Dengue

Question 1

Define

Answer 1

Caused by dengue arbovirus transmitted by Aedes Aegyptii mosquito

• Flavivirus
• Short incubation period (~5 days)
• Usually imported from SE Asia & South Africa

Question 2

Symptoms

Answer 2

Signs & symptoms (low WCC, low plts, low Hb):

Primary infection:

• Headache (retro-orbital)
• Fine erythematous sunburn-like rash (50%)
• High fever and myalgia

o Other = hepatomegaly, abdominal distension

o Severe = low WCC, low platelets, haemorrhage

Dengue haemorrhagic fever (secondary infection):
* Previously infected child -> subsequent infection (different strain) -> severe capillary leak, hypotension, haemorrhagic manifestations -> fluid resuscitation usually helps a lot

Due to partially effective host immune response augmenting the severity of the infection

Question 3

Investigations

Answer 3

o Gold standard – PCR viral antigen, serology IgM

o FBC, LFTs, serum albumin

Low WCC, low plts - severe

Question 4

Management

Answer 4

Treat those in shock or high risk

Supportive