Mexico City health officials took the drastic step today of closing schools, from kindergartens to universities, in an effort to control an outbreak of swine flu that has killed at least 16 people in the last few weeks. It was clear that Mexican health officials were alarmed. Besides shutting classes, the government urged people to avoid large gatherings and to refrain from the common greetings of a hand shake or kiss on the cheek. City buses continued to operate but some passengers were seen wearing masks, and a cough or a sneeze by one passenger prompted others to relocate [The New York Times].
Experts say that the swine flu virus, which usually infects just a few humans who are in direct contact with pigs, has mutated into a more dangerous form that can be passed between people, and fear that it could cause a pandemic.
Meanwhile, officials are scrambling to understand how the deadly Mexican virus is related to an apparently weaker strain circulating in the American Southwest, which is not known to have caused any deaths. The first two cases in the United States were reported on Tuesday in Southern California. There are now five cases in California, including the father of one of the original patients. The other two cases are near San Antonio, Texas…. “We believe at this point that human-to-human spreading is occurring” [ABC News], says Anne Schuchat of the Centers for Disease Control and Prevention. However, she stressed that the U.S. virus does not currently appear to be a cause for serious concern.
(more…)
People fighting off winter colds and bouts of the flu typically reach for a glass vitamin C-packed orange juice, but new research suggests that vitamin D may be a better protector. People with low levels of the vitamin, which is often called the sunshine vitamin because sun exposure triggers its production in the body, are more likely to catch colds, the flu, and even pneumonia, a broad new study reports. The effect was magnified in people with asthma or other lung diseases.
Vitamin D deficiency is quite common in the United States — particularly in winter…. “People think that if they have a good, balanced diet that they will get enough vitamin D, and that’s actually not true,” said Dr. Michal Melamed…. “Unless you eat a lot of fish and drink a lot of milk, you can’t get enough vitamin D from diet” [CNN].
(more…)
Researchers have engineered antibodies that could potentially lead to a cure-all for multiple strains of influenza, including the dangerous H5N1 strain of bird flu, according to a study published in Nature Structural and Molecular Biology. Mice that were infected with bird flu and three days later were injected with the treatment exhibited no symptoms of illness. Whereas existing flu vaccines are able to target only one strain of virus at a time and need to be redeveloped every year, the new research suggests that a single treatment may work against many strains.
For the study, the scientists scoured a library of 27 billion human antibodies to influenza, eventually finding an antibody which inactivated bird flu in cell cultures and when injected into mice. The group then decided to see how the antibody fared against an entirely different subtype of flu—the influenza that killed millions across the globe in World War I. “To our amazement, the antibodies inactivated the 1918 pandemic,” [study author Wayne] Marasco said. Subsequent studies showed the virus could disarm multiple strains of flu [The Scientist]. The treatment is made from a laboratory-produced version of human immune system defenses called monoclonal antibodies. It targets a different part of the flu virus than the body’s naturally produced antibodies [Bloomberg].
(more…)
Everyone knows that winter is flu season, but until now scientists didn’t know why influenza cases spiked during the colder months. They came up with plenty of hypotheses–for example, they proposed that people are more exposed when huddled indoors, and that lower melatonin and vitamin-D levels can weaken immune systems [ScienceNOW Daily News]–but none of the previous suggestions proved correct. Now, however, researchers say they have the answer: The influenza virus thrives in the cold, dry air of winter. “The correlations were surprisingly strong. When absolute humidity is low, influenza virus survival is prolonged and transmission rates go up” [AP], said lead researcher Jeffrey Shaman.
Researchers had previously looked for a link between flu rates and relative humidity, but Shaman says that absolute humidity (which measures the amount of water in the air, regardless of temperature) is the real key. Relative humidity varies with air temperature, because more moisture can be present in warm air than in cold…. What that means is warm air at 30 percent relative humidity and cold air at 60 percent relative humidity may actually have the same amount of water in the air. So, while the cold air sounds moist, it might be pretty dry — just what the flu likes [AP].
(more…)
Somewhere in the world within the next five years, terrorists are likely to use a biological agent like anthrax or Ebola in a major attack, a new congressional report predicts. The report acknowledges that terrorist groups still lack the needed scientific and technical ability to make weapons out of pathogens…. But it warns that gap can be easily overcome, if terrorists find scientists willing to share or sell their know-how. “The United States should be less concerned that terrorists will become biologists and far more concerned that biologists will become terrorists,” the report states [AP].
The report, which will be officially released on Wednesday by the Commission on the Prevention of Weapons of Mass Destruction and Terrorism, covers the threat of both biological and nuclear attacks. It argues that bioterrorism is a greater threat: Nuclear facilities are closely guarded, the report says, while many civilian labs contain dangerous pathogens and could more easily be breached. The number of such “high-containment” labs in the United States has tripled since 2001, yet U.S. officials have not implemented adequate safeguards to prevent deadly germs from being stolen or accidentally released, it says. “The rapid growth in the number of such labs in recent years has created new safety and security risks which must be managed,” the draft report states [Washington Post].
(more…)
People who lived through the 1918 flu pandemic still have antibodies in their immune systems that can recognize and fight that flu virus, although the haven’t been exposed to it for 90 years. Such long-lived immunity was thought to be impossible without periodic exposure to the microbe that stimulated the immune system in the first place [Science News]. Researchers say these antibodies could be helpful in developing treatments for viruses similar to the deadly one that swept around the world in 1918, killing an estimated 50 million people.
For the study, which will be published in this week’s issue of Nature [subscription required], lead researcher James Crowe’s team studied antibodies in the blood of 32 people in their 90s and 100s, born during or before 1915. They found that all 32 people had antibodies to the 1918 strain of flu virus [HealthDay News]. In lab tests, the antibodies mounted a powerfully effective attack against a modern version of the virus. “This is entirely counter to everyone’s intuition — that elderly people would have such potent antibodies,” Crowe says. Aging typically reduces a person’s ability to build antibodies and develop immunity to diseases [Science News].
(more…)
