DENGUE HEMORRHAGIC FEVER

CASE STUDY

INTRODUCTION

DEFINITION

An acute febrile disease caused by infection with one of the serotypes of dengue virus which are transmitted by mosquitoes Genus Aedes.

Refers to a benign form of disease with systemic symptoms, fever and often rash associated with pain behind the eyes, the joints and bones.

DENGUE HEMORRHAGIC FEVER is a severe, sometimes fatal manifestations of dengue virus infection characterized by a bleeding diathesis and hypovolemic shock.

ETIOLOGIC AGENT

Flaviviruses 1,2,3,4, a family of Togaviridae, are small viruses that contain single-stranded RNA.

Arboviruses group B.

MODE OF TRANSMISSION

Bite of an infected mosquito, principally the Aedes Aegypti Aedes aegypti is a day biting mosquito

(they appear 2hours after sunrise and 2hours before sunset).

It breeds in areas of stagnant water. It has limited, low-flying movement. It has fine white dots at the base of the

wings and white bands on the legs.

(Left) Aedes Aegypti (Right) Aedes Albopictus

Aedes albopictus may contribute to the transmission of the dengue virus in rural areas.

Other mosquitoes: Aedes polynensis Aedes scutellaris simplex

INCUBATION PERIOD

The incubation period is 3-14 days; commonly 7-10 days.

PERIOD OF COMMUNICABILITY Patients are usually infective to the

mosquito from a day before the febrile period to the end of it.

The mosquito becomes infective from day 8 to 12 after the blood meal and remains infective throughout its life.

SOURCES OF INFECTION

Infected persons the virus is present in the blood of patients during the acute phase of the disease and will become a reservoir of the virus, sucked by mosquitoes, which may then transmit disease.

Standing water any stagnant water in the household and its premises are usual breeding places of these mosquitoes.

INCIDENCE

Age Dengue fever may occur at any age, it is common among children and peaks between 4-9 years old.

Sex Both sexes can be affected. Season It is more frequent during the

rainy season. Location Dengue fever is more

prevalent in urban communities.

PATHOGENESIS AND PATHOLOGY The infectious virus is deposited in the skin by

the vector and initial replication occurs at the site of infection and in local lymphatic tissues.

Within a few days, viremia occurs, lasting until the 4th or 5th day after the onset of symptoms.

Evidence indicates that macrophages are the principal site of replication.

At the site of petechial rash, non-specific changes are noted, which include endothelial swelling, perivascular edema, and extravasation of blood.

There is marked increase in vascular permeability, hypotension, hemoconcentration, thrombocytopenia with increased platelet agglutinability, or moderate disseminated intravascular coagulation.

The most serious abnormality is hypovolemic shock resulting from the increased permeability of the vascular endothelium and loss of plasma from the intravascular space.

CLINICAL MANIFESTATIONS

Dengue Fever1. Prodromal symptoms characterized by:

A. malaise and anorexia up to 12 hoursB. fever and chills accompanied by severe frontal headache, ocular pain, myalgia with severe backache, and arthralgia

2. Nausea and vomiting3. Fever is non-remitting and persists for 3-

7days.

4. Rash is more prominent on the extremities and the trunk. It may involve the face in some isolated cases.

5. Petechiae usually appears near the end of the febrile period and most commonly on the lower extremities.

DENGUE HEMORRHAGIC FEVER

This severe form of dengue virus infection is manifested by fever, hemorrhagic diathesis, hepatomegaly and hypovolemic shock.

PHASES OF ILLNESS

1. Initial febrile phase lasting from two to three days

A. Fever (39-40 C) accompanied by headache

B. Febrile convulsions may appearC. Palms and sole are usually flushedD. Positive tourniquet testE. Anorexia, vomiting, myalgia

F. Maculopapular or petechial rash may be present and usually starts in the distal portion of the extremities (sparing the axilla and chest), the skin appears purple, with blanched areas of varying size (herman’s sign, considered pathognomonic to the disease).

G. Generalized or abdominal painH. Hemorrhagic manifestations like

positive tourniquet test, purpura, epistaxis, and gum bleeding by present

2. Circulatory phaseA. There is a fall of temperature

accompanied by profound circulatory changes, usually on the 3rd to 5th days.

B. Patient becomes restless, with cool, clammy skin.

C. Cyanosis is present.D. Profound thrombocytopenia

accompanies the onset of shock.

E. Bleeding diathesis become more severe and lead to GIT hemorrhage.

F. Shock may occur due to loss of plasma from the intravascular spaces; hemoconcentration with markedly elevated hematocrit is present.

G. Pulse is rapid and weak; pulse pressure becomes narrow and blood pressure may drop to an unobtained level.

H. Untreated shock may result in coma; metabolic acidosis and death may occur within 2 days.

I. With effective therapy, recovery may follow in 2-3 days.

CLASSIFICATION ACCORDING TO SEVERITY (Halstead & Nimmanitya)

Grade IThere is fever accompanied with non-

specific constitutional symptoms and the only hemorrhagic manifestation is positive in the torniquet test.

Grade IIAll signs of Grade I, plus spontaneous

bleeding from the nose, gums, and GIT, are present.

Grade IIIThere is the presence of circulatory

failure as manifested by a weak pulse, narrow pulse pressure, hypotension, cold, clammy skin, and restlessness.

Grade IVThere is profound shock, and

undetectable blood pressure and pulse.

COMPLICATIONS

Dengue feverA. Epistaxis, menorrhagiaB. Gastrointestinal bleedingC. Concomitant gastrointestinal disorder (peptic ulcer)

Dengue hemorrhagic feverA. Metabolic acidosisB. HyperkalemiaC. Tissue anoxiaD. Hemorrhage into the CNS or

adrenal glands E. Uterine bleeding may occurF. myocarditis

Severe manifestationsDengue encephalopathy is

manifested by increasing restlessness, apprehension or anxiety, disturbed sensorium, convulsions, spacity and hyporeflexia.

DIAGNOSTIC TESTS

Tourniquet test screening test, done by occluding the arm veins for about five minutes, to detect capillary fragility

Platelet count (decreased) confirmatory test

Hemoconcentration an increase of at least 20% in the hematocrit or a steady rise in the hematocrit

Occult blood

Hemoglobin determination

TREATMENT

There is no effective antiviral therapy for dengue.Treatment is entirely symptomatic.

Analgesic drugs other than aspirin may be required for relief from headache, occular pain, and myalgia.

Initial phase may require intravenous infusion to prevent dehydration and replacement of plasma

Blood transfusion is indicated in patients with severe bleeding.

Oxygen therapy is indicated for all patients in shock.

Sedatives may be needed to allay anxiety and apprehension.

HOME TREATMENT Determine the vital signs/status Encourage ORS Note warning signs (bleeding, vomiting,

black stool) Give paracetamol Use insect repellants and advice intake of

Vitamin C Early consultation

NURSING MANAGEMENT

Nursing Management1. Patient should be kept in a mosquito-free environment to

avoid further transmission of infection.2. Keep patient at rest during bleeding episodes.3. Vital signs must be promptly monitored.4. In cases of nose bleeding, keep the patient’s trunk elevated;

apply ice bag to the bridge of nose and to the forehead.5. Observe for signs of shock, such as slow pulse, cold, clammy

skin, prostration, and fall of blood pressure.6. Restore blood volume by putting the patient in

Trendelenberg position to provide greater blood volume to the head part.

7. Patient with dengue is not infectious; therefore, isolation is not required.

Prevention and ControlDOH Health Advisory: 4S’

S-earch and DestroyS-elf ProtectionS-eek Early ConsultationS-ay NO to Discrimination Fogging

STATISTICS

DOH Secretary Enrique Ona said that while dengue cases are down from January to July 23 this year compared to the same period last year, there is no reason to relax.

The DOH’s figures showed that from January to July 23, there were 38,876 dengue cases, 25.85 percent lower compared to the 52,428 cases in the same period last year.

HOT SPOTS