ABOUT CAUSING AGENT

What is it?
It is a new strain of Influenza virus A/H1N1. There have been reports of influenza-like illness (ILI) and severe pneumonia cases in Mexico, USA and Canada. Cases began to appear on 17 March 2009 in Mexico. Two cases in children were reported in Southern California in USA on 17 April, 2009. Neither child had contact with animals. Between 17 March and now, clusters of outbreaks have appeared in multiple locations in Mexico and USA. These clusters are consistent with human-to-human spread.

What are the characteristics of the novel human virus?
The virus is being described in the USA as a new subtype of A/H1N1 not previously detected in swine or humans. The 2009 H1N1 strain contains such an unusual mix of gene segments. The genetic sequencing of samples in CDC Atlanta shows that new flu virus contains segments from four different viruses: some North American swine, some North American avian, one human influenza, and two Eurasian swine.

How swine flu viruses infect humans?
Swine flu viruses do not normally infect humans. However, sporadic human infections have occurred. Most commonly, these cases occur in persons with direct exposure to pigs, such as children near pigs at a fair or workers in the swine industry. In addition, there have been documented cases of one person spreading swine flu to others. Novel A/H1N1 is the virus that mutated from pigs and then at some point was transmitted to humans.

How many swine flu viruses are there?
There are four main influenza type A swine flu viruses that have been isolated in pigs: H1N1, H1N2, H3N2, and H3N1. The classical swine flu virus (an influenza type A H1N1 virus) was first isolated from a pig in 1930. Most of the flu viruses recently found in pigs have been H1N1 and H3N2 strains. Current swine flu H3N2 viruses are closely related to human H3N2 viruses, because they were introduced into pigs from humans in the late 1990s. But H1N1 swine viruses have been known to circulate in pigs at least since the 1930s.


SWINE INFLUENZA IN HUMANS

How common is swine flu infection in humans?
Although swine influenza viruses are normally species specific and only infect pigs, they do sometimes cross the species barrier to cause disease in humans. Since the implementation of IHR(2005) in 2007, WHO has been notified of swine influenza cases from the United States and Spain. These are some documented cases in USA. The most well known outbreak of swine flu was 1976 one among soldiers in Fort Dix, N.J. The virus caused illnesses in at least four soldiers and one death. In September 1988, a healthy 32-year-old pregnant woman was hospitalized for pneumonia and died eight days later. A swine H1N1 flu virus was detected. Four days before getting sick, she had visited a county fair swine exhibition where there was widespread flu-like illness among the pigs. Twelve cases of human infection with swine flu have been reported in USA from December 2005 to February 2009. Five of the 12 cases occurred in patients who had direct exposure to pigs, six in patients reported being near pigs, and the exposure in one case was unknown.

Who are affected?
Seasonal influenza affects people of younger or older age group whereas novel A/H1N1 affects all age groups. Most of the cases in Mexico have been found in healthy young adults between the age of 4 and 45 years old.

How does it spread?
This is thought to occur in the same way as seasonal flu occurs in people, which is mainly person-to-person transmission through coughing or sneezing of people infected with the flu virus. People may become infected by touching something with flu viruses on it and then touching their mouth or nose.

Can people catch swine influenza from eating pork?
No. Swine influenza viruses are not transmitted by food. Eating properly handled and cooked pork (pig meat) or other heat treated products derived from pigs are safe. The swine influenza virus is killed by cooking temperatures of 70°C.

What are the clinical symptoms of swine flu in humans?
Patients experience high fever, cough, and sore throat, symptoms similar to typical influenza, with some patients experiencing diarrhoea and vomiting. The cases can rapidly progress to severe and unusual pneumonia.


SWINE INFLUENZA AND PIG

Why pigs are implicated as a source of human infection?
It is interesting that pigs can be infected by avian, human and swine influenza viruses. When influenza viruses from different species infect pigs, the viruses can reassort and new ones emerge that are a mix of swine, human and/or avian influenza viruses. Therefore, pigs act as ‘mixing vessel’ of different animal influenza viruses and human influenza viruses which may lead to emergence of potential new human influenza virus.

How frequent swine flu outbreaks are reported?
Swine influenza viruses cause regular outbreaks of influenza in pigs. The viruses may circulate among pigs throughout the year, but most outbreaks occur during the late fall and winter months similar to outbreaks in humans. Large numbers of pigs may be affected during swine influenza outbreak but few sick pigs die. Therefore it is not notifiable disease whereas Swine fever, Swine Vesicular Disease and Foot-and-Mouth Disease are notifiable due to its impact on trade restriction.
Swine influenza is not notifiable to international animal health authorities (OIE, www.oie.int), therefore its international distribution in animals is not well known. The disease is considered endemic in North America, South America, Europe, Africa and Asia.


ROLE OF DRUGS AND VACCINES

What medicines can be used for treatment of an infection by this new virus?
This virus is susceptible to oseltamivir and zanamivir. The virus strain has been shown to be resistant to rimantadine and amantadine. The medicine should be used strictly under medical supervision because the virus may develop resistance quickly if it is used haphazardly.

Is there a human vaccine to protect from swine influenza?
There are no vaccines that contain the current swine influenza virus causing illness in humans. It is not known whether current human seasonal influenza vaccines can provide any protection. Influenza viruses change very quickly.


PERSONAL HYGIENE IS IMPORTANT

What should I do to keep from getting the flu?
First and most important: wash your hands. Get plenty of sleep, be physically active, manage your stress, drink plenty of fluids, and eat nutritious food. Try not touch surfaces that may be contaminated with the flu virus. Avoid close contact with people who are sick.

What is the best way to keep from spreading the virus through coughing or sneezing?
If you are sick, limit your contact with other people as much as possible. Do not go to work or school if ill. Cover your mouth and nose with a tissue when coughing or sneezing. It may prevent those around you from getting sick. Cover your cough or sneeze if you do not have a tissue. Then, clean your hands, and do so every time you cough or sneeze.

How long can viruses live outside the body?
We know that some viruses can live two hours or longer on surfaces like cafeteria tables, doorknobs, and desks. Frequent handwashing will help you reduce the chance of getting contamination from these common surfaces.

What can I do to protect myself from getting sick?
There is no vaccine available right now to protect against swine flu. There are everyday actions that can help prevent the spread of germs that cause respiratory illnesses like influenza. Take these everyday steps to protect your health:
• Cover your nose and mouth with a tissue when you cough or sneeze. Throw the tissue in the trash after you use it.
• Wash your hands often with soap and water, especially after you cough or sneeze.
• Avoid touching your eyes, nose or mouth.
• Try to avoid close contact with sick people.
• Stay home from work or school and limit contact with others to keep from infecting them.


PUBLIC HEALTH ACTION NEEDED

What control measures should be implemented?
Right now, people must be vigilant. Countries should ensure proper surveillance of severe or unusual pneumonia cases or of a sudden increase in ILI cases. In Mexico, the government closed the schools, universities and day cares and asked government employees to work from home. They also closed many public services in order to minimize the spread of disease. People are being reminded of the importance of frequent handwashing. People should follow cough etiquette and crowding should be avoided.

What measures have been taken by public health authorities in Asian countries?
Many Asian countries have conducted high level consultation to assess the situation and prepare for prevention and control of novel A/H1N1. WHO is urging Member countries to enhance surveillance of ILI, severe pneumonia. Health authorities have increased surveillance at all entry points for travelers coming from affected countries with flu-like symptoms using thermosensor devices at airports.

Source: http://www.searo.who.int/EN/

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By Maggie Fox, Health and Science Editor

WASHINGTON (Reuters) - U.S. health officials predicted worsening outbreaks of the new H1N1 flu on Thursday, and a top global health official predicted up to a third of the world's population could eventually become infected even as Mexican officials said the worst was over.

A batch of detailed studies on the new swine flu virus showed it was a strange marriage between a triple-hybrid virus with pig, human and bird elements and a European swine virus not seen before in North America.

But some pork bans appeared to be easing and U.S. agriculture officials promised unspecified help to farmers.

Mexico's confirmed death toll ticked up to 44 as labs tested a backlog of samples from people who died in March and April. The U.S. Centers for Disease Control and Prevention reported 896 confirmed cases of the new H1N1 flu in 41 states.

U.S. officials have said they expect the swine influenza virus to spread to all 50 states and to cause many infections ranging from mild to severe. There have been two deaths in the United States.

"So far we are not seeing any signs of this petering out," acting CDC Director Dr Richard Besser said. "We are on the upswing."

And even though Mexican officials said they were over the worst, Besser said there was still significant transmission there, too.

More than 2,000 people in 24 countries have been infected with the virus, the World Health Organization said.

The WHO's Dr. Keiji Fukuda urged Asian governments to stay alert for a possible wider pandemic that "could infect a third or more of the world's population in the next several months, in the next year.

"Even if the illnesses appear relatively mild on an individual level, with large numbers of infections on the global population, you can get large numbers of seriously ill people," Fukuda told a conference in Bangkok.

Fukuda said H1N1 flu is not yet spreading in a sustained way outside North America, so the global pandemic level remains at 5 out of 6.

Fukuda said governments should be ready for H1N1 to turn into something far more serious. "This is a time in which we can work with countries to be as prepared as possible," he said.

In a series of reports rushed into the New England Journal of Medicine on Thursday, researchers said influenza viruses from animals are an ongoing threat and doctors need to keep a lookout for them.

"As recent events suggest, the generation of novel influenza viruses through the reassortment of swine influenza viruses with other human and animal influenza viruses may be inevitable," the CDC's Dr Lyn Finelli and colleagues wrote in one report.

So far the genetic analysis gives no clue about where the new virus came from, the researchers told a news conference. The European genes were especially mystifying. "Those genes had never been seen in the United States before," the CDC's Dr Michael Shaw said.

"We have no idea whether they came to this hemisphere by human or animal."

BACK TO SCHOOL

In Mexico, millions of high school and university students returned to classes as the country got back on its feet after shutting public places last week to avoid spread of the disease.

After a five-day business shutdown, the government has let bars, cinemas, restaurants and workplaces reopen. Theme park operator Six Flags said it planned to reopen its Mexico City park on Friday after being given permission by Mexico's government to do so.

But visitors to government-run buildings were asked to wear surgical masks and wash their hands with antibacterial soap before entering. Restaurants also sanitized diners' hands as they arrived.

"It's obviously a worry for us that after we allow many activities people can forget the (health) recommendations," Health Minister Jose Angel Cordova said.

This might not be easy for many, like hair salon operator Miriam Guerrero in drought-stricken Ciudad Nezahualcoyotl, a Mexico City-area slum.

"When the water's running short it's not easy to keep washing your hands like they say, and there's not enough to disinfect all the furniture," Guerrero said.

The U.S. pork industry got some good news after being battered by import bans by nearly two-dozen countries.

"Clearly pork producers have suffered and will continue to do so until we get this turned around," Agriculture Secretary Tom Vilsack told a Senate Appropriations subcommittee. "We are looking at ways we can be of assistance or help.

And Russia signaled it may lift bans placed on pork by June 1, a spokeswoman for the U.S. Trade Representative said. Russia, the fourth-largest export market for U.S. pork, has banned all meat from five U.S. states and banned raw pork from a few others. It has also banned pork from certain Canadian provinces, the United Kingdom and Spain.

Source: www.reuters.com/article/worldNews

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By Maggie Fox, Health and Science Editor

WASHINGTON (Reuters) - Outbreaks of the new H1N1 swine flu continue to spread across the United States, with 896 confirmed cases and more to come, the U.S. Centers for Disease Control and Prevention reported on Thursday.

U.S. officials have said they expect the swine influenza virus to spread to all 50 states and to cause many infections ranging from mild to severe.

Acting CDC Director Dr Richard Besser said the actual numbers matter less than the pattern of disease. "So far we are not seeing any signs of this petering out," Besser told reporters. "We are on the upswing."

And even though Mexican officials said they were over the worst, Besser said there was still significant transmission there, too.

"We are reporting 1,823 probable and confirmed cases in 44 states," Besser said. He has said that 99 percent of probable cases later turn out to be the new flu, so this is a good indication of how many true cases there are.

On Wednesday, the CDC had confirmed 642 U.S. cases of H1N1.

"Only about 10 percent of confirmed cases have a travel history for Mexico," he said. This suggests the virus is still passing very easily from one person to another.

The new virus looks very much like seasonal flu and it takes two rounds of tests to confirm a patient has the new H1N1 swine variety. Besser said the CDC was sending test kits out as quickly as possible and had filled requests for 78 countries, out of 131 who want them.

So far the influenza strain remains mild, with 5 percent of cases sick enough to be hospitalized and two U.S. deaths. Besser cautioned that the sickest patients are likely to be tested first, which could make an outbreak look more severe than it really is.

CDC scientists are trying to answer many questions about the new strain, including how long a person sheds the virus, meaning how long a patient is infectious after recovering.

Other questions:

-- Does treatment with the antiviral drugs Tamiflu, made by Roche AG, and Relenza, made by GlaxoSmithKline, affect whether a person can spread the virus?

-- Are healthcare workers at risk of infection?

-- How many people have been infected and do not know it?

-- How many cases of regular, seasonal H1N1 flu are still occurring?

Besser said people have several months to prepare for the possibility the virus could come back in the cooler months in a more dangerous form. "This time between now and the fall is of critical importance to prepare," Besser said.

This will include planning for extended school closures and possible disruptions to supply, he said.

Source: www.reuters.com/article/domesticNews

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MEXICO CITY (Reuters) - Mexico began shutting down parts of its economy on Thursday to slow the spread of a new flu strain as officials urged increased worldwide precautions against an imminent pandemic.

The World Health Organization said it would remain for now at its current alert level -- one step below full pandemic -- and that it would no longer refer to the H1N1 virus as "swine flu" to appease beleaguered meat producers.

New confirmed flu cases were reported in the United States, Canada and Europe, although a case in Peru, which would have been the first confirmed case in Latin America outside of Mexico, was later discounted.

Almost all cases outside of Mexico have been mild, only a handful of patients have required hospital treatment, and most global markets have shrugged off concerns.

But the case count continues to rise, and officials say there are many unanswered questions about the outbreak.

U.S. officials said new infections were occurring and at least 298 U.S. schools closed around the country because of possible infections. Canada recorded its first case of person-to person transmission of the virus.

In Mexico, the worst hit country with up to 176 deaths, President Felipe Calderon told government offices and private businesses not crucial to the economy to stop work beginning on Friday to avoid further spreading a virus that is striking across age and class lines.

"There is no safer place than your own home to avoid being infected with the flu virus," Calderon said in his first televised address since the outbreak started.

In Mexico City, where the virus has already brought public life to a standstill, some were skeptical while others vowed not to take part in the shutdown.

"Closing businesses is not right and not fair. What are we going to live on? Air?" said Andres Garcia, who works in a tailor shop in the old colonial center of the capital.

CURE WORSE THAN DISEASE?

Mexico's assembly for export factories known as maquiladoras, a pillar of the economy, said it would defy the shutdown call while some of the country's mines also vowed to stay in operation.

"We have commitments that we have to meet, and if we don't meet them, the cure will end up being worse than the disease," council head Cesar Castro told reporters.

With its tourism industry savaged, shoppers staying home and exports to the United States in steep decline, Mexico could find itself in the longest, deepest recession it has seen in years, according to analysts.

Mexico's peso was hammered by flu fears on Thursday and its stock market slid. But most global markets were taking the flu news in stride as traders focused on hopes that a deep U.S. recession may be nearing its end.

"The information that we have at this stage is it is a relatively minor (economic) event," International Monetary Fund chief economist Olivier Blanchard said, although he added that some countries and sectors could see "quite dramatic" fallout from the outbreak.

Previous studies at the World Bank have said a severe flu pandemic which triggers a clampdown on trade could cost the global economy trillions of dollars.

The WHO and flu experts say they do not yet know enough about this new strain to say how deadly it actually is, how far it might spread and how long any potential pandemic may last.

Flu epidemics generally last a few weeks or months in any single community, and can pass around the world in one or two waves over 18 months to two years before fading out.

U.S. officials have reported 109 confirmed swine flu infections in at least 11 states and the only death recorded outside of Mexico -- a Mexican toddler visiting Texas.

The White House said on Thursday that a member of the advance team that went with Obama to Mexico had also come down with flu-like symptoms and passed them to his family, although all of them had recovered.

OPEN QUESTIONS

U.S. Health and Human Services Secretary Kathleen Sebelius told a public webcast there were still many unanswered questions. "We know what happens year in, year out with seasonal flu. What we don't know is if this is going to be more virulent or milder," she said.

Normal seasonal flu kills between 250,000 and 500,000 people around the globe in an average year, including about 36,000 in the United States.

Worldwide, 11 countries have reported confirmed cases of the H1N1 strain, with the Netherlands the latest to join the list. It said a 3-year-old who had recently returned from Mexico had contracted the virus.

Switzerland also confirmed its first case on Thursday in a man returning from Mexico. Peru's health minister Oscar Ugarte told Reuters that further tests on a suspected case there had determined it was not the new flu strain.

Flu preparations were intensified after the WHO raised its alert level to phase 5, the last step before a pandemic.

The WHO recommended all countries track any suspect cases and ensure medical workers dealing with them wear protective masks and gloves. But it stopped short of recommending travel restrictions, border closures or any limitation on the movement of people, goods or services.

Keiji Fukuda, acting WHO assistant director-general, told reporters there was no new evidence to prompt the agency to move to its top alert level which would signal a global pandemic was under way.

Fukuda said Swiss drugmaker Roche was stepping up production of Tamiflu to deal with the infection at that the WHO had released some of its own stockpiles of the drug -- known generically as oseltamivir and proven effective against the new strain -- to developing countries deemed most at need, including Mexico.

The World Bank also announced it was beginning to transfer flu emergency funds to Mexico and Argentina.

Source: www.reuters.com/article/newsOne

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