Tuesday, November 6, 2007

Influenza season could be worst in years

AUSTRALIA is facing its worst influenza season in years, as specialists warn that even young, fit adults could be affected.

This year, 3084 cases of influenza have been reported to health authorities -- compared with 1213 cases for the entire 2006. Queensland has been hardest hit, with 1414 cases this year, compared with 518 in NSW, 498 in Western Australia and 220 in Victoria.

Ian Barr, deputy director of the World Health Organisation Collaborating Centre for Reference and Research on Influenza in Melbourne, said this year's flu season was the most serious since 2003 and 1997.

Six people -- five children and a 37-year-old man -- have died of influenza this year. A report in The Daily Telegraph today reveals that influenza played a role in the death of 30-year-old heart transplant recipient Joseph David, from Sydney.

"It's certainly bigger this year than it has been in the last couple of years," Dr Barr said. "The last serious flu season was in 2003. We had very mild seasons in 2004, 2005 and 2006."

Experts are at a loss to explain why the outbreak is spreading so rapidly. "We've definitely seen a higher rate of cases in Sydney, Canberra, Brisbane and Perth than in the past few years," said Canberra Hospital director of infectious diseases and microbiology Peter Collignon. "But it's not clear why. It's puzzling because there hasn't been a great change in the virus."

Dr Barr said people's immunity might have fallen in recent years. "We often see a serious season following after a few mild seasons in a row," he said. "That may be due to a lack of circulation of strains, and a lack of exposure to people with influenza for a few years. Their immunity wanes and then they come down with it. People think it only affects the young, sick and elderly, but ... everyone is susceptible."

Three children in Western Australia, one in Queensland and one in Victoria have died from influenza in the past five weeks.

On Thursday, Queenslander Glen Kindness -- a healthy 37-year-old -- died after developing flu-like symptoms.

"About 20 per cent of the population gets vaccinated," Dr Barr said. "I think we'd all like to see that rate higher."

Experts have long warned there is no way to vaccinate people against a new strain of influenza until that strain evolves. However, yesterday, researchers revealed they might have come up with a way to vaccinate people before an influenza pandemic.

The World Health Organisation has confirmed that 319 people have contracted H5N1 avian flu virus from contact with infected chickens, ducks and other fowl, and 192 of them have died. Researchers at the National Institute of Allergy and Infectious Diseases in Maryland claim they have discovered a way to anticipate how H5N1 may jump to humans and ways to respond to it.

They found a mutation that causes one strain of the H1N1 virus to infect birds, while another strain prefers humans. The team made the same alteration in an H5N1 virus, and vaccinated mice with this genetically engineered H5N1 DNA. They found an antibody that could neutralise both types of H5N1.

"It delivers a powerful blow against this virus and really hits it where it lives," said institute director and lead author Gary Nabel. If a vaccine could be developed to protect people against viruses with this mutation, it could be used before a pandemic even started, Dr Nabel said.

Flu Season - Influenza

Influenza-like illness (ILI) is defined as a temperature of > 100.0?F (> 37.8?C) and either cough or sore throat in the absence of a known cause. Levels of influenza activity are 1) no activity, 2) sporadic-small numbers of laboratory-confirmed influenza cases or a single influenza outbreak reported but no increase in cases of ILI, 3) local-outbreaks of influenza or increases in ILI cases and recent laboratory-confirmed influenza in a single region of a state, 4) regional-outbreaks of influenza or increases in ILI cases and recent laboratory-confirmed influenza in at least two but less than half the regions of a state, and 5) widespread-outbreaks of influenza or increases in ILI cases and recent laboratory-confirmed influenza in at least half the regions of a state.

Influenza incidence exhibits strong seasonal fluctuations in temperate regions throughout the world, concentrating the mortality and morbidity burden of the disease into a few months each year. Influenza is more likely to spread in the winter than the summer. This may be caused by an increased infectiousness of the disease, an increased susceptibility of people, or an increased number contacts with others that might result in transmitting the infection during the winter. For example, people may spend more time indoors.

The reason that more people catch the flu in the winter appears to be that small seasonal changes in flu transmission at the individual level are greatly amplified as the disease spreads through communities. The underlying cause of seasonal fluctuations in transmission may be too small to measure. Large fluctuations in the number of flu cases between winter and other seasons may be caused by very small changes in the number of people infected by a single infectious person. These small changes in transmission rate are amplified by interactions between the evolving virus and the changing level of immunity that people have to specific strains.

The cause of influenza's seasonality has remained elusive. Studies have failed to establish whether these transmission changes are due to direct effects of temperature and humidity on transmission, to changes in mixing patterns [e.g., school terms or simply more time spent indoors], or to other factors, such as increased viral production under winter conditions. In fact, it may be impossible to establish the underlying cause of seasonality in influenza epidemics, since the large observed oscillations in incidence can be generated by seasonal changes in the transmission rate that are too small to measure. The large oscillations in incidence may be caused by undetectably small seasonal changes in the influenza transmission rate that are amplified by dynamical resonance.

Data can be evaluated quantitatively, and graphic representation of this information, known as epidemic curves (epi-curves), may prove especially useful in this endeavor. These visual representations depict case frequency over time, and are initially used to obtain tentative answers to questions concerning origin, propagation, incidence, prevalence, and likely modes of transmission. The nature of the epidemic curve varies with the pathogen. The frequency curve for most infectious diseases resembles a logarithmic normal curve. Epidemics such as infuenza have distinctive patterns of initiation and spread.

Influenza Vaccination Season Begins

The Michigan Department of Community Health (MDCH) is gearing up for the 2007-2008 influenza season by making special efforts to reach out to high-risk patients as well as children in need of a second dose of influenza vaccine. Vaccine manufacturers expect shipments to be made on-time this year and MDCH is urging providers, local health departments, and community vaccinators to begin vaccinating patients.

"As the 2007-2008 flu season approaches, we encourage all of Michigan's residents to be vaccinated against the flu," said Janet Olszewski, MDCH Director. "Ask your doctor if you are at high-risk for influenza-related complications and be sure to get vaccinated. If you are a new parent, a health care professional, and/or have contact with people age 65 and older, protect those high-risk individuals by getting vaccinated."

According to the U.S. Centers for Disease Control and Prevention (CDC), every year in the United States, an average of 5 percent to 20 percent of the population gets the flu, more than 200,000 people are hospitalized from flu complications, and about 36,000 people die from flu. More than 90 percent of those deaths are among persons age 65 or older. Even though last year's flu season was mild, 68 deaths among children were reported to CDC.

"The single best way to prevent the flu is to get vaccinated each year," said Dr. Greg Holzman, State Chief Medical Executive. "Contrary to popular myth, the flu vaccine cannot give you the flu. There are two types of flu vaccinations available: the "flu shot" and the nasal-spray flu vaccine; both are effective in preventing the flu."

Studies show people with flu can infect others up to 1 day before they start having symptoms and, once sick, they can infect others for up to 5 days. About half of all people with influenza infections do not have any symptoms; these people can infect others without knowing they are sick.

Influenza activity most often occurs in January or later, therefore it is important to know that if you do not get vaccinated in October or November, you can still get get vaccinated in December or later. Though it varies, flu season can last until May. For information on receiving the flu vaccine, please contact your doctor's office or your local health department.


According to the Centers for Disease Control and Prevention, although October and November are the recommended months for vaccination, a flu vaccine given later in the season -- December through March -- still can help protect from influenza.

This year, flu vaccine manufacturers plan to have more then 130 million doses of influenza vaccine available for distribution in the United States, more than ever before.

The two vaccines available to the public are:

The traditional injectable flu vaccine, which contains inactivated (killed) virus, is for anyone age 6 months and older. Some patients experience soreness at the injection site lasting less than two days, but serious side effects are extremely rare. This vaccine may come in a multiple-dose vial or in single-dose syringes. Syringes for children 3 and younger are thimerosal-free.

A live weakened virus vaccine called LAIV or "FluMist" is sprayed into the nose and is for healthy people ages 2 through 49. A small amount of vaccine is sprayed into each nostril, instead of getting an injection.

Source: CDC, Public Health -- Seattle & King County

Monday, November 5, 2007

Flu Season, When Does It Start?

Flu season starts to peak in November and continues to peak through April. The Centers for Disease Control and Prevention (CDC) recommend getting your 2004 flu vaccine in the months of October and November in order to prevent an outbreak to the flu virus. Every flu season a new batch of the flu vaccine is made. Scientists consider what strains of the virus are going to be a threat that flu season and develop the vaccine accordingly. There are usually 3 deactivated or killed stains of the flu virus in the vaccine each new flu season.

This flu season, due to the vaccination shortages, the CDC is recommending that specific priority groups get their vaccinations first, and then the non-priority group forgoes their vaccination all together this 2004-2005 flu season. The priority group is as follows:
  • Children between ages 6-23 months
  • Adults aged 65+
  • Individuals with chronic conditions aged 2-64
  • All women who will be pregnant during the 2004-2005 flu season
  • Residents of nursing homes/long term facilities
  • Children between 6 months to 18 years of age on chronic aspirin therapy
  • Health care workers that work in direct patient care
  • Household contacts/out-side caregivers of children under 6 months of age

People who have severe allergies to chicken eggs or those who have Guillain-Barre syndrome (obtained after a flu vaccine) should not receive get a 2004-2005 flu vaccine.

The best tip for flu prevention for those unable to get a flu vaccination or for those in the priority group to further protect them selves this flu season is to maintain a healthy immune system.

Växa's Flu Prevention Pac is a Scientifically Advanced homeopathic medicinal strategy engineered to naturally support the function, and thereby the resistance, of the Immune System. When the Immune System is weakened it is prone to common bacterial and viral infections, including the flu virus, colds, chronic fatigue, laryngitis, asthma and emphysema, as well as bacillary dysentery, toxic radiation and chemical poisoning (and the defective elimination of such poisons), vaccinal poisonings, herpes simplex & zoster (shingles), mononucleosis and lymphadenitis, anemia, typhoid and typhus fever, encephalitis, hepatitis, tuberculosis, pneumonia, septic blood and auto-infections, and subsequent diminution of the population of red blood cells. Växa's Flu Prevention Pac is formulated to provide nutritional support for the Immune System.

Two types of flu vaccine

The single best way to protect against the flu is to get vaccinated each fall.

There are two types of vaccines:
The "flu shot"— an inactivated vaccine (containing killed virus) that is given with a needle, usually in the arm. The flu shot is approved for use in people older than 6 months, including healthy people and people with chronic medical conditions. For more, please read the Flu Vaccine article.
The nasal-spray flu vaccine — a vaccine made with live, weakened flu viruses that do not cause the flu (sometimes called LAIV for “Live Attenuated Influenza Vaccine”). LAIV is approved for use in healthy people 5 years to 49 years of age who are not pregnant. Each vaccine contains three influenza viruses—one A (H3N2) virus, one A (H1N1) virus, and one B virus. The viruses in the vaccine change each year based on international surveillance and scientists' estimations about which types and strains of viruses will circulate in a given year. For more, please read the Influenza Nasal Vaccine (FluMist) article.

About 2 weeks after vaccination, antibodies that provide protection against influenza virus infection develop in the body.

When should you get vaccinated?

October or November is the best time to get vaccinated, but you can still get vaccinated in December and later. Flu season can begin as early as October and last as late as May.

Who should get vaccinated this season?

In general, anyone who wants to reduce their chances of getting the flu can get vaccinated. However, certain people should get vaccinated each year. They are either people who are at high risk of having serious flu complications or people who live with or care for those at high risk for serious complications.

Widespread vitamin D deficiency may be cause of post-Winter flu outbreaks, scientists suggest

A team of researchers is gathering data in an attempt to determine why flu outbreaks hit the Northern Hemisphere during winter months and tend to peak between December and March, and a new theory suggests it may be a lack of sunshine-produced vitamin D.

In the past, many theories have been put forward to explain the seasonal flu flux, but explanations such as cold air and the tendency of people to group together "remain astonishingly superficial and full of inconsistencies," said Dr. Scott Dowell, director of the Global Disease Protection Program at the Centers for Disease Control and Prevention in Atlanta.

Theories about a chill causing the disease's prevalence is upended by evidence from tropical locations, where flu remains common and follows a similar seasonal pattern to its cold-climate counterpart. The grouping theory is debunked by the fact that certain groups of people are stuck in small spaces together year round, with no greater likelihood of contracting flu than anyone else.

Now, the Harvard-University-led team is investigating whether inadequate sun exposure during the winter may open people up to infection, since exposure to ultraviolet B radiation (UVB) radiation from the sun causes vitamin D production in the skin. If the lack of vitamin D and increased flu cases in the winter are connected, it could have a significant impact on public health, as an average of 36,000 people die from flu in the United States every winter, primarily the elderly or the very young.

R. Edgar Hope-Simpson published the first paper that identified a link between flu epidemics and the winter solstice -- usually indentified as the start of winter and the shortest day of the year -- in 1981, despite having no formal training in the field of epidemiology. Simpson noted that flu infections spiked just before and after the winter solstice, and theorized that solar radiation might cause a sort of "seasonal stimulus" in the virus, the host or both, although he could not identify the stimulus.

Simpson's work was largely ignored, according to Dr. John Cannell, a psychiatrist at the Atascadero State Hospital in California. However, Cannel and his Harvard colleagues suggest the stimulus to which Simpson referred may be vitamin D. Cannell began investigating the possibility when a flu outbreak hit Atascadero in April of 2005 and all the wards surrounding his were infected, Cannell's patients were not. All of his patients, he said, were taking high daily doses of vitamin D.

During the winter, people are outdoors less often and the skin has less opportunity to produce vitamin D, and the atmosphere during that season is adept at blocking UVB radiation. This is why some health experts warn that Americans may not be getting sufficient vitamin D, especially with the resurgence of the vitamin-deficiency-related bone disorder known as rickets.

In the report -- published in the December issue of Epidemiology and Infection -- the researchers posit that the vitamin D stimulated by sunlight may, in turn, cause the body to produce the infection-fighting peptide cathelcidin. No studies been conducted that to show whether cathelcidin effects influenza, but previous studies in the March issue of Science have shown it attacks a range of fungi, viruses and bacteria, including the bacteria that causes tuberculosis.

The tropical evidence that upsets the chill theory does not preclude the vitamin D theory, as Cannell and colleagues point out, as studies show that vitamin D deficiencies have even been recorded in equatorial locations. Additionally, a 2003 analysis of flu cases found they were greatest during the rainy season, when there is a significant cloud cover and reduced sun exposure.

Despite the evidence offered by Cannell and colleagues, some members of the scientific community remain skeptical about the theory.

"They have manipulated the literature -- some of it very bad literature -- to prove their points," said Dr. James Cherry, a pediatric infectious disease specialist at UCLA's David Geffen School of Medicine. However, he added, "The hypothesis should be easy to prove or disprove with a controlled, blinded study."

Cannell, for his part, said he takes more than twice the recommended daily dose of vitamin D during winter months and reports he rarely gets sick.