Dengue and dengue treatment
Dengue is a viral infection transmitted by mosquitoes.
This infection causes an influenza-like syndrome and may occasionally progress to life-threatening complications called severe dengue fever.
The global incidence of dengue fever has increased dramatically in recent decades.Dengue fever occurs in tropical and subtropical regions around the world, with a predilection for urban and semi-urban areas.
Severe dengue fever is a major cause of serious illness and death in children in some Asian and Latin American countries.
There is no specific treatment for dengue or severe dengue, but early detection and access to adequate medical care can reduce mortality rates to below 1%.
Prevention and control of dengue
is based on effective vector control measures.
Dengue fever is a mosquito-borne viral disease that has spread rapidly in all WHO regions in recent years. The virus is transmitted to humans through the bite of female mosquitoes, mainly Aedes aegypti, but to a lesser extent Aedes albopictus. This vector also transmits chikungunya, yellow fever and Zika viruses. Dengue fever is widespread in the tropics, with local variations in risk, mainly a function of rainfall, temperature, and rapid and uncontrolled urbanization.
Severe dengue fever (formerly known as dengue haemorrhagic fever) was first recognized in the 1950s during epidemics in the Philippines and Thailand. Today, the Asian and Latin American countries are the most affected and have become a major cause of hospitalization and mortality for children and adults in these regions.
There are 4 closely related serotypes of the dengue virus (DEN-1, DEN-2, DEN-3 and DEN-4). Healing results in lifetime immunity against the serotype causing the infection. On the other hand, cross-immunity with other serotypes after healing is only partial and temporary. Subsequent infections with other serotypes increase the risk of developing severe dengue fever.
Global burden of dengue fever
The incidence of dengue fever has increased dramatically worldwide in recent decades. The actual number of cases is underreported and many cases are not properly classified.
According to a recent estimate, there are 390 million cases of dengue fever per year (95% credible interval 284-528 million), of which 96 million (67-136 million) have clinical manifestations (regardless of the severity of the disease) .1 Another dengue prevalence study estimates that 3.9 billion people in 128 countries are exposed to dengue virus infection.2
The Aedes aegypti mosquito is vector of dengue fever. The virus is transmitted to humans by the bite of infected females. After an incubation period of 4 to 10 days, an infected mosquito can transmit the virus for the rest of its life.
The infected human being, with or without symptoms, is the main carrier of the virus; it allows its proliferation and serves as a source of contamination for mosquitoes that are not yet infected. Subjects infected with the dengue virus can transmit the infection (for 4 to 5 days and up to 12 days) via Aedes mosquitoes after the onset of symptoms.
Aedes aegypti lives in urban areas and breeds mainly in man-made containers. Unlike other mosquitoes, it feeds during the day, with a peak of activity early in the morning and in the evening before dusk. During each period she feeds, the female stings multiple people.
Aedes albopictus, a secondary vector of dengue in Asia, has spread to North America and more than 25 European countries, largely as a result of international trade in used tires (a larval bed) and the movement of goods (by example the Chinese cane or lucky bamboo). This species has a very high adaptability and can survive in the cooler and cooler regions of Europe. Its spread is due to its tolerance to temperatures below 0 °, its ability to hibernate and its ability to shelter in micro-habitats.
Dengue fever is a serious influenza-like illness that affects infants, young children and adults but is rarely fatal.
Dengue fever is suspected in the presence of high fever (40 ° C), accompanied by 2 of the following symptoms: severe headache, retro-orbital pain, muscle, joint, nausea, vomiting, lymphadenopathy or rash. Symptoms usually last for 2 to 7 days and develop after an incubation period of 4 to 10 days after the bite of an infected mosquito.
Severe dengue fever is a life-threatening complication due to plasma leakage, fluid accumulation, respiratory distress, profuse hemorrhages, or organ failure. The warning signs occur 3 to 7 days after the first symptoms, together with a drop in temperature (below 38 ° C).
Severe abdominal pain, persistent vomiting, hyperpnea, bleeding gums, fatigue, agitation, blood in the vomit may occur. Death can occur within 24 to 48 hours of this critical phase; appropriate medical treatment is needed to avoid complications and the risk of death.
There is no specific treatment for dengue.
For severe dengue, care by experienced doctors and nurses who are aware of the effects and course of the disease can save lives by reducing the mortality rate from over 20% to less than 1%. It is essential to maintain the patient’s fluid volumes in the treatment of severe dengue fever.
Vaccination dengue treatment
At the end of 2015 and the beginning of 2016, the first dengue vaccine, Dengvaxia (CYD-TDV), developed by the Sanofi Pasteur laboratory, was registered in several countries for use in people aged 9 to 45 years. living in endemic areas.
WHO recommends that countries consider the introduction of the CYD-TDV dengue vaccine only in geographical areas (national or subnational) where epidemiological data indicate a high disease burden. The full recommendations can be found in the WHO Executive Summary on Dengue Vaccine:
WHO Executive Summary on Dengue Vaccine
Weekly Epidemiological Record – July 2016
Other live attenuated tretravalent vaccines are being developed in Phase III clinical trials and other candidate vaccines (subunit, DNA or prepared from purified inactivated virus) are in earlier stages clinical development.)
Prevention and fight dengue treatment
Currently, the only method to prevent or control the transmission of the virus is to control the vectors by:
to prevent mosquitoes from gaining access to breeding sites through management and modification of the environment;
properly dispose of solid wastes and remove man-made habitats;
cover, empty and clean containers every week for the conservation of domestic water;
apply suitable insecticides to containers for outdoor water conservation;
take measures to protect people and the home by installing mosquito nets on windows, wearing long-sleeved clothing, using insecticide-treated materials, spirals and sprayers;
improve community participation and mobilization for sustainable vector control;
in the event of an epidemic emergency, vector control measures also include spraying and insecticide spraying;
actively monitor and monitor vectors to determine the effectiveness of control interventions.
Reliable clinical detection and management of dengue patients can significantly reduce death rates from severe dengue fever.