Dengue Hemorrhagic Fever: Prof. Chhour Y Meng

DENGUE HEMORRHAGIC FEVER

Prof. CHHOUR Y MENG MD, MPH Director National Pediatric Hospital

The key components are represented by 4 W’s: • WHAT ? • WHO ? • WHEN ? • WHERE ?

1) WHAT IS DENGUE ? • Dengue is a vector borne disease • Serious public health problem in Cambodia • Constitutes as one of the ten leading causes of hospitalization and death of childhood.

2) WHO AFFECTED BY THE DENGUE ? All people ( Male / Female ), especially: • Children < 15 years old, • The most affected, children 4–6 y • High mortality, children from 1 – 4 y.

3)WHERE DOES THE DENGUE OCCUR ?

• Rural: along the river, bamboo, coconut shells, earthen jars… • Urban: slum areas, overcrowded places, containers, water jars, anttraps, unused-containers…

Larvae

Adult mosquito

Indoor

Outdoor

Water containers

Water containers

Water jars Pots of flowers

Water jars Unused containers

Ant-traps

Tires, cans, coconut

Clothes

shells Plastic bags, broken earthen jars Bamboos Holes in tree

Curtains

4) WHEN DOES THE DENGUE HAPPEN? • Rainy seasons(May–October, November) - Poor sanitation + lifestyle - A lot of breeding sites - Increase the mosquito density. • But the transmission is happen all long year • Epidemic occurs every 2 to 3 years.

T H E 3 P R E D O M IN A N T D IS E A S E S i n N P H 2 0 0

250 200 150 100 50 0 J an F eb M ar A pr M ay J un J ul A ug S ep O c t N o v D ec D iarrhea A R I D HF

HOW DOES THE DENGUE TRANSMIT?

Etiology • 4 sertypes of dengue viruses: – Serotypes 1, 2, 3, 4 – Members of the family Flaviviridae

The infection in human by anyone of theses serotypes can produce life-long immunity against reinfection of the same serotype, but only temporary and partial protection against the others.

CLINICAL MANIFESTATIONS

INCUBATION PERIOD 5 – 8 DAYS

CLINICAL MANIFESTATIONS IN TYPICAL CASE OF DHF 1. 2. 3. 4.

High, continuous fever Hemorrhagic manifestation Hepatomegaly Circulatory disturbance / shock.

LABORATORY CRITERIA 1. Haemoconcentration ( ≥ 20% increase in HCT level ). 2.Thrombocytopenia ( ≤ 100,000/mm3).

Clinical Manifestations Contd. • Incubation: 1-7 days • Acute Febrile Phase (2- 7 days): – Typically, sudden on set of fever, Temperature: 39.5 – 41ºc – Facial flushing, skin erythema, headache and muscle pain – Convulsion may be present in infants – Mild conjunctival injection – Injected Pharynx, anorexia, vomiting and abdominal pain are common

Acute Febrile Phase (cont.): – Hemorrhagic manifestations: • • • •

Skin petechia (invariable) Positive Tourniquet test ( more than 10 per 2.5cm²) Easy bruising Epistaxis, gum bleeding, gastrointestinal bleeding are less common, but may be severe. Massive gastrointestinal hemorrhage may be present in association with prolonged shock. Hematuria is extremely rare.

– Soft and tender Hepatomegaly is often found – Generalized lymphadenopathy occurs in some cases

Tourniquet test positive

• Critical Phase (24-48 hours) occurs at the end of febrile phase. – Rapid drop of temperature (subnormal temp.) – Circulatory disturbances – Sweating, restless, cold extremities.

In mild DHF cases, the changes of vital signs are minimal and transient. Patients will recover shortly after an appropriate treatment.

In more DHF severe cases, the disease develops rapidly a stage of shock. DHF/DSS: – Acute onset – Acute abdominal pain – Restless – Subnormal temperature – Cold and clammy skin – Weak and rapid pulses – Narrow blood pressure (≤20mmHg) – Respiration rapid and labored.

SEVERITY OF DHF

GRADE I Fever accompanied by non-specific symptoms with a positive tourniquet test.

GRADE II Spontaneous bleeding-skin and/or other haemorrhage are in additional to those of Grade I

GRADE III Circulatory failure

GRADE IV Profound shock with undetectable BP and Pulse

MANAGEMENT Symptomatic and Supportive

Type of solutions • Crystalloid solutions: - 5%D/NSS - 5%DLR* - 5%D/AR • Colloid solution: - Dextran 40 - FWB • Lactate Ringer solutions are contra-indicated in case of acidosis. • NSS or Acetate Ringer should be instead of LR in case of shock

WARNING SIGNS OF SHOCK 1. Sudden drop of temperaturesubnormal level. 2. Restless. 3. Acute abdominal pain. 4. Cold at extremities. 5. Oliguria.

Causes of death in DHF • • • •

Prolonged shock Fluid overload Massive bleeding Unusual manifestations: – Encephalopathy/ Encephalitis – Hepatic failure – Dual Infections

Drowsiness, shock. Platelet count only 1000/mm3

DHF/DSS + restlessness

DHF/DSS with profound shock + respiratory failure

Shock, very severe dyspnea and massive ascites

DHF/DSS with respiratory failure + renal failure

DHF/DSS + very severe respiratory distress + massive ascites

PREVENTION AND CONTROL