December 2025

There is a Dengue outbreak in Fiji. The outbreak started this year, with 23,500 suspected cases recorded in the Pacific so far, and 1900 in Samoa just last week. The outbreak is the largest in a decade, according to the WHO (ref). Dengue is a mosquito-borne illness. There is no human transmission. In Australia, Dengue outbreaks occur in North and Central Queensland when an imported case is exposed to the local Aedes aegypti mosquito facilitating spread to other individuals. But these outbreaks are limited and the disease has never gained endemicity in Australia. Aedes mosquitoes live in urban areas, preferring urban environments so that they lay their eggs in the stagnant water trapped in man-made containers. Aedes bite during the day.

Patients present with sudden onset malaise, lethargy, fever and body ache and headache. The headache often intense, behind the eyes. There is muscle and joint pain. There is loss of appetite, vomiting, diarrhoea, abdominal pain. There may be a skin rash--on the face, neck, arms. Most cases are mild but many cases can present with a level of coagulopathy and plasma leak. These Dengue Haemorrhagic Fevers (and Dengue Shock Syndrome) have mortality rates of up to 40%. My patient presented on the Monday having returned from Fiji on Saturday, her symptoms starting suddenly on the Sunday. She was unwell, with headache, intense body aches and high fever. She had been taking Panadol and Nurofen and it still wasn’t holding her pain. She was lethargic and fatigued easily. She said she had had many mosquito bites while away, and that there was an outbreak (of Dengue) in Fiji at the time. She was drinking copious amounts of water and urinating briskly. I rang her the next day, her D-Dimer had returned 0.82 ng/L (< 0.5). She was sounding drained, her voice weak, but was keeping up her fluids (with the help of some Maxolon) and her urine straw-coloured. Nevertheless, her elevated D-Dimer suggested the possibility for a haemorrhagic fever, so I referred her to the ED. WHO data showed sky-high rates of Dengue in Fiji this year, rates still at times double the 5-Year Median.

Severe abdominal pain (from hepatitis; Kwo, 2016), persistent vomiting, bleeding gums, vomiting blood, rapid breathing, fatigue, and restlessness are signs of severe Dengue (Dengue Haemorrhagic Fever/Dengue Shock Syndrome). This is more common in a person who has had Dengue Fever previously. There are four Dengue virus types, designated Dengue Virus 1, 2, 3, and 4. A second Dengue infection with a different serotype poses risk for DHF/DSS from cytokine response (Fink, 2006).

Ultrasound examination (POCUS) may be most useful around the time of defervescence (Srikiatkhachorn, 2007) and is likely superior to clinical and laboratory assessment for the diagnosis of plasma leakage (Balasubramanian, 2006):

• CXR/USS (Pleural effusion):
  • most common sign
  • 1 day after defervescence
• Abdo. USS (Ascites):
  • detected prior to and even in cases without haemoconcetration
  • from 2 days before to 3 days after defervescence
  • resolved more rapidly than pleural effusion
• [Ultrasonographic signs of plasma leakage were detectable before changes in hematocrits. The Pediatric Infectious Disease Journal 26(4):p 283-290, April 2007.]
• FBC (Haemoconcentration > 20%): 48% Sensitive; 83% Specific; PPV 70%; NPV 67%
• LFT (Hypoproteinemia): 25% Sensitive; 90% Specific; PPV 73%, NPV 47%

The Western Pacific Region has seen 53, 397 cases of Dengue this year. This compares to 16,346 cases at similar time for last year, case fatality rate of 0.12%.

References:

Balasubramanian, S., et al. “A reappraisal of the criteria to diagnose plasma leakage in dengue hemorrhagic fever.” Indian pediatrics 43.4 (2006): 334.

Fink, J., Gu, F. and Vasudevan, S.G. (2006), Role of T cells, cytokines and antibody in dengue fever and dengue haemorrhagic fever. Rev. Med. Virol., 16: 263-275. https://doi.org/10.1002/rmv.507

Srikiatkhachorn, Anon MD^*; Krautrachue, Anchalee MD^†; Ratanaprakarn, Warangkana MD^†; Wongtapradit, Lawan MD^†; Nithipanya, Narong MD^†; Kalayanarooj, Siripen MD^†; Nisalak, Ananda MD^‡; Thomas, Stephen J. MD^‡; Gibbons, Robert V. MD^‡; Mammen, Mammen P. Jr MD^‡; Libraty, Daniel H. MD^*; Ennis, Francis A. MD^*; Rothman, Alan L. MD^*; Green, Sharone MD^*. Natural History of Plasma Leakage in Dengue Hemorrhagic Fever: A Serial Ultrasonographic Study. The Pediatric Infectious Disease Journal 26(4):p 283-290, April 2007. | DOI: 10.1097/01.inf.0000258612.26743.10

Regional Emergencies Programme and Division of Health Security and Emergencies (DSE), WHO Western Pacific