Giant rats to sniff out tuberculosis -- old news, but new to me ..
16 December 2003
NewScientist.com news service
Maggie McKee
"Giant rats in Sub-Saharan Africa are being trained to sniff out tuberculosis in humans. The rats have already been successfully used to detect land mines by their odour.
Preliminary tests suggest the rats could test as many as 150 saliva samples for TB in just 30 minutes. By contrast, human technicians using a microscope can test only 20 samples a day. The World Bank has now provided $165,000 for a full study of the rats' diagnostic potential.
'Tuberculosis is a growing worldwide epidemic,' says Bart Weetjens, director of the rat programme at Apopo, a Belgian research organisation hosted by Sokoine University of Agriculture in Tanzania. 'It makes sense to detect those cases to be able to treat them...'"
...The rat study, which will begin in July 2004, will test the olfactory abilities of about 30 giant pouched rats (Cricetomys gambianus). The researchers will compare the rats' adeptness with the 95 per cent accuracy of smear microscopy.
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---Life span: up to 8 years, can reach a total length of 30 inches or more - half made up by the tail, Weight: usually about 3-4 pounds ---
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Preliminary results look positive. Apopo researchers used bananas and peanuts to reward rats when they stopped beside a target smell. In this way, they sensitised five rats to the smell of TB bacteria in saliva and another five to the smell of TB bacteria grown in cultures.
The rats were then tested using 10,000 saliva samples and identified about 77 per cent of infected saliva samples. Weetjens hopes that using three or four trained rats on each sample will increase the accuracy.
The rats scored better - nearly 92 per cent - with cultured bacteria. The number of "false positives," where rats stopped at uninfected samples, was less than 2 per cent for both cultures and saliva.
The idea came to Weetjens through a clue in his native language, Dutch. The Dutch word for TB is tering, which translates roughly as "the process of developing the smell of tar".
He also had read reports of traditional Chinese healers diagnosing the disease by smelling the patient's saliva as it evaporated over a flame. "In principle, everything has a smell," he told New Scientist. Researchers have already studied whether dogs can sniff out cancers, he says.
The rats, which can grow as big as cats, have been studied by Apopo since 1997. In their first field deployment, 12 rats were sent to Mozambique, where they sniffed out 20 landmines without detonating them.
Link
NewScientist.com news service
Maggie McKee
"Giant rats in Sub-Saharan Africa are being trained to sniff out tuberculosis in humans. The rats have already been successfully used to detect land mines by their odour.
Preliminary tests suggest the rats could test as many as 150 saliva samples for TB in just 30 minutes. By contrast, human technicians using a microscope can test only 20 samples a day. The World Bank has now provided $165,000 for a full study of the rats' diagnostic potential.
'Tuberculosis is a growing worldwide epidemic,' says Bart Weetjens, director of the rat programme at Apopo, a Belgian research organisation hosted by Sokoine University of Agriculture in Tanzania. 'It makes sense to detect those cases to be able to treat them...'"
...The rat study, which will begin in July 2004, will test the olfactory abilities of about 30 giant pouched rats (Cricetomys gambianus). The researchers will compare the rats' adeptness with the 95 per cent accuracy of smear microscopy.
****
---Life span: up to 8 years, can reach a total length of 30 inches or more - half made up by the tail, Weight: usually about 3-4 pounds ---
****
Preliminary results look positive. Apopo researchers used bananas and peanuts to reward rats when they stopped beside a target smell. In this way, they sensitised five rats to the smell of TB bacteria in saliva and another five to the smell of TB bacteria grown in cultures.
The rats were then tested using 10,000 saliva samples and identified about 77 per cent of infected saliva samples. Weetjens hopes that using three or four trained rats on each sample will increase the accuracy.
The rats scored better - nearly 92 per cent - with cultured bacteria. The number of "false positives," where rats stopped at uninfected samples, was less than 2 per cent for both cultures and saliva.
The idea came to Weetjens through a clue in his native language, Dutch. The Dutch word for TB is tering, which translates roughly as "the process of developing the smell of tar".
He also had read reports of traditional Chinese healers diagnosing the disease by smelling the patient's saliva as it evaporated over a flame. "In principle, everything has a smell," he told New Scientist. Researchers have already studied whether dogs can sniff out cancers, he says.
The rats, which can grow as big as cats, have been studied by Apopo since 1997. In their first field deployment, 12 rats were sent to Mozambique, where they sniffed out 20 landmines without detonating them.
Link
posted by Saintperle at
10:58 AM
