Dengue fever: symptoms, treatment and prevention

Table of Contents

• 1 How is dengue fever transmitted?
• 2 Simplome febra Dengue
• 3 Dengue virus disease forms
• 4 Dengue fever diagnosis
• 5 Is there a treatment for Dengue fever?
• 6 Dengue fever prevention measures
• 7 Explain the type of immunity that develops after infection with one serotype of ‍the dengue virus

The movement of tourists to these endemic areas has increased the number of infections caused by the Dengue virus in other regions of the world, in March of this year, new cases of illness were reported in the United States – Puerto Rico, Florida and California. Other countries where an increase in the number of Dengue virus cases have been reported include: Afghanistan, Burkina Faso, Colombia, Dominican Republic, Ecuador, Ethiopia, Ghana, Grenada, India, Mali, Mexico and more.

Recent climate changes have created favorable conditions for the spread, including in Europe, of invasive species of mosquitoes that spread various pathogens to humans, including Dengue viruses.. In Romania, 7 cases of Dengue fever have been confirmed this year, including a one-year-old child, the mosquito responsible for transmitting this virus has been identified in several counties in the country, the among Giurgiu, Dambovita, Mehedinti, Sibiu and Bihor.

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How is dengue fever transmitted?

The mosquito species involved in the transmission of Dengue viruses are represented by Aedes albopictus or Ae. aegypti which usually lives in areas with high humidity and dense vegetation in the tropical and subtropical regions of the world. These species of mosquitoes are involved in the appearance of several zoonosis (human diseases transferred from animals / insects), being able to transmit various types of pathogens to humans and to other mammals (domestic or wild animals) during hematophagous feeding.

Dengue fever or hemorrhagic fever caused by infection with Dengue viruses 1, 2, 3 and 4, mosquitoes carrying one of these serotypes, become infected when they feed on the blood of an infected person who associates with a febrile syndrome (day 2-7 of the evolution of the disease).

The studies carried out so far have shown that the Dengue virus can be transmitted directly from mother to fetus during pregnancy, and the main problems that can occur as a result of the infection are represented with premature birth, delayed growth and development of the fetus and fetal distress at various stages of age.

Other ways of transmitting the Dengue virus that are less common in current medical practice include organ transplants and blood transfusions and the products that come from patients.

Simplome febra Dengue

After an incubation period that is usually between 4 and 10 days from the bite of a carrier mosquito, the viral infection can generate a wide range of clinical manifestations, but in most cases the infection is asymptomatic or subclinical.

The main manifestations that make up the clinical picture of Dengue fever is similar to the flu syndrome and includes:

• RECOMMENDATIONS
• Fever
• Eye pain
• arthralgia
• myalgia
• Skin spots
• Pain in the neck
• General condition changed.

The disease usually develops for about 7 days and is transmitted without the appearance of problems in young people with a strong immune system.

Dengue virus disease forms

Depending on the severity of the clinical manifestations that the patient shows, Dengue virus infection can be classified as follows:

• Easy shapes develops abnormally or resembles a flu-like syndrome and remit after an evolution period of about 7 days
• Heavy form which connects:
• High febrile syndrome above 41°C
• seizures
• Hepatomegaly (increased liver volume)
• Distribution incompatibility
• Hemorrhages (epistaxis, hematemesis, melena, gingivorrhea, hematuria)
• Heart rhythm problems
• Throwing out
• Abdominal pain
• Severe hydro-electrolytic imbalance
• MSOF multiple organ failure that can result in the death of the patient.

After the infectious event is removed, the antibodies generated by the host’s immune system offer life-long protection against the viral serotype that caused the infection and a partial and temporary immunity that lasts between 2-3 months against other viral serotypes.

Dengue fever diagnosis

The diagnosis of Dengue fever is established by the infection doctor based on the information obtained from the anamnesis and a detailed clinical examination of the patient, as well as the paraclinical studies for the detection of anti-viral IgM and IgG antibodies that circulation.

IgM antibodies appear first, about 3-5 days after the symptoms appear and increase gradually until the 10th day of the evolution of the disease. Antibodies of the IgG type against the Dengue virus are synthesized later, starting with the 7th day of the development of the disease, they increase gradually and are still available in the blood for the rest of life.

Rapid diagnosis of diseases caused by the Dengue virus can be achieved using the PCR method polymerase chain reaction which identifies the viral RNA genetic material at the level of the patient’s biological results (blood or liver tissue).

Is there a treatment for Dengue fever?

Dengue fever benefits from supportive treatment aimed at the patient’s hydro-electrolytic balance by increasing fluid consumption, reducing the patient’s pain discomfort and the febrile syndrome by giving non-steroidal anti-inflammatory drugs.

Severe cases of the disease require hospitalization for permanent monitoring of the patient and implementing corrective measures that may include oxygen administration, blood transfusions and parenteral hydroelectrolytic rebalancing.

Children and the elderly represent the categories of people who associate a greater risk of unfortunate complications occurring as a result of infection with the Dengue virus due to the limited mechanisms for compensating fluid loss in the body.

Dengue fever prevention measures

The main measures to prevent the spread of Dengue virus include:

• Personal protection against mosquitoes by wearing suitable clothing that covers as much of the body as possible, using repellants, mosquito nets and household appliances equipped with products against mosquitoes and other insects (pills, strips fillers, aerosols)
• Prevent mosquito breeding by covering water containers in the house, cleaning lakes and ponds near residential areas and regularly spraying insecticides in parks and densely vegetated areas in cities
• Restricting travel in dengue virus endemic areas
• Limiting outdoor activity, especially during periods of increased mosquito activity around sunrise and sunset
• Administration of the tetravalent vaccine for Dengue disease to people older than 4 years who come from endemic areas of this pathogen and to those who plan to travel to these regions.

People who plan to move to endemic areas are advised to contact the epidemiologist to prevent various exotic pathological conditions. Travel therapy is more accepting international vaccination and chemoprophylaxis of various hemorrhagic fevers, a series of aspects that must be addressed according to the specific characteristics of each traveler (pregnant woman, elderly with multiple comorbidities, child).

In this sense, the epidemiologist can issue a series of symptoms and recommendations based on evidence and studies recently carried out in the medical field, to effectively prevent various tropical pathologies ‘ can be contracted when they travel to endemic areas of these exotic pathogens.

References:

• Aedes albopictus – Fact sheet for expertsEuropean Center for Disease Prevention and Control (ECDC)
• Current Dengue OutbreakCDC
• Dengue and severe dengueWorld Health Organization (WHO)
• Diagnosis of Dengue using Reverse Transcriptase-Polymerase Chain Reaction
• Dengue feverDSP Timis
• Global dengueCDC
• The risk of the emergence of Dengue fever in Romania, in the context of global warmingLarisa Maria Ivanescu, Ilie Bodale, Smaranda Grigore-Hristodorescu, Gabriela Martinescu, Bianca Andronic, Simona Matiut, Doina Azoicai, Liviu Miron