand.”

“Monkeypox has been spreading rapidly throughout Brazil,” says researcher Isaac Schrarstzhaupt, a fellow at the Instituto Capixaba de Ensino, Pesquisa e Inovação em Saúde (Icepi), in Espírito Santo, and coordinator of the Data Modeling Group at Rede Análise, first article author. “In this way, our work sought to estimate, in a preliminary way, this growth.” Until August 22, the states with the most cases were São Paulo (2,528), Rio de Janeiro (445), Federal District and Goiás (316) and Minas Gerais (206).

weekly growth
“We calculated the percentage growth of weekly incidence in each state with more than 110 reported cases using statistical methods, and the effective reproductive number (Rt) of the disease using serial interval from a UK study, as we do not have this data yet. in Brazil. Cases are counted from the notification and not from the onset of symptoms”, reports the researcher. “The serial interval is the time that the symptoms of the disease manifest after transmission, measured in days. The Rt is the average number of people infected for each infected person, and when this number is greater than 1, it indicates that the disease is growing, that is, the number of new cases is increasing.”

The research shows that São Paulo, Rio and Minas had weekly growth of around 40%, and Goiás and the Federal District around 80%. “The Rts were above 1 in all estimates, which indicates a sustained growth of the disease”, highlights Schrarstzhaupt. Quijano adds that, although a serial interval from another population was used, a sensitivity analysis was performed, which pointed out that even changing this parameter a lot, the Rt would still be above 1 in the communities studied. “This suggests that there is still a lack of control over the transmission”, he emphasizes.

The authors of the work show that, due to the growth of the disease, it is recommended to adopt public health measures such as testing, contact tracing and also isolation of confirmed cases. “We also recommend vaccination. Although we don’t have a specific vaccine for monkeypox , smallpox immunization could act as a complement,” says Schrarstzhaupt.

“The study is considered preliminary because the inclusion of more data could lead to further analysis. Furthermore, the investigation refers only to the first two months of the epidemic”, comments Professor Quijano. “However, the work shows that during the first two months there was a trend towards an increase in the number of cases that can only be explained by a lack of control over transmissibility.”

time to act
In the opinion of Leonardo Bastos, an epidemiologist at Fiocruz who did not participate in this study, the authors propose an important manuscript to understand the current state of the dynamics of monkeypox in some regions of the country, using successfully aggregated case data published by the Ministry of Health. . “Incidence estimates and the effective number Rt are presented for four locations (SP, RJ, MG and GO/DF), and all of them show a clear behavior of case growth”, he highlights.

For him, the results reinforce that this is the moment to act in order to reduce the transmission and the speed of growth of new cases. “Some suggested actions are increased testing, contact tracing, isolation of confirmed cases and vaccination. I would also add efficient communication from the government to the general population in order to reduce all kinds of prejudice associated with the disease and also helping to reduce transmission through knowledge, that is, teaching people in a didactic way about the transmission process and how to avoid it. -there. Something that should have been done with covid in the first few months of 2020.”

The research was carried out by Isaac Schrarstzhaupt, Mellanie Fontes-Dutra, from the Universidade do Vale do Rio dos Sinos (Unisinos), in Rio Grande do Sul, and Fredi Alexander Diaz-Quijano. The Analysis Network, formed after the beginning of the covid-19 pandemic, brings together volunteer researchers from all over Brazil to expand the performance and dissemination of scientific studies and combat the spread of fake news. The article describing the study, Early estimates of the incidence trend and the reproductive number of the monkeypox epidemic in Brazil , was published as a preprint on the medRxiv website on August 25.