DENGUE FEVERPresented by: Naraino Majie Nabiilah

Date: 14th April 2014

Introduction

• Fever Dengue (pronounced DEN-gee) is caused by viruses that are transmitted by mosquito bites.

• Aedes aegypti is the mosquito that most commonly spreads this disease through its bite.

• It is a severe illness with symptoms as fever, headache, intense muscle and joint pains, exhaustion, lymphadenopathy (swollen glands) and rashes.

• There are other name for dengue is "breakbone."

• Because dengue fever is caused by a virus, there is no specific medicine or antibiotic to treat it.

• For typical dengue fever, the treatment is directed toward relief of the symptoms (symptomatic treatment).

• The acute phase of the illness with fever lasts about one to two weeks.

• Dengue can affect anyone but tends to be more severe in people with compromised immune systems.

• Because it is caused by one of five serotypes of virus, it is possible to get dengue fever multiple times.

• However, an attack of dengue produces immunity for a lifetime to that particular viral serotype to which the patient was exposed.

Epidemiology of dengue fever• Dengue is prevalent throughout the tropics and

subtropics.• Dengue is also known as “breakbone fever” because

of the intense joint and bone pain caused by the infection.

• About 40 percent of the world is currently at risk for dengue.

• Only forty years ago, according to the WHO, there were only nine countries worldwide that experienced severe dengue epidemics.

• Today, the WHO estimates between 50 and 100 million dengue infections every year, and dengue is endemic in over 100 countries worldwide.

Causes of dengue fever

• It is caused by the following four serotypes:– DENV-1, – DENV-2, – DENV-3, and – DENV-4 (the numbers reflect the order of discovery

and have no relation to disease severity)• These four serotypes originated in monkeys and jumped to

humans in tropic and sub tropic regions over a century ago.• However a fifth type has been discovered by Nikos

Vasilakis, PhD of the University of Texas Medical Branch in Galveston: – DENV-5

How dengue spreads?

• The virus is contracted from the bite of a striped Aedes aegypti mosquito that has previously bitten an infected person.

• The mosquito flourishes during rainy seasons but can breed in water-filled flower pots, plastic bags, and cans year-round. One mosquito bite can cause the disease.

• The virus is not contagious and cannot be spread directly from person to person. There must be a person-to-mosquito-to-another-person pathway.

What are dengue fever signs and symptoms?

• After being bitten by a mosquito carrying the

virus, the incubation period ranges from three

to 15 (usually five to eight) days before the

signs and symptoms of dengue appear in

stages.

The signs and symptoms are as follows:• Sudden onset of fever for 2 to 7 days

(40°C)• Severe headache with retro-orbital (behind

the eye) pain• Joint and muscle pain• Skin rashes• Nausea and vomiting• Bleeding from the nose or gums or easy

bruising in the skin

Treatment

• There are currently no licensed dengue vaccines available. Several vaccine candidates are in clinical or pre-clinical development.

• The most advanced candidate, a chimeric tetravalent vaccine based on the yellow fever 17d backbone, is currently under evaluation in Phase III clinical trials.

• Prevention is currently the best method of dengue control

• For typical dengue, the treatment is concerned with relief of the symptoms.

• Bed rest and mild analgesic-antipyretic therapy are

often helpful in relieving lethargy, malaise, and fever

associated with the disease.

• Aspirin and non steroidal anti-inflammatory drugs

should only be taken under a doctor's supervision

because of the possibility of worsening bleeding

complications.

• Acetaminophen (paracetamol) and codeine may be

given for severe headache and for joint and muscle

pain (myalgia).

• Oral rehydration therapy is recommended for patients with moderate dehydration caused by high fever and vomiting.

• Patients with known or suspected dengue fever should have their platelet count and hematocrit measured daily from the third day of illness until 1-2 days after defervescence.

• Patients with clinical signs of dehydration and patients with a rising hematocrit level or falling platelet count should have intravascular volume deficits replaced under close observation.

• Those who improve can continue to be monitored in an outpatient setting, and those who do not improve should be admitted to the hospital for continued hydration.

When to admit the patient?

• BP < 90/60 mm Hg • HCt > 50 % • Platelets < 50,000/cu.mm • Bleeding other than petechiae • When danger signs develop

Factors that affect disease severity include the following:

• Patient age• Pregnancy• Nutritional status• Sequence of infection with different dengue

serotypes• Hepatic failure• Virus genotype• Quality and extent of available medical care

Prevention• Stay in air-conditioned or well-screened

housing. It's particularly important to keep mosquitoes out at night.

• Reschedule outdoor activities. Avoid being outdoors at dawn, dusk and early evening, when more mosquitoes are out.

• Wear protective clothing. When you go into mosquito-infested areas, wear a long-sleeved shirt, long pants, socks and shoes.

• Use mosquito repellent. Permethrin can be applied to your clothing, shoes, camping gear and bed netting. You can also buy clothing made with permethrin already in it. For your skin, use a repellent containing at least a 10 percent concentration of DEET.

• Reduce mosquito habitat. The mosquitoes that carry the dengue virus typically live in and around houses, breeding in standing water that can collect in such things as used automobile tyres. Reduce the breeding habitat to lower mosquito populations.

Summary• Dengue is an infectious disease caused by a virus.• You can get it if an infected mosquito bites you. • It is common in warm, wet areas of the world.•  Outbreaks happen in the rainy season.• Most people with dengue recover within 2 weeks. • However, some dengue infections are severe and

cause bleeding from your nose, gums or under your skin.

• Early diagnosis and treatment of dengue is critical as epidemics of the disease become larger and more frequent.

• An estimated 50 to 100 million people are infected with dengue each year in over 100 countries.

• In severe cases, people infected with dengue may experience severe bleeding, shock and death.

• Severe dengue is often treated with aggressive emergency treatment, which includes fluid and electrolyte replacement.

• Prompt treatment can be life saving. Dengue can be prevented by limiting exposure to the mosquitoes that carry the virus.

REFERENCES• Abdullah, 2013, Dengue, Arabic health

encyclopedia. Available at: http://www.kaahe.org/health/en/418-dengue/all.html

• Mayo clinic staff, 2013, Dengue fever, Disease and conditions. Available at: http://www.mayoclinic.org/diseases-conditions/dengue-fever/basics/causes/con-20032868

• John, 2013, Dengue fever Diagnosis, MedicineNet.com, Available at: http://www.medicinenet.com/dengue_fever/page4.htm#how_is_dengue_fever_diagnosed

• Adam, 2009, Dengue fever explained, Ezine articles. Available at: http://ezinearticles.com/?Dengue-Fever-Explained&id=5642474

• Suzanne et al, 2014, Dengue treatment and management, Medscape. Available at: http://emedicine.medscape.com/article/215840-treatment

• WHO, 2014, Dengue, Vaccines and disease. Available at: http://www.who.int/immunization/diseases/dengue/en/

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