He summer 2023/2024 was marked by the largest dengue outbreak that Argentina has ever had on record: 583,297 cases were confirmed and 419 deaths were recorded. The disease was present throughout the year, and did not disappear in the winter, such is the case of the provinces of Chaco and Formosa, which already have indigenous circulation of the virus that causes the disease. There are now eight jurisdictions in the country in which indigenous cases of dengue have been recorded (that is, without there having been a trip that could explain the contagion): City of Buenos Aires, Córdoba, Tucumán, Salta, Santa Fe, Province of Buenos Aires (in La Matanza), Entre Ríos and Mendoza.
Throughout the American continent, and according to data from the Pan American Health Organization (PAHO), the year 2023 was the year with “the highest historical report of dengue cases in the region, with more than 4.1 million new infections. These figures exceed those of 2019, in which more than 3.1 million cases were recorded, including 28,203 serious cases and 1,823 deaths. As of September 9, more than 11.7 million cases of dengue had been reported in the Americas, more than double the number in 2023. “All four serotypes of the dengue virus are currently circulating in the region, which increases the risk of serious illness – warns a document from the health organization -. The Southern Cone has experienced significant growth in cases, with increases of more than 250% compared to the same period last year.” Across America, there were 7,399 dengue deaths this year.
It is in this context that the National Administration of Drugs, Foods and Medical Technology (ANMAT) approved the Detect-AR Dengue TEST Kit by ELISA NS1he first national antigen test for the diagnosis of the disease. Developed in the Molecular Virology Laboratory who directs the CONICET researcher Andrea Gamarnik in it Leloir Institutethe new test is intended for clinical analysis laboratories, to be used by trained personnel. It will be produced and marketed by the Lemos Laboratory and one of the main objectives is to resolve the lack of supplies in the face of a possible new health crisis.
“Before starting to work on this development, we conducted a survey among specialists from clinical analysis laboratories to understand what the urgent needs were regarding the diagnosis of dengue, and the response was overwhelming. need to be able to detect the NS1 viral antigen -explains Andrea Gamarnik-. There are two main methods to diagnose dengue: one detects the presence of the virus proteins in the blood; the other, to viral RNA through molecular techniques such as PCR. “Both procedures are complementary and provide useful information.”
Jorge CarradoriTechnical Director of Laboratorio Lemos points out that “the kit whose commercial name registered with the ANMAT is Detect-AR Dengue TEST de ELISA NS1, is for professional use only in diagnostics for in vitro use by health providers, especially clinical analysis laboratories. It is not for the general public, therefore, It will not be sold in pharmacies. The kit will be available soon throughout the country. We are in the process of scaling up its production to provide it to the entire scientific community that requests it in our country and for export.
The kit allows establishing infection by any of the four serotypes of the virus by identifying the viral NS1 protein in patients in the acute phase of the disease. The result is obtained in three hours and up to 92 samples can be processed simultaneously.
Garmarnik points out: “In our country, tests with characteristics similar to the Detect-AR dengue are imported, which is the one we developed at CONICET. The advantage of having a nationally produced kit is that It guarantees the availability of reagents in the country and at affordable prices.. gives us independence for an input required by the health system that may be in short supply when we need it most.” Another advantage of the Argentine kit is that It is easier to measure and Does not require sophisticated equipment or additional supplies.
News: Are there situations in which the test can give false positives or negatives?
Andrea Gamarnik: The performance of the kit was studied with many positive and negative samples, and this analysis yielded a 98% sensitivity (which evaluates whether there are false negatives) and a specificity of 99% (which evaluates whether there are false positives). We are very satisfied with this performance and it is comparable to the best imported kits that have been used in our country.
News: The number of people who have dengue but who are asymptomaticWhat should be taken into account when indicating testing?
Gamarnik: Dengue infections occur without symptoms in approximately 75% of cases, and then go unnoticed, without diagnosis. The kit we developed can detect the presence of a virus protein in samples from people who have the infection symptomatically or asymptotically. Then, health professionals indicate testing against the appearance of symptoms. The test can detect the infection in a window that can extend up to approximately 10 days from the onset of symptoms.
The symptoms dengue fever, headache, muscle and joint pain, but in some situations dengue infections can cause serious bleeding. In these situations, a early diagnosis It is essential so that health professionals can properly manage the case. Furthermore, early diagnosis of dengue infection allows you to take preventive measures that help stop the spread of an outbreak. “Let us remember that the infection is transmitted through the bite of an infected mosquito (the Aedes aegypti), which acquires the virus by biting an already infected person. Preventing infected people from being in contact with mosquitoes is key to controlling the spread of an outbreak,” adds the researcher.
Experience
Both Andrea Gamarnik and her team of researchers and Laboratorio Lemos have previous experiences that were seen enhanced in the Covid-19 pandemic. “During the pandemic we form multidisciplinary work teams where CONICET researchers, health professionals and health authorities participated. The work we did during the pandemic left us many lessons, recalls Gamarnik.” And he details: “Perhaps one of the most important was the creation of collaboration networks between different actors in the scientific and health system. This communication and cooperation based on trust between different actors is something very valuable, the connection was established and this year it helped us identify what the needs were to diagnose dengue infections. Based on these interactions and with the promotion of a program of the former Ministry of Science, a high-impact federal networks program, we carried out the development that has now been approved by ANMAT.”
Lemos, for its part, was already specialized in immunodiagnostic products with special interest in Chagas disease and toxoplasmosis. “He had an outstanding performance during the pandemic, in which he co-developed, in record time together with CONICET, Fundación Instituto Leloir and the University of San Martín, the first national COVIDAR line kit for the detection of specific antibodies. Today, because this pandemic is considered controlled, its preparation and provision is limited,” explains Carradori, who also highlights that “the development of This dengue detection kit is the result of joint public-private work constituted by an extraordinary human group, led by Andrea Gamarnik, whose interaction has been synergistic and enhanced in their scientific knowledge.”
News: What is the future work?
Gamarnik: This year we have many challenges, we want to continue generating tools that allow us to have information about the dengue situation in our country. For example, now we want develop a new kit that allows measuring specific antibodies against dengue. This will give us epidemiological information to know how many people in our population were infected with dengue. But the reality is that we are in a time of great uncertainty because Financing for the projects is not being granted selected by the Scientific Promotion Agency, called PICTs, and we have no response in this regard from the authorities of that organization. Furthermore, even We are not certain about the payment of the second year of the federal networks program (projects originally scheduled for four years). This adds to the paralysis in the entry into the career of CONICET researchers.
