COMMUNICABLE DIEASES THAT CAN CAUSE MORE DEATH IN FEW TIME

Dengue fever is an arbovirus transmitted by Aedes mosquitoes (both Ae. aegypti and Ae. albopiticus). It is a severe, flu-like illness that affects infants, young children and adults, but seldom causes death.

Dengue haemorrhagic fever (DHF) is a potentially deadly complication that has become a leading cause of hospitalization and death among children in Asia. There is good evidence that sequential infection with the different serotypes of dengue virus increases the risk of more severe disease that can result in shock syndrome and death. 

There is no specific treatment for dengue, but appropriate medical care frequently saves the lives of patients with dengue haemorrhagic fever.  

Infected humans are the main carriers and multipliers of the virus, serving a source of the virus for uninfected Aedes aegypti mosquitoes which maintain the urban dengue transmission cycle. The virus circulates in the blood of infected human for 2 to 7 days, at approximately the same time that they have a fever. 

At present, the only method of controlling or preventing dengue virus transmission is to combat the vector mosquitoes using environmental management and chemical methods. 

Communicable, or infectious diseases, are caused by microorganisms such as bacteria, viruses, parasites and fungi that can be spread, directly or indirectly, from one person to another. Some are transmitted through bites from insects while others are caused by ingesting contaminated food or water.

A variety of disease-producing bacteria and viruses are carried in the mouth, nose, throat and respiratory tract. Conditions such as leprosy, tuberculosis (TB) and different strains of influenza (flu) can be spread by coughing, sneezing, and saliva or mucus on unwashed hands.

• Dengue is a mosquito-borne viral infection.
• The infection causes flu-like illness, and occasionally develops into a potentially lethal complication called severe dengue.
• The global incidence of dengue has grown dramatically in recent decades. About half of the world's population is now at risk.
• Dengue is found in tropical and sub-tropical climates worldwide, mostly in urban and semi-urban areas.
• Severe dengue is a leading cause of serious illness and death among children in some Asian and Latin American countries.
• There is no specific treatment for dengue/ severe dengue, but early detection and access to proper medical care lowers fatality rates below 1%.
• Dengue prevention and control depends on effective vector control measures.
• A dengue vaccine has been licensed by several National Regulatory Authorities for use in people 9-45 years of age living in endemic settings.

Dengue is a mosquito-borne viral disease that has rapidly spread in all regions of WHO in recent years. Dengue virus is transmitted by female mosquitoes mainly of the species Aedes aegypti and, to a lesser extent, Ae. albopictus. This mosquito also transmits chikungunya, yellow fever and Zika infection. Dengue is widespread throughout the tropics, with local variations in risk influenced by rainfall, temperature and unplanned rapid urbanization.

Severe dengue (also known as Dengue Haemorrhagic Fever) was first recognized in the 1950s during dengue epidemics in the Philippines and Thailand. Today, severe dengue affects most Asian and Latin American countries and has become a leading cause of hospitalization and death among children and adults in these regions.

See the report from WHO here

    TREATMENT 

There is no specific treatment for dengue fever.

For severe dengue, medical care by physicians and nurses experienced with the effects and progression of the disease can save lives – decreasing mortality rates from more than 20% to less than 1%. Maintenance of the patient's body fluid volume is critical to severe dengue care.

In late 2015 and early 2016, the first dengue vaccine, Dengvaxia (CYD-TDV) by Sanofi Pasteur, was registered in several countries for use in individuals 9-45 years of age living in endemic areas.

WHO recommends that countries should consider introduction of the dengue vaccine CYD-TDV only in geographic settings (national or subnational) where epidemiological data indicate a high burden of disease. Complete recommendations may be found in the WHO position paper on dengue vaccines by WHO

Other tetravalent live-attenuated vaccines are under development in phase III clinical trials, and other vaccine candidates (based on subunit, DNA and purified inactivated virus platforms) are at earlier stages of clinical development. WHO provides technical advice and guidance to countries and private partners to support vaccine research and evaluation.

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PREVENSION AND CONTROL

At present, the main method to control or prevent the transmission of dengue virus is to combat vector mosquitoes through:

• preventing mosquitoes from accessing egg-laying habitats by environmental management and modification;
• disposing of solid waste properly and removing artificial man-made habitats;
• covering, emptying and cleaning of domestic water storage containers on a weekly basis;
• applying appropriate insecticides to water storage outdoor containers;
• using of personal household protection such as window screens, long-sleeved clothes, insecticide treated materials, coils and vaporizers;
• improving community participation and mobilization for sustained vector control;
• applying insecticides as space spraying during outbreaks as one of the emergency vector-control measures;
• active monitoring and surveillance of vectors should be carried out to determine effectiveness of control interventions.

                   PREVENTION AND CONTROL 

At present, the main method to control or prevent the transmission of dengue virus is to combat vector mosquitoes through:

• preventing mosquitoes from accessing egg-laying habitats by environmental management and modification;
• disposing of solid waste properly and removing artificial man-made habitats;
• covering, emptying and cleaning of domestic water storage containers on a weekly basis;
• applying appropriate insecticides to water storage outdoor containers;
• using of personal household protection such as window screens, long-sleeved clothes, insecticide treated materials, coils and vaporizers;
• improving community participation and mobilization for sustained vector control;
• applying insecticides as space spraying during outbreaks as one of the emergency vector-control measures;
• active monitoring and surveillance of vectors should be carried out to determine effectiveness of control interventions.

Careful clinical detection and management of dengue patients can significantly reduce mortality rates from severe dengue.