In the midst of the novel coronavirus pandemic, the number of cases of dengue fever continues to rise in Brazil. Between 2018 and 2019, the country saw a 488% increase in infections and this year alone, just in the first 14 weeks, 525.381 dengue cases have been registered, with 181 deaths due to the disease.
The information was published in the Health Ministry’s epidemiological bulletin, up to date till April 4th.
The press release from the Ministry doesn’t compare the numbers year to year, but their March 2019 data showed 273.193 registered cases and 80 deaths. Analyzing these numbers there is a notable 129% increase in contagion, and 226% more deaths.
The document points out that until the tenth week of this year, the pace at which people are falling ill is quicker than what was observed in 2019, without quantifying by how much, also stating that there was a drop in new cases over the last four weeks. They acknowledge that this decrease could be due to under reporting, seeing that the data is still being updated.
This year, 15.051 and three deaths by chikungunya, and 2.054 cases of zika. These two diseases, like dengue fever, are transmitted by the Aedes Aegypti mosquito.
Evaldo Stanislau, a virologist at the Clínicas Hospital in São Paulo, explains that this ballooning of the number of dengue cases could have three main concomitant causes.
“First you have a normal seasonal increase, a period in which the number of cases rise after a few years of calm, then, the rise due to the arrival of new people into areas where we have previously had dengue, and the third hypothesis is that, in certain places, preventive measures have been relaxed. All three alternatives are possible, however, it’s more likely than not that a combination of, or all three together explain this increase”, he affirms.
Dengue and covid-19
Though according to the expert, dengue doesn’t have a direct relation to the novel coronavirus, the existence of simultaneous epidemics, one transmitted by air (covid-19) and the other by vectors (dengue), is “extremely worrisome”, seeing that the initial symptoms for both diseases are similar, which can further impede the correct diagnosis and adequate treatment from being applied.
“Covid-19 creates clinical complications that if not full blown at the beginning, may seem similar to dengue, because it causes fever, muscle ache and nausea. Dengue also causes fever, muscle ache and nausea. They both have some laboratory mutations that can be similar too. How will you know the difference between one and the other? When respiratory issues occur right at the outset, with covid you have very classic respiratory complications that lack in dengue”, Stanislau explains.
He warns us that this confusion can cause serious issues, because dengue can turn fatal much faster, if people are not treated for dehydration and properly monitored.
The expert clarifies that in theory, it is possible for a person to contract both diseases at the same time, but in practice, this would very unlikely because biologically, there is a competition between the infecting agents.
Chikungunya on the other hand, has a lower mortality rate than dengue, but is nevertheless “a terrible infection” as the doctor sees it, since 70% of those who get it, mainly women, will have chronic side effects that are very painful and debilitating - a scenario of severe pain that incapacitates the person completely - rendering them unable to work or engage in any normal activities.
“There is a potential scenario where we have a chikungunya outbreak at the same time as the covid pandemic, that would be disastrous. Chikungunya is an illness that really incapacitates people, and in enough numbers could interrupt the economic chain of production. If you have lots of cases in a factory for example, no one goes to work, everyone will be away for a few months. You really cannot work when you have chikunguya”, says Stanislau.
The infectious disease doctor emphasizes that, for the time being, none of these disease are preventable with a vaccine, and that dengue, chikungunya and covid-10 are all epidemics we will have to resolve with our behavior, on a societal and governmental level.
“The public sector needs to act in a way that maintains our common spaces, combats the vector and puts forth measures people can undertake. People on their part need to adhere to social distancing and good hygiene to avoid contagion, the government on theirs, needs to ensure people are able to engage in these practices”, he concludes.
Edited by: Ítalo Piva e Leandro Melito