 |
|
 |
|
|
|
| ||||||||||||||||
Alarm at human bird flu cluster |
|||
The World Health Organization (WHO) says it is extremely worried about a cluster of recent human deaths from the virulent H5N1 strain of bird flu. Seven people from the same family in northern Sumatra, Indonesia, died from the disease earlier this month. WHO spokesman Peter Cordingley said there was no sign of diseased poultry in the immediate area. Investigators are looking into the possibility that the virus spread from human to human, Mr Cordingley said. But he emphasised that there was no indication the virus had mutated. Experts are worried that if it does mutate, the H5N1 strain could become more easily transmitted between humans, leading to a worldwide pandemic of the killer disease. The H5N1 virus has already killed more than 120 people worldwide since 2003. It has also devastated poultry stocks. The majority of deaths have occurred in Asia, but cases in people and birds have also been recorded in Europe and Africa. Almost all human infections so far are thought to have been caused by direct contact with sick poultry. Family tragedy Mr Cordingley said that the Sumatran cases presented a major puzzle, as they were the largest cluster of human cases to date. "[This] is probably the most worrying incident so far since bird flu started nearly three years ago and we can't find any obvious source of infection. We can find no sign of infected chickens; no sign of the virus in the environment around where they live," he said. All seven people who died were members of the same family. An eighth family member is also thought to have the disease. So far investigators know that the initial victim was a woman, who became ill at the end of April. She died in early May and was buried before laboratory tests could be carried out. The subsequent six victims - all of whom were positively identified as having the virus - had close and prolonged exposure to either her or other family members with the disease, the WHO said. Clusters of bird flu cases are viewed with far more concern than isolated infections, because of the possibility of transmission between humans. There have already been several cluster cases - such as one seen in Thailand in 2004 - although they have always involved fewer individuals than the Indonesian case. But the possibility scientists are most worried about, genetic mutation of the virus, has been effectively ruled out in this case. "Sequencing of all eight gene segments found no evidence of genetic reassortment with human or pig influenza viruses, and no evidence of significant mutations," the WHO said in a statement on Wednesday. The WHO is continuing its investigations into the Sumatran case. But the organisation says there is so much grief in the village that it is difficult for officials to get enough co-operation from local people to do their job. |
|
|
|
Colonoscopy may not benefit the very elderly
Last Updated: 2006-05-23 16:40:33 -0400 (Reuters Health)
NEW YORK (Reuters Health) - For people in their 80s and 90s, the risks of colonoscopy appear to outweigh the benefits, investigators report in the Journal of the American Medical Association. The slow development of colorectal cancer means that these patients are more likely to die of other causes, even if cancer is identified.
Meanwhile, for average-risk individuals, the decreased risk of developing colorectal cancer after a normal result on an initial colonoscopy remains lower than that of the general population for more than 10 years, according to a second study published in JAMA.
Current guidelines do not include an age at which colorectal cancer screening with colonoscopy should be stopped, Dr. Otto S. Lin and his associates note, even though the procedure is associated with higher complication rates among the very elderly.
Physicians need to consider whether the risk and cost of screening colonoscopy can be justified by potential benefits in very elderly patients, Lin's team notes.
The investigators evaluated data for 1,034 symptom-free individuals, 50 to 54 years of age, 147 between 75 and 79 years of age, and 63 who were at least 80 years of age. The subjects all underwent colonoscopy at Virginia Mason Medical Center in Seattle between 2002 and 2005.
The rate of tumors increased with age, from 3.2 percent among the youngest group to 14 percent among the oldest group. However, screening colonoscopy added little to the lifespan of the older patients, just 0.13 years.
These findings should help doctors and patients "decide whether screening colonoscopy should be performed and help avoid its use in patients who are unlikely to benefit substantively," Lin and his associates conclude.
In the second paper, a group led by Dr. Harminder Singh points out that the interval for screening colonoscopy that has been widely adopted is based on the estimated time required for a polyp to transform into cancer. However, the average duration of lowered risk of colorectal cancer risk after a normal colonoscopy is not known.
To estimate this risk over time, Singh and colleagues at the University of Manitoba in Winnipeg evaluated cancer diagnoses and cancer-related deaths reported in the Manitoba Cancer Registry and the Manitoba Health Population Registry. This included 32,203 individuals with normal colonoscopy results and who had been followed for more than 6 months.
The results showed that even after 10 years, people with normal colonoscopy results had a lower cancer risk than people in the general population. This suggests that a screening interval of longer than 10 years may be appropriate.
In a related editorial, Dr. Timothy R. Church, from the University of Minnesota School of Public Health in Minneapolis , reminds readers that the benefits of screening were originally based on trials of stool blood testing, rather than on much more expensive strategies.
He estimates that at a cost of $500 per colonoscopy, screening 10 percent of individuals 50 years or older in the US every year would cost more than $4 billion annually.
SOURCE: Journal of the American Medical Association, May 24/31, 2006.
Copyright © 2006 Reuters Limited. All rights reserved. Republication or redistribution of Reuters content, including by framing or similar means, is expressly prohibited without the prior written consent of Reuters. Reuters shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon. Reuters and the Reuters sphere logo are registered trademarks and trademarks of the Reuters group of companies around the world.
Continue with:
| © 2002-2006 |
Keywords: |
