Furunculosis

Definition

Furunculosis is an infection where furuncles are present over a period of weeks to months. Species of Staphylococcus aureus are usually the causative agents. Furunculosis is systemic in nature as it travels through the bloodstream and affects all parts of the body, especially the vital organs. The rapid multiplication of bacteria in the bloodstream causes smaller blood vessels to rupture allowing the bacteria to spread to surrounding tissue. When allowed to advance to this stage, the disease is always fatal.

Causes of Furunculosis

Boils can develop in any hairy area of the skin. In particular, in sites where there is friction, or where the skin is sweaty. For example, the neck, face, armpit, arms, wrists, buttocks, and around the anus. Carbuncles most commonly develop on the back of the neck or on the thighs.

A boil or carbuncle can occur in anyone at any age. However, they are uncommon in children, and most commonly occur in teenagers and young adults. You have a higher risk of developing a boil or carbuncle if you have:

• other skin conditions that may cause you to scratch and damage the skin. For example, eczema or scabies.
• obesity.
• a poor immune system.
• an illness making you frail or generally unwell.
• you are a 'carrier' of Staphylococcus bacteria

Symptoms of Furunculosis

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.

Furunculosis Symptoms at the farm level

• high mortality

Furunculosis Symptoms at the tank and pond level

• lethargy
• cessation of feeding
• swimming just below surface
• respiratory distress and random jumping from water immediately before an outbreak

Clinical Symptoms of Furunculosis in an infected animal

• furuncles (or boils) causing deep abscesses, usually in adult salmon in the acute phase of infection
• haemorrhages on skin, mouth and fin bases (mainly paired fins)
• darkening of body colour
• exophthalmus (pop eye)

Gross Symptoms of Furunculosis in an infected animal

• haemorrhages in muscle and internal organs
• enlarged spleen and focal necrosis of the liver
• stomach filled with mucus, blood and sloughed epithelial cells
• congested intestine
• fusion of gill lamellae

While classical furunculosis (as described above) occurs in both juvenile and adult salmon, peracute infections in juvenile salmon can result in death without the fish showing any clinical signs other than darkening of the skin.

Treatment of Furunculosis

• Avoid leisure activities which cause sweating and friction from clothing, such as squash and jogging.
• If you are iron deficient, a course of iron tablets may help reduce infection.
• 1000mg of vitamin C each day has also been advocated.
• Consult your doctor about your general health.
• If you are overweight, try to reduce your weight; take regular exercise.
• Follow a balanced healthy diet with meat, plenty of fruit and vegetables.
• Wash your whole body once a day with soap and water. Wash your hands several times daily.
• Don't share your flannel or towel with other family members.
• Maintain a clean handkerchief and don't pick your nose!
• Change your underclothes and night attire regularly.