Dengue. Dengue is an acute viral infection transmitted by mosquitoes , therefore we will say that dengue is an arbovirus. Arbovirus means arthropod-borne virus.
Dengue is considered the most important arbovirus. The virus that causes this disease is the dengue virus and there are 4 serotypes: DENV 1, 2, 3 and 4. Recovery from the infection grants lifelong immunity , grants this lifelong immunity against the serotype that caused the infection however subsequent or secondary infections caused by other serotypes increase the risk of developing severe dengue.
For this reason, it is said that a person can be infected with the dengue virus up to four times during his life. Dengue virus belongs to the flaviviridae family and the flavivirus genus. It is a single-stranded RNA virus.
The most important reservoir of the dengue virus, as we already know, is the human being. Remember that it is an arbovirus, the vector of dengue is Aedes aegypti. Aedes aegypti is the main vector of dengue, to a lesser extent transmission by the aedes albopictus mosquito , also known as the tiger mosquito , is also possible.
These mosquitoes generally live and lay their eggs near stagnant water, for example in containers such as buckets or some container. The female Aedes feeds during the day, the periods where the bites intensify are in the early morning and at dusk, before dark. Transmission: how does the transmission occur ?
: the dengue virus is transmitted to humans by the bite of infected female mosquitoes, mainly, as we said, aedes aegypti. After the mosquito bites an infected person, the virus will replicate and then reach the mosquito's salivary gland, all this time that elapses since the virus enters the mosquito until it reaches its salivary glands is called the period of extrinsic incubation that lasts between 8 to 12 days and then the mosquito remains infected for the rest of its life. Then that mosquito goes and infects another person and now, how long do symptoms appear ?
That is, how long is the intrinsic incubation period, intrinsic because we are talking about the patient, it is an average of 4 to 7 days. Another important point to mention in the transmission is that a vertical transmission has also been reported, that is, from a pregnant woman to her baby. Let's talk about the dengue clinic: there are three clinical phases, depending on the course of the disease.
First we have the feverish phase, then the critical phase and finally the recovery phase. Let's talk about the febrile phase: the febrile phase has a sudden onset, usually with a high fever, which can reach 41 degrees, in addition to the fever there are also bone pain and arthralgias, that is why it is called a vulture fever , a vulture fever, or a vulture fever. The febrile phase lasts from 2 to 7 days, is usually accompanied by facial redness, a generalized erythema , headache, myalgias, a retroocular pain that is very characteristic, nausea, vomiting and diarrhea are also common and the positive tourniquet test increases the possibility dengue diagnosis.
Minor hemorrhagic manifestations such as bleeding gums, epistaxis, or petechiae may also occur , and the liver may be palpable and early leukocyte drop is common. Critical phase: the fall of the fever, the increase of the capillary permeability and the increase of the hematocrit mark the beginning of the critical phase. In this phase, patients can evolve favorably or worsen.
Patients with severe plasma extravasation may have pleural effusions and ascites. Serious hemorrhagic manifestations may also occur. Moderate to severe thrombocytopenia is also common in this phase , generally lasting 24 to 48 hours.
Recovery phase: it is when the patient survives a critical phase that does not exceed 48 to 72 hours, this phase is characterized by a feeling of well-being, a recovery of appetite, a decrease in gastrointestinal symptoms, stabilization of the hemodynamic state, that is, vital signs and an increase in urine output, hematocrit stabilizes, leukocytes increase, followed by an increase in platelets, there is a recovery in platelet count. Now there is also a classification: we have dengue and severe dengue. Dengue is going to be divided without warning signs and with warning signs.
Let's talk about dengue without warning signs: it is a person who lives or traveled to an endemic area who has a fever + 2 of the following criteria that can be: nausea, vomiting, rash, myalgia, arthralgia, petechiae or a positive tourniquet test, leukopenia and obviously that it is confirmed by laboratory. Now with warning signs: we have intense and continuous abdominal pain, persistent vomiting , clinical accumulation of fluids, mucosal bleeding, lethargy, irritability, a hepatomegaly more than two centimeters and in the laboratory we will find an increase in hematocrit along with a rapid drop in platelets. Then, in severe dengue, we will have a severe escape of plasma that leads to shock, fluid accumulation and respiratory distress.
It also leads to severe bleeding and also to severe organ damage, such as: the liver, the central nervous system and the heart. Virological and serological tests are used to establish the diagnosis . As for example there is the reverse transcriptase polymerase chain reaction, we also have the detection of the NS1 antigen , which is a protein produced by the virus and as a serological test we have the ELISA with the detection of immunoglobulin M and immunoglobulin G antibodies against dengue virus .
In dengue there is no specific treatment, the treatment will be symptomatic. Antipyretics can be taken to reduce fever and pain relievers. We have, for example, paracetamol and we must avoid NSAIDs such as ibuprofen and aspirin, since they could worsen the prognosis because they are anticoagulants and that could be harmful in this disease with risk of bleeding.
And depending on whether it is a patient with dengue without warning signs or with an alarm sign or severe dengue, the treatment could be at home, hospitalized or in the ICU. Prevention: There is a dengue vaccine called DENGVAXIA, but it can only be given to people who have had a previous infection with the dengue virus , because if the person has not had dengue, they could be at risk of developing severe dengue, if get dengue fever after being vaccinated. Remember that at the beginning we said that there were four serotypes.
And then what would be the most important measure? : Avoid the mosquito bite . And how is this achieved?
For example with repellants, wearing clothing that covers the arms and legs if necessary, the use of mosquito nets or taking measures to control mosquitoes inside and outside the house. And this is how we culminate with the dengue issue. LIKE IT, SHARE AND SUBSCRIBE.