Patients informed of increased risk of vCJD contact
http://www.100md.com
《英国医生杂志》
Up to 4000 patients in the United Kingdom are being sent a letter this week explaining they may be at increased risk of carrying variant Creutzfeldt-Jakob disease (vCJD) because they have received blood products donated by people who have gone on to develop the disease.
The step is a highly precautionary one to try to limit the spread of the agent to other people, says the Department of Health. It follows the identification of two cases of vCJD that may have been transmitted through a blood transfusion, one last December and the other in July this year (BMJ 2004;329:251).
The patients who have been sent a letter, most of whom have haemophilia, will be invited to find out more about their individual risk from their local treatment centre. All of them are also being advised to tell their doctors and dentists about their potential increased risk so that steps can be taken to reduce the risk of further potential contamination.
About 6000 people in the United Kingdom have haemophilia, but only about 4000 are thought to be directly affected by the risk as they received blood products before 1998, when the United Kingdom started to import plasma derived products from the United States. About 50 people with primary immunodeficiency and a small number of people who have been treated with large quantities of plasma products may also have been exposed to contaminated products.
No one who received blood products before 1998 can be given the all-clear, however, because people who donated blood in the past may develop vCJD in the future and their donations would have had the potential to spread vCJD, explained Dr Angela Robinson from the National Blood Service.
The National Blood Service has identified that nine donors between 1985 and 1999 went on to develop vCJD. Between them they made 23 blood donations, which are thought to have contributed to 200 batches of plasma products that are used treat a range of conditions that require blood clotting factors, immunoglobulin, and albumin factors.
The exact risk to someone who has received one of these products is difficult to estimate, however, because the blood service collects about 600 000 litres of blood each year and thousands of donations are used to make up one treatment, making any contaminated product very dilute, said Dr Robinson. It’s also thought that the fractionating process used to prepare plasma products may itself reduce the infectivity of the agent, making the chance of transmission even smaller.
Professor Liam Donaldson, the chief medical officer, said: "Throughout our handling of the issues of vCJD we have adopted a highly precautionary approach, taking a series of steps when new evidence became available to maximise the protection of the public. This risk assessment continues this approach and identified three groups of patients who need to know that they may be at a small increased risk of developing vCJD compared with the rest of the population who ate beef during the 1980s and 1990s. This information will enable these people and their doctors to take the necessary steps to minimise the risk of onward transmission of vCJD."
· More than 1000 former patients of the Royal Melbourne Hospital, Australia, have been warned they might have been exposed to a strain of Creutzfeldt-Jakob disease (CJD) after a postmortem examination showed that a man who had had brain surgery there had the condition. The hospital said the case involved sporadic CJD and not variant CJD and that the risk of transmission was extremely remote.(London Zosia Kmietowicz)
The step is a highly precautionary one to try to limit the spread of the agent to other people, says the Department of Health. It follows the identification of two cases of vCJD that may have been transmitted through a blood transfusion, one last December and the other in July this year (BMJ 2004;329:251).
The patients who have been sent a letter, most of whom have haemophilia, will be invited to find out more about their individual risk from their local treatment centre. All of them are also being advised to tell their doctors and dentists about their potential increased risk so that steps can be taken to reduce the risk of further potential contamination.
About 6000 people in the United Kingdom have haemophilia, but only about 4000 are thought to be directly affected by the risk as they received blood products before 1998, when the United Kingdom started to import plasma derived products from the United States. About 50 people with primary immunodeficiency and a small number of people who have been treated with large quantities of plasma products may also have been exposed to contaminated products.
No one who received blood products before 1998 can be given the all-clear, however, because people who donated blood in the past may develop vCJD in the future and their donations would have had the potential to spread vCJD, explained Dr Angela Robinson from the National Blood Service.
The National Blood Service has identified that nine donors between 1985 and 1999 went on to develop vCJD. Between them they made 23 blood donations, which are thought to have contributed to 200 batches of plasma products that are used treat a range of conditions that require blood clotting factors, immunoglobulin, and albumin factors.
The exact risk to someone who has received one of these products is difficult to estimate, however, because the blood service collects about 600 000 litres of blood each year and thousands of donations are used to make up one treatment, making any contaminated product very dilute, said Dr Robinson. It’s also thought that the fractionating process used to prepare plasma products may itself reduce the infectivity of the agent, making the chance of transmission even smaller.
Professor Liam Donaldson, the chief medical officer, said: "Throughout our handling of the issues of vCJD we have adopted a highly precautionary approach, taking a series of steps when new evidence became available to maximise the protection of the public. This risk assessment continues this approach and identified three groups of patients who need to know that they may be at a small increased risk of developing vCJD compared with the rest of the population who ate beef during the 1980s and 1990s. This information will enable these people and their doctors to take the necessary steps to minimise the risk of onward transmission of vCJD."
· More than 1000 former patients of the Royal Melbourne Hospital, Australia, have been warned they might have been exposed to a strain of Creutzfeldt-Jakob disease (CJD) after a postmortem examination showed that a man who had had brain surgery there had the condition. The hospital said the case involved sporadic CJD and not variant CJD and that the risk of transmission was extremely remote.(London Zosia Kmietowicz)