Swine influenza frequently asked questions by 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 meat and products?
• What about the pandemic risk?
• Is there a human vaccine to protect swine influenza?
• What drugs are available for treatment?
What is swine influenza?
Swine influenza, or “swine flu”, is a highly contagious acute respiratory disease of pigs, caused by oneof several swine influenza A viruses. Morbidity tends to be high and mortality low (1-4%). The virusis spread among pigs by aerosols, direct and indirect contact, and asymptomatic carrierpigs. Outbreaks in pigs occur year round, with an increased incidence in the fall and winter intemperate zones. Many countries routinely vaccinate swine populations against swine influenza.Swine influenza viruses are most commonly of the H1N1 subtype, but other subtypes are alsocirculating 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 wasthought to have been originally introduced into pigs by humans. Sometimes pigs can be infected withmore than one virus type at a time, which can allow the genes from these viruses to mix. This canresult 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 dosometimes 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 rangesbroadly from asymptomatic infection to severe pneumonia resulting in death.Since typical clinical presentation of swine influenza infection in humans resembles seasonalinfluenza and other acute upper respiratory tract infections, most of the cases have been detected bychance through seasonal influenza surveillance. Mild or asymptomatic cases may have escaped fromrecognition; 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 casesfrom the United States and Spain.

How do people become infected?
People usually get swine influenza from infected pigs, however, some human cases lack contacthistory with pigs or environments where pigs have been located. Human-to-human transmission hasoccurred in some instances but was limited to close contacts and closed groups of people.

Is it safe to eat pork meat and pork products?
Yes. Swine influenza has not been shown to be transmissible to people through eating properlyhandled and prepared pork (pig meat) or other products derived from pigs. The swine influenza virusis killed by cooking temperatures of 160°F/70°C, corresponding to the general guidance for thepreparation 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 endemicin the United States. Outbreaks in pigs are also known to have occurred in North America, SouthAmerica, Europe (including the UK, Sweden, and Italy), Africa (Kenya), and in parts of eastern Asiaincluding China and Japan.

What about the pandemic risk?
It is likely that most of people, especially those who do not have regular contact with pigs, do not haveimmunity to swine influenza viruses that can prevent the virus infection. If a swine virus establishesefficient human-to human transmission, it can cause an influenza pandemic. The impact of a pandemiccaused by such a virus is difficult to predict: it depends on virulence of the virus, existing immunityamong people, cross protection by antibodies acquired from seasonal influenza infection and hostfactors.

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 notknown whether current human seasonal influenza vaccines can provide any protection. Influenzaviruses change very quickly. It is important to develop a vaccine against the currently circulating virusstrain for it to provide maximum protection to the vaccinated people. This is why WHO needs accessto as many viruses as possible in order to select the most appropriate candidate vaccine virus.

What drugs are available for treatment?

1 International Health Regulation (2005) http://www.who.int/ihr/about/en/Antiviral drugs for seasonal influenza are available in some countries and effectively prevent and treatthe illness. 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 withoutrequiring medical attention and without antiviral medicines.Some influenza viruses develop resistance to the antiviral medicines, limiting the effectiveness ofchemoprophylaxis and treatment. The viruses obtained from the recent human cases with swineinfluenza in the United States were sensitive to oselatmivir and zanamivir but resistant to amantadineand remantadine.Information is insufficient to make recommendation on the use of the antivirals in prevention andtreatment of swine influenza virus infection. Clinicians have to make decisions based on the clinicaland epidemiological assessment and harms and benefit of the prophylaxis/treatment of the patient2.For the ongoing outbreak of the swine influenza infection in the United States and Mexico, thenational and the local authorities are recommending to use oseltamivir or zanamivir for treatment andprevention of the disease based on the virus’s susceptibility profile.2 For benefits and harms of influenza-specific antivirals, see
http://www.who.int/csr/disease/avian_influenza/guidelines/pharmamanagement/en/index.html

Influenza -highly contagious infection cuased by viruses

Influenza,commonly known as the flu, is an acute, highly contagious infection of the respiratory tract which commonly occurs in the winter, caused by influenza viruses.

Symptoms

Chills and Fever (usually high), severe headache ,tiredness (can be extreme),cough ,sore throat ,runny or stuffy nose ,body aches ,diarrhea and vomiting (more common among children than adults),muscle pains,fatigue,irritated watering eyes,nasal congestion,reddened eyes,skin,mouth,throat and nose, loss of appetite,weakness,ear pain.

Causes:

viruses is a much more severe disease and is caused by a different type of virus.They are:influenza A, B and C. Type A is responsible for the deadly influenza pandemics (worldwide epidemics) that strike every 10 to 40 years, whereas type B causes smaller, more localized outbreaks. Type C is less common and causes only mild symptoms. The influenza virus is generally passed from person to person by airborne transmission (i.e., sneezing or coughing.It may also be spread by touching something that has been handled by someone infected with the virus and then touching your own mouth, nose, or eyes. Influenza virus is spread by inhaling droplets that have been coughed or sneezed out by an infected person or by having direct contact with an infected person's secretions.

Treatment:

The most common human vaccine is the trivalent influenza vaccine that contains purified and inactivated material from three viral strains.Anti-flue medications is necessary. .Anti viral medications are neuraminidase inhibitors such as oseltamivir(Tamiflu) and Zanamivir(relenza) and M2 inhibitors(adamantanes) such as Amantadine and rimantadine are effective anti-influenza drugs .Two newer medications, Relenza and Tamiflu work on influenza subtypes A and B. Relenza is an inhaled powder, while Tamiflu is an oral medication

Prevention:

Influenza vaccination and infection control,good personal health and hygiene habits are effective in avoiding and minimizing influenza. Avoiding large crowds Wash your hands thoroughly and frequently, never pick up used tissues,never share cups and eating utensils,stay home from work or school when you're sick with the flu. Cover your mouth and nose with a tissue when you cough or sneeze.

Altrnative Treatment:

Drink lots of water to prevent dehydration,get plenty of sleep,Avoid alcohol,take acetaminophen or ibuprofen to relieve fever and aches, wear layers, since the flu often makes them cold one minute and hot.

BIRD FLU - Avian influenza - A widely spread viral rare diseases

Avian influenza (AI) or Bird Flu is a viral disease that primarily effects fowl such as chickens, turkeys, guinea fowls, ducks, and other avian species. Fowl plague has been described as early as 1878 as a disease of chickens in Italy. In 1955 it was determined that it was one of the influenza viruses.

There are three types of influenza, A, B and C. Only type A infects animals and only type A can cause a panepidemic. To date, all outbreaks of the highly pathogenic form have been from the H5N1 subtype.

The flu is transmitted from bird to bird by direct contact with the discharge from infected birds, contaminated feed, water, cages, equipment, vehicles and clothing. Eggs from infected hens can break and contaminate incubators.

Humans become infected after direct or indirect contact with infected wild ducks and chickens through infected aerosols, discharges and surfaces. There is no evidence of human-to-human transmission.