Once the coronavirus pandemic has been neutralized, the great concern of the health authorities of our country and the province of Santa Fe is the rapid proliferation of dengue cases. A disease that is transmitted through the bite of the Aedes aegypti mosquito and that can affect people of all ages, with symptoms ranging from “a mild fever to a disabling fever, accompanied by severe headache, pain behind the eyes, pain in muscles and joints, and erythema”, as listed by the Pan American Health Organization, but which can progress to other more serious forms, with “shock, respiratory distress and/or serious organ damage”, until it leads to patient death.
Dengue has a stationary behavior, corresponding to the warmest and rainiest months, and therefore this first stage of the year is the one that presents the greatest complication for the countries of the Southern hemisphere. In Argentina, and particularly in our province and in Rosario, it is hitting hard: in the department there are 1,252 confirmed cases -the previous week there were 775-, of which 1,179 correspond to people who live in the city. Granadero Baigorria (25), Pérez (18), Funes (7) and Villa Gobernador Gálvez are the other towns in the region with the most infections.
In addition, the health portfolio confirmed that of a total of 14 hospitalized there are 3 patients in intensive care, 2 of them in the Children’s Hospital of the city of Santa Fe and the rest in Rafaela, after the first death from dengue, that of a 77-year-old man from Reconquista.
Given this complex scenario, society has many questions ranging from what to do if symptoms appear, why there is talk that the most serious complications appear in the face of reinfection, to the question of whether or not there will be a vaccine that allows (as happened with covid-19) to lower the number of infected and prevent our lives from being at risk.
To these questions he responded infectologist Ricardo Teijeiro, member of the Argentine Society of Infectious Diseaseswho left very interesting definitions:
How is it determined if I have dengue: swab or blood test?
The diagnosis of the disease, once the symptoms appear, is made through the blood, with a study called serology. This is a difference with the Covid or the flu, which are diagnosed through a nasal swab, because the virus is searched for there.
How do we react if we have symptoms?
The reaction that everyone should have, being in Santa Fe or in any place where dengue fever circulates, if we have symptoms such as fever, muscle pain, headache or diarrhea, is to go to the doctor. Very easy. Do not self-medicate, do not cover up the symptoms: the one who must decide what to do is the doctor: neither the pharmacist, nor the greengrocer, nor the patient himself.
Why is reinfection the one that generates complications?
Once the first contagion has occurred and the disease has passed, the body generates exclusive antibodies for that strain: if you had DENV-1, which is one of the four strains that exist in addition to DENV-2, DENV-3 AND DENV-4 , you are protected against that one but not against the others. So, when you have contact with another strain, the organism can develop an immunity that causes a more important inflammatory process than usual, and complications can be generated there. That is why the arrival of a vaccine that contemplates the four strains is important, which would give you a high level of protection for any contact you have with the virus.
Can any reinfection cause me complications?
No. And you have to be very clear with this. In order to have complications with reinfection, you have to reinfect yourself with a different strain than the one that previously infected you. Dengue has four strains. Today in Argentina we have only one in circulation, which is DENV-1. Therefore, you will not be able to reinfect yourself with another strain. Now, if you were infected with another strain years ago, at another time and in any place, and today you are reinfected with the current one, there it can be a problem.
How likely is a reinfection?
In itself, infection is not so easy, and it is not that you are going to get infected twice with different strains, at least not today. And also, it is worth remembering that this disease is not transmitted from person to person: there must be an Aedes aegypti mosquito in the middle, contacting a sick patient, having the virus and going to bite another patient and transmitting the disease .
What is the vaccine that is about to be approved and how does it work?
It is a vaccine that is being brought by a Japanese laboratory, Takeda, which is not yet approved in our country, although it is by the FDA (Food and Drug Administration, an agency of the United States Department of Health and Human Services) and will be presented at the Anmat (National Administration of Medicines, Food and Medical Technology of our country) shortly. I don’t know when because it depends on the regulatory frameworks and the laboratory itself, but I think that by August or September it would already be presented. It will be important because we will know that at the end of the year and we would have that vaccine.
Does it protect against all strains?
Yes, this vaccine protects against all strains, but like any vaccine, it is not one hundred percent effective. Yes, his average effectiveness of 75%, more or less, is very interesting. This vaccine would be essential for the region, not only for Argentina: Brazil, Paraguay, Bolivia or Peru are having a worse time. And these diseases must be looked at from a regional perspective.
Is it the only vaccine in the world?
No. There is another French vaccine, developed by the Sanofi Pasteur company, which has already been authorized in some countries but is exclusively for people who have already had a previous infection. This generated some inconveniences: when you applied the vaccine, having already had the disease, you could have a significant adverse effect due to the effect of reinfection. With the Japanese vaccine, that is avoided. The French one is out of use, because here the main thing is to avoid the first contact. And if you have a contact, that does not cause you any type of complication.
How would the vaccine be administered?
That will be determined by Anmat. In general there are two doses, from 9 months of life or one year of age. And we still don’t know if he’ll call for reinforcements. You have to continue studying the patients, to know if something else will be needed.
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While medicine and science do their thing, and the states contribute with fumigation and awareness campaigns so that we do not self-medicate and go to the doctor, we can contribute ours: it has already been heard several times that “if there are no mosquitoes, there is no there is dengue”, so the most important measure of prevention is the elimination of all mosquito breeding sites: that is to say, any container that contains water, both inside the houses and in their surroundings.
