#Aerial mosquito spraying study finds no immediate public health risksin what researchers say is the first public health study of the aerial mosquito spraying method to prevent West Nile virus a UC Davis study analyzed emergency
which will likely magnify the incidence West Nile virus and the risks of human transmission.
Unfortunately West Nile virus is endemic in California and the United states and the controversy of mosquito management will likely arise every summer said Estella Geraghty associate professor of clinical internal medicine at UC Davis
West Nile virus has become an increasingly serious problem throughout the United states and may become more of a threat as the climate warms.
According to the Centers for Disease Control and Prevention West Nile virus is the leading cause of viral encephalitis in the United states. The virus is transmitted to humans and animals through the bite of an infected mosquito.
Mosquitoes become infected with the virus when they feed on infected birds. In California around the time of the study#2004 and 2005#hundreds of people were sickened by West Nile virus
and 48 died. Most people exposed to the disease do not have symptoms but in about 1-in-150 people it can be fatal
and the killing of larval and adult mosquitoes#are used all in California to control the spread of mosquito-borne diseases such as West Nile virus
The article is titled Correlation between aerial insecticide spraying to interrupt West Nile virus transmission and emergency department visits in Sacramento County California.
and U s. scientists have used virus isolated from a person who died from H7n9 avian influenza infection to determine
whether the virus could infect and be transmitted between ferrets. Ferrets are used often as a mammalian model in influenza research
and efficient transmission of influenza virus between ferrets can provide clues as to how well the same process might occur in people.
The researchers dropped H7n9 virus into the noses of six ferrets. A day later three uninfected ferrets were placed inside cages with the infected animals
The team concluded that the virus can infect ferrets and be transmitted between ferrets both by direct contact and less efficiently by air.
The potential public health implication of this observation is that a person infected by H7n9 avian influenza virus who does not show symptoms could
nevertheless spread the virus to others. The researchers also infected pigs with the human-derived H7n9 virus. In natural settings pigs can act as a virtual mixing bowl to combine avian-and mammalian-specific influenza strains potentially allowing avian strains to better adapt to humans.
New strains arising from such mixing have the potential to infect humans and spark a pandemic so information about swine susceptibility to H7n9 could help scientists gauge the pandemic potential of the avian virus. Unlike the ferrets infected pigs in this small study did not transmit virus to uninfected pigs
either through direct contact or by air. All the infected ferrets and pigs showed mild signs of illness such as sneezing nasal discharge
#Bird flu in live poultry markets are the source of viruses causing human infectionson 31 march 2013 the Chinese National Health and Family planning Commission announced human cases of novel
H7n9 influenza virus infections. A group of scientists led by Professor Chen Hualan of the Harbin Veterinary Research Institute at the Chinese Academy of Agricultural Sciences has investigated the origins of this novel H7n9 influenza virus
and published their results in Springer's open access journal Chinese Science Bulletin (Springeropen). Following analysis of H7n9 influenza viruses collected from live poultry markets it was found that these viruses circulating among birds were responsible for human infections.
These results provide a basis for the government to take actions for controlling this public health threat.
The novel H7n9 influenza virus was identified in China as the agent that causes a flu-like disease in humans resulting in some deaths.
Of these samples 20 were positive for the presence of H7n9 influenza viruses. All of the positive samples originated from live poultry markets in Shanghai.
The analysis of these novel H7n9 influenza virus isolates showed that that the six internal genes were derived from avian H9n2 viruses
HA receptor-binding specificity is a major molecular determinant for the host range of influenza viruses.
Within the HA protein of novel H7n9 viruses there was a leucine residue at position 226
which is characteristic of the HA gene in human influenza viruses. This finding implies that H7n9 viruses have acquired partially human receptor-binding specificity.
The authors conclude: We suggest that strong measures such as continued surveillance of avian and human hosts control of animal movement shutdown of live poultry markets
and culling of poultry in affected areas should be taken during this initial stage of virus prevalence to prevent a possible pandemic.
and transmissibility of these H7n9 viruses and to develop effective vaccines and antiviral drugs so as to reduce their adverse effects upon human health.
Influenza viruses circulating in pigs, birds could pose risk to humansin the summer of 1968 a new strain of influenza appeared in Hong kong.
Influenza evolutionin the past 100 years influenza viruses that emerged from pigs or birds have caused several notable flu pandemics.
When one of these avian or swine viruses gains the ability to infect humans it can often evade the immune system which is primed to recognize only strains that commonly infect humans.
In 2009 a strain of H1n1 emerged that was very similar to the virus that caused a 1918 pandemic that killed 50 million to 100 million people.
After comparing HA genetic sequences in five key locations that control the viruses'interactions with infected hosts the researchers calculated an antigenic index for each strain.
and helps determine how well an influenza virus can evade a host's immune response. The researchers also took into account the patterns of attachment of the HA protein to sugar molecules called glycans.
The virus'ability to attach to glycan receptors found on human respiratory-tract cells is key to infecting humans.
Seeking viruses with an antigenic index of at least 49 percent and glycan-attachment patterns identical to those of the 1968 virus the research team identified 581 H3 viruses isolated
One of the amazing things about the influenza virus is its ability to grab genes from different pools he says.
Fauquet and his colleagues in the GCP21--an alliance of scientists developers donors and industry representatives--are gathering at the Rockefeller Foundation Bellagio Center in Italy this week for a conference dedicated to declaring war on cassava viruses in Africa.
and little-known until about ten years ago CBSD has emerged as the most serious threat among the various cassava viruses.
and numerous small-scale processors CMD--a Scourge for Cassava on the African Continentscientists at the conference will also consider options for dealing with another devastating virus--the Cassava Mosaic Disease (CMD).
The disease is caused by several viruses and the African continent witnessed several major CMD epidemics over the past decades the most recent and devastating
which carry the viruses that cause CMD and CBSD and pass it along as they feed on the plant's sap.
Experts to Develop Plan to Stop Viruses in their Tracksat the Italy meeting experts will discuss a variety of tactics for combating virus diseases such as developing more disease-resistant varieties like those recently released in Tanzania.
how to eradicate cassava viruses altogether. The aim will be to develop a bold regional strategy that will gradually step-by-step village-by-village replace farmers'existing infested cassava plants with virus-free planting material of the best and most resistant available cultivars.
Approaches will include new molecular breeding and genetic engineering technologies to speed up the selection and production of CMD and CBSD resistant cassava cultivars more appealing to farmers.
and poverty in Africa but CBSD and other viruses are crippling yields. We need to treat CBSD
and other destructive viruses like the smallpox of cassava--formidable diseases but threats we can eradicate
or viruses that can make us sick. But in California's Salinas Valley some more vigorous interventions are cutting into the last corners of wildlife habitat and potentially threatening water quality without evidence of food safety benefits.
A lack of information about the virus and its mode of transmission has led to public concerns that H7n9 could be a pandemic waiting to happen.
The four clones show certain resistance to the pathogens analysed such as the potato virus Y as well as the Pectobacterium atrosepticum bacteria
The measures in place on these farms would not be sufficient to prevent an H7n9 influenza virus from gaining entry to farms
This means that for areas where this virus is not yet present farm biosecurity measures need to be strengthened as recommended also by FAO
Studies on wild birds conducted as part of APEIR demonstrated the importance of undertaking surveillance in wild birds to characterise the influenza viruses carried by these birds.
The genetic information obtained so far on the H7n9 virus suggests that the H and N components of this virus were derived probably from wild birds and also possibly from poultry.
It is also evident from the genetic studies that the surveillance systems in place have not detected close relatives of the original host of these viruses
and need to be strengthened. The studies conducted by APEIR did find some additional influenza virus subtypes other than H5n1 viruses
and this information helps in understanding the transmission of other influenza viruses by wild birds.
Although no H7n9 viruses were detected the viruses found were fully characterised and gene sequences uploaded to gene databases adding to the pool of data available for comparison by scientists trying to unravel the origin of novel viruses.
APEIR recommended that all gene sequences of influenza viruses should be shared as soon as they are available
and this has been done by Chinese scientists for H7n9 viruses. APEIR researchers including Professor Lei Fumin of the Institute of Zoology of the Chinese Academy of Sciences are currently investigating the possible role of wild birds in transmission of H7n9 avian influenza.
Professor Lei Fumin said We have seen already suggestions that this virus could be transmitted widely among migratory birds
and poultry and it is important to assess the likelihood of this through scientific studies on wild birds as they fly north through China to their summer breeding grounds.
Policy makers in China may again be faced with a decision on whether or not to use vaccination to contain this disease so as to reduce the likelihood of exposure of humans to the H7n9 virus. APEIR studies on policy development showed the importance of having sound evidence on the merits
and pitfalls of vaccination so that these can be weighed up scientifically without outside interference. Although there is no evidence so far that this virus will result in a human pandemic this outbreak provides a reminder of the importance for all countries to ensure they have an appropriate stockpile of antiviral medication.
This study on avian influenza policies also found that agriculture sectoral policy should be coherent with public health sectoral policy
#Chink in the armor of Schmallenberg virus identifieda key building block in the Schmallenberg virus could be targeted by antiviral drugs according to a new study led from the University of Leeds. The disease
but a study published in Nucleic acids Research reports that the Schmallenberg virus nucleocapsid protein which protects its genetic material could be its Achilles'heel.
A University of Leeds-led team of virologists and structural biologists used X-ray crystallography and electron microscopy to decipher the three-dimensional shape of the nucleocapsid protein
and also show how it builds the inner workings of the virus itself. Dr John Barr of the University of Leeds'Faculty of Biological sciences and co-leader of the study said:
and protects the RNA the genetic material of the virus. This chain also recruits other proteins that are vital to the virus'ability to multiply
This not only tells us how the virus works but importantly we think we can block that interaction
and would essentially kill the virus. We are now designing small molecules that could block ring formation
The Schmallenberg virus appears to be spread by midges. It causes a relatively mild illness in adult animals
There is new evidence that the Schmallenberg virus can also spread to wild animal populations such as deer
Developing a vaccine for the Schmallenberg virus is a possibility. One already exists for the similar Akabane virus
but the discovery by the Leeds-led team is the first step toward developing a treatment that could be used after an animal is infected.
At the same time the pathogens in wastewater such as viruses fungi and bacteria could destroy the algae themselves
For example when gypsy moth caterpillars consume foliage high in certain toxic compounds transmission of viruses between the caterpillars is reduced facilitating moth outbreaks.
When infected with the bacteria Wolbachia mosquitoes are unable to spread viruses such as dengue a disease
which is a strong blocker of dengue and other viruses. Insecticide use is very common in dengue
but then these insects would be unable to pass on a virus to humans. Prof Hoffmann added that insecticide resistance genes would not spread to the uninfected mosquito populations
For the first time researchers at the University of North carolina have discovered that Hepatitis a virus a common cause of enterically-transmitted hepatitis takes on characteristics of both virus types depending on
The whole universe of virology is divided into two types of viruses--viruses that are enveloped and viruses that are enveloped not.
If you look at any basic virology textbook it will say that these are categories that distinguish all viruses said lead researcher Stanley M. Lemon MD professor of medicine and a member of UNC Lineberger and the Center for Translational Immunology.
In a paper published online in Nature on March 31 Dr. Lemon's team discovered that Hepatitis a virus does not have an envelope
What we have discovered is that a virus that has been considered classically to be enveloped'non'that is Hepatitis a virus actually hijacks membranes from the cells it grows in to wrap itself in an envelope.
No one has shown that previously for a virus. It really blurs that classic distinction between these two types of viruses said Dr. Lemon.
being enveloped in host membranes helps the virus to evade host immune systems and spread within the liver.
Enveloped viruses are generally quite fragile in the environment while non-enveloped viruses are hardier outside of a host
and can survive for longer periods between hosts. Dr. Lemon believes the dual nature of Hepatitis a virus allows it to use the advantages of both virus types to enhance its survivability.
What Hepatitis a virus has done and we don't totally understand how it has accomplished this is to have the advantage of existing as a virus with no envelope
and being very stable in the environment so it can be transmitted efficiently between people but to wrap itself in a membrane to evade neutralizing antibodies
While no other virus has been shown to exhibit this particular behavior Dr. Lemon said that it is likely that Hepatitis a virus is not unique in its dual nature.
The virus is transmitted orally and then passed back into the environment through feces. By not needing its envelope to survive outside the host the virus gains the ability of non-enveloped viruses to survive longer
and be transmitted efficiently. One major question raised by the finding is why the Hepatitis a vaccine works so well to contain the infection.
The vaccine one of the most effective in use was thought to elicit neutralizing antibodies that attack the virus in the blood.
Since it is known now that the envelope surrounding the virus in the blood prevents this the vaccine cannot work as previously thought.
While it was thought previously that vaccine-induced antibodies attacked the virus outside of the cell the new findings suggest antibodies may actually be able to restrict viral replication within a cell.
Understanding how this really good vaccine works will help us in the future to develop better vaccines for other viruses that we are having difficulty developing vaccines for said Dr. Lemon.
and counter the killer viruses they transmit. The dual resistant insect and virus varieties may reduce
or even eliminate the need for pesticides in several regions. Thrips are tiny insects that pierce
They also transmit such diseases as the tomato spotted wilt virus causing millions of dollars in damage to U s. agricultural crops each year.
one or both of two natural genes known to resist the so-called TOSPO viruses which include tomato spotted wilt virus
. If some thrips get through with the virus the virus resistance genes are there to mop it up Mutschler-Chu said.
The Cornell thrips-resistant tomato lines with and without the virus resistance genes will be used by Mutschler-Chu
and an interdisciplinary team of eight other scientists from seven other institutions nationwide as part of a new five-year $3. 75 million project to control thrips and TOSPO viruses in tomatoes.
The project is funded by the U s. Department of agriculture's Agriculture and Food Research Initiative and is led by entomologist Diane Ullman of the University of California Davis
or tweaking virus resistance Mutschler-Chu wants to discover the best package for insect and virus control.
and birds we've come up with a technique to predict sites where these viruses could mix
That could help detect a novel flu virus before it spreads worldwide the researchers said.
The research paper Predicting Hotspots for Influenza Virus Reassortment was published March 13 in the peer-reviewed public health journal Emerging Infectious diseases.
when viruses from humans and animals exchanged genes to create a new virus in a process called reassortment.
and human flu could serve as a mixing vessel for reassortment between the two viruses.
The mixing of genetic material between the seasonal human flu virus and bird flu can create novel virus strains that are more lethal than either of the original viruses said senior author Thomas Smith director of the Center for Tropical
and animals should be monitored for novel viruses which could help predict and prevent the next pandemic he said.
For each type of flu we identified variables that were predictive of the various virus strains Fuller said.
and sample foreign matter such as vaccines bacteria or viruses they come together as a group during what he and his team call the critical differentiation period.
#Pesticide application as potential source of noroviruses in fresh food supply chainscontaminated water used to dilute pesticides could be responsible for viruses entering the food chain warn scientists.
The virus is highly contagious causing vomiting and diarrhea and the number of affected cases is growing.
sufferers have to let the virus run its course for a few days. The consumption of fresh produce is associated frequently with outbreaks of hnov
but it remains difficult to identify where in the supply chain the virus first enters production.
whether traces of the virus were present in the samples after the two elements were combined.
but when the selfish genes come in the form of viruses or other kinds of transposons there can be trouble.
Historically we've seen symptoms similar to IBDS associated with viruses spread by large-scale infestations of parasitic mites says Dr. David Tarpy an associate professor of entomology at North carolina State university
But they did note that diet affected the transport of bacteriophages--viruses that invade bacteria--in field runoff.
#Microbes team up to boost plants stress tolerancewhile most farmers consider viruses and fungi potential threats to their crops these microbes can help wild plants adapt to extreme conditions according to a Penn State virologist.
Discovering how microbes collaborate to improve the hardiness of plants is a key to sustainable agriculture that can help meet increasing food demands
and her colleagues found an example of a collaboration between plants and viruses that confer drought tolerance to many different crop plants.
The researchers tested four different viruses and several different plants including crops such as rice tomato squash
and beets and showed that the viruses increased the plants'ability to tolerate drought. Virus infection also provided cold tolerance in some cases.
A leafy plant related to a common weed known as lamb's quarter was infected also with a virus that caused a local infection.
The infection was enough to boost the plant's drought tolerance and may mean that the virus does not have to actively replicate in the cells where the resistance to drought occurs according to Roossinck.
In studies on plants that thrive in the volcanic soils of Costa rica and in the hot geothermal ground in Yellowstone national park viruses and fungi work together with plants to confer temperature hardiness said Roossinck.
Researchers found that fungi and a type of grass--tropical panic grass--found in Yellowstone national park grow together in temperatures above 125 degrees Fahrenheit.
Because viruses are often present in plant fungi Roossinck wondered if viruses played a role in the reaction.
I noticed that all of the samples from the geothermal soils had a virus so it seemed worth it to take a deeper look said Roossinck.
The researchers found that there was no heat tolerance without the virus. Once the researchers cured the fungus of the virus the plant was unable to withstand the heat.
When the virus was reintroduced the plant regained heat tolerance. A virus is required absolutely for thermal tolerance said Roossinck.
If you cure the fungus of the virus you no longer have the thermal tolerance. While researchers do not entirely understand the role of viruses in helping plants withstand extreme conditions Roossinck said that future research may help the agricultural industry naturally develop hardier plants rather than rely on chemical solutions that threaten the environment.
The question is can we restore the natural level of microbes in plants and grow them better and more tolerant of environmental stress like heat and drought or pathogens?
Roossinck said. This may lead to more natural methods of creating crops that are more heat drought and stress tolerant.
Story Source: The above story is provided based on materials by Penn State. Note: Materials may be edited for content and length h
#Avoiding virus dangers in domesticating wild plants for biofuel usein our ongoing quest for alternative energy sources researchers are looking more to plants that grow in the wild for use in biofuels plants such as switchgrass.
If pest control measures aren't taken these annual plants can serve as amplifiers producing lots of viruses
and insects to move the viruses around. In contrast perennial plants in nature grow slower
but are equipped usually better to fight off invading viruses. When wild-growing perennials do get infected they can serve as reservoirs for viruses Malmstrom said a place where viruses can hang out a long time.
In the domestication of wild plants for bioenergy long-lived plants are being selected for fast growth like annuals.
and can serve as an amplifier for viruses. This all-in-one combination could increase virus pressure in crop areas unless mitigated.
Malmstrom said that plant virus ecology and the study of viral interactions between wild-growing plants and agricultural crops is an expanding field.
To understand the complete ecology of viruses researchers are now studying these tiny organisms in nature too.
whether viruses can be used in agricultural terrorism how to recognize a novel virus and what happens
if a virus is modified genetically and then let loose? Story Source: The above story is provided based on materials by Michigan State university.
#Wild plants are infected with many viruses and still thriveresearchers have studied viruses as agents of disease in humans domestic animals
and plants but a study of plant viruses in the wild may point to a more cooperative benevolent role of the microbe according to a Penn State virologist.
Most of these wild plants have said viruses Marilyn Roossinck professor of plant pathology and environmental microbiology and biology who has examined more than 7000 individual plants for viruses.
But they don't have any of the symptoms that we usually see in crop plants with viruses.
Most of the viruses Roossinck studied are new viruses although they are related to viruses that have been examined in crops.
According to the researcher about half of the viruses that infect wild plants tend to be continually present in the plant--persistent.
The viruses get passed from plants to their offspring through the seeds. Researchers are still trying to uncover exactly
what viruses are doing in the plants. Since the viruses are found so often they may be playing some role in the life of the plant according to Roossinck.
In fact studies indicate that viruses can be beneficial to some plants making them hardier and helping them survive extreme temperatures
and drought said Roossinck who reported on her research today (Feb 17) at the annual meeting of the American Association for the Advancement of Science.
When most people think of viruses they think of serious diseases and death such as the AIDS virus Roossinck said.
However on a research trip in Costa rica a biodiversity hot spot in Central america she noticed that unmanaged wild plants looked healthier than managed agricultural fields.
During her research Roossinck observed that most of the approximately 10000 species of wild plants at the study site appeared healthy.
The wild plants she studied included Fabaceae an abundant family of plants related to beans. However commercial crops--melons oranges pineapple and aloe--that were growing near the site were not as healthy.
When I went to the forest the wild plants looked healthy and gorgeous Roossinck said.
viruses fungi and bacteria whereas in crops farmers try to eliminate the microbes. Perhaps there is a connection.
Analyzing the viruses suggested that they were moving from the crops into the wild plants
Overtext Web Module V3.0 Alpha
Copyright Semantic-Knowledge, 1994-2011