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Q & A: Spreading Smallpox
By C. CLAIBORNE RAY, The New York Times, March 13, 2007
Q. Would it really have been possible for Europeans to infect Native Americans with the smallpox virus by giving them blankets used by other victims? How long could the virus live on a blanket?
A. It would be at least theoretically possible, experts at the Centers for Disease Control and Prevention said, though some historians doubt that the plan to infect enemy tribes, which the British general Lord Jeffery Amherst notoriously wrote about in 1763, during the French and Indian War, was actually carried out.
Dr. Inger Damon, a researcher and epidemiologist at the centers, said the virus, called variola, lives longer in smallpox scabs than in the droplets spread from person to person, the normal mode of transmission.
“In a humidity-controlled environment, like a cool, dry cabinet,” Dr. Damon said, “viruses in scabs have been shown in certain studies to be quite long-lived, from some months to a year, possibly longer.”
Though person-to-person transmission usually requires close, prolonged contact (a distance of about six or seven feet for about three hours), there are reported instances of fabric-borne infections among people who worked in smallpox hospitals, doing laundry or changing bed linens. Even a mortuary worker was infected this way, Dr. Damon said.
“The disease is now eradicated, though the virus lives in a freezer,” she said, where it is potentially useful for studying the effectiveness of new drugs or vaccines.
Epic of Human Migration Is Carved in Parasites’ DNA
By NICHOLAS WADE, The New York Times, March 13, 2007
A human body is not the individual organism its proud owner may suppose but rather a walking zoo of microbes and parasites, each exploiting a special ecological niche in its comfortable, temperature-controlled conveyance. Some of these fellow travelers live so intimately with their hosts, biologists are finding, that they accompany them not just in space but also in time, passing from generation to generation for thousands of years.
The latest organism to be identified as a longtime member of the human biota club is Streptococcus mutans, the bacterium that causes tooth decay. From samples collected around the world, Dr. Page W. Caufield and colleagues at New York University have found that the bacterium can be assigned by its DNA to several distinct lineages. One is found in Africans, one in Asians and a third in Caucasians (the people of Europe, the Near East and India), his team reported in last month’s Journal of Bacteriology.
The geographical distribution of these lineages reflects the pattern of human migration out of the ancestral homeland in Africa. If the tooth decay bacterium spreads easily from person to person, any geographical pattern would soon be blurred. But Streptococcus mutans is transmitted almost entirely from mother to child, preserving its lineages over thousands of years. The bacteria apparently infect the infant during birth, beginning the work that provides the dentistry profession its livelihood. “We’ve never seen father-to-child transmission,” Dr. Caulfield said. Thanks, Mom.
Another faithful member of the human road show is Helicobacter pylori, a bacterium that inhabits half the stomachs in the world. It is a usually well-behaved guest, but gives its hosts ulcers when it acts up. Its pattern of geographic distribution matches that of its host’s migrations, Dr. Mark Achtman of the Max Planck Institute in Berlin and colleagues reported in the journal Nature last month.
There are five ancestral populations of H. pylori — two in Africa, two in Europe and one in East Asia. But all had a common origin, Dr. Achtman said, in a bacterium that started to spread out from East Africa 58,000 years ago, give or take 3,000 years. This is the same time period in which modern humans are thought to have begun their migration out of Africa. The match in dates “implies that H. pylori was present in Africa before the migrations, suggesting that Africa is the source of both H. pylori and humans,” Dr. Achtman and colleagues conclude evenhandedly.
H. pylori seems to be transmitted within families but the exact route — perhaps vomit — is unclear. “It’s amazing that any microbe’s geographical distribution would parallel that of humans as well as pylori’s does,” Dr. Achtman said. “You think of microbes as being easily transmissible and they are carried all over the world on ships and planes, yet some have not lost these signals of ancient migrations.”
DNA analysis has also shed light on the origin of the tapeworm, one of the 400 or so nonmicrobial parasites that regard the human body as home. The lifecycle of the tapeworm Taenia asiatica alternates between people and pigs, an animal that the religious authorities of both Judaism and Islam agree is unclean. It would be of interest to know just when these filthy animals infected people with their parasites. But the answer is not quite what had been expected.
Eric P. Hoberg, of the U.S.D.A.’s Agricultural Research Service in Beltsville, Md., concluded in 2001 that people contracted tapeworms millions of years ago in Africa, long before the emergence of agriculture and domestic animals. It was humans who infected pigs with tapeworms, not the other way around, Dr. Hoberg and colleagues reported. Indeed, people infected pigs not only with Taenia asiatica but also with a second species of tapeworm, Taenia solium, which humans seem to have acquired either by eating each other or by eating dogs.
If pigs had a religion, it is pretty easy to guess which species they would designate as unclean.
Top Scientists Warn of Water Shortages and Disease Linked to Global Warming
By THE ASSOCIATED PRESS, The New York Times, March 12, 2007
WASHINGTON, March 11 (AP) — The harmful effects of global warming on daily life are already showing up, and within a couple of decades hundreds of millions of people will not have enough water, top scientists are likely to say next month at a meeting in Belgium.
At the same time, tens of millions of others will be flooded out of their homes each year as the earth reels from rising temperatures and sea levels, according to portions of a draft of an international scientific report by the authoritative Intergovernmental Panel on Climate Change.
Tropical diseases like malaria will spread, the draft says. By 2050, polar bears will mostly be found in zoos, their habitats gone. Pests like fire ants will thrive.
For a time, food will be plentiful because of the longer growing season in northern regions. But by 2080, hundreds of millions of people could face starvation, according to the report, which is still being revised.
The draft document, the second of a series of four being issued this year, focuses on global warming’s effects. Written and reviewed by more than 1,000 scientists from dozens of countries, it still must be edited by government officials.
But some scientists said the overall message is not likely to change when it is issued in early April in Brussels, where European Union leaders agreed Friday to work to cut greenhouse gas emissions substantially by 2020. Their plan will be presented to President Bush and other world leaders at a summit meeting in June.
The draft report offers some hope if nations slow and then reduce their greenhouse gas emissions, but it says what has been happening has not been encouraging.
“Changes in climate are now affecting physical and biological systems on every continent,” the report says, in marked contrast to a 2001 report by the same international group that said the effects of global warming were coming. But that report mentioned only scattered regional effects.
“Things are happening and happening faster than we expected,” said Patricia Romero Lankao of the National Center for Atmospheric Research in Boulder, Colo., one of the many co-authors of the new report.
The draft document says scientists are highly confident that many current problems — change in species’ habits and habitats, more acidified oceans, loss of wetlands, bleaching of coral reefs and increases in allergy-inducing pollen — can be attributed to global warming.
For example, the report says North America “has already experienced substantial ecosystem, social and cultural disruption from recent climate extremes,” like hurricanes and wildfires.
But Ms. Romero Lankao said that global warming soon would “affect everyone’s life,” and added that “it’s the poor sectors that will be most affected.”
Another co-author, Terry Root of Stanford University, said, “We truly are standing at the edge of mass extinction” of species.
The United Nations-organized network of 2,000 scientists was established in 1988 to give regular assessments of the earth’s environment.
The draft report says that hundreds of millions of Africans and tens of millions of Latin Americans who now have water will be short of it in less than 20 years. By 2050, more than a billion people in Asia could face water shortages. By 2080, water shortages could threaten 1.1 billion to 3.2 billion people, depending on the level of greenhouse gases that cars and industry spew into the air.
It says that death rates for the world’s poor from conditions worsened by the changes global warming brings, like malnutrition and diarrhea, will rise by 2030. By 2080, 200 million to 600 million people could be hungry because of global warming’s effects, it says.
It also says that Europe’s small glaciers will disappear, with many of the continent’s large glaciers shrinking sharply by 2050. And half of Europe’s plant species could be vulnerable, endangered or extinct by 2100.
The hardest-hit continents are likely to be Africa and Asia, with major harm also coming to small islands and some aspects of ecosystems near the poles. North America, Europe and Australia are predicted to suffer the fewest of the harmful effects.
“In most parts of the world and most segments of populations, lifestyles are likely to change as a result of climate change,” the draft report said. “Net valuations of benefits vs. costs will vary, but they are more likely to be negative if climate change is substantial and rapid, rather than if it is moderate and gradual.”
Many, though not all, of those effects can be prevented, the report says, if within a generation the world slows down its emissions of carbon dioxide and if the level of greenhouse gases sticking around in the atmosphere stabilizes. If that is the case, the report says, “most major impacts on human welfare would be avoided; but some major impacts on ecosystems are likely to occur.”
Judge Stops Sale of Monsanto’s Genetically Engineered Alfalfa
By ANDREW POLLACK, The New York Times, March 13, 2007
A federal judge revoked the government’s approval of Monsanto’s genetically engineered alfalfa yesterday, ordering a halt to seed sales and banning any planting of the crop after March 30.
The decision, by Judge Charles R. Breyer of Federal District Court in San Francisco, came after a ruling he made a month ago that the Agriculture Department had violated the law by failing to prepare an environmental impact statement before approving the crop in June 2005.
Yesterday’s order, the first time that approval of a genetically engineered crop had been revoked by a court, was a preliminary injunction. The judge said he would consider whether to make the injunction permanent at a hearing in late April.
The lawsuit had been filed by some alfalfa seed companies and environmental and farm advocacy groups against the department.
Monsanto intervened in the case after Judge Breyer’s ruling last month in an effort to keep the crop on the market. It was joined by several alfalfa growers and by Forage Genetics International, an alfalfa breeder that worked with Monsanto and now handles the sale of the seeds to farmers.
The alfalfa is resistant to Monsanto’s Roundup herbicide, allowing farmers to kill weeds without hurting the crop.
Monsanto said it was disappointed. “We are hopeful that a reasoned approach in this matter will address questions about the regulatory approval process for Roundup Ready alfalfa while maintaining farmer access to this beneficial technology,” Jerry Steiner, an executive vice president, said in a statement.
In an effort to soften the impact of his ruling on farmers, Judge Breyer said seed already purchased could be planted until March 30.
But in its news release, Monsanto said the deadline was too soon. It quoted Dale Scheps, a dairy farmer in Almena, Wis., saying he had already purchased enough seed for 35 acres but did not plant alfalfa until mid-May.
About 200,000 acres of the Roundup Ready crop were planted last year, but Forage Genetics had expected the acreage to increase to 550,000 this year, according to Monsanto. About 22 million acres of alfalfa are grown in the United States, most of which is used for feeding livestock. Compared with its genetically modified soybean and corn, alfalfa is not yet a big product for Monsanto.
The Center for Food Safety, an advocacy group that organized the lawsuit, hailed the latest ruling. The Agriculture Department did not have immediate comment.
In his earlier decision, Judge Breyer had said the government had failed to assess adequately whether the Roundup Ready trait could be transferred to organic or conventional alfalfa, hurting sales of organic farmers or alfalfa exports to countries like Japan that did not want the genetically engineered variety.
By C. CLAIBORNE RAY, The New York Times, March 13, 2007
Q. Would it really have been possible for Europeans to infect Native Americans with the smallpox virus by giving them blankets used by other victims? How long could the virus live on a blanket?
A. It would be at least theoretically possible, experts at the Centers for Disease Control and Prevention said, though some historians doubt that the plan to infect enemy tribes, which the British general Lord Jeffery Amherst notoriously wrote about in 1763, during the French and Indian War, was actually carried out.
Dr. Inger Damon, a researcher and epidemiologist at the centers, said the virus, called variola, lives longer in smallpox scabs than in the droplets spread from person to person, the normal mode of transmission.
“In a humidity-controlled environment, like a cool, dry cabinet,” Dr. Damon said, “viruses in scabs have been shown in certain studies to be quite long-lived, from some months to a year, possibly longer.”
Though person-to-person transmission usually requires close, prolonged contact (a distance of about six or seven feet for about three hours), there are reported instances of fabric-borne infections among people who worked in smallpox hospitals, doing laundry or changing bed linens. Even a mortuary worker was infected this way, Dr. Damon said.
“The disease is now eradicated, though the virus lives in a freezer,” she said, where it is potentially useful for studying the effectiveness of new drugs or vaccines.
Epic of Human Migration Is Carved in Parasites’ DNA
By NICHOLAS WADE, The New York Times, March 13, 2007
A human body is not the individual organism its proud owner may suppose but rather a walking zoo of microbes and parasites, each exploiting a special ecological niche in its comfortable, temperature-controlled conveyance. Some of these fellow travelers live so intimately with their hosts, biologists are finding, that they accompany them not just in space but also in time, passing from generation to generation for thousands of years.
The latest organism to be identified as a longtime member of the human biota club is Streptococcus mutans, the bacterium that causes tooth decay. From samples collected around the world, Dr. Page W. Caufield and colleagues at New York University have found that the bacterium can be assigned by its DNA to several distinct lineages. One is found in Africans, one in Asians and a third in Caucasians (the people of Europe, the Near East and India), his team reported in last month’s Journal of Bacteriology.
The geographical distribution of these lineages reflects the pattern of human migration out of the ancestral homeland in Africa. If the tooth decay bacterium spreads easily from person to person, any geographical pattern would soon be blurred. But Streptococcus mutans is transmitted almost entirely from mother to child, preserving its lineages over thousands of years. The bacteria apparently infect the infant during birth, beginning the work that provides the dentistry profession its livelihood. “We’ve never seen father-to-child transmission,” Dr. Caulfield said. Thanks, Mom.
Another faithful member of the human road show is Helicobacter pylori, a bacterium that inhabits half the stomachs in the world. It is a usually well-behaved guest, but gives its hosts ulcers when it acts up. Its pattern of geographic distribution matches that of its host’s migrations, Dr. Mark Achtman of the Max Planck Institute in Berlin and colleagues reported in the journal Nature last month.
There are five ancestral populations of H. pylori — two in Africa, two in Europe and one in East Asia. But all had a common origin, Dr. Achtman said, in a bacterium that started to spread out from East Africa 58,000 years ago, give or take 3,000 years. This is the same time period in which modern humans are thought to have begun their migration out of Africa. The match in dates “implies that H. pylori was present in Africa before the migrations, suggesting that Africa is the source of both H. pylori and humans,” Dr. Achtman and colleagues conclude evenhandedly.
H. pylori seems to be transmitted within families but the exact route — perhaps vomit — is unclear. “It’s amazing that any microbe’s geographical distribution would parallel that of humans as well as pylori’s does,” Dr. Achtman said. “You think of microbes as being easily transmissible and they are carried all over the world on ships and planes, yet some have not lost these signals of ancient migrations.”
DNA analysis has also shed light on the origin of the tapeworm, one of the 400 or so nonmicrobial parasites that regard the human body as home. The lifecycle of the tapeworm Taenia asiatica alternates between people and pigs, an animal that the religious authorities of both Judaism and Islam agree is unclean. It would be of interest to know just when these filthy animals infected people with their parasites. But the answer is not quite what had been expected.
Eric P. Hoberg, of the U.S.D.A.’s Agricultural Research Service in Beltsville, Md., concluded in 2001 that people contracted tapeworms millions of years ago in Africa, long before the emergence of agriculture and domestic animals. It was humans who infected pigs with tapeworms, not the other way around, Dr. Hoberg and colleagues reported. Indeed, people infected pigs not only with Taenia asiatica but also with a second species of tapeworm, Taenia solium, which humans seem to have acquired either by eating each other or by eating dogs.
If pigs had a religion, it is pretty easy to guess which species they would designate as unclean.
Top Scientists Warn of Water Shortages and Disease Linked to Global Warming
By THE ASSOCIATED PRESS, The New York Times, March 12, 2007
WASHINGTON, March 11 (AP) — The harmful effects of global warming on daily life are already showing up, and within a couple of decades hundreds of millions of people will not have enough water, top scientists are likely to say next month at a meeting in Belgium.
At the same time, tens of millions of others will be flooded out of their homes each year as the earth reels from rising temperatures and sea levels, according to portions of a draft of an international scientific report by the authoritative Intergovernmental Panel on Climate Change.
Tropical diseases like malaria will spread, the draft says. By 2050, polar bears will mostly be found in zoos, their habitats gone. Pests like fire ants will thrive.
For a time, food will be plentiful because of the longer growing season in northern regions. But by 2080, hundreds of millions of people could face starvation, according to the report, which is still being revised.
The draft document, the second of a series of four being issued this year, focuses on global warming’s effects. Written and reviewed by more than 1,000 scientists from dozens of countries, it still must be edited by government officials.
But some scientists said the overall message is not likely to change when it is issued in early April in Brussels, where European Union leaders agreed Friday to work to cut greenhouse gas emissions substantially by 2020. Their plan will be presented to President Bush and other world leaders at a summit meeting in June.
The draft report offers some hope if nations slow and then reduce their greenhouse gas emissions, but it says what has been happening has not been encouraging.
“Changes in climate are now affecting physical and biological systems on every continent,” the report says, in marked contrast to a 2001 report by the same international group that said the effects of global warming were coming. But that report mentioned only scattered regional effects.
“Things are happening and happening faster than we expected,” said Patricia Romero Lankao of the National Center for Atmospheric Research in Boulder, Colo., one of the many co-authors of the new report.
The draft document says scientists are highly confident that many current problems — change in species’ habits and habitats, more acidified oceans, loss of wetlands, bleaching of coral reefs and increases in allergy-inducing pollen — can be attributed to global warming.
For example, the report says North America “has already experienced substantial ecosystem, social and cultural disruption from recent climate extremes,” like hurricanes and wildfires.
But Ms. Romero Lankao said that global warming soon would “affect everyone’s life,” and added that “it’s the poor sectors that will be most affected.”
Another co-author, Terry Root of Stanford University, said, “We truly are standing at the edge of mass extinction” of species.
The United Nations-organized network of 2,000 scientists was established in 1988 to give regular assessments of the earth’s environment.
The draft report says that hundreds of millions of Africans and tens of millions of Latin Americans who now have water will be short of it in less than 20 years. By 2050, more than a billion people in Asia could face water shortages. By 2080, water shortages could threaten 1.1 billion to 3.2 billion people, depending on the level of greenhouse gases that cars and industry spew into the air.
It says that death rates for the world’s poor from conditions worsened by the changes global warming brings, like malnutrition and diarrhea, will rise by 2030. By 2080, 200 million to 600 million people could be hungry because of global warming’s effects, it says.
It also says that Europe’s small glaciers will disappear, with many of the continent’s large glaciers shrinking sharply by 2050. And half of Europe’s plant species could be vulnerable, endangered or extinct by 2100.
The hardest-hit continents are likely to be Africa and Asia, with major harm also coming to small islands and some aspects of ecosystems near the poles. North America, Europe and Australia are predicted to suffer the fewest of the harmful effects.
“In most parts of the world and most segments of populations, lifestyles are likely to change as a result of climate change,” the draft report said. “Net valuations of benefits vs. costs will vary, but they are more likely to be negative if climate change is substantial and rapid, rather than if it is moderate and gradual.”
Many, though not all, of those effects can be prevented, the report says, if within a generation the world slows down its emissions of carbon dioxide and if the level of greenhouse gases sticking around in the atmosphere stabilizes. If that is the case, the report says, “most major impacts on human welfare would be avoided; but some major impacts on ecosystems are likely to occur.”
Judge Stops Sale of Monsanto’s Genetically Engineered Alfalfa
By ANDREW POLLACK, The New York Times, March 13, 2007
A federal judge revoked the government’s approval of Monsanto’s genetically engineered alfalfa yesterday, ordering a halt to seed sales and banning any planting of the crop after March 30.
The decision, by Judge Charles R. Breyer of Federal District Court in San Francisco, came after a ruling he made a month ago that the Agriculture Department had violated the law by failing to prepare an environmental impact statement before approving the crop in June 2005.
Yesterday’s order, the first time that approval of a genetically engineered crop had been revoked by a court, was a preliminary injunction. The judge said he would consider whether to make the injunction permanent at a hearing in late April.
The lawsuit had been filed by some alfalfa seed companies and environmental and farm advocacy groups against the department.
Monsanto intervened in the case after Judge Breyer’s ruling last month in an effort to keep the crop on the market. It was joined by several alfalfa growers and by Forage Genetics International, an alfalfa breeder that worked with Monsanto and now handles the sale of the seeds to farmers.
The alfalfa is resistant to Monsanto’s Roundup herbicide, allowing farmers to kill weeds without hurting the crop.
Monsanto said it was disappointed. “We are hopeful that a reasoned approach in this matter will address questions about the regulatory approval process for Roundup Ready alfalfa while maintaining farmer access to this beneficial technology,” Jerry Steiner, an executive vice president, said in a statement.
In an effort to soften the impact of his ruling on farmers, Judge Breyer said seed already purchased could be planted until March 30.
But in its news release, Monsanto said the deadline was too soon. It quoted Dale Scheps, a dairy farmer in Almena, Wis., saying he had already purchased enough seed for 35 acres but did not plant alfalfa until mid-May.
About 200,000 acres of the Roundup Ready crop were planted last year, but Forage Genetics had expected the acreage to increase to 550,000 this year, according to Monsanto. About 22 million acres of alfalfa are grown in the United States, most of which is used for feeding livestock. Compared with its genetically modified soybean and corn, alfalfa is not yet a big product for Monsanto.
The Center for Food Safety, an advocacy group that organized the lawsuit, hailed the latest ruling. The Agriculture Department did not have immediate comment.
In his earlier decision, Judge Breyer had said the government had failed to assess adequately whether the Roundup Ready trait could be transferred to organic or conventional alfalfa, hurting sales of organic farmers or alfalfa exports to countries like Japan that did not want the genetically engineered variety.
