Infection

Puerto Rico facing ‘disaster of major proportions’: �鶹��Ƶ public health expert

ullahnor — Thu, 28 Sep 2017 20:32:07 +0000

Puerto Rico facing ‘disaster of major proportions’: �鶹��Ƶ public health expert

ullahnor Thu, 09/28/2017 - 16:32

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People carry water in bottles retrieved from a canal due to lack of water after Hurricane Maria struck Puerto Rico a week ago (photo by Hector Retamal/AFP/Getty Images)

Noreen Ahmed-Ullah

Author legacy

Noreen Ahmed-Ullah

Topic

Global Lens

Dalla School of Public Health

Faculty of Medicine

Infection

Global

Health

A week after Hurricane Maria rolled through Puerto Rico, the island faces a public health crisis with no power and a growing shortage of drinking water and food.

The majority of the island’s 69 hospitals are without electricity or fuel for generators, according to the U.S. Department of Defense, and at least two people have died in an intensive care unit after it ran out of diesel. In many places, there’s no water to drink or bathe in or to flush toilets, with residents forced to use rainwater. U.S. Customs and Border Protection says a plane carrying 3,500 pounds of water, ready-to-eat Army meals, diapers and other supplies is on its way.

“This is a disaster of major proportions,” said Brian Schwartz, interim vice-president, science and health protection for Public Health Ontario, who is also an associate professor in the Faculty of Medicine and the Dalla Lana School of Public Health.

�鶹��Ƶ News spoke with Schwartz about the humanitarian crisis unfolding in Puerto Rico.

“I think the real concerns are injuries, heat-related illnesses and dehydration, and infections, both food- and water-borne and then potentially vector-borne as well,” he said. “Because of the power outages and because of the very likely years of inadequate infrastructure and lack of backup generators and backup power, this is going to be a very prolonged and painful recovery period.”

What are the public health and medical concerns right now?

Early on, there were injuries. Now, there’s water shortages and problems especially with heat and dehydration, floodwater from runoffs and tainted food that may be spoiled because of lack of refrigeration. Then, you’ve also got exacerbation of people with chronic diseases like diabetes and heart disease. If people don’t have access to medications or to their health practitioners, their regular diseases are going to get much worse on top of all the things that have happened to them in the first week. The other thing is mental illness. People with mental illness may be in big trouble and not be able to take care of themselves. It’s just a culmination of the injuries of the first week – the heat-related illnesses, dehydration and, on top of that, infections. Going forward, there’s concerns now about vector-borne diseases as well, which we know have been in the Caribbean. This has all been made worse by the fact that there’s no power, and it interferes with transportation. People can't get around, and they don’t have access to the basics of life, in terms of food and water and shelter.

Which vector-diseases are you concerned about at this stage?

Mosquito-borne diseases like malaria, Zika, chikungunya and Dengue fever. And of course, water-borne diseases like cholera are a big concern as well.

Would you consider it a public health crisis at this point?

This is definitely a public health crisis. If you look at the World Health Organization definitions, this fulfils the definition of a disaster. The difference between an emergency and a disaster is an emergency overwhelms a public health system. A disaster actually takes out the health system and the public health system, and so you have neither. This is a disaster of major proportions.

So if we have a disaster here, what should be the next priorities? What needs to happen?

The priority is to get the infrastructure up and running so that services can be provided. Failing that, getting field hospitals with generators to look after the injured, and most importantly getting potable drinking water and proper sanitation. Those basics are the most important things for the population. You can treat the injured, but you also need to look after the entire population. That may be happening, but it’s not happening very quickly. That may be related to a lot of the assets being deployed in other places right now.

Because of the power outages and because of the very likely years of inadequate infrastructure, and lack of backup generators and backup power, this is going to be a very prolonged and painful recovery period.

How to treat a leading cause of potentially fatal hospital-acquired infections?

sgupta — Fri, 06 Feb 2015 10:42:54 +0000

How to treat a leading cause of potentially fatal hospital-acquired infections? sgupta Fri, 02/06/2015 - 05:42

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Professor Leah Cowen, lead researcher on the study and Canada Research Chair in Microbial Genomics and Infectious Disease in �鶹��Ƶ's department of molecular genetics (photo courtesy NSERC)

Jim Oldfield

Author legacy

Jim Oldfield

Subheadline

Try combination drug therapy, new research suggests

Researchers at the University of Toronto have discovered that Candida albicans – a leading cause of potentially fatal hospital-acquired infections – rarely develops resistance to combination drug therapy and, when it becomes resistant, it also becomes less dangerous.

The team may also have found a new way to eliminate Candida albicans in humans.

Treating fungal infections through a single drug is increasingly ineffective because fungi quickly evolve drug resistance. Combination therapies have shown great promise in overcoming this problem, but scientists are concerned these combinations will spur even stronger resistance.

By testing combination therapies in Candida albicans, the �鶹��Ƶ researchers found that only a few strains of this fungus became drug-resistant, and that resistance came at a cost to the fungus.

“Drug resistance in fungal infections is a huge problem,” says Professor Leah Cowen, the lead researcher on the study who holds the Canada Research Chair in Microbial Genomics and Infectious Disease in �鶹��Ƶ's department of molecular genetics. “And if we’re going to treat these infections with drug combinations we need to know if they’ll readily become resistant. In Candida albicans we found a trade-off: a few strains gain some resistance but they become less ‘fit’ or functional when the drug is not present.”

The strains of the yeast that became resistant to drug combinations grew poorly in several stress conditions which are connected to human infections. For example, the resistant strains became weaker when they encountered oxidative stress, which happens when people become sick.

The researchers also found that resistant strains were vulnerable to immune cells called macrophages – further evidence that drug combinations may minimize drug resistance.

Cowen and her colleagues used Candida albicans strains they created in the lab, and they compared them to strains that were sensitive to combination therapy. They also confirmed their findings with yeast that had evolved resistance in a patient. “This was an important step, because what you learn in a test tube often doesn’t correspond to what happens in a patient,” says Cowen.

The journal Cell Reports published the findings.

Candida albicans is the third-leading cause of intravascular catheter-related infections, and when acquired from implanted medical devices, it kills one-third of people it infects. The number of fungal bloodstream infections has more than doubled over the last two decades, partly because successful treatments for cancer and AIDS have left many patients immune-compromised and vulnerable to infection.

Cowen and her lab have developed a combination therapy for Candida albicans that inhibits a protein in the yeast called Heat-shock protein 90 (Hsp90). They’re eager to test the therapy in patients, especially given Candida’s limited resistance to it. But a big challenge is that Hsp90 is also an important protein in humans, so they need to develop fungal-selective inhibitors that target it in yeast exclusively.

Recently, they found a way to do that.

Cowen’s team created and compared detailed maps of the drug-binding structure of Hsp90 in Candida albicans and in humans. In the yeast, the Hsp90 protein contains a larger pocket through which drugs can bind to it. So by increasing the size of the drug-like molecules, they engineered a potential therapy that targets Hsp90 only in yeast – the molecules are too big to bind in the Hsp90 drug-binding pocket in people.

“It seems to work,” says Cowen. “We have a handful of structures that preferentially inhibit the fungal protein over the human counterpart. With a little more funding we can improve on these molecules and ultimately test this treatment in patients.”

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