As bird flu cases mount, a new tool for containing global outbreaks

Source: St. Michael's Hospital

Another day, another handful of new H7N9 cases, another death to report in eastern China.

The new bird flu strain continues to puzzle and alarm health officials in China and around the world. But thankfully, H7N9 isn't spreading easily between people -- yet.

Public health authorities are tightly crossing their fingers that the virus fails to mutate into a more dangerous form and will eventually just sputter out. The fear is that it will evolve into something more infectious -- like H1N1, which popped up in Mexico and caused a pandemic in 2009.

Luckily, H1N1 wound up being a pretty wimpy virus and caused mostly just mild disease -- but from the looks of it, an H7N9 pandemic would prove much more devastating.

You can bet public health officials worldwide are already preparing for that eventuality, which is why there is no better timing for this new paper, published in the Bulletin of the World Health Organization.

The paper comes from a group of scientists led by Dr. Kamran Khan, an infectious disease physician at St. Michael's Hospital and founder of BioDiaspora, a really interesting program that uses global flight patterns to predict the spread of new infectious diseases. (Khan spoke to the Toronto Star earlier this week about the likelihood of an H7N9-infected traveller from China coming to Canada -- for now, the chances of that are pretty low).

When outbreaks hit, public health officials have to make difficult but necessary decisions to prevent a virus from spreading further. They might consider airport screening, for instance -- but such measures should not be taken lightly, because they are hugely disruptive and require major resources.

So such actions need to have a strong scientific basis -- and that's where Khan's paper comes in. Looking at the 2009 H1N1 pandemic, Khan and his co-authors analyzed flight itineraries for more than 580,000 at-risk travellers who flew out of Mexico in May 2009.

They concluded it is much more efficient to screen passengers exiting an outbreak country than those arriving at their destination airports. According to Khan's estimates, all at-risk travellers during H1N1 could have been assessed with exit screening at Mexico's 36 international airports.

And 90 per cent of all at-risk travellers worldwide could have been captured by screening at just six of Mexico's largest international airports, coupled with targeted screening at two airports in Shanghai and Tokyo.

On the other hand, trying to screen those same travellers when they arrived at their destination airports would have required setting up checkpoints at 82 international airports in 26 countries.

And screening all international travellers at their arrival destinations would have been staggeringly difficult. During the H1N1 pandemic, this would have meant screening 67.3 million grumpy travellers at 1,111 airports -- and for every one person who actually had exposure to H1N1, 116 people would have been unnecessarily screened.

Using their findings, Khan and his co-authors developed a basic tool to help public health officials decide whether, and how, to set up airport screening. The tool takes three things into account: 1) whether there is effective exit screening at the source of the outbreak 2) whether a city receives direct flights from the outbreak country 3) the incubation period of the disease.

"One never waits for a fire to spread before putting it out," Khan said in a press release. For now, the H7N9 situation is just a few dozen sparks in eastern China -- let's hope it doesn't become a flame we have to snuff out.

Update: Canadian Press reporter Helen Branswell has written a great article about Khan's study, which has now been posted on the Toronto Star's website here.

Jennifer Yang is the Star’s global health reporter. She previously worked as a general assignment reporter and won a NNA in 2011 for her explanatory piece on the Chilean mining disaster. Follow her on Twitter: @jyangstar

PHOTOS: From destroyed weapons to musical instruments

Mexican artist Pedro Reyes holds one of his musical instruments sculpted from recycled guns at the Lisson Gallery on Tuesday in London. Reyes received 6,700 destroyed weapons from the Mexican government from which he sculpted two groups of instruments. (Peter Macdiarmid/Getty Images)

The first, a series titled "Imagine", is an orchestra of 50 instruments, from flutes to string and percussion instruments, designed to be played live. (Peter Macdiarmid/Getty Images)

The second, "Disarm", is an installation of mechanical musical instruments, which can either be automated or played live by an individual operator using a laptop computer or midi keyboard. (Peter Macdiarmid/Getty Images)

A guitar made from recycled gun parts is shown at Reyes' "Disarm" exhibition. (Peter Macdiarmid/Getty Images)

Tom Lamb plays a musical instrument made from recycled gun parts at the Lisson Gallery. (Peter Macdiarmid/Getty Images)

Musical instruments made from recycled gun parts are played at the Lisson Gallery. (Peter Macdiarmid/Getty Images)

Mexico's 'missing' and a debate at Harvard

It’s a staggering figure: 26,121.

That’s the number of people who have “disappeared” in Mexico during the past six years as the government took its war against the country’s drug cartels into the streets.

And that’s the government’s own number.

It was released this week, hard on the heels of a Human Rights Watch report that was harshly critical of the government’s use of violence against violence in combating the country’s drug scourge.

But in conducting that war, HRW charges, the government threw fundamental human rights under the bus.

“Mexico’s security forces have participated in widespread enforced disappearances,” Human Rights Watch charged in a 176-page report.

The NGO documented some 250 “disappearances” from Dec. 2006 to Dec. 2012, and in 149 of those found compelling evidence of direct participation by state security forces.

None of that can be good for at least one lecturer at Harvard’s prestigious Kennedy School of Government: former Mexican President Felipe Calderon.

The disappearances occurred during his watch and, according to the report, involved every branch of the state’s security apparatus: Army, Navy, federal and local police.

While the report stops short of baldly accusing Calderon of approving such methods – the inference is mighty strong.

A former Harvard alum, Calderon is currently teaching and compiling case studies at the KSG as part of a year-long residency that began in January.

His successor, President Pena Nieto, is now dealing with the aftermath.

One HRW official called Mexico’s problem, “one of the worst crises of disappearances in the history of Latin America.”

From the get-go, Calderon’s Harvard appointment was controversial and could now become more so.

A U.S. Border Patrol agent and a Mexican citizen compiled an online petition last month, endorsed by 35,000 people, urging Harvard to rescind the appointment.

“Calderon’s legacy is one of blood and corruption,” border agent John Randolph told BostInno, a Boston-based website. “Americans are very uninformed about the Mexican drug war.”

But Calderon’s removal is not likely to happen.

“We recognize that not everyone agreed with his policies or his approaches,” KSG Dean David T. Ellwood told the Cambridge Chronicle, “…but one of the fundamental tenets of the Kennedy School and all American universities is a free exchange of ideas.”

Bill Schiller has held bureau postings for the Toronto Star in Johannesburg, Berlin, London and Beijing. He is a NNA and Amnesty International Award winner, and a Harvard Nieman Fellow from the class of '06. Follow him on Twitter @wschiller

Canada and Mexico may be good friends, but don’t drive across the border...

Canada’s Foreign Affairs Minister John Baird reports he has just had an excellent meeting in Mexico, highlighting recent efforts to “facilitate trade and travel.”

It’s been 20 years since the North American Free Trade Agreement was signed and Mexico is now Canada’s third largest trading partner.

But, matters of money aside, according to the government of Canada’s website, Canadians are advised to “exercise a high degree of caution” while travelling through parts of the country.

In fact, things are so bad, we are being told to fly, not drive over the border.

“It is highly advisable to travel to Mexico by air in order to avoid land border crossings through potentially dangerous regions. High levels of criminal activity, as well as occasional illegal roadblocks, demonstrations and protests remain a concern throughout the country,” the advisory said.

Baird did take a moment, while meeting Mexican officials, to speak of Canada’s need to continue “joint efforts to tackle security issues affecting both our countries and specifically, the fight against international drug trafficking, human smuggling and transnational organized crime.”

It was Baird’s second bilateral visit to Mexico.

We hope he flew.

Tanya Talaga is the Star's Global Economics reporter. Follow her on Twitter @tanyatalaga