Stories tagged public health

Jan
03
2010

Pretty bacteria: Do not be fooled by the pastel colors- these things will kill you.
Pretty bacteria: Do not be fooled by the pastel colors- these things will kill you.Courtesy esterase
I bet regular bacteria have posters of their favorite superbug hung on their bedroom walls. I mean superbugs are just so much cooler than regular bacteria; they’re kind of the bad boys of the bacteria world. Regular bacteria do what they are told: they keel over when exposed to disinfectants and antibiotics. But not those rebellious superbugs. Superbugs have some kind of genetic mutation that allows them to survive in hostile, antimicrobial environments. Basic principles of natural selection come into play: the mutant bacterium survives in the presence of the antibiotic/disinfectant and then goes on to produce other bacteria with the same mutation, ultimately creating a new resistant colony. In this scenario, exposure to the antimicrobial agent (the antibiotic or disinfectant) is imperative. However, scientists now think that another scenario exists; one in which exposure is not required. In a recent study, these scientists found that the use of disinfectants in hospitals can lead to bacterial resistance to antibiotics, even if the bacteria haven’t been exposed to the antibiotics.

Researchers from the National University of Ireland added increasing amounts of disinfectant to petri dishes full of Pseudomonas aeruginosa (a bug that causes pneumonia in hospital patients, among other things) and the bug became immune not only to the disinfectant, but also to ciprofloxacin- the antibiotic used to treat the bug. Superbugs are essentially using their exposure to disinfectants as “teachable moments” for resisting antibiotics.

This is significant because now it seems that bacteria have one less hurdle to overcome in their mission to cause serious harm to patients (that’s not really their “mission,” I say that for dramatic effect). If superbugs can resist the disinfectant slathered on the countertops and doorknobs of hospitals, it’s possible that they could go on to infect patients who “for some reason” won’t respond to the antibiotics. Man, regular bacteria must be so jealous.

Officials in Cardiff confirmed today the world's first cases of human-to-human transmission of Tamiflu-resistant H1N1 influenza. It's not unexpected, but it is worrisome. Even though flu cases are down here in Minnesota and across the US, keep washing your hands!

How much do you really know about the new H1N1 flu? CNN's testing your knowledge about the virus. Answer these 10 questions and see how you do.

The WHO has raised the swine flu pandemic alert to the highest level. (A/H1N1 is the first flu pandemic in 41 years.) This doesn't mean the disease is more dangerous, just that it's in more places and continuing to spread. As of this morning, 28,774 confirmed A/H1N1 cases have been reported in 74 countries, with 144 deaths. (These counts are not precise anymore, however, because many people who catch this flu are recovering at home without being tested.)

Watch/listen to the press conference

Map of the outbreak

BBC coverage

Graduating seniors at Bloomington high schools this week will don caps and gowns, get their diplomas, but won't get any congratulatory handshakes from school administrators on the commencement ceremony stage. In recent days, separate confirmed cases of swine (H1N1) flu have been recorded at Bloomington Kennedy and Jefferson high schools, prompting officials to skip the traditional handshakes for public health concerns. Instead, students will get a nod of the head from school district leaders.

May
31
2009

Vaccine production
Vaccine productionCourtesy AJC1

US pays billion dollars for developing new flu vaccine

The latest information from Pandemicflu.gov explains the next steps toward an H1N1 influenza vaccine.

BARDA

The Biomedical Advanced Research and Development Authority (BARDA), which is part of the Dept. on HHS, has an official "fact sheet" explaining 2009 H1N1 Vaccine Development Activities.

U.S. Department of Health & Human Services (HHS) Secretary Kathleen Sebelius is directing nearly $1.1 billion in existing preparedness funds to manufacture two important parts of a vaccine for the Strategic National Stockpile, to produce small amounts of potential vaccine for research, and to perform clinical research over the summer. HHS press release

How do vaccines work?

Vaccines work by tricking the immune system into thinking it has been infected with the H1N1 swine flu virus so that it creates antibodies against it. The vaccine is a hybrid of the virus which is similar enough that our immune system will develop antibodies against a specific virus.

How is swine flu vaccine made?

We are now starting step 4.

  1. obtain typical sample of novel H1N1 virus
  2. reproduce sample in eggs
  3. Mix H1N1 and PR8 viruses into eggs and allowing a hybrid strain to be created through a natural re-assortment of their genes
  4. Multiply seed virus into millions of doses
  5. test virus in people to determine the most effective and safest dose to generate a strong immune response to the 2009-H1N1 virus
  6. decide whether to use adjuvants
  7. mass produce vaccine

What is an adjuvant?

An adjuvant is an additive to a vaccine that helps to generate a stronger immune response to the vaccine. When using an adjuvant it is often possible to reduce the size of the vaccine dose and the number of doses needed. Special permission from the Food and Drug Administration will be needed for the adjuvants to be used, as neither one is currently approved for use in this country. Washington Post

Can vaccines be made without using eggs?

"The federal government has given the vaccine industry $1.3 billion to spur a shift from growing the viruses in eggs to growing them in stainless steel tanks containing mammalian cells.

Such cell culture could shave a few weeks off the process, experts estimate, and would eliminate the need for millions of eggs on short notice. Some vaccines made in cells have been approved in Europe but not in the United States." New York Times

Learn more about making swine flu vaccine

How to make a swine flu vaccine BBC
CDC May 28 Press Briefing transcript
Flu vaccine development questions and answers BARDA

May
24
2009

Antigenic shift in flu viruses: is when at least two different strains of a virus combine to form a new subtype having a mixture of the surface antigens of the two original strains.
Antigenic shift in flu viruses: is when at least two different strains of a virus combine to form a new subtype having a mixture of the surface antigens of the two original strains.Courtesy National Institute of Allergy and Infectious Diseases (NIAID)

Model of H1N1 flu virus takes shape

Genetic analysis of the new H1N1 virus shows that the hemagglutinin (the H in H1N1) and two other genes are from the 1918 Spanish flu virus and have been living in pigs ever since. Studies also show that the neuraminidase (the N in H1N1) segment is from the Eurasian swine flu virus that probably leaped from birds to pigs in about 1979.

The new virus differs in 21 of 387 amino acids from the H5N1 virus and the 1918 Spanish flu (also an H1N1 virus). - Singapore’s Agency for Science and Technology Research report in Biology Direct.

Shape shifting viral surface challenges vaccination success

"Viruses isolated from patients during the first two weeks of the current outbreak already have changes on the outer surface on the neuraminidase protein that could interfere with antibodies against the virus or alter the effectiveness of future vaccines. But none of the changes have altered the parts of the protein targeted by antiviral drugs, such as Tamiflu or Relenza." Science News

Learn more
If you click through to the source article in Science News, you will see a great three dimensional model of the influenza A/H1N1 virus with the origin of each of the virus's pieces explained.

May
17
2009

Cold noses are good for preventing bird flu

Don't let your children do this
Don't let your children do thisCourtesy KnOizKi

A recent study may explain why the bird flu has not become a pandemic. The human nose is too cold. Avian flu viruses prefer 104 degree F. The temperature in our noses is usually less than 90 degrees F. Critics of the study point out that it was only done in petri dishes so may not be an accurate reflection of what happens in humans.

Since the bird flu virus re-emerged in 2003, there have been only 423 reported cases. If the viruses manage to get into the lower lung, however, they replicate so quickly that 6 out of 10 victims (258) died.

The normal seasonal flu kills only 1 out of 1000 victims (250,000 to 500,000 people per year world wide).

Figuring the odds of a deadly mutation

Please comment what you think about this logic.

"When more people get the flu, the chances of a deadly mutation increases. Say the chance of a deadly mutation is one in a million. If 10,000 people get sick, the odds are 10,000/1,000,000 or 1/100. If a million people get sick the chance of a deadly mutation is almost a sure thing."

The new H1N1 virus appears to be more contagious

The percentage of contacts who catch the regular variety of flu from an infected person is between 5 and 15 percent, but current estimates for H1N1 being spread range from 22 to 33 per cent (according to WHO). Reuters via Yahoo News

As of May 15, 2009, 34 countries have officially reported 7520 cases of influenza A(H1N1) infection. World Health Organization

An intriguing mutation has been detected

The virus isolated from the second swine flu patient in the Netherlands has an intriguing mutation in a gene called PB2 that could mean that the virus has become better at spreading from person to person, a team of Dutch researchers reported on Friday on ProMED, a monitoring system for disease outbreaks. But they're the first to acknowledge that it could also be a red herring. Science Insider

You can make a difference

If you can behave in ways that prevent you from catching or spreading this new type of H1N1 flu, you will minimize the odds its changing into a more deadly form.

The Texas Department of State Health Services announced today that they're attributing a second US death to the A/H1N1 virus. The Cameron County woman, who had unspecified underlying health problems, died earlier this week. The CDC also reported that, so far, 35 people have been hospitalized in the US. However, the new flu virus doesn't seem as dangerous as public health officials feared last week. And because of that, and because the strategy no longer seems to be containing the spread of the disease, federal officials rescinded the recommendation that schools close when they discover suspected cases of the flu.

Official CDC case counts