Major health problems among children adopted from foreign countries have more than halved since 2000, when Malta started applying strict protocols.

More than five per cent of children adopted from abroad between 1987 and 2000 had major medical problems, including infections like HIV or Hepatitis B and C, an analysis of the 750 children adopted from abroad over the past 22 years has found.

Sixteen per cent of children adopted from Romania before 2000 were found to be Hepatitis B positive.

Although there were times when the foreign institution told the adoptive parents that the child they were going to adopt had incurable liver disease, on many occasions they had no idea what the condition really was.

"Only when the child arrived in Malta and we ran tests would we find out that they were sick," Mater Dei Hospital's paediatric department chairman Simon Attard Montalto told The Sunday Times.

There were cases when young children had serious liver cirrhosis, even needing a liver transplant.

But serious infections have fizzled out since 2000 when the local authorities demanded HIV and Hepatitis tests before issuing children with a visa. The first step is sending a medical questionnaire to the institute where the child is being kept. They also request photos to get an idea of whether the baby is the appropriate size for his age, whether he has any syndromes or other visible problems.

Only seven out of the 297 children adopted in the past 10 years had major health problems, the study, presented during the recent Malta Medical School Conference, found. None of these was an infection.

But despite tightening the net, the authorities were still unhappy at the information received from certain countries and recently stopped adoptions from Pakistan following suspicions that blood tests were being forged.

Pakistan was the third most popular country for adoptions before 2000, following Romania and Albania. But now the trend has been reversed and adoptions from Russia and Ethiopia have become the most common.