DENGUE FEVER
Moderator :
Assot. Prof . DR ARUN GIRI
Asst. Prof DR BABITA KHANAL
PRESENTOR :
DR SUBODH KUMAR SHAH
2ND YEAR PEDIATRIC RESIDENT

INTRODUCTION :
• Dengue is a mosquito-borne viral disease that has rapidly spread in
many countries worldwide in recent years.
• In Nepal, dengue is a rapidly emerging disease. Endemic across most
provinces, dengue incidence has increased in recent years largely due
to expansion of the vector Aedes aegypti and Aedes albopictus, as
well as the movement of people and the introduction of imported
cases.
• All 4 dengue serotypes exist in Nepal, with DENV-1 historically
contributing the highest burden.

Epidemiology:

Outbreak at a glance
• Dengue is endemic in Nepal. The country is experiencing a surge in cases
that started from the week commencing 8 August to 26 August.
• Between January to 28 September 2022, a total of 28 109 confirmed and
suspected dengue cases and 38 confirmed deaths due to dengue have been
recorded, affecting all seven provinces.
• The causative serotype(s) is unknown. This represents the largest dengue
outbreak in Nepal with regard to the cumulative number of cases reported
nationwide per year.

Epidemiology of the disease
• Dengue is a viral infection transmitted to humans through the
bite of infected mosquitoes and is found in tropical and sub-
tropical climates worldwide, mostly in urban and semi-urban
areas.
• The primary vectors that transmit the disease are Aedes
aegypti mosquitoes and, to a lesser extent, Aedes albopictus.

Description of the outbreak

CONTINUE…
• Dengue virus (DENV) has four serotypes (DENV-1, DENV-2, DENV-
3, DENV-4) and it is possible to be infected by each.
• Infection with one serotype provides long-term immunity to the
homologous serotype but not to the other serotypes; sequential
infections put people at greater risk for severe dengue.
• Many DENV infections produce only mild illness; over 80% of cases
are asymptomatic.
• DENV can cause an acute flu-like illness.

Transmission:
• Virus:
• Virus Dengue virus (DENV) is a small single stranded RNA virus
comprising four distinct serotypes (DEN-1 to DEN-4).
• These closely related serotypes of the dengue virus belong to the
genus Flavivirus, family Flaviviridae.
• They are spherical enveloped viruses that contain a single-stranded,
positive RNA genome that encodes three structural proteins (capsid
C, membrane M, and envelope E) and seven nonstructural proteins
(NS1, NS2a, NS2b, NS3, NS4a, NS4b, and NS5).

CONTINUE….
• The E protein has an important function in the development of
antibodies and the protective immune response, as well as in the viral
immuno-amplification phenomenon.
• The NS1 protein appears in association with the infected cell on its
surface and can be detected in the early stages of infection and mark
virus replication.

Vector :
• Aedes aegypti Dengue is transmitted primarily by the female
mosquito Aedes aegypti , which thrives in and around urbanized
areas. It is diurnal and highly anthropophilic, with domestic forms
showing increased propensity towards exclusive human feeding.

Host:
• Once infected, humans are the main carriers and multipliers of the
virus, serving as a source of virus for the uninfected mosquitoes. The
virus circulates in the blood of an infected person for 2-7 days, at
approximately the same time that the person develops a fever. After
an incubation period of 4- 10 days,
• In Nepal, monsoon season occurs during June – August every year.
The dengue season closely follows this period with seasonal cases
occurring between September and November.

Natural Course of Dengue Illness
• After the incubation period, the illness begins abruptly and is
followed by three phases.
• 1. Febrile Phase
• 2. Critical Phase
• 3. Recovery Phase

Severe Dengue:
A case of severe dengue is defined as a suspected dengue patient with
one or more of the following:
a. Severe plasma leakage that leads to shock (dengue shock) and/or
fluid accumulation, with respiratory distress
b. Severe bleeding,
c. Severe organ impairment
National Guidelines on Prevention, Management and Control of Dengue in Nepal

Severe plasma leakage and dengue shock:
• As dengue vascular permeability progresses and plasma leakage occurs,
hypovolemia worsens and results in dengue shock syndrome.
• usually on day 4 or 5 (range days 3–7) of illness,
• Evidence of plasma leakage:
high or progressively rising hematocrit
pleural effusions or ascites
circulatory compromise or shock (tachycardia, cold and clammy extremities,
capillary refill time greater than three seconds, weak or undetectable pulse,
narrow pulse pressure or, in late shock, unrecordable blood pressure)
Significant bleeding
Altered level of consciousness
Severe gastrointestinal involvement
Severe organ impairment or other unusual manifestations.
National Guidelines on Prevention, Management and Control of Dengue in Nepal

Dengue diagnostics in relation to
time of clinical illness :
National Guidelines on Prevention, Management and Control of Dengue in Nepal

. Step wise approach for case management
National Guidelines on Prevention, Management and Control of Dengue in Nepal

MANAGEMENT:
• Case management for Group A dengue patient:
National Guidelines on Prevention, Management and Control of Dengue in Nepal

Continue…
• Case management for
• Group B dengue patient :

Continue….
• Case management for Group C dengue patient:

Reference:
• World Health Organization (10 October 2022). Disease Outbreak News; Dengue fever - Nepal. Available at:
https://www.who.int/emergencies/disease-outbreak-news/item/2022- DON412
• Hung NT. Fluid management for dengue in children. Paediatr Int Child Health. 2012 May;32 Suppl 1(s1):39-42. doi:
10.1179/2046904712Z.00000000051. PMID: 22668449; PMCID: PMC3381450.
• Nelson Textbook of Pediatrics, 2-Volume Set, 21st Edition
• https://emedicine.medscape.com/article/215840-overview