Wednesday, August 12, 2009

How experts are preparing their families

I'm keeping a stock of a dose of 10 Tamiflu capsules for each of my family.

8 of the 60 respondents (see table 'Preparing for the worst') were stocking up on antibiotics for bacterial pneumonia infection that can arise secondary to flu. Should I consider stocking Tetracycline antibiotic?

The latest Health Protection Agency Report states:
'Bacterial susceptibility to antimicrobial agents is monitored by the HPA for lower respiratory tract isolates of Staphylococcus aureus, Streptococcus pneumoniae and Haemophilus influenzae. According to guidelines for clinical management of patients with an influenza-like illness during an influenza pandemic (W S Lim, Thorax 2007;62;1-46) the antibiotics recommended for treating bacterial pneumonia in a primary care setting are co-amoxiclav or a tetracycline (Section 8.1.3 of the guidelines). There have been no significant changes to susceptibility trends for these two antibiotics in recent years and the results of a twelve week analysis (Table 5) show that over 90% of all isolates of the three organisms were susceptible to tetracyclines. '

I'm off to 'Boots the Chemists' to check out Tetracyline...

AS THE swine flu pandemic continues to sweep the world, what do public health officials, epidemiologists and flu researchers think will happen in the coming months? When New Scientist asked 60 of them, it turned out that half are concerned enough about the possibility of a virulent swine flu outbreak to take precautions such as acquiring a supply of Tamiflu for their families. Though most do not think it likely that a nastier strain will emerge, many are worried that if it did, their local hospitals and other parts of the health infrastructure could not cope.

Since the emergence of H1N1 swine flu in Mexico and the USMovie Camera five months ago, the virus has affected 168 countries in all continents. More than 160,000 infections have been confirmed and the true figure could well be 10 times that ifcases have gone undetected. "This flu spreads very well," says Angela McLean, co-director of the Institute for Emerging Infections at the University of Oxford. While over 1000 people are known to have died, this is a fairly low fatality rate, she says.

No one can say for sure what will happen in the coming months. In the 1918 pandemic, the virus mutated and became more pathogenic over time. Last week, when swine flu fatalities doubled in Argentina - now in its winter flu season - the fear was that the virus had changed, though genetic sequencing proved that wasn't the case.

Although it is not yet possible to predict how the virus might evolve, researchers have hunches like everyone else. So New Scientist decided to email a list of carefully selected individuals from around the world.

We asked three simple questions: how concerned were they about an increase in viral virulence, did they think their country's infrastructure could cope if this happened, and were they taking extra personal precautions for themselves and their families.

The exercise was not intended to be scientific. The aim was simply to get a snapshot of opinion at this stage of the pandemic. Do their personal views matter? Probably. After all, these are the people who work day-to-day either studying flu or planning how to deal with it, and they influence regional, national and international strategies for managing the pandemic.

John Oxford, professor of virology at the Institute of Cell and Molecular Biology in London thinks the timing of the straw poll is right. "It's done just at the right moment," he says. "We have reached a balance point between the summer wave and a possible autumn wave. This is an excellent time to stand back a little and reassess and reflect upon the flu situation."

How likely is it that a more virulent strain will emerge? The majority of respondents did not rule it out: two thirds said they thought that higher virulence was "possible". Only a small proportion said it was "likely" (see table).

One respondent, Laurence Tiley, a molecular virologist at the University of Cambridge, says there is no reason to expect that the virus will become substantially more virulent. There have been too few pandemics to make any concrete predictions, he explains.

Around 30 per cent of respondents believe there is a fifty-fifty chance or greater of increased virulence. Oxford adds a caveat to this group's choice. "There is a tendency for people to hark back to 1918 when there was an increase in virulence, but it's different now. In 1918 it was like a missile into a virgin community, where everyone was susceptible," he says. Many people's immune systems have encountered a similar seasonal flu virus, which might lend them some protection against H1N1-type viruses, he adds. "I don't envisage at all a 1918-type scenario, and I'm glad that your experts here agreed."

The 1918 flu pandemic was like a missile into a virgin community

However, Walter Fiers, a molecular biologist at the University of Ghent in Belgium warns that there is still no way of knowing whether the 2009 H1N1 flu virus will mutate, making vaccines under development useless. So he and many of his colleagues are pressing for systematic surveillance of the virus to pick up any changes in behaviour.

A big worry is the possible appearance of a hybrid virus, one that combines the high transmissibility of H1N1 swine flu with the virulence of H5N1 bird flu, where 30 per cent of those infected die. "The nightmare scenario is that someone who is already infected with H5N1 gets swine flu," which would give the two viruses the opportunity to recombine, says John Edmunds, an epidemiologist at the London School of Hygiene and Tropical Medicine, UK.

The nightmare scenario is that someone infected with bird flu gets swine flu

Doubts also emerged over the ability of health infrastructures to cope, should the pandemic mirror that of 1918. Over half of those polled answered that they are "very" or "extremely concerned" that their local health services would be unable to deal with such a virulent wave of swine flu.

So are the respondents worried enough about a severe swine flu outbreak to take their own special measures? They are divided. Half say they have taken no measures. Reasons were mixed: some believe a serious flu outbreak unlikely, others don't feel they are at risk of serious disease, and many stated that they can easily access drugs via their local health infrastructure if necessary. Robert Dingwall, director of the Institute for Science and Society at the University of Nottingham, UK, says, "I am not planning to stockpile. I have every confidence in the availability of [UK] stocks of antivirals and in their continued availability."

The other half of those questioned are taking at least one precaution in anticipation of a severe swine flu outbreak. These include acquiring antivirals such as Tamiflu, or antibiotics for them and their families. Some have had the pneumococcal vaccine to protect against pneumonia, which can occur as a secondary infection. A few have even stockpiled food and water in their homes in case civic services, such as transport networks and food supplies, break down (see table).

Some of them seemed motivated by concern that stocks of antivirals or antibiotics were either absent or likely to run out. One health official in Africa said people in her country are "totally relying on the grace of God" to protect them from the pandemic. Although the respondents were evenly split between lower and high-income countries, around two-thirds of those who had taken special measures were from high-income countries, such as the US, western Europe, Japan and Australia, where government plans are relatively well formed and shortages of medicines are unlikely.

Oxford says that stocking antivirals is not necessary for most people, but he is surprised that more respondents have not chosen to do so because they have easier access to medicines via their work. He adds that such personal preparations can sometimes be prudent, for example, if a person was travelling to the southern hemisphere where swine flu cases are rising fast in the winter season.

These actions may prove to be unpalatable for policy-makers in well-prepared countries because they can fuel public anxieties. Dingwall warns that stocking antivirals may be rational for an individual, but if everybody followed suit the result would be "the very shortages that we might fear".

When New Scientist asked Marie-Paule Kieny, director of the World Health Organization Initiative for Vaccine Research, to comment on the results, she felt the snapshot represented a balanced view of the pandemic. "The experts seem to understand well the challenges ahead: they recognise the risks, but also the uncertainty of these risks," she says.

In the coming months, health authorities should not be complacent just "because they know that the vaccine is coming in a few months and because they have large stocks of Tamiflu in their freezers," says Walter Fiers of the University of Ghent. After all, if the virus mutates significantly before asubstantial percentage of the population are vaccinated it will be useless. What's more, Tamiflu resistance can emerge if the drug is widely used on those with very mild symptoms. "The situation needs to be carefully monitored," says Fiers. "Influenza has surprised us many times before."

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