Dengue

What is dengue?

Dengue or dengue fever, is a viral disease transmitted by the bite of any of the dengue viruses. Dengue patients generally have fever, headache, eruption, nausea, vomiting, aches and pains.

In some cases, dengue can progress to a serious form called severe dengue (previously known as dengue. hemorrhagic fever), characterized by plasma leak with or without hemorrhage. Severe bleeding or severe organ damage may occur, with or without shock characteristics [1].

Who gets dengue?

Several hundred years ago, the dengue virus probably changed from a mosquito-mono-mosquito transmission cycle to become endemic Inhuman.

There are an estimated 400 million infections in more than 100 countries worldwide each year, especially in tropical areas.

Children, the elderly and immunosuppressed individuals tend to be more likely to have atypical or severe forms of dengue virus infection. Severe dengue was first recognized in the 1950s during dengue. epidemics in the Philippines and Thailand, but is now reported worldwide.

The global spread and increasing severity of dengue were allowed by:

• Population increase
• International travel

• Climate change with increasing temperatures in subtropical areas

• More abundant mosquito breeding sites (small freshwater pools such as those found in discarded tires, vases, or uncovered water containers) [1,2].

What causes dengue?

Dengue virus belongs to the flavivirus family, the same family of viruses that includes yellow fever and zika. Also called arboviruses, because they are transmitted by arthropod bites (in the case of dengue by Aedes mosquitoes, especially Aedes aegyptiDengue viruses (DENV) are small, spherical, single-stranded envelopes RNA viruses with four different viral serotypes, DENV 1–4.

Once a person becomes infected, the virus is transported and multiplies in the blood, serving as the source of the virus for uninfected mosquitoes. Patients who are already infected with dengue virus can transmit the infection through mosquitoes after the first symptoms appear for up to two weeks later. [1,2].

What are the clinical characteristics of dengue?

A person infected with the dengue virus develops severe flu-like symptoms. The clinical characteristics of dengue fever vary according to the characteristics of the infected individual. Symptoms generally last 2 to 7 days, after a incubation period of 4 to 10 days after the bite of an infected mosquito [1,3].

In 2009, the WHO reclassified dengue infections as dengue fever and divided it into three groups. [one].

Probable dengue fever: fever (usually up to 40 ° C) plus two of the following:

• Nausea and / or vomiting
• Rash (red and confluent spots and spots)
• Leukopenia (low white blood cells)
• Aches and pains (“bone fracture”) especially arms and legs
• Positive tourniquet test (a test done by doctors)
• A retroocular headache (pain behind the eyes)

Dengue fever with warning signs: Dengue fever plus at least one of the following:

• Abdominal pain or tenderness
• Persistent vomiting
• Mucous membrane bleeding (from the nose and gums)
• Lethargy (drowsiness) or restlessness.
• Hepatomegaly (enlarged liver)
• Increased hematocrit (a characteristic of fluid loss)
• Thrombocytopenia (low platelet tell)
• Pleural or peritoneal effusion (fluid in the lining of the lungs or abdominal organs).

Severe Dengue: Dengue fever plus at least one of the following:

• Renal insufficiency
• Acute pulmonary edema (sudden accumulation of fluid in the lungs)
• Shock characteristics (low blood pressure, fast heart rate)
• Severe bleeding
• Heart failure AST or ALT > 1000 IU (very abnormal liver function tests)
• Altered level of consciousness (drowsiness or even coma).

What are the complications of dengue?

The most feared complication of dengue is its severe form. Major bleeding, deep shock, multiple organ failure, and brain or heart damage can generally lead to death when present. This is fortunately rare [1].

How is dengue diagnosed?

Dengue infection is diagnosed by analyzing blood samples during the first 5 days of symptoms and / or early recovery phase (more than 5 days of symptoms) confirming the presence of the virus. The diagnosis can also be confirmed by:

• The presence of IgM against dengue virus (IgM is a antibody produced in acute infections); or;
• The increase in IgG titers against dengue virus in two different blood samples (IgG is an antibody produced when the person has been previously infected) [4].

Which is the differential diagnosis for dengue?

This can be infectious (mainly) or non-infectious.

Infectious conditions

• Viruses: chikungunya, zika, influenza, acute human immunodeficiency virus (HIV) infection, measles, rubella

• The bacteriaLeptospirosis, typhoid fever, typhus, bacterial septicemiascarlet fever
• Protozoamalaria

Non-infectious conditions

• Inflammatory: systemic lupus erythematosus, Adverse reactions to medications
• Hematological disorders: aplastic anemia, leukemia, purple syndromes

What is the treatment of dengue?

There is no specific treatment for dengue fever. Patients should seek medical advice, rest, and drink plenty of fluids.

• Paracetamol can be taken to lower fever and reduce joint pain.
• Aspirin or non-steroidal anti-inflammatory drugs (NSAID) such as ibuprofen should not be taken as they may increase the risk of bleeding [1,5].

In the case of severe dengue, the patient should be admitted to the hospital for maintenance of the patient's circulating fluid volume and treatment of bleeding complications.

What is the result of dengue?

After recovering from dengue fever, the person develops lifelong immunity against that particular dengue virus serotype, but confers temporary and partial protection against the other three virus serotypes.

Sequential infections appear to increase the risk of developing severe dengue. The person with uncomplicated dengue recovers without any residual problem. [one].

Dengue prevention

Research is ongoing on dengue virus drugs and vaccines, and also for the reduction and / or elimination of Aedes mosquitoes. [1.6].

Vector control

Mosquito breeding sites must be eliminated or controlled. The dengue virus-carrying mosquito often breeds in artificial containers and receptacles containing water. The following steps can be taken to reduce mosquito breeding.

• Cover all water tanks, cisterns, barrels, trash bins.
• Remove or empty the water in old tires, cans, bottles, trays.
• Check and clean clogged gutters and flat roofs where water may have accumulated.
• Change the water regularly at pet water dishes, birdbaths and plant trays.
• Introduce larvivorous fish (such as the guppy) to the ornamental features of the water, as they eat mosquito larvae.
• Trim weeds and tall grasses as adult mosquitoes seek them out for shade.

People should avoid being bitten by mosquitoes.

• Wear long sleeves and pants.
• Install secure screens on windows and doors to keep mosquitoes away.
• Use an insect repellent like DEET.
• Sleep under mosquito nets or curtains, this is particularly important when children sleep or rest during the day.
• In high-risk areas, insecticide sprays can be used to kill mosquitoes.