Skip to main content
ultrasound.myby AA Alive Sdn Bhd
ENBM

Ultrasound in Dengue: Finding Plasma Leakage Before It Shows

Malaysia passed 76,000 dengue cases by mid-October 2026. Plasma leakage is what makes dengue dangerous, and ultrasound can often show the fluid before the bedside examination does. What to look for, what the Malaysian guideline says, and what a scan cannot tell you.

Also called Dengue ultrasound, Plasma leakage ultrasound, Dengue POCUS

Published:

Dengue in Malaysia in 2026

The national iDengue dashboard showed 76,167 dengue cases from 4 January to 14 October 2026, and 68 deaths up to 11 October. By epidemiological week 35 the Health Ministry had already reported 65,979 cases, against 39,616 in the same weeks of 2025. The ministry and dengue advocates have linked the rise to DENV-3 replacing DENV-2 as the dominant serotype — a strain many Malaysians have not met before. Selangor has the most cases, followed by the Federal Territories and Johor. With the year-end monsoon rains still to come, clinics and emergency departments should plan for busy months.

Read next Serial FBC and haematocrit in dengue (hematologyanalyser.my)Baca dalam Bahasa Malaysia

Why plasma leakage is the thing to find

In the critical phase — often after the third day of fever, around the time the temperature falls — fluid leaks out of the capillaries into the chest, the abdomen and the tissues. The Malaysian Clinical Practice Guidelines on dengue in adults list a raised haematocrit, haemodynamic instability, fluid in the extravascular space and low protein as evidence of leakage, and count third-space fluid — ascites, pleural and pericardial effusion — among the warning signs. Small collections are hard to find by examination. Ultrasound can show them early, and repeat scans show whether they are growing.

What the scan looks for

FindingWhere to lookWhat it suggests
Gallbladder wall thickeningRight upper quadrant, measuring the anterior wallMost studies call a wall above 3 mm thickened. Often the earliest sign: a 2026 review notes it can appear one to three days before ascites or effusion
Pleural effusionThe costophrenic angles on both sides, scanning from the flankFluid in the chest
AscitesMorison’s pouch between the liver and right kidney, around the spleen and in the pelvisFree fluid collects first in these dependent spaces
Pericardial effusionSubcostal or parasternal view of the heartFluid around the heart, usually with more severe leakage
Inferior vena cava (IVC)Subcostal long-axis view, just below where it joins the right atriumIts size and how much it collapses with breathing — an indirect guide to intravascular volume, read with the clinical picture
B-linesAnterior and lateral chest wallFluid in the lung interstitium, which may also follow generous IV fluid

Read next Lung signs: B-lines and effusions

What the Malaysian guideline says

The CPG Management of Dengue Infection in Adults (third edition, 2015, published by MaHTAS) states that chest X-ray and ultrasound, where available, are required for patients suspected of vascular leakage, but must not delay admission. It says ultrasonography may be performed by trained personnel to look for third-space fluid — pleural effusion, pericardial effusion, gallbladder wall oedema and intraperitoneal fluid — and for collapsibility of the IVC as an indirect indicator of the intravascular fluid compartment and the response to IV fluids.

  • Ultrasound is an adjunct. Monitoring still rests on serial FBC and haematocrit, vital signs, urine output and the warning signs.
  • The CPG advises primary care providers without immediate haematocrit testing to refer patients to the nearest health facility — with or without an ultrasound machine.
  • A normal scan early in the illness does not rule out leakage later. Findings change day by day through the critical phase, so repeat the scan.
  • There is no validated dengue-specific POCUS protocol yet. A 2026 review in the World Journal of Critical Care Medicine proposed a structured one, which shows how unsettled practice still is.

Read next POCUS equipment and governance

How useful is gallbladder wall thickening?

It is the most-studied single sign. At Hospital Sungai Buloh, Ibrahim and colleagues (The Ultrasound Journal, 2022) scanned 44 adults with dengue in the emergency department using a 3 mm cut-off. Gallbladder wall thickening had 90.5% sensitivity and 69.6% specificity for severe dengue, compared with dengue with warning signs. A 2025 meta-analysis of 19 studies found a pooled sensitivity of 88% and specificity of 63%. In practice, a normal wall makes severe disease less likely, and a thick wall is a prompt to look harder — not a diagnosis on its own. A recent meal, hepatitis, heart failure and low albumin also thicken the wall.

Probes and machine features for a dengue scan

Convex probe

Covers the gallbladder, Morison’s pouch, the spleen, the pelvis and the pleural bases. It is the one probe a dengue scan cannot do without.

Phased-array probe

Optional, for the pericardium and the IVC between the ribs. The convex probe can usually see both through the subcostal window.

Linear probe

Shows the pleural line in fine detail and helps in small children, but is not essential for adults.

Portable or handheld

Many dengue scans happen in a crowded ward or observation area. A portable or handheld system with abdomen and lung presets and a quick start-up suits that work; check depth on larger adults before buying.

Handheld scanners compared

Measurement and storage

Calipers for wall thickness and IVC diameter, M-mode for IVC collapse, and clips saved under the patient’s name so the next scan can be compared with this one.

Read next Portable ultrasound machinesCleaning probes between patients

Related guides

Point-of-Care Ultrasound (POCUS) EquipmentPOCUS answers focused clinical questions at the bedside. Here are the common exams, the equipment that suits them and how to start safely.Lung Ultrasound: The Signs, the BLUE Protocol and the Right MachineAir blocks ultrasound, so a lung scan reads artefacts as much as anatomy. The signs every lung scan is built on, how the BLUE protocol puts them together, and what to look for in the probe and settings.Ultrasound untuk Pesakit Denggi: Apa yang Boleh DilihatLebih 76,000 kes denggi direkodkan di Malaysia setakat pertengahan Oktober 2026. Panduan ringkas untuk doktor dan staf klinik: tanda kebocoran plasma pada ultrasound, apa kata garis panduan KKM, dan had imbasan.

Ultrasound Machine supply near you

Delivery, installation and training across Malaysia from Batu Caves, Kota Kinabalu and Kuching.

See all 28 locations

Frequently asked questions

Can ultrasound diagnose dengue?
No. Dengue is diagnosed with NS1 antigen, antibody or PCR tests together with the clinical picture. Ultrasound looks for complications of dengue — mainly plasma leakage — once the diagnosis is suspected or confirmed.
What is gallbladder wall thickening in dengue?
Fluid leaking into the gallbladder wall makes it look thick and layered, usually above 3 mm. It is often the earliest ultrasound sign of plasma leakage and is linked to more severe disease, but a recent meal and other conditions can thicken the wall too.
Does a GP clinic need ultrasound to manage dengue?
No. Malaysian guidance builds outpatient dengue care on clinical review, warning signs and serial FBC with haematocrit. Ultrasound is a useful extra in trained hands, but a clinic without immediate haematocrit testing should refer patients regardless.
Which probe is used to look for plasma leakage?
A convex abdominal probe covers the gallbladder, free fluid and the pleural bases. A phased-array probe helps with the pericardium and the IVC, but it is not essential.

Get a written quotation

Tell us your clinic or lab type, daily workload and location. We match suitable models and send a written quotation with delivery, installation and training spelled out.