AN ESTIMATED 4000 people in Scotland are living with chronic Hepatitis B without knowing it, health protection experts have warned.

Health Protection Scotland called for targeted screening of at-risk communities after its first ever report bringing together Scotland-wide data on the disease estimated that 4000 out of the 9000 people thought to be living with chronic Hepatitis B do not know they are ill.

By 2020, the World Health Organisation wants 90 per cent of infected individuals to be aware of their condition as part of a global elimination strategy.

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Left untreated, chronic Hepatitis B can morph into life-threatening problems such as scarring of the liver - known as cirrhosis - or liver cancer.

Although more than 95 per cent of people who contract the virus will fight it off naturally, those who do not may never experience any symptoms or mistake the symptoms for flu or food poisoning.

Babies and children under six are also more vulnerable as they are less able to shake the virus.

It is most commonly passed by unprotected sex, sharing needles, from a mother to baby during birth or via a contaminated blood transfusion. Many new cases are only detected by chance when someone donates blood.

Health Protection Scotland said annual diagnoses of chronic Hepatitis B had been stable in recent years, averaging 369 a year between 2011 and 2015, with 4966 known cases.

Three in four of these patients are of non-British ethnicity and there was evidence that "some individuals are being diagnosed at the stage of advanced liver disease".

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Prevalence is highest among people of South and South East Asian origin where rates of the Hepatitis B virus are much higher than in Scotland.

A vaccine is available to prevent infection and drug treatments can also suppress the virus.

In its report, Health Protection Scotland said: "The data indicates that, in Scotland, while the treatment targets are being achieved, the diagnosis target is not. Indeed, there is evidence from the data on advanced liver disease that infected individuals are presenting and being diagnosed late.

"While there are high levels of testing in clinical settings, this report highlights the need for further case finding, potentially targeting groups at risk, to identify those infected who might benefit from specialist treatment and care."