Apr 22, 2011
Researchers identify protein that may help combat flu
A new study has shown that a protein administered nasally can protect mice against influenza, according to a press release today from the American Thoracic Society, publisher of the American Journal of Respiratory and Critical Care Medicine, in which the study appears. The study involved two steps. First, researchers from the University of Texas, the US CDC, Pfizer, and other institutions infected two types of mice with influenza virus: normal "wild-type" mice and mice genetically modified to possess a protein calledgranulocyte macrophage-colony stimulating factor, or GM-CSF, in the lungs. GM-CSF enhances alveolar macrophages, which are part of the innate immune response. After infection with either seasonal H1N1, pandemic 2009 H1N1, or H3N2 flu, all the wild-type mice died. The GM-CSF mice, after a brief period of weight loss, survived and regained lost weight. In the second part of the experiment, the team applied GM-CSF in a nasal spray to wild-type mice and then challenged them with flu virus. Those mice likewise all survived. "Such unique and unambiguous results demonstrate the great potential of GM-CSF," said Homayoun Shams, PhD, of the University of Texas, the study's principal investigator. "Unlike a vaccine, GM-CSF does not rely heavily on the body's ability to mount an immune counter-attack against a specific antigen or virus strain, but enhances the speed of local responses to virus infection and delicately balances the host immune responses." But John Oxford, a University of London virologist, said in a BBC News story today, "Transferring [the technology] into humans can be quite difficult. . . . So first we'll see how it pans out in mice, then see how it can possibly apply to humans."
Apr 22 American Thoracic Society news release
Apr 7 Am J Resp Crit Care Med abstract
Apr 22 BBC News story
Bangladesh reports H5N1 outbreaks at 30 more farms
Bangladesh's livestock ministry yesterday reported 31 more H5N1 avian influenza outbreaks, according to an update to the World Organization for Animal Health (OIE). The outbreaks occurred between the middle of March through mid April, and all but one involved a commercial poultry farm. The outbreaks struck birds in five different provinces, with most of them occurring in Rajshahi, Dhaka, and Chittagong. The virus killed 26,543 poultry, and the remaining 153,888 birds at the affected sites were culled to curb the spread of the disease.
Apr 21 OIE report
Study finds dengue risk among travelers
About 1% of Dutch travelers to dengue-endemic regions had antibodies to the disease in their blood after returning home, with about a third of those experiencing dengue-like illness, according to a study in Emerging Infectious Diseases. Researchers studied blood samples from 1,207 adults who traveled to areas known to harbor the mosquito-borne disease, which causes fever, severe headaches, a rash, and eye, joint, and muscle pain. They found antibodies in 14 of the travelers, or 1.2%, which translates to an incidence of 14.6 per 1,000 person-months of travel, and the incidence rose significantly during the rainy season. Five of the 14 reported dengue-like illness, and the presence of antibodies was "significantly related" to dengue symptoms. The authors say the incidence is comparable to that found in two similar studies conducted in the 1990s.
Apr 21 Emerg Infect Dis study
Pakistan secures World Bank loan for polio immunization
The World Bank yesterday approved a $41 million loan to help Pakistan boost its polio immunization efforts. The funds will help the country immunize 32 million children and help the country progress toward its polio eradication goal, according to a World Bank press release. Pakistan is one of only four countries in which the poliovirus remains endemic. Over the past few years the country saw its polio cases drop due to immunization campaigns, but two factors have pushed cases up again: monsoon flooding in 2010 and a deteriorating security situation in two areas. The floods forced large populations into crowded living conditions with inadequate water and sanitation, allowing the disease to spread. The security situation in areas of Khyber Pakhtunkhaw and the Federally Administered Tribal Areas has blocked health workers from reaching children under age 5 who are targeted to receive the polio vaccine. According to the press release, 75% of the confirmed cases are from those two areas.
Apr 21 World Bank press release
Researchers find clues to malaria parasite drug resistance
Researcher s have identified several genes that could be involved in the malaria parasite's ability to resist drug treatment, according to findings in Public Library of Science (PLoS) Genetics. The investigators are from Harvard University and the Massachusetts Institute of Technology (MIT). They analyzed the DNA of 57 malaria parasites from three different continents with a powerful array that explores more than 17,000 mutations. They also measured the parasites' responses to 13 different medications. After they identified 20 rapidly evolving loci in the genome, they looked for variants that were linked to the drug-resistance trait. That search identified 11 genes implicated in drug resistance, including 10 that weren't known before. When researchers introduced a copy of one of the newly identified genes into a drug-sensitive parasite, the organism became more resistant to three antimalarial drugs. Dr Sarah Volkman, a senior researcher at the Harvard School of Public health who coauthored the report, said in a press release that the findings will help scientists develop new drugs and new tools for monitoring drug resistance and may help extend the life of current drugs.
Apr 21 PLoS Genetics study
Apr 21 Harvard School of Public Health press release
Study shows continued evolution of West Nile virus in North America
Studies of North American isolates of the West Nile virus (WNV) between 1999 and 2005 suggested that the virus was genetically fairly static, but genomic sequencing of WNV isolates in the Houston area now shows that the virus is continuing to evolve, according to a report in Emerging Infectious Diseases. In analyzing isolates collected from 2002 to 2009, researchers identified three new genetic groups that have emerged since 2005. What the researchers call the southwestern US genotype has spread from Arizona, Colorado, and Mexico to California, Illinois, New Mexico, New York, North Dakota, and the Texas Gulf Coast, demonstrating continued evolution of the virus, the report says. The researchers write that further studies are needed to look for potential phenotypic changes that may accompany the noted genotype changes and to determine if the southwestern genotype will replace the current dominant North American genotype.
Apr 21 Emerg Infect Dis report