Home | Help

Diseases of crustaceans

Viral diseases—Yellowhead disease

CLICK ON IMAGE TO ENLARGE yellowhead disease

Yellowhead disease in giant black tiger prawn (Penaeus monodon). Note yellow heads of infected prawns on left. Prawns on right are normal

Source: DV Lightner

Signs of disease

Important: animals with disease may show one or more of the signs below, but disease may still be present in the absence of any signs.

Disease signs at the farm level

Clinical signs of disease in an infected animal

Disease agent

The causative agent of yellowhead disease is yellowhead virus (YHV), a corona-like RNA viruses in the genus Okavirus, family Ronaviridae and order Nidovirales.

Host range

YHV is highly infectious for most known species of cultivated penaeid prawns.

Crustaceans known to be susceptible to yellowhead disease:
black tiger prawn* (Penaeus monodon) - primarily
Gulf banana prawn* (Penaeus merguiensis)
northern white shrimp* (Penaeus setiferus)
prawn* (Palaemon styliferus)
red endeavour prawn* (Metapenaeus ensis)
tropical krill* (Acetes spp)
blue shrimp (Penaeus stylirostris)
northern brown shrimp (Penaeus aztecus)
northern pink shrimp (Penaeus duorarum)
Pacific white shrimp (Penaeus vannamei)

* naturally susceptible (other species have been shown to be experimentally susceptible)

Until proven otherwise, it should be assumed that most penaeid prawns worldwide are susceptible to infection with yellowhead disease.

Presence in Asia–Pacific

Map showing presence in Asia–Pacific

Yellowhead disease has been officially reported from India, Thailand and Vietnam.


Gill-associated virus, which has a similar ultrastructure to that of YHV, has been reported from Australia:

Comparison of DNA sequences of reverse-transcription polymerase chain reaction (RT PCR) products from YHV and GAV suggests that they are closely related, but distinctly different viral strains or species.

Differential diagnosis

The differential diagnostic table and the list of similar diseases appearing at the bottom of each disease page refer only to the diseases covered by this field guide. Gross signs observed might well be representative of a wider range of diseases not included here. Therefore, these diagnostic aids should not be read as a guide to a definitive diagnosis, but rather as a tool to help identify the listed diseases that most closely account for the gross signs.

Similar diseases

Taura syndrome

Further images

Sample collection

Because of uncertainty in differentiating diseases using only gross signs, and because some aquatic animal disease agents might pose a risk to humans, you should not try to collect samples unless you have been trained. Instead, you should phone your national hotline number and report your observations. If samples have to be collected, the agency taking the call will advise you on what you need to do. Local or district fisheries/veterinary authorities could advise you on sampling.

Emergency disease hotline

For your national emergency disease hotline number, see Whom to contact if you suspect a disease.

Further reading


The currently accepted procedures for a conclusive diagnosis of yellowhead disease are summarised at http://www.oie.int/eng/normes/fmanual/A_00050.htm

These hyperlinks were correct and functioning at the time of publication. yellowhead disease

Return to top

Home | Help

| Information | Introduction | Anatomy | Differential Diagnostic Table | Diseases of Finfish | Diseases of Molluscs | Diseases of Crustaceans | Common Names | Contacts | Links | Further Reading |