Monday, July 25, 2011

Less spotty

On CNN today: Deaths from chickenpox down
Deaths from chickenpox (the varicella virus) have dropped 97 percent in adolescents and children since the use of the vaccine began in 1995, new analysis shows.

"Every kid did get chickenpox and, in the pre-vaccine era, there were 3-4 million cases a year," Seward said. "What people may not have realized, every year, about 105 people died of chickenpox. About half of those were children and about 11,000-12,000 were hospitalized with severe complications. We started preventing the disease to really prevent those very serious complications."

Saturday, July 23, 2011


The report of the 30 June - 1 July meeting of the Independent Monitoring Board (IMB) report has been released. Although affirming that polio eradication can be achieved in the near-term, the IMB states that 'this will not happen if things continue as they are'. 

You can read the latest about the global battle to eradicate polio at the Global Eradication Initiative website.

For a contrary view check out this New York Times article about Polio eradication that contains some interesting comments about Bill Gates funding for the initiative in particular:

The effort has now cost $9 billion, and each year consumes another $1 billion. By contrast, the 14-year drive to wipe out smallpox cost only $500 million in today’s dollars. 

“Bill Gates’s obsession with polio is distorting priorities in other ... areas. Global health does not depend on polio eradication.” 

Tuesday, July 19, 2011

Attractiveness of humans to mosquitoes

There were a couple of questions on this paper, Malaria Infection Increases Attractiveness of Humans to Mosquitoes, that I wanted to check up on, and like I said, the answer is usually more complicated and more interesting than expected.

First, children infected with malaria but NOT producing gametocytes were no more attractive to mosquitoes than uninfected children. Not even slightly. The data points are practically on top of one another.

BUT, what I hadn't realized was that when they treated the children the ones that had been infected with gametocytes were then LESS attractive to mosquitoes. Strange.

A striking aspect of our results is that former gametocyte carriers (i.e., after treatment) seem to repel mosquitoes, as only 22%, i.e., less than one third, of the responding mosquitoes prefer these children (t-test: t = −2.203, df = 11, p = 0.050; Wilcoxon signed-rank test: p = 0.040). An explanation for this result could be based on the slight anaemia in previously infected children. Mosquitoes might sense this anaemia and prefer those children with a higher concentration of red blood cells as it is these that the mosquitoes require. This would indicate a remarkable adaptation by the mosquitoes. The interpretation, however, would predict that the children previously infected with the asexual stage should also repel mosquitoes—but this was not observed.

Monday, July 18, 2011

Good news for tea and coffee drinkers

It's amazing how many times there is a story in the news at the same time we cover the topic in class.

In the news at the moment is the interesting story that coffee and tea drinkers could be at lower risk of a developing a deadly drug-resistant staph infection.

As part of the 2003-04 National Health and Nutrition Examination Survey (NHANES), more than 5,000 Americans from across the country were tested for methicillin-resistant Staphylococcus aureus — better known by its abbreviation, MRSA — in the nasal cavity. Although carrying MRSA in the nose is not at all dangerous by itself, some studies show that nasal colonization may put people at higher risk of systemic MRSA infection throughout the body, and that can be fatal.

The results of the NHANES testing, published in the July/August issue of the journal Annals of Family Medicine, showed that 1.4% of the nationally representative survey participants had nasal MRSA carriage. However, people who drank coffee or hot tea at least once a month were only about half as likely to be infected as those who did not — even after adjusting for age, race, sex, recent antibiotic use and hospitalization history, and a few other variables.

Coffee and tea drinkers saw advantages of about the same magnitude, no matter which drink they favored. The study authors say they cannot be sure why people drinking tea or coffee might be less likely to have nasal MRSA carriage, but that it could be the result of antimicrobial compounds known to exist in the beverages.

The actual research paper in the Annals of Family Medicine, Tea and Coffee Consumption and MRSA Nasal Carriage, is very readable. It's also interesting to see that statistic that 1.4% of people had nasal MRSA. Given that about 25% of people are carriers of S.aureus (actually 28% in this study) it means that about 1 in 17 of those carriers had the MRSA strain.

Sunday, July 17, 2011

Researchers believe they may be a step closer to HIV vaccine

Researchers are hoping they are one step closer to a HIV vaccine – using HIV. At the 6th International AIDS Society Conference on HIV Pathogens, Treatment, and Prevention in Rome, researchers with the Maryland-based VirxSys Corporation announced the findings of their VRX1273 vaccine.

The vaccine is a genetically altered version of SIV, the version of HIV found in non-human primates. Over the course of six months, five infected monkeys were injected with the vaccine three times, while five others were given a placebo vaccine. After 18 months, it was found that 40% of the vaccinated monkeys had very low to undetectable amounts of virus in their bodies.

Friday, July 15, 2011

Pills to prevent HIV

Pills found to be highly effective in preventing HIV transmission
Experts hail a pair of trials involving heterosexual couples in Africa as a breakthrough in AIDS prevention. The studies show that taking a pill containing one or two drugs each day can decrease transmission of HIV by as much as three-quarters.

The report above is from the LA Times. The report from the Guardian seems a little more realistic:
Daily pill can prevent HIV infection
Groundbreaking studies suggest tablets could help partners of people with HIV protect themselves – secretly, if necessary.

Wednesday, July 13, 2011

Did the CIA Fake a Vaccination Campaign?

Apparently the CIA faked a vaccination campaign in an attempt to collect DNA samples from Bin Laden's children. The scheme was concocted by the C.I.A. earlier this year when they were struggling to learn whether Bin Laden was hiding in the compound in Pakistan.

There's a fairly factual report in the New York Times, Vaccination Ruse Used in Pursuit of Bin Laden, but they miss the serious implications of this that are discussed in this post at Wired, File Under WTF: Did the CIA Fake a Vaccination Campaign?

This is awful. It plays, so precisely that it might have been scripted, into the most paranoid conspiracy theories about vaccines: that they are pointless, poisonous, covert shields for nefarious government agendas meant to do children harm.

The fallout from this scheme has already begun, Reported CIA vaccine ruse sparks fear in Pakistan.

One of the Pakistani Taliban's top commanders, Maulvi Faqir Mohammed, recently called on people in the northwest to avoid vaccines offered by the international community, claiming they were made with "extracts from bones and fat of an animal prohibited by God — the pig."
"Don't fall prey to these infidel NGOs and this U.S.-allied government and its army," said Mohammed over the illegal radio station he transmits from his sanctuary in eastern Afghanistan.
Pakistani officials and their international partners have pushed back against these claims, but the CIA's reported activities in the country may have made their job that much harder. 

Tuesday, July 12, 2011

The Emerging Race to Cure HIV Infections

 A recent article in Science, The Emerging Race to Cure HIV Infections, describes the effect that Timothy Ray Brown's cure has had on the research community. The abstract is below but the full article is fairly short and very interesting.

Four years after Timothy Ray Brown received bone-marrow transplants to fight leukemia, the most sophisticated labs in the world cannot find any trace in his body of the HIV that had infected him for 12 years. Brown is the only living human, a growing consensus contends, to be cured. Brown's treatment clearly does not offer a road map for many others. After all, the expensive, complex, and risky transplant only made sense because Brown was dying from leukemia. Nor is it clear exactly which components of the extensive transplant regimen cleared the virus from his body. But Brown's case has moved the much-ridiculed idea of curing HIV onto the most scientifically solid ground it has yet occupied, say leading AIDS researchers. Brown's case showed for the first time that it is possible to rid the body of the virus—even from the minuscule reservoirs where the virus can hide out for years, evading both the immune system and antiretroviral drugs (ARVs). His astonishing turnaround also raised hopes that other, more practical drugs and immune system modulators might find and destroy every last bit of virus—or at least reduce it to such low levels that people no longer need ARVs.

Monday, July 11, 2011

Bad news everyone..

 Hitting the news today is a report on a new strain of gonorrhea that is resistant to all available antibiotics.

Here's a link to the MSNBC article quoted below, but you can find hundreds of news reports on the story via google news.

For several years, public health officials have been concerned that gonorrhea, one of the most prevalent STDs in the world, might become resistant to the last widely available antibiotics used to treat it, a class of drugs called cephalosporins.  

Now, it has.

In the space of one week, infectious disease specialists have received a one-two punch of bad news that confirms those fears, including the discovery of a new, cephalosporin-resistant strain of the bacteria.

Saturday, July 9, 2011

Cholera returns

From the Washington Post today:
Cholera returns to rural Haiti amid fears that relief funds to contain it are running dry

The epidemic began in rural Haiti last fall, likely brought by U.N. peacekeepers from Nepal. It swept through the countryside of an impoverished nation already overwhelmed by a January 2010 earthquake that left hundreds of thousands homeless and by political instability following disputed elections.
The disease faded in winter and spring, when rain is less frequent, and many aid workers moved on. U.N. troops in Haiti turned their attention to the country’s many other pressing problems.
Now there is a fear among aid workers who remain that there won’t be enough resources if the latest surge gets much worse.

Wednesday, July 6, 2011

Insects, disease and history

If you are interested in history then there are a number of interesting articles at the 'Insects, disease and history' website: a site devoted to understanding the impact that insects have had on world history. This site focuses on the influence of insect-borne disease on history...

There are several articles on Typhus including, The Historical Impact of Epidemic Typhus , Typhus Fever on the Eastern Front in World War I and Insects, Disease, and Military History: The Napoleonic Campaigns and Historical Perception.

Tuesday, July 5, 2011

Bone Church

I was reading a novel this weekend and came across a reference to the Bone Church outside Prague in the Czech Republic. The Sedlec ossuary contains between 40,000 and 70,000 human skeletons which have been artistically arranged to form decorations and furnishings for the chapel. During the Black Death thousands of people were buried in the cemetery, many in mass graves, and when the cemetery was full and needed expanding a church was built in the center. Skeletons exhumed during the construction of the church were used to decorate it.

Saturday, July 2, 2011

The smart of the knife...

I mention the Crimean war (1853-1856) in this class a couple of times and I've posted on it here a couple of times previously (eg Crimean War Photographs and MiniƩ balls and infection before penicillin) but like most of you, I suspect, I don't really know much about it. So when I was in Goleta library last week and noticed Orlando Figes new history of the Crimean War I thought I'd pick up a little holiday weekend reading.

Interesting stuff, I had no idea the extent to which this was a religious war. But most shocking was the passage on the armies response to the new anaesthetic gases such as chloroform which were just becoming available. The use of such anaesthetic gases was embraced by the Russians, who used them to increase their surgical survival rates, but rejected by the British who favored a stiff upper lip. The Principal medical officer of the British Army, Dr John Hall, issued a memorandum cautioning:

'against the use of chloroform in the severe shock of serious gunshot wounds... for however barbarous it may appear, the smart of the knife is a powerful stimulant; and it is much better to hear a man bawl lustily than to see him sink silently into the grave.'

All this surgical amputation was, of course necessary because of the threat of infection - mainly by gram positive bacteria. For upper leg amputations, the most dangerous and the most common type of surgery, the Russian army used the new anaesthetics to improve their survival rate to 25%. In the British army it remained at 10%....