Andrea Montelibano Isabelle Escobillo. The Virus Flavivirus Single strand RNA 4 serotypes – DENV-1...

Andrea MontelibanoIsabelle Escobillo

The Virus

• Flavivirus• Single strand RNA• 4 serotypes– DENV-1– DENV-2– DENV-3– DENV-4

• Infection with one serotype confers lifelong immunity to that serotype but not for the other

• Secondary infection leads to severe form

The Virus

• Vectors– Aedes aegypti– Aedies alpobtica

Transmission

• Female mosquito infects human during the viremic phase

• Virus replicates in the epithelial cell lining of the midgut hemocele salivary glands

• Usually occurs during the rainy season• High vector population is also found in man-

made storage containers

Clinical Features

• Incubation: 4-6 days (range 3-14)• Constitutional symptoms• Sharp rise in temperature • Flushing, headache, chills, retro-orbital pain,

photophobia, joint pains, anorexia, constipations, colicky pain, abdominal tenderness

Clinical Features

• Fever– Usually between 39C and 40C, biphasic, lasting 5-7

days• Rash– Day 1-3: Diffuse flushing or fleeting eruptions on

the face neck and chest– Day 3-4: Maculopapular or rubelliform– Convalescence: confluent petechiae surround

scattered pale areas or normal skin

Clinical Features

• Hemorrhagic manifestations– Positive tourniquet test– Massive epistaxis, hypermenorrhea, GI bleeding

Laboratory Features

• Leukopenia: WBC =< 5000 cells/mm3• Mild thrombocytopenia (100,000 to 150,000

cells/mm3)• Mild hematocrit rise (=10%)• Elevated liver enzymes

Classification

Dengue without Warning Signs

Lives in or travels to dengue-endemic area, with fever, plus any 2 of the following:– Headache, body malaise, myalgia, arthralgia,

retro-orbital pain, anorexia, nausea, vomiting, diarrhea, flushed skin, rash, positive Tourniquet test

– CBC with leukopenia, with or without thrombocytopenia and/or dengue NS1 antigen test or dengue IGM antibody test

Dengue with Warning Signs

• Lives in or travels to dengue-endemic area, with fever of 2-7 days, plus any of the following:– Abdominal pain or tenderness, persistent

vomiting, clinical signs of fluid accumulation, mucosal bleeding, lethargy or restlessness, liver enlargement, decreased or no urine output within 6 hours

– Increase in hematocrit and/or decreasing platelet

Severe Dengue

• Lives in or travels to dengue-endemic area, with fever of 2-7 days and any of the manifestations of dengue with/without warning signs, plus any of the following– Severe plasma leakage: shock, fluid accumulation with

respiratory distress– Severe bleeding– Severe organ impairment

• Liver: AST or ALT >= 1000• CNS: Seizures, impaired consciousness• Heart: Myocarditis• Kidneys: Renal failsure

Laboratory Diagnosis• Dengue NS1– Detectable on Day 1 to 5

• Dengue IgM/ IgG– Day 3-5 onwards

Clinical Course

Management

Management

Management

• When sending home a patient, patient and family advice should be given:

Management

• Follow-up:– Daily follow-up is recommended for all patients

except those who have resumed normal activities or are normal when the temperature subsides

Fluid Management

Fluid management for patients who are not admitted

Calculation of Oral Rehydration Fluids Using Weight (Ludan Method)

Fluid management for patients who are admitted without shock

• Isotonic solutions: D5 LRS, D5 NSS, D5 0.9 NaCl, PLR, 0.9 NaCl

• Infants <6 months: Dr 0.45 NaCl

Calculation of Maintenance IV Fluid Infusions (Holliday and Segar Method)

Fluid management for patients who are admitted without shock

• Signs of mild dehydration– TFR = Maintenance IVF + Fluids for Mild

Dehydration– Infant (age =< 12 months): 50 ml/kg– Older Child or Adult (age > 12 months): 30 ml/kg

• Clinical parameters should be monitored and correlated with hematocrit

• Use Ideal body weight for overweight patients

Fluid Management for Patients with Compensated Shock

Hemodynamic Assessment: Continuum of Hemodynamic Changes

Fluid Management for Patients with Hypotensive Shock

Prevention

• Success is dependent on – Effectiveness of the initiatives to control the

breeding sites of the vector– Improving public and household environmental

sanitation and water supply,– Sustained modification of human behaviour

Prevention

• Community Participation– active voluntary engagement of individuals and

groups to change problematic conditions and influence policies and programmes that affect the quality of their lives or the lives of others

– households which do follow the recommended actions for prevention may still harbour Ae. aegypti or other mosquitoes

Prevention

• Surveillance• Vector Control• (Future) Vaccination

Thank You!!