Thursday, April 30, 2009

Swine Flu - Question and answer

What is Swine Influenza?

Swine Influenza (swine flu) is a respiratory disease of pigs caused by type A influenza that regularly cause outbreaks of influenza among pigs. Swine flu viruses cause high levels of illness and low death rates among pigs. Swine influenza viruses may circulate in swine throughout the year, but most outbreaks among swine herds occur during the late fall and winter months similar to humans. The classical swine flu virus (an influenza type A H1N1 virus) was first isolated from a pig in 1930.

How common is swine flu among pigs?

H1N1 and H3N2 swine flu viruses are endemic among pig populations in the United States and something that the industry deals with routinely. Outbreaks among pigs normally occur in colder weather months (late fall and winter) and sometimes with the introduction of new pigs into susceptible herds. Studies have shown that the swine flu H1N1 is common throughout pig populations worldwide, with 25 percent of animals showing antibody evidence of infection. In the U.S. studies have shown that 30 percent of the pig population in the U.S. has antibody evidence of having had H1N1 infection. More specifically, 51 percent of pigs in the northcentral U.S. have been shown to have antibody evidence of infection with swine H1N1. Human infections with swine flu H1N1 viruses are rare. There is currently no way to differentiate antibody produced in response to flu vaccination in pigs from antibody made in response to pig infections with swine H1N1 influenza.

While H1N1 swine viruses have been known to circulate among pig populations since at least 1930, H3N2 influenza viruses did not begin circulating among US pigs until 1998. The H3N2 viruses initially were

introduced into the pig population from humans. The current swine flu H3N2 viruses are closely related to human H3N2 viruses.

Can humans catch swine flu?

Swine flu viruses do not normally infect humans. However, sporadic human infections with swine flu have occurred. In the past several years, on average CDC has received about one influenza virus isolate from a human that tests positive for swine flu each year. Most commonly, these cases occur in persons with direct exposure to pigs (workers in the swine industry, for example). In addition, there have been rare documented cases of one person spreading swine flu to others. For example, an outbreak of apparent swine flu infection in pigs in Wisconsin in 1988 resulted in multiple human infections, and, although no community outbreak resulted, there was antibody evidence of virus transmission from the patient to health care workers who had close contact with the patient.

How does swine flu spread?

· Pigs infected with influenza virus have a runny nose, lethargy, cough and decreased appetite. The virus likely spreads from pig to pig through contact with infected mucous secretions. (When the pigs are really sick, their mucous carries high levels of virus.) · Strains of swine flu virus can also be directly transmissible to humans. Most human infections have occurred following direct contact with infected pigs. However, there has been at least one documented case of humantohuman transmission of swine flu.

What is Swine Influenza?

Swine Influenza (swine flu) is a respiratory disease of pigs caused by type A influenza that regularly cause outbreaks of influenza among pigs. Swine flu viruses cause high levels of illness and low death rates among pigs. Swine influenza viruses may circulate in swine throughout the year, but most outbreaks among swine herds occur during the late fall and winter months similar to humans. The classical swine flu virus (an influenza type A H1N1 virus) was first isolated from a pig in 1930.

How common is swine flu among pigs?

H1N1 and H3N2 swine flu viruses are endemic among pig populations in the United States and something that the industry deals with routinely. Outbreaks among pigs normally occur in colder weather months (late fall and winter) and sometimes with the introduction of new pigs into susceptible herds. Studies have shown that the swine flu H1N1 is common throughout pig populations worldwide, with 25 percent of animals showing antibody evidence of infection. In the U.S. studies have shown that 30 percent of the pig population in the U.S. has antibody evidence of having had H1N1 infection. More specifically, 51 percent of pigs in the northcentral U.S. have been shown to have antibody evidence of infection with swine H1N1. Human infections with swine flu H1N1 viruses are rare. There is currently no way to differentiate antibody produced in response to flu vaccination in pigs from antibody made in response to pig infections with swine H1N1 influenza.

While H1N1 swine viruses have been known to circulate among pig populations since at least 1930, H3N2 influenza viruses did not begin circulating among US pigs until 1998. The H3N2 viruses initially were

introduced into the pig population from humans. The current swine flu H3N2 viruses are closely related to human H3N2 viruses.

Can humans catch swine flu?

Swine flu viruses do not normally infect humans. However, sporadic human infections with swine flu have occurred. In the past several years, on average CDC has received about one influenza virus isolate from a human that tests positive for swine flu each year. Most commonly, these cases occur in persons with direct exposure to pigs (workers in the swine industry, for example). In addition, there have been rare documented cases of one person spreading swine flu to others. For example, an outbreak of apparent swine flu infection in pigs in Wisconsin in 1988 resulted in multiple human infections, and, although no community outbreak resulted, there was antibody evidence of virus transmission from the patient to health care workers who had close contact with the patient.

How does swine flu spread?

· Pigs infected with influenza virus have a runny nose, lethargy, cough and decreased appetite. The virus likely spreads from pig to pig through contact with infected mucous secretions. (When the pigs are really sick, their mucous carries high levels of virus.) · Strains of swine flu virus can also be directly transmissible to humans. Most human infections have occurred following direct contact with infected pigs. However, there has been at least one documented case of human to human transmission of swine flu.

What do we know about human to human spread of swine flu?

In September 1988, a previously healthy 32yearold pregnant woman was hospitalized for pneumonia and died 8 days later. A swine H1N1 flu virus was detected. Four days before getting sick, the patient

visited a county fair swine exhibition where there was widespread influenza like illness among the swine. In follow up studies, 76% of swine exhibitors tested had antibody evidence of swine flu infection but no serious illnesses were detected among this group. Additional studies suggest that one to three health care personnel who had contact with the patient developed mild influenza like illnesses with antibody evidence of swine flu infection.

What other examples of swine flu outbreaks are there?

Probably most well known is an outbreak of swine flu among soldiers in Fort Dix, New Jersey in 1976. The virus caused disease with xray evidence of pneumonia in at least 4 soldiers and 1 death; all of these patients had previously been healthy. The virus was transmitted to close contacts in a basic training environment, with limited transmission outside the basic training group. The virus is thought to have circulated for a month and disappeared. The source of the virus, the exact time of its introduction into Fort Dix, and factors limiting its spread and duration are unknown. The Fort Dix outbreak may have been an animal anomaly caused by introduction of an animal virus into a stressed human population in close contact in crowded facilities during the winter. The swine influenza A virus collected from a Fort Dix soldier was named A/New Jersey/76 (Hsw1N1).

How many swine flu viruses are there?

Like all influenza viruses, swine flu viruses change constantly. Pigs can be infected by avian influenza and human influenza viruses as well as swine flu viruses. When influenza viruses from different species infect pigs, the viruses can reassort (i.e. swap genes) and new viruses that are a mix of swine, human and/or avian influenza viruses can emerge. Over the years, different variations of swine flu viruses have emerged. At this time, there are four main influenza type A virus subtypes that have been isolated in pigs: H1N1, H1N2, H3N2, and H3N1. However, most of the recently isolated influenza viruses from pigs have been H3N2 and H1N1 viruses.

Is the H1N1 swine flu virus the same as human H1N1 viruses?

No. The H1N1 swine flu viruses are antigenically very different from human H1N1 viruses.

Is there a vaccine for swine flu?

Vaccines are available to be given to pigs to prevent swine influenza. There is no vaccine to protect humans from swine flu. The seasonal influenza vaccine will likely help provide partial protection against

swine H3N2, but not swine H1N1 viruses.

What are the public health implications of human infections with swine influenza viruses?

Human infections with animal influenza A viruses against which the human population has little immunity should be investigated to determine the source of infection, and the extent of spread and evidence of human to human transmission. Influenza A viruses new to the human population that are able to efficiently transmit from person to person and cause illness may represent a pandemic threat. Although immunity to swine H1N1 viruses is low in the human population, a high proportion of persons occupationally exposed to pigs (such as pig farmers or pig veterinarians) have been shown in several studies to have antibody evidence of prior swine H1N1 flu infection. And, for swine H1N1 viruses, only rare person to person transmission has been documented in the past. Thus, human infections with swine H1N1 viruses should be investigated particularly when they are detected among non-occupationally exposed persons to ensure that human to human transmission is not occurring and to monitor for changes in circulating viruses and the emergence of novel viruses.

Because most persons have some antibody to influenza H3N2 viruses since H3N2 viruses occur commonly in humans and because the swine and human H3N2 viruses are similar, swine H3N2 virus infections in humans would not represent a possible pandemic threat.

Source: CDC

Find more about Pig flu at:

http://www.journals.uchicago.edu/ucp/WebIntegrationServlet?call=ContentWeblet&url=http%3A//www.journals.uchicago.edu/CID/journal/issues/v42n1/37983/37983.html&current_page=content

http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6T32-4C7DGH7-3-7&_cdi=4934&_user=856389&_orig=search&_coverDate=07/31/2004&_sk=998969998&view=c&wchp=dGLbVzb-zSkzS&md5=aad169da48e8be083041c80aeea8a39d&ie=/sdarticle.pdf
http://www.pork.org/PorkScience/Documents/PUBLICHEALTH%20influenza.pdf



WHO guidance for the surveillance of human infection with A(H1N1) virus

Interim WHO guidance for the surveillance of human infection
with swine influenza A(H1N1) virus
29 April 2009
Introduction
The audiences for this guidance document are the National Focal Points for the International
Health Regulations (IHR(2005)) and competent national public health authorities. The primary
focus of this guidance document is global surveillance. It also gives some suggestions on the
types of signals that Member States and IHR States Parties can capture in their event-based
surveillance. These signals can aid identification of individuals for whom investigation of swine
influenza A(H1N1) virus infection is warranted.
This is an interim WHO guidance on the global surveillance of the emerging swine influenza
A(H1N1) virus infection. This is a living document that will be reviewed on a weekly basis and
modified in accordance with changes in the epidemiology of this virus. As the event evolves,
there will be a need to switch surveillance activities to the longer-term monitoring of the
disease. WHO will alert countries when a change in surveillance objectives and methods occurs.
WHO’s data requirements will remain as flexible as possible to accommodate different
surveillance systems and reporting capacity around the world.
This document will form part of a suite of guidance documents being produced by WHO in
response to this public health emergency of international concern as determined by the Director
General of WHO on 25 April 2009. New influenza virus sub-types and clusters of unknown and
unusual disease are notifiable to WHO in accordance with the Annex 2 decision instrument of
the IHR (2005).
At this early stage of the outbreak of swine influenza A(H1N1) virus, the main aims of
surveillance are the early warning of virus spread and laboratory confirmation of virus
circulating in new geographical areas and countries. Accordingly, WHO encourages all Member
States and IHR States Parties to enhance their surveillance and diagnostic capacity for influenza
and other acute respiratory infections, building on exiting surveillance structure and resources.
Objectives of enhanced global surveillance for human infections with swine influenza
A(H1N1) virus
Specific objectives of this surveillance activity are to guide global prevention and control
activities through the following actions:
1. Detect and confirm cases of swine influenza A(H1N1) virus infection
2. Establish the extent of international spread of swine influenza A(H1N1) virus infection
3. Assist in the early severity assessment of the disease
Case definitions for infections with swine influenza A(H1N1) Virus
In order to understand the spectrum of severity of the disease caused by swine influenza
A(H1N1) virus infection , the clinical case description includes both mild form of influenza-like
illness (ILI) and more severe forms (lower respiratory tract infections including pneumonia and
severe acute respiratory illness (SARI)). In addition, asymptomatic laboratory-confirmed
infections should be reported.
The following case definitions are for the purpose of reporting probable and confirmed cases of
swine influenza A(H1N1) virus infection to WHO.
Clinical case description
Acute febrile respiratory illness (fever >38°C ) with the spectrum of disease from influenza-like
illness to pneumonia.
1. A Confirmed case of swine influenza A(H1N1) virus infection is defined as an individual
with laboratory confirmed swine influenza A(H1N1) virus infection by one or more of
the following tests*:
• real-time RT-PCR
• viral culture
• four-fold rise in swine influenza A(H1N1) virus specific neutralizing antibodies.
2. A Probable case of swine influenza A(H1N1) virus infection is defined as an individual
with an influenza test that is positive for influenza A, but is unsubtypable by reagents
used to detect seasonal influenza virus infection OR
A individual with a clinically compatible illness or who died of an unexplained acute
respiratory illness who is considered to be epidemiologically linked to a probable or
confirmed case.
* Note: The test(s) should be performed according to the most currently available guidance on
testing (http://www.who.int/csr/disease/swineflu/en/index.html).
Reporting requirements for confirmed and probable cases of swine influenza A(H1N1)
Under the IHR (2005), immediate reporting to WHO is required for human influenza due to a
new influenza virus sub-type. All information will be treated in accordance with the IHR (2005)
provisions. If available, countries should report travel history of case(s).
Reports should be sent by the National IHR Focal Point to the relevant WHO IHR Contact Point at
the WHO Regional Office, the WHO Country Representative, where applicable, and WHO
headquarters in Geneva should be copied on the correspondence
(http://www.who.int/csr/alertresponse/ihreventinfo/).
Reporting of individual(s) or clusters under investigation for swine influenza A(H1N1)
virus infection
Countries that identify unusual clusters of acute respiratory illness should immediately notify
WHO. These consultations will not be reflected in global statistics until their investigation
confirms that they are laboratory-confirmed or probable cases.
Definition of cluster
A cluster is defined as two or more persons presenting with manifestations of unexplained,
acute respiratory illness with fever >38°C or who died of an unexplained respiratory illness and
that are detected with onset of illness within a period of 14 days and in the same geographical
area and/or are epidemiologically linked.
Triggers/signals for the investigation of possible cases of swine influenza A(H1N1)
The primary focus of early investigation is to trigger the initial investigation. Specific triggers
include:
• Clusters of cases of unexplained ILI or acute lower respiratory disease
• Severe, unexplained respiratory illness occurring in one or more health care worker(s)
who provide care for patients with respiratory disease
• Changes in the epidemiology of mortality associated with the occurrence of ILI or lower
respiratory tract illness, an increase in deaths observed from respiratory illness or an
increase in the occurrence of severe respiratory disease in previously healthy adults or
adolescents
• Persistent changes noted in the treatment response or outcome of severe lower
respiratory illness.
Epidemiological risk factors that should raise suspicion of swine influenza A(H1N1) include:
• Close contact# to a confirmed case of swine influenza A(H1N1) virus infection while the
case was ill
• Recent travel to an area where there are confirmed cases of swine influenza A (H1N1)
#Close contact: having cared for, lived with, or had direct contact with respiratory secretions or
body fluids of a probable or confirmed case of swine influenza A(H1N1).
Member States reporting cases of swine influenza A(H1N1) virus infection for the first time
As soon as a the National IHR Focal Point or competent national public health authority notifies
WHO of the first laboratory-confirmed or probable case(s) of swine influenza A(H1N1), WHO will
make available the case summary form and database for the recording of detailed clinical,
laboratory and epidemiological data in accordance with WHO pandemic surveillance guidelines.
WHO Swine Influenza A(H1N1) Case Summary Form for case-based data collection [pdf 318kb]
http://www.who.int/csr/resources/publications/swineflu/WHOcasebasedsummaryform.pdf
A(H1N1) daily aggregated indicators [pdf 64kb]
http://www.who.int/csr/resources/publications/swineflu/AH1N1_daily_aggregated.pdf
WHO also requires information to assess whether sustained community transmission is
occurring. Wherever possible, a detailed exposure history should be collected by Member
States and shared with WHO.
Member States where cases of swine influenza A(H1N1) virus infection have already been
reported
Until further notice, the National IHR Focal Points or competent national public health
authorities should report to WHO all probable and confirmed cases on a daily basis. Deaths
should be reported for both probable and confirmed cases. A reporting format has been posted
on the web (link).
WHO will present the cumulative number of cases for global reporting back to Member States
and the public. This activity will only continue for the initial period of data collection.
In order to understand the severity of the disease it is very important that comprehensive data
collection and follow up is carried out for all probable and confirmed cases of swine influenza
A(H1N1) virus infection. WHO’s data requirements are detailed in the Global Surveillance during
an Influenza Pandemic Version 1 Updated draft April 2009 (Comprehensive Assessment, Clinical
characteristics: Database of information for 100 cases). A WHO Swine Influenza A(H1N1) Case
Summary Form has been posted on the web (Link). Member States are encouraged to report on
methods used for the selection of cases for inclusion into the dataset in order to assist the
interpretation of any result.
Confirmed and probable cases reported are to be attributed to the country or territory in which
they are currently located or where they have died.
The reported case-based data will be used by WHO to assess the clinical disease spectrum and
severity, and guide treatment recommendations.
National Influenza Centres and National reference centres should continue to report virological
information to Flu Net.
Access to Laboratory Confirmation
Countries without current capacity to confirm swine influenza A(H1N1) should contact WHO to
arrange access to a laboratory with this capability.

Source WHO

Swine influenza frequently asked questions

* What is swine influenza?
* What are the implications for human health?
* Where have human cases occurred?
* How do people become infected?
* Is it safe to eat pork and pork products?
* Which countries have been affected by outbreaks in pigs?
* What about the pandemic risk?
* Is there a human vaccine to protect from swine influenza?
* What drugs are available for treatment?
* What should I do if I am in regular contact with pigs?
* How can I protect myself from getting swine influenza from infected people?
* What should I do if I think I have swine influenza?


What is swine influenza?

Swine influenza, or “swine flu”, is a highly contagious acute respiratory disease of pigs, caused by one of several swine influenza A viruses. Morbidity tends to be high and mortality low (1-4%). The virus is spread among pigs by aerosols, direct and indirect contact, and asymptomatic carrier pigs. Outbreaks in pigs occur year round, with an increased incidence in the autumn and winter in temperate zones. Many countries routinely vaccinate swine populations against swine influenza.

Swine influenza viruses are most commonly of the H1N1 subtype, but other subtypes are also circulating in pigs (e.g., H1N2, H3N1, H3N2). Pigs can also be infected with avian influenza viruses and human seasonal influenza viruses as well as swine influenza viruses. The H3N2 swine virus was thought to have been originally introduced into pigs by humans. Sometimes pigs can be infected with more than one virus type at a time, which can allow the genes from these viruses to mix. This can result in an influenza virus containing genes from a number of sources, called a "reassortant" virus. Although swine influenza viruses are normally species specific and only infect pigs, they do sometimes cross the species barrier to cause disease in humans.

What are the implications for human health?

Outbreaks and sporadic human infection with swine influenza have been occasionally reported. Generally clinical symptoms are similar to seasonal influenza but reported clinical presentation ranges broadly from asymptomatic infection to severe pneumonia resulting in death.

Since typical clinical presentation of swine influenza infection in humans resembles seasonal influenza and other acute upper respiratory tract infections, most of the cases have been detected by chance through seasonal influenza surveillance. Mild or asymptomatic cases may have escaped from recognition; therefore the true extent of this disease among humans is unknown.

Where have human cases occurred?

Since the implementation of IHR(2005)1 in 2007, WHO has been notified of swine influenza cases from the United States and Spain.

How do people become infected?

Humans usually contract swine influenza from infected pigs, however, some cases lack contact history with pigs or environments where pigs have been located. Human-to-human transmission has occurred in some instances but was limited to close contacts and closed groups of people.

Is it safe to eat pork and pork products?

Yes. Swine influenza has not been shown to be transmissible to people through eating properly handled and prepared pork (pig meat) or other products derived from pigs. The swine influenza virus is killed by cooking temperatures of 160°F/70°C, corresponding to the general guidance for the preparation of pork and other meat.

Which countries have been affected by outbreaks in pigs?

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 the United States. Outbreaks in pigs are also known to have occurred in North America, South America, Europe (including the UK, Sweden, and Italy), Africa (Kenya), and in parts of eastern Asia including China and Japan.

What about the pandemic risk?

It is likely that most people, especially those who do not have regular contact with pigs, do not have immunity to swine influenza viruses that can prevent the virus infection. If a swine virus establishes efficient human-to human transmission, it can cause an influenza pandemic. The impact of a pandemic caused by such a virus is difficult to predict: it depends on virulence of the virus, existing immunity among people, cross protection by antibodies acquired from seasonal influenza infection and host factors.

Is there a human vaccine to protect against 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. It is important to develop a vaccine against the currently circulating virus strain for it to provide maximum protection to the vaccinated people. This is why WHO needs access to as many viruses as possible in order to select the most appropriate candidate vaccine virus.

What medicines are available for treatment?

There are two classes of such medicines, 1) adamantanes (amantadine and remantadine), and 2) inhibitors of influenza neuraminidase (oseltamivir and zanamivir).

Most of the previously reported swine influenza cases recovered fully from the disease without requiring medical attention and without antiviral medicines.

Some influenza viruses develop resistance to the antiviral medicines, limiting the effectiveness of treatment. The viruses obtained from the recent human cases with swine influenza in the United States are sensitive to oselatmivir and zanamivir but resistant to amantadine and remantadine.

Information is insufficient to make recommendations on the use of the antivirals in treatment of swine influenza virus infection. Clinicians should make decisions based on the clinical and epidemiological assessment and harms and benefits of the treatment of the patient2. For the ongoing outbreak of the swine influenza infection in the United States and Mexico, national and local authorities are recommending use oseltamivir or zanamivir for treatment of the disease based on the virus’s susceptibility profile.

What should I do if I am in regular contact with pigs?

Even though there is no clear indication that the current human cases with swine influenza infection are related to recent or ongoing influenza-like disease events in pigs, it would be advisable to minimize contact with sick pigs and report such animals to relevant animal health authorities.

Most people are infected through prolonged, close contact with infected pigs. Good hygiene practices are essential in all contact with animals and are especially important during slaughter and post-slaughter handling to prevent exposure to disease agents. Sick animals or animals that died from disease should not be undergoing slaughtering procedures. Follow further advice from relevant national authorities.

Swine influenza has not been shown to be transmissible to people through eating properly handled and prepared pork (pig meat) or other products derived from pigs. The swine influenza virus is killed by cooking temperatures of 160°F/70°C corresponding to the general guidance for the preparation of pork and other meat.

How can I protect myself from getting swine influenza from infected people?

In the past, human infection with swine influenza was generally mild but is known to have caused severe illness such as pneumonia For the current outbreaks in the United States and Mexico however, the clinical pictures have been different. None of the confirmed cases in the United States have had the severe form of the disease and the patients recovered from illness without requiring medical care. In Mexico, some patients reportedly had the severe form of the disease.

To protect yourself, practice general preventive measures for influenza:

* Avoid close contact with people who appear unwell and who have fever and cough.
* Wash your hands with soap and water frequently and thoroughly.
* Practice good health habits including adequate sleep, eating nutritious food, and keeping physically active.

If there is an ill person at home:

* Try to provide the ill person a separate section in the house. If this is not possible, keep the patient at least 1 meter in distance from others.
* Cover mouth and nose when caring for the ill person. Masks can be bought commercially or made using the readily available materials as long as they are disposed of or cleaned properly.
* Wash your hands with soap and water thoroughly after each contact with the ill person.
* Try to improve the air flow in the area where the ill person stays. Use doors and windows to take advantage of breezes.
* Keep the environment clean with readily available household cleaning agents.

If you are living in a country where swine influenza has caused disease in humans, follow additional advice from national and local health authorities.

What should I do if I think I have swine influenza?

If you feel unwell, have high fever, cough and/or sore throat:

* Stay at home and keep away from work, school or crowds as much as possible.
* Rest and take plenty of fluids.
* Cover your mouth and nose with disposable tissues when coughing and sneezing and dispose of the used tissues properly.
* Wash your hands with soap and water frequently and thoroughly, especially after coughing or sneezing.
* Inform family and friends about your illness and seek help for household chores that require contact with other people such as shopping.

If you need medical attention:

* Contact your doctor or healthcare provider before travelling to see them and report your symptoms. Explain why you think you have swine influenza (for example, if you have recently travelled to a country where there is a swine influenza outbreak in humans). Follow the advice given to you for care.
* If it is not possible to contact your healthcare provider in advance, communicate your suspicion of having swine influenza immediately upon arrival at the healthcare facility.
* Take care to cover your nose and mouth during travel.

Source: WHO

Friday, February 13, 2009

Nutrition for health

Nutrition plays an important role in enhancing your health and fitness. Use right nutrition help improving the use of exercise,eliminate diseases,drive back the the aged. Nowadays, people seem like using functional food to enhance their health and fitness.