DENGUE FEVER

Dengue and dengue haemorrhagic fever

Dengue is a mosquito-borne infection which in recent years has become a major international public health concern. Dengue is found in tropical and sub-tropical regions around the world, predominantly in urban and semi-urban areas.

Dengue haemorrhagic fever (DHF), a potentially lethal complication, was first recognized in the 1950s during the dengue epidemics in the Philippines and Thailand, but today DHF affects most Asian countries and has become a leading cause of hospitalisation and death among children in several of them.

There are four distinct, but closely related, viruses that cause dengue. Recovery from infection by one provides lifelong immunity against that serotype but confers only partial and transient protection against subsequent infection by the other three. There is good evidence that sequential infection increases the risk of more serious disease resulting in DHF.
Prevalence

The global prevalence of dengue has grown dramatically in recent decades. The disease is now endemic in more than 100 countries in Africa, the Americas, the Eastern Mediterranean, South-east Asia and the Western Pacific. South-east Asia and the Western Pacific are most seriously affected. Before 1970 only nine countries had experienced DHF epidemics, a number that had increased more than four-fold by 1995.

Some 2500 million people — two fifths of the world’s population — are now at risk from dengue. WHO currently estimates there may be 50 million cases of dengue infection worldwide every year.

In 2001 alone, there were more than 609 000 reported cases of dengue in the Americas, of which 15 000 cases were DHF. This is greater than double the number of dengue cases which were recorded in the same region in 1995.

Not only is the number of cases increasing as the disease is spreading to new areas, but explosive outbreaks are occurring. In 2001, Brazil reported over 390 000 cases including more than 670 cases of DHF.

Some other statistics:

* During epidemics of dengue, attack rates among susceptibles are often 40 — 50%, but may reach 80 — 90%.
* An estimated 500 000 cases of DHF require hospitalisation each year, of whom a very large proportion are children. At least 2.5% of cases die, although case fatality could be twice as high.
* Without proper treatment, DHF case fatality rates can exceed 20%. With modern intensive supportive therapy, such rates can be reduced to less than 1%.

The spread of dengue is attributed to expanding geographic distribution of the four dengue viruses and of their mosquito vectors, the most important of which is the predominantly urban species Aedes aegypti. A rapid rise in urban populations is bringing ever greater numbers of people into contact with this vector, especially in areas that are favourable for mosquito breeding, e.g. where household water storage is common and where solid waste disposal services are inadequate.
Transmission

Dengue viruses are transmitted to humans through the bites of infective female Aedes mosquitoes. Mosquitoes generally acquire the virus while feeding on the blood of an infected person. After virus incubation for 8-10 days, an infected mosquito is capable, during probing and blood feeding, of transmitting the virus, to susceptible individuals for the rest of its life. Infected female mosquitoes may also transmit the virus to their offspring by transovarial (via the eggs) transmission, but the role of this in sustaining transmission of virus to humans has not yet been delineated.

Humans are the main amplifying host of the virus, although studies have shown that in some parts of the world monkeys may become infected and perhaps serve as a source of virus for uninfected mosquitoes. The virus circulates in the blood of infected humans for two to seven days, at approximately the same time as they have fever; Aedes mosquitoes may acquire the virus when they feed on an individual during this period.
Characteristics

Dengue fever is a severe, flu-like illness that affects infants, young children and adults, but seldom causes death.

The clinical features of dengue fever vary according to the age of the patient. Infants and young children may have a non-specific febrile illness with rash. Older children and adults may have either a mild febrile syndrome or the classical incapacitating disease with abrupt onset and high fever, severe headache, pain behind the eyes, muscle and joint pains, and rash.

Dengue haemorrhagic fever is a potentially deadly complication that is characterized by high fever, haemorrhagic phenomena–often with enlargement of the liver–and in severe cases, circulatory failure. The illness commonly begins with a sudden rise in temperature accompanied by facial flush and other non-specific constitutional symptoms of dengue fever. The fever usually continues for two to seven days and can be as high as 40-41°C, possibly with febrile convulsions and haemorrhagic phenomena.

In moderate DHF cases, all signs and symptoms abate after the fever subsides. In severe cases, the patient’s condition may suddenly deteriorate after a few days of fever; the temperature drops, followed by signs of circulatory failure, and the patient may rapidly go into a critical state of shock and die within 12-24 hours, or quickly recover following appropriate volume replacement therapy.
Treatment

There is no specific treatment for dengue fever. However, careful clinical management by experienced physicians and nurses frequently saves the lives of DHF patients. With appropriate intensive supportive therapy, mortality may be reduced to less than 1%. Maintenance of the circulating fluid volume is the central feature of DHF case management.
Immunization

Vaccine development for dengue and DHF is difficult because any of four different viruses may cause disease, and because protection against only one or two dengue viruses could actually increase the risk of more serious disease. Nonetheless, progress is being made in the development of vaccines that may protect against all four dengue viruses. Such products may become available for public health use within several years.
Prevention and control

At present, the only method of controlling or preventing dengue and DHF is to combat the vector mosquitoes.

In Asia and the Americas, Aedes aegypti breeds primarily in man-made containers like earthenware jars, metal drums and concrete cisterns used for domestic water storage, as well as discarded plastic food containers, used automobile tyres and other items that collect rainwater. In Africa it also breeds extensively in natural habitats such as tree holes and leaf axils.

In recent years, Aedes albopictus, a secondary dengue vector in Asia, has become established in: the United States, several Latin American and Caribbean countries, in parts of Europe and in one African country. The rapid geographic spread of this species has been largely attributed to the international trade in used tyres.

Vector control is implemented using environmental management and chemical methods. Proper solid waste disposal and improved water storage practices, including covering containers to prevent access by egg laying female mosquitoes are among methods that are encouraged through community-based programmes.

The application of appropriate insecticides to larval habitats, particularly those which are considered useful by the householders, e.g. water storage vessels, prevent mosquito breeding for several weeks but must be re-applied periodically. Small, mosquito-eating fish and copepods (tiny crustaceans) have also been used with some success. During outbreaks, emergency control measures may also include the application of insecticides as space sprays to kill adult mosquitoes using portable or truck-mounted machines or even aircraft. However, the killing effect is only transient, variable in its effectiveness because the aerosol droplets may not penetrate indoors to microhabitats where adult mosquitoes are sequestered, and the procedure is costly and operationally very demanding. Regular monitoring of the vectors’ susceptibility to the most widely used insecticides is necessary to ensure the appropriate choice of chemicals. Active monitoring and surveillance of the natural mosquito population should accompany control efforts in order to determine the impact of the program.

Manifestation of Dengue Infection
Dengue Haemorrhagic Fever in Small Hospitals
Dengue is the most important emerging tropical viral disease of humans in the world today. It is
estimated that there are between 50 and 100 million cases of dengue fever (DF) and about
500,000 cases of dengue haemorrhagic fever (DHF) each year which require hospitalization. Over
the last 10-15 years, DF/DHF has become a leading cause of hospitalization and death among
children in the South-East Asia Region of WHO, following diarrhoeal diseases and acute respiratory
infections.
Standard treatment of DF/DHF has many advantages. Deaths due to DHF can be reduced to
less than 1% among hospitalized patients by the widespread use of standard treatment. It also
rationalizes hospitalization, reduces the pressure of admissions, and prevents unnecessary blood
transfusions.
A large number of DF/DHF patients first visit small hospitals in their countries. Small hospitals
vary from country to country and within each country. There are common features which will help
in categorization of health facilities into small hospitals and referral hospitals. A small hospital is a
health facility where doctors are responsible for treatment of patients and where there are facilities
to admit sick individuals. It is possible to give intravenous fluids and blood transfusion. Essential
drugs are available. Blood haematocrit, haemoglobin and platelet counts can be done. In some
small hospitals, basic intensive care can also be provided. Examples of small hospitals in countries of
the Region include district hospitals in Bhutan, Nepal, Sri Lanka and Thailand; thana health centres
in Bangladesh; community health centers and subdistrict hospitals in India; health centers
(puskesmas) in Indonesia, and township hospitals in Myanmar. Small hospitals which are privately
run including nursing homes and other hospitals which admit patients and have the above
mentioned facilities should also be encouraged to use these guidelines.
The present guidelines on treatment of DF/DHF in small hospitals were adapted from the
WHO document, Dengue Haemorrhagic Fever – Diagnosis, Treatment, Prevention and Control,
1997 (2nd Edition). These guidelines do not address details of prevention of the disease (Staff in
small hospitals should refer to specific guidelines on the prevention and control of DF/DHF). These
guidelines are intended to help the staff working in small hospitals to treat uncomplicated cases of
DF/DHF. However, detailed instructions on intensive care are not included. It is possible that an
occasional patient may develop complications. In such cases, if it is not feasible to refer the patient,
the guidelines given in this document should be used and other materials for providing intensive
care should also be used. These simplified, and practical guidelines can be further adapted by
Member States. Wherever English is not commonly known in small hospitals, the guidelines should
be translated into the local language for effective use at country level.
Manifestation of Dengue Infection
All four dengue virus (Den 1, 2, 3 and 4) infections may be
asymptomatic or may lead to undifferentiated fever, dengue fever
(DF), or dengue haemorrhagic fever (DHF) with plasma leakage that
may lead to hypovolemic shock, dengue shock syndrome (DSS).
Manifestation of dengue virus infections:
ASYMPTOMATIC
SYMPTOMATIC
Undifferentiated
Fever
Dengue Fever
Without haemorrhage
With unusual
haemorrhage
No shock
DSS
Dengue
Haemorrhagic
Fever

Recognition of Dengue Fever/Dengue
Haemorrhagic Fever (DF/DHF)
Dengue Fever is an acute febrile illness of 2-7 days duration
(sometimes with two peaks) with two or more of the following
manifestations:
Ø headache
Ø retro -orbital pain
Ø myalgia/arthralgia
Ø rash
Ø haemorrhagic manifestation (petechiae and positive
tourniquet test1) and,
Ø leukopenia.
In children, DF is usually mild. In some adults, DF may be the
classic incapacitating disease with severe bone pain and recovery may
be associated with prolonged fatigue and depression.
Dengue Haemorrhagic Fever is a probable case of dengue and
haemorrhagic tendency evidenced by one or more of the following:
Ø Positive tourniquet test
Ø Petechiae, ecchymosis or purpura
Ø Bleeding from mucosa (mostly epistaxis or bleeding from
gums), injection sites or other sites
Ø Haematemesis or melena
1 The tourniquet test is performed by inflating a blood pressure cuff to a point mid-way between the systolic and
diastolic pressures for five minutes. A test is considered positive when 10 or more petechiae per 2.5 cm2 (1 inch)
are observed. In DHF, the test usually gives a definite positive result (i.e. >20 petechiae). The test may be
negative or mildly positive during the phase of profound shock.
Guidelines for Treatment of Dengue Fever/Dengue Haemorrhagic Fever in Small Hospitals
3
Ø Thrombocytopaenia (platelets 100,000/cu.mm or less) and
Ø Evidence of plasma leakage due to increased capillary
permeability manifested by one or more of the following:
– A >20% rise in haemotocrit for age and sex
– A >20% drop in haemotocrit following treatment with
fluids as compared to baseline
– Signs of plasma leakage (pleural effusion, ascites or
hypoproteinaemia).
Dengue Shock Syndrome (DSS) All the above criteria of DHF
plus signs of circulatory failure manifested by rapid and weak pulse,
narrow pulse pressure (< or equal to 20 mm Hg); hypotension for
age, cold and clammy skin and restlessness.
The above descriptions of DF/DHF/DSS are adequate for guiding
doctors to treat the disease. However, for reporting of the disease,
cases should be classified as suspected DF/DHF/DSS on the basis of
above the criteria. Added serological evidence would categorize them
into probable and confirmed cases. Serological and virological
diagnosis is not possible in most small hospitals. It is recommended
that blood samples of patients be sent to a laboratory according to the
guidelines provided at Annex 1.
There are difficulties in categorizing the disease. A patient can
progress from DHF to DSS, and depending on the stage of the disease
when the patient reports, a mixed picture can be seen. However, as
long as the patient evaluation is done systematically, there should be
no difficulties in providing treatment, or in decision making about
admission to a hospital, or in referring patients for specialised care.

Disease Course
DF/DHF has an unpredictable course. Most patients have a febrile
phase lasting 2 -7 days. This is followed by a critical phase which is of
about 2-3 days duration. During this phase, the patient is afebrile, and
is at risk of developing DHF/DSS which may prove fatal if prompt and
appropriate treatment is not provided. Since haemorrhage and or
shock can occur rapidly, arrangements for rapid and appropriate
treatment should be always available. By doing this, the case fatality
rate can be substantially reduced. The disease course of DF/DHF is
summarised below:
DHF (Grades)
DF
I II III IV
Febrile
Phase
(3-7 days)
Afebrile Phase(critical stage)
*Convalescent Phase
RECOVERY
* If appropriate treatment is not provided, there is a high risk of death.
Grading the Severity of Dengue Infection
To decide about where to treat the patient, it is important to classify
the severity of dengue infection. The severity of dengue infection is
classified into the grades described in Table 1 below.
DF/DHF Grade* Symptoms Laboratory
DF Fever with two or
more of the following
signs: headache,
retro -orbital pain,
myalgia, arthralgia
Leukopenia
occasionally.
Thrombocytopenia,
may be present, no
evidence of plasma loss
DHF I Above signs plus
positive tourniquet
test
Thrombocytopenia
<100,000, Hct rise
>20%
DHF II Above signs plus
spontaneous bleeding
Thrombocytopenia
<100,000, Hct rise
>20%
DHF III Above signs plus
circulatory failure
(weak pulse,
hypotension,
restlessness)
Thrombocytopenia
<100,000, Hct rise
>20%
DHF IV Profound shock with
undetectable blood
pressure and pulse
Thrombocytopenia
<100,000, Hct rise
>20%
* DHF Grade III and IV are also called as Dengue Shock Syndrome (DSS)
Treatment of DF and DHF
Febrile Phase
In the early febrile phase, it is not possible to distinguish DF from DHF.
Their treatments during the febrile phase are the same, i.e. symptomatic
and supportive:
Ø Rest.
Ø Paracetamol (not more than 4 times in 24 hours) according
to age for fever above 390C.
Age Dose
(tablet 250 mg)
Mg/Dose
< 1 year ¼ tablet 60
1-4 years ½ tablet 60-120
5 years and above 1 tablet 240
Ø Do not give Aspirin or Brufen. Aspirin can cause gastritis
and/or bleeding. In children, Reye’s syndrome
(encephalopathy) may be a serious complication.
Ø Do not give antibiotics as these do not help.
Ø Oral rehydration therapy2 is recommended for patients with
moderate dehydration caused by vomiting and high
temperature.
Ø Food should be given according to appetite.
2 In Children, with signs of some dehydration, oral rehydration solution which is commonly used in the treatment
of diarrhoeal diseases and/or fresh juices are preferable(50ml/kg bodyweight fluids should be given during the first
4-6 hr)s. After correction of dehydration, the child should be given maintenance fluids orally at the rate of 80-100
ml/kg bodyweight in the next 24 hrs . Children who are breastfed should continue to be breasfed in addition to
ORS administration. In adults, oral fluid intake of 2.5-4.0 litres should be given per day.
All dengue patients must be carefully observed for
complications for at least 2 days after recovery from fever. This is
because life threatening complications often occur during this phase.
Patients and households should be informed that severe
abdominal pain, passage of black stools, bleeding into the skin or
from the nose or gums, sweating, and cold skin are danger signs.
If any of these signs is noticed, the patient should be taken to the
hospital. Detailed information which should be provided to all
patients and households by the doctor is given in Annex 2. The
patient who does not have any evidence of complications and who
has been afebrile for 2-3 days does not need further observation.
Afebrile Phase
(1) Dengue Fever
Constitutional symptoms in patients with DF after the fall of fever are
as during the febrile stage. Most patients will recover without
complication.
(2) Dengue Haemorrhagic Fever (DHF) Grades I and II
As in DF, during the afebrile phase of DHF Grades I and II, the patient
has the same symptoms as during the febrile phase. The clinical signs
plus thrombocytopenia and haemoconcentration or rise in
haematocrit are sufficient to establish a clinical diagnosis of DHF.
During this phase, the patients should be observed for at least 2-3
days after the fall in temperature, for rashes on the skin, bleeding from
nose or gums, blue spots on the skin or tarry stools. If any of these
signs are observed, the patients should be brought to the hospital
without delay. The only difference between th e DF and DHF Grade I
is the presence of thrombocytopenia and rise in haematocrit (>20%).
Patients with DHF Grade I do not usually require intravenous fluid
therapy and ORT is sufficient. Intravenous fluid therapy may need to
DF/DHF Management Charts
Dengue Fever
Febrile phase Manifestation Management
Duration 2-7 days
– Temp 39-40ºC
– Headache
– Retro-orbital pain
– Muscle pain
– Joint/bone pain
– Flushed face
– Rash
– Skin haemorrhage, bleeding
from nose, gums
– Positive tourniquet test
– Liver often enlarged
– Leucopenia
– Platelet/haematocrit normal
– At home*
– Bed rest
– Keep the body temperature
below 390
– Paracetamol-Yes**
– Aspirin-No
– Brufen-No
– Oral fluids and electrolyte
therapy
– Follow-up for any change in
platelet/haematocrit
Afebrile phase
(critical stage) Manifestation Management
Duration – 2-3 days
after febrile stage
– Same as during febrile phase
– Improvement in general
condition
– Platelet/haematocrit normal
– Appetite rapidly regained
– Bed rest
– Check platelets/haematocrit
– Oral fluids and electrolyte
therapy
Convalescence
Phase Manifestation Management
Duration – 7-10
days after critical
stage
– Further improvement in general
condition and return of appetite
– Bradycardia
– Confluent petechial rash with
white centre/ itching
– Weakness for 1 or 2 weeks
– No special advice.
– No restrictions.
– Normal diet
* Patients and household members should be informed by the doctor that abdominal pain, passing of black stools,
bleeding, sweating, and cold skin are danger signs, and if any of these signs is noticed, the patient should be taken
to the hospital immediately.
** Paracetamol should be administered not more than 4 times in a 24-hour period. Paracetamol (250mg): <1yr-1/4
tablet; 1-4 years – ½ tablet; 5 yrs and above – one tablet to be administered only
when the patient is vomiting persistently or
severely, or refusing to accept oral fluids. Patients with DHF Grade I
who live far away from the hospital or those who are not likely to be
able to follow the medical advice should be kept in the hospital for
observation.
During the afebrile phase of DHF Grade II, the complications
usually seen, in addition to those observed during the DHF Grade I
phase, are abdominal pain, black tarry stools, epistaxis, bleeding from
the gums, and continued bleeding from injection sites. Immediately
after hospitalization, haematocrit and platelet count must be carried
out to assess the patient’s condition. A reduction in the platelet count
to £100,000/mm3 or less than 1-2 platelets/oil field (average of 10 oil
field counts) usually precedes a rise in haematocrit. A rise in
haematocrit of 20% or more (e.g. increase from 35% to 42%) reflects a
significant plasma loss and indicates the need for intravenous fluid
therapy. Early volume replacement of lost plasma with Cystalloid3
solution (e.g. isotonic saline solution) can reduce the severity of the
disease and prevent shock. Intravenous fluid therapy before leakage is
not recommended. In mild to moderate cases of DHF Grade II,
intravenous fluid therapy may be given for a period of 12-24 hours in
a small hospital or short stay unit (OPD) of a large hospital. This is an
important life saving measure. Patients should be monitored on an
hourly basis by medical personnel. Based on periodic
haematocrit/platelet count determinations and vital signs, the
treatment should be reviewed and revised. Treatment should be
performed as indicated in Chart 2. Graphical presentation of the
treatment of DHF is given in Figure 1.
3 Crystalloid Solutions :
(a) 5% dextrose in isotonic normal saline solution (5% D/NSS)
(b) 5% dextrose in half-strength normal saline solution (5% D/1/2/NSS)
(c) 5% dextrose in lactated Ringer’s solution (5% D/RL)
(d) 5% dextrose in acetated Ringer’s solution (5% D/RA).

Dengue Haemorrhagic Fever (Grades I and II)
(The manifestations and management of DF and DHF during the febrile phase are the same)
Afebrile Phase
(critical stage) Manifes tation Management
Duration 2-3 days
– Same as during febrile phase.
– Thrombocytopenia and rise in
haematocrit level (more than
20%)
– OPD or hospital
– ORS
– Check platelets/haematocrit. If
haematocrit is more than 20%:
– Initiate IV therapy (5% D/NSS) 6
ml/kg/hr (for 3 hours)
– Check haematocrit/vital
signs/urine output after 3 hours,
and in case of improvement4
– Reduce IV therapy to 3ml/kg/hr
(for 3 hours)
– In case of further improvement,
continue IV therapy at 3ml/kg/hr (6-
12 hours) and then discontinue IV
therapy
– In case of no improvement5
increase IV therapy to 10 ml/kg/hr
(for 1 hr). In case of improvement
now, reduce the volume of IV from
10ml/kg/hr to 6ml/kg/hr and further
to 3ml/kg/hr accordingly.
– Generally, DHF Grades I and II
do not give complications
Convalescence Phase
Manifestation Management
Duration 2-3 days
after critical stage
– Further improvement in general
condition and return of appetite
– Bradycardia
– Confluent petechial rash with
white centre/ itching
– Asthenia and depression
(sometimes for a few weeks,
common in adults)
– Normal diet
– No need for any medication
Improvement: Haematocrit falls, pulse rate and blood pressure stable, urine output rises
No Improvement: Haematocrit or pulse rate rises, pulse pressure below 20 mm Hg, urine output falls
Guidelines for Treatment of Dengue Fever/Dengue Haemorrhagic Fever in Small Hospitals

Volume Replacement Flow Chart for Patients with
DHF Grades I and II
Haemorrhagic (bleeding) tendencies,
Thrombocytopenia,
Haematocrit rise. Pulse pressure is low
Initiate IV Therapy 6m l/kg/hr
Crystalloid solution for 1-2 hrs
Improvement No Improvement
Reduce IV 3ml/kg/h
Crystalloid duration
6-12 hrs
Increase IV 10 ml/kg/h
crystalloid duration 2 hrs.
Further
Improvement Improvement
No Improvement
Unstable Vital Signs
Discontinue IV
after 24 hrs
Reduce IV to
6ml/kg/h
crystalloid with
further reduction
to 3 ml/kg/h.
discontinue after
24-48 hrs
Haematocrit Rises
Haematocrit Falls
IV Colloid (Dextran
(40) 10ml/kg/hr
duration 1 hr.
Blood transfusion
10 ml/kg/hr
duration 1 hr.
Improvement
IV therapy by crystalloid Successively
reduce the flow from 10 to 6, 6 to
3ml/kg/hr Discontinue after 24-48 hrs
Improvement: Haematocrit falls, pulse rate and blood pressure stable, urine output rises
No improvement: Haematocrit or pulse rate rises, pulse pressure falls below 20mmHg (2.7kPa), urine output falls
Unstable vital signs:Urine output falls, signs of shock
DHF Grades III and IV
Common signs of complications observed during the afebrile phase of
DHF Grade III include circulatory failure manifested by rapid and weak
pulse, narrowing of the pulse pressure and hypotension, characterised
by high diastolic pressure relative to systolic pressure (for example
90/80) and the presence of cold clammy skin and restlessness. These
complications occur because of thrombocytopenia, abnormal
haemostasis and plasma leakage, or also from substantial blood loss.
Immediately after hospitalization, the haematocrit, platelet count and
vital signs should be examined to assess the patient’s condition and
intravenous fluid therapy should be started. The patient requires
regular and sustained monitoring. If the patient has already received
about 1,000 ml of intravenous fluids and the vital signs are still not
stable, the haematocrit should be repeated and: (a) if the haematocrit
is increasing, intravenous fluid should be changed to colloidal solution
preferably Dextran, or (b) if haematocrit is decreasing, fresh whole
blood transfusion 10ml/kg/dose should be given.
During the afebrile phase of DHF Grade IV, vital signs are
unstable. The patient, in the early stage of shock, has acute abdominal
pain, restlessness, cold and clammy skin, rapid and weak pulse. The
patient should be administered intravenous fluid therapy immediately.
In case of continued or profound shock when pulse and blood
pressure are undetectable, the patient should be given colloidal fluid
following the initial fluid bolus.
However, in the case of persistent shock when, after initial fluid
replacement and resuscitation with plasma or plasma expanders, the
haematocrit continues to decline, internal bleeding should be
suspected. It may be difficult to recognize and estimate the degree of
internal blood loss in the presence of haemoconcentration. It is thus
recommended to give fresh whole blood in small volumes of 10ml/kg
bodyweight at one time. Blood grouping and matching should be done
for all patients in shock as a routine precaution. Oxygen should be
given to all patients in shock. The detailed treatment for patients with
DHF Grades III and IV is given in Chart 3. The graphical presentation
of treatment of DHF Grades III and IV is given in Figure 2.
Dengue Haemorrhagic Fever (Grades III and IV)
The patient in this category should be admitted to a hospital where trained personnel can
manage shock and blood transfusion facilities are available (referral hospital).
Afebrile phase Manifestation Management
Duration two days
after febrile stage
In addition to the manifestations of
DHF Grade II:
– Circulatory failure manifested by
rapid and weak pulse, narrowing
of pulse pressure (20 mmHg or
less) or hypotension with the
presence of cold clammy skin
and restlessness
– Capillary relief time more than
two seconds
– Check haematocrits/platelet
– Initiate IV therapy (5% D/NSS)
10 ml/kg/h
– Check haematocrit, vital signs,
urine output every hour
– If patient improves, IV fluids
should be reduced every hour
from 10 to 6, and from 6 to 3
ml/kg/h which can be
maintained up to 24 to 48 hours
– If patient has already received
one hour treatment of 20
ml/kg/hr of IV fluids and vital
signs are not stable, check
haematocrit again and
– If haematocrit is increasing,
change IV fluid to colloidal
solution preferably Dextran or
Plasma at 10 ml/kg/h every hr.
– If haematocrit is decreasing
from initial value, give fresh
whole blood transfusion, 10
ml/kg/h and continue fluid
therapy at 10 ml/kg/h and
reducing it stepwise bring down
the volume to 3 ml/kg/h and
maintain it up to 24-48 hours
Profound shock with undetectable
pulse and blood pressure
– Initiate IV therapy (5% D/NSS) 20
ml/kg as a bolus one or two times
– Oxygen therapy should be
given to all patients6
– In case of continued shock,
colloidal fluids (Dextran or
Plasma) should be given at 10-
20 ml/kg/hr.
6 Oxygen is obligatory until shock has been overcome. Pulse, blood pressure, and temp should be recorded every
15-30 minutes.
Afebrile phase Manifestation Management
Profound shock with undetectable
pulse and blood pressure
– If shock still persists and the
haematocrit level continues
declining, give fresh whole
blood 10 ml/kg as a bolus
– Vital signs should be monitored
every 30-60 minutes
– In case of severe bleeding, give
fresh whole blood 20 ml/kg as a
bolus
– Give platelet rich plasma
transfusion exceptionally when
platelet counts are below
5,000–10,000/ mm3 .
– After blood transfusion,
continue fluid therapy at 10
ml/kg/h and reduce it stepwise
to bring it down to 3 ml/kg/h
and maintain it for 24-48 hrs
Con. Phase Manifestation Management
Duration 2-3 days
after recovery from
critical/shock stage
– 6-12 hours after critical/shock
stage, some symptoms of
respiratory distress (pleural
effusion or ascites)
– 2-3 days after critical stage,
strong pulse, normal blood
pressure
– Improved general
condition/return of appetite
– Good urine output
– Stable haematocrit
– Platelet count >50,000 per mm3
– Patient could be discharged from
hospital 2-3 days after critical
stage
– Bradycardia/arrhythmia
– Asthenia and depression (few
weeks) in adults
– Rest for 1-2 days
– Normal diet
– No need for medication
Volume Replacement Flow Chart for patient with
DHF Grades III and IV
UNSTABLE VITAL SIGNS
Urine Output Falls
Signs Of Shock
Immediate, rapid volume replacement*: Initiate IV therapy
10-20ml/kg/h Cystalloid solution for 1 hr
Improvement No Improvement
Further Improvement
Haematocrit Rises
Haematocrit Falls
Improvement
IV Therapy by crystalloid
successively reducing from 20
to10, 10 to 6, and 6 to 3ml/kg/hr
Oxygen
Discontinue intravenous
therapy after 24-48 hrs
IV Colloid (Dextran 40)
or plasma 10ml/kg/hr as
intravenous bolus
(repeat if necessary)
IV therapy by crystalloid,
successively reducing the flow
from 10 to 6, 6 to 3ml/kg/hr
Discontinue after 24-48 hrs
* In cases of acidosis, hyperosmolar or Ringer’s lactate solution should not be used
Blood transfusion
(10 ml/kg/hr) if
haematocrit is
still >35%
Fluids Required for Intravenous Therapy
Fluids Recommended
Crystalloid:
(a) 5% dextrose in isotonic normal saline solution (5% D/NSS)
(b) 5% dextrose in half-strength normal saline solution
(5% D/1/2/NSS)
(c) 5% dextrose in lactated Ringer’s solution (5% D/RL)
(d) 5% dextrose in acetated Ringer’s solution (5% D/RA)
Colloidal: Dextran 40; Plasma:
In order to ensure adequate fluid replacement and avoid over-fluid
infusion, the rate of intravenous fluid should be adjusted
throughout the 24 to 48 hour period of plasma leakage by periodic
haematocrit determinations and frequent assessment of vital signs.
The volume of fluid replacement should be just sufficient to
maintain effective circulation during the period of plasma
leakage. Excessive fluid replacement and continuation for a longer
period after cessation of leakage will cause respiratory distress from
massive pleural effusion, ascites, and pulmonary congestion/
oedema. This can be dangerous.
The required regimen of fluid should be calculated on the basis
of bodyweight and charted on a 1-3 hourly basis, or even more
frequently in the case of shock. The regimen of the flow of fluid and
the time of infusion are dependent on the severity of DHF. The
schedule given below is recommended as a guideline. It is calculated
for moderate dehydration of about 6% deficit (plus maintenance).
Ml/lb Weight on admission
Bodyweight/day Lbs Kgs
Ml/kg
Body weight/day
100 <15 <7 220
75 16-25 7-11 165
60 26-40 12-18 130
40 >40 >18 90
In older children who weigh more than 40 kgs, the volume
needed for 24 hours should be calculated as twice that required for
maintenance (using the Holliday and Segar formula). The
maintenance fluid should be calculated as follows:
Body weight (kgs) Maintenance volume (ml)
administered over 24 hrs
<10 100/Kg
10-20 1000+50 for each kg in excess of 10
>20 1500+20 for each kg in excess of 20
For a child weighing 40 kgs, the maintenance is: 1500 +
(20×20) = 1900 ml. This means that the child requires 3800 ml IV
fluid during 24 hours.
For intravenous fluid therapy of patients with DHF, four
regimens of flow of fluid are suggested.: 3ml/kg/hr; 6ml/kg/hr;
10ml/kg/hr, and 20ml/kg/hr.
For ready reference, the calculation of fluid requirements, based
on bodyweight and rate of flow of fluid volume for the four regimen
are given in Table 2.

Table 2. Requirement of fluid based on bodyweight
Bodyweight Rate of fluid (ml/hour)
(in kgs)
Volume of fluid
to be given in
24 hrs R*1 R*2 R*3 R*4
10 1500 30 60 100 200
15 2000 45 60 150 300
20 2500 60 90 200 400
25 2800 75 120 250 500
30 3200 90 150 300 600
35 3500 105 180 350 700
40 3800 120 210 400 800
45 4000 135 240 450 900
50 4200 150 270 500 1000
55 4400 165 300 550 1100
60 4600 180 360 600 1200
* Regimen 1 – 3ml/kg/hr; 2 – 6ml/kg/hr; 3 – 10ml/kg/hr, and 4 – 20ml/kg/hr
Ø The fluid volumes mentioned are approximations.
Ø Normally change should not be drastic. Do not jump from R-2 to
R-4 since this can overload the patient with fluids. Similarly,
reduce the volume of fluid from R-4 to R-3, from R-3 to R2, and
from R-2 to R-1 in a stepwise manner.
Ø REMEMBER that ONE ML is equal to 20 DROPS. In case of
MACRO system, one ml is equal to 15 drops. (if needed adjust
fluid speed in drops according to equipment used)
Ø It is advised to procure only a bottle of 500 ml initially, and order
more as and when required. The decision about the sp eed of IV
fluid should be reviewed every 1-3 hours. The frequency of
monitoring should be determined on the basis of the condition of
the patient.
Important Instructions for Treatment of DHF
Ø Cases of DHF should be observed every hour.
Ø Serial platelet and haematocrit determinations, drop in
plaelets and rise in haematocrits are essential for early
diagnosis of DHF.
Ø Timely intravenous therapy – isotonic crystalloid solution –
can prevent shock and/or lessen its severity.
Ø If the patient’s condition becomes worse despite giving
20ml/kg/hr for one hour, replace crystalloid solution with
colloid solution such as Dextran or plasma. As soon as
improvement occurs replace with crystalloid.
Ø If improvement occurs, reduce the speed from 20 ml to 10
ml, then to 6 ml, and finally to 3 ml/kg.
Ø If haematocrit falls, give blood transfusion 10 ml/kg and
then give crystalloid IV fluids at the rate of 10ml/kg/hr.
Ø In case of severe bleeding, give fresh blood transfusion
about 20 ml/kg for two hours. Then give crystalloid at 10
ml/kg/hr for a short time (30-60 minutes) and later reduce
the speed.
Ø In case of shock, give oxygen.
Ø For correction of acidosis (sign: deep breathing), use sodium
bicarbonate7.
For more details on management of DFH/DSS cases, the
physician is advised to consult other appropriate references on their
treatment. A list of references is provided in Section 12.
7 In the case of acidosis, one-third of the total fluids should consist of 0.167 mol/litre of sodium bicarbonate (threequarters
of crystalloid solution plus glucose plus one-quarter sodium bicarbonate)
What not to do
Ø Do not give Aspirin or Brufen for treatment of fever.
Ø Avoid giving intravenous therapy before there is evidence of
haemorrhage and bleeding.
Ø Avoid giving blood transfusion unless indicated, reduction in
haematocrit or severe bleeding.
Ø Avoid giving steroids. They do not show any benefit.
Ø Do not use antibiotics
Ø Do not change the speed of fluid rapidly, i.e. avoid rapidly
increasing or rapidly slowing the speed of fluids.
Ø Insertion of nasogastric tube to determine concealed
bleeding or to stop bleeding (by cold lavage) is not
recommended since it is hazardous.
Signs of Recovery
Ø Stable pulse, blood pressure and breathing rate
Ø Normal temperature
Ø No evidence of external or internal bleeding
Ø Return of appetite
Ø No vomiting
Ø Good urinary output
Ø Stable haematocrit
Ø Convalescent confluent petechiae rash

Criteria for Discharging Patients
Ø Absence of fever for at least 24 hours without the use of
anti-fever therapy
Ø Return of appetite
Ø Visible clinical improvement
Ø Good urine output
Ø Minimum of three days after recovery from shock
Ø No respiratory distress from pleural effusion and no ascites
Ø Platelet count of more than 50,000/mm3
Reporting
Based on case-definitions, all suspected, probable and confirmed
cases of DF/DHF should be reported to the District Health Officer.

Blood samples should be drawn from
suspected DF/DHF/DSS cases
(1) In the acute stage – 0-5 days after onset (serum specimen S1), volume
0.5-1.0 ml;
(2) Shortly before discharge from the hospital – 6-10 days after onset
(serum specimen S2), and
(3) If possible, 14-21 days after the onset of disease (serum specimen S3)
The serum should be separated from the red blood cells and stored
frozen before examination.
If refrigeration is not possible for keeping blood samples, Whatman
No.3 filter paper discs 12.7mm (1/2 inch) in diameter may be used. Collect
the blood on the filter paper and fully saturate it through to the reverse side.
Allow the filter paper to dry in a place that is protected from direct sunlight
and insects. Place the dried strips in plastic bags and staple them to the
laboratory examination request form (sample below). Store without
refrigeration.
All collected samples should be adequately labelled with the name of
the patient, their identification number and date of collection.
Laboratory Investigation Form for Dengue Infection
(Using Filter Paper Discs)
Hospital:_________________________________ Regn.no. _______________
Name of Patient:____________________ Age:___________Sex: _____________
Date of Admission:__________________ Date of Onset:________________
Suspected Diagnosis __________________________________________________
Clinical Findings:
1. Fever:_____________0C Duration:_________________Days
2. Petechiae____________Epistaxis_____________Melaena_________________
Other Bleeding:___________________________________________________
3. Tourniquet Test:___________________________________________________
4. Shock:___________________________________________________________
Specimen Date of Collection Result of Serology
Acute (S1) ________________ ________________
Early Convalescent (S2)
(before discharge from hospital) ________________ ________________
Late Convalescent (S3) ________________ ________________
Laboratory Diagnosis:______________________________________________
Haematocrit every two hours during the first six hours and later every four hours
until stable. A fluid balance sheet, recording type, rate and quantity of fluids
administered should be kept. Record urine output.
Handout for Patients with Dengue Fever
(Important information to be given to the parents or family members
of outpatients with suspected dengue fever)
Your child or family member probably has dengue fever.
Since this disease can rapidly become very serious and lead to a medical
emergency, it is important for you to carefully watch your child or relative for
the next few days. The complications associated with dengue fever usually
appear between the third and fifth day of illness. You should therefore watch
the patient for two days after the fever disappears.
“What should you do?”
Keep body temperature below 39oC. Give the patient paracetamol (not more
than four times in 24 hours) as per the dose prescribed below:
Age Dose (tablet 250 mg) Mg/dose
< 1 year ¼ tablet 60
1-4 years ½ tablet 60-120
5 and above 1 tablet 240
Do not give the patient Aspirin or Brufen or Ibubrufen
Give large amounts of fluids (water, soups, milk and juices) along with the
patient’s normal diet.
The patient should rest.
Immediately consult your physician if any of the following manifestations
appear: Red spots or points on the skin; bleeding from the nose or gums;
frequent vomiting; vomiting with blood; black stools; sleepiness; constant
crying; abdominal pain; excessive thirst (dry mouth); pale, cold or clammy
skin; or difficulty in breathing.
Do not wait. Immediately consult your physician. It is crucial to quickly
treat anyone with these complications.
Information on Personal Protection against Dengue
Fever and Dengue Haemorrhagic Fever
What is dengue infection?
Dengue is an acute flu-like fever caused by a virus. It occurs in two forms:
(a) Dengue fever (DF)
(b) Dengue haemorrhagic fever (DHF)
Dengue fever is marked by an onset of sudden high fever, severe
headache, pain behind the eyes, and pain in the muscles and joints.
Dengue haemorrhagic fever (DHF) is a more severe form, in which
bleeding and sometimes shock occurs. This can lead to death. It is most serious
in children. Symptoms of bleeding usually occur after 2-3 days of fever.
The high fever continues for 5-6 days (103-105°F or 39–40°C). It comes
down on the third or the fourth day but rises again. The patient feels a lot of
discomfort and is very weak after the illness.
Dengue spreads rapidly and may affect large numbers of people during an
epidemic, resulting in reduced work productivity. More importantly, it causes the
loss of lives.
Recognition of Dengue Fever
(1) Sudden onset of high fever
(2) Severe headache (mostly in the forehead)
(3) Pain behind the eyes which worsens with eye movement
(4) Body aches and joint pains
(5) Nausea or vomiting
Recognition of Dengue Haemorrhagic Fever and Shock
Symptoms similar to dengue fever, plus any one or a combination of the
following:
(1) Severe and continuous pain in the abdomen
(2) Bleeding from the nose, mouth and gums or skin bruising
(3) Frequent vomiting with or without blood
(4) Black stools like coal tar
(5) Excessive thirst (dry mouth)
(6) Pale, cold skin
Diagnosis
Confirmation of DF and DHF can be done by specific laboratory tests.
However, specific diagnosis is not required for treatment of patients with
DF/DHF.
Treatment
Patient(s) suspected of having DF or DHF must be examined by a doctor.
Proper and early treatment can relieve the symptoms and prevent
complications and death. Aspirin and Brufen should be avoided in dengue
fever, as they are known to increase the bleeding tendency and may lead to
serious complications. Paracetamol can be given on medical advice. Severe
abdominal pain (black stools); bleeding on the skin or from the nose or gums;
sweating, and cold skin, etc. are danger signs. If any one of them is noticed,
take the patient to a hospital immediately. Give the patient fluids to drink
while transferring him/her to the hospital.
Basic facts on Dengue
(1) How does dengue spread? Dengue is spread through the bite of an
infected Aedes aegypti mosquito. The mosquito gets the virus by biting an
infected person. The first symptoms of the disease occur about 5-7 days after
the infected bite.
There is no way to tell if a mosquito is carrying the dengue virus.
Therefore, people must protect themselves from all mosquito bites.
(2) Where does this mosquito live? This mosquito rests indoors, in
closets and other dark places. Outside, it rests where it is cool and shaded. The
female mosquito lays her eggs in water containers in and around homes, schools
and other areas in towns or villages. These eggs become adults in about 10 days.
(3) Where does the mosquito breed? Dengue mosquitoes breed in
stored, exposed, water collection systems. The favoured breeding places are:
barrels, drums, jars, pots, buckets, flower vases, plant saucers, tanks, discarded
bottles/tins, tyres, water coolers, etc. and a lot more places where rainwater
collects or is stored.
Prevention of Dengue
All control efforts should be directed against the mosquitoes. It is important to take
control measures to eliminate the mosquitoes and their breeding places. Efforts
should be intensified before the transmission season (during and after the rainy
season) and during epidemics.
(1) Prevent mosquito bites:
(a) Dengue Mosquitoes Bite During the Daytime – Protect Yourself
From the Bite
(b) Wear full-sleeve clothes and long dresses to cover the limbs.
(c) Use repellents – care should be taken in using repellents on young
children and elders.
(d) Use mosquito coils and electric vapour mats during the daytime to
prevent dengue.
(e) Use mosquito nets to protect babies, old people and others who may
rest during the day. The effectiveness of such nets can be improved
by treating them with permethrin (pyrethroid insecticide). Curtains
(cloth or bamboo) can also be treated with insecticide and hung at
windows or doorways, to repel or kill mosquitoes.
(f) Break the cycle of mosquito-human-mosquito infection. Mosquitoes
become infected when they bite people who are sick with dengue.
Mosquito nets and mosquito coils will effectively prevent more
mosquitoes from biting sick people and help stop the spread of
dengue.
(2) Prevent the multiplication of mosquitoes:
Mosquitoes which spread dengue live and breed in stagnant water in and
around houses.
(a) Drain out the water from desert/window air coolers (when not in
use), tanks, barrels, drums, buckets, etc.
(b) Remove all objects containing water (e.g. plant saucers, etc.) from the
house.
(c) All stored water containers should be kept covered at all times.
(d) Collect and destroy discarded containers in which water collects, e.g.
bottles, plastic bags, tins, tyres, etc.

~ by ikenya5 on February 5, 2008.