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Global Health, Haiti, Infectious Disease, Public Health, Technology

A sanitation solution: Stanford students introduce dry toilets in Haiti

A sanitation solution: Stanford students introduce dry toilets in Haiti

sanitation-toilet-movedIn the United States, we often take for granted the relationship between health and sanitation. Not so in Haiti, where some people dispose of their feces in plastic bags they throw into waterways. As a result, waterborne diseases like cholera are common.

But what’s to be done? Flush toilets guzzle gallons of water and depend on an entire sewage system — an unfeasible option in many developing nations. To fill the gap, a pair of Stanford civil and environmental engineering graduate students have developed a program called re.source, which provides dry household toilets, and empties them for about $5 a month.

From a recent Stanford News story:

Unlike most sanitation solutions that only address one part of a dysfunctional supply chain, container-based sanitation models, such as the re.source service, tackle the whole sanitation chain. The re.source toilets separate solid and liquid waste into sealable containers, and dispense a cover material made of crushed peanut shells and sugarcane fibers that eliminates odors and insect infestations. The solid waste is regularly removed by a service, which takes it to a disposal or processing site to be converted to compost and sold to agricultural businesses.

The re.source students — Kory Russel and Sebastien Tilmans — work under the guidance of Jenna Davis, PhD, an associate professor of civil and environmental engineering. They started small, with a free pilot phase in 130 households in a Haitian slum, but the service has expanded to include 300 additional households with plans to introduce a service in the capital, Port-au-Prince.

The project is part of a larger Stanford focus on water issues ranging from safe drinking water to environmental concerns.

Previously: Waste not, want not, say global sanitation innovators, Stanford pump project makes clean water no longer a pipe dream and Award-winning Stanford documentary to air on PBS tonight
Photo by Rob Jordan

CDC, Ebola, Global Health, In the News, Infectious Disease

All hands on deck: Doctor answers call to work on largest Ebola epidemic in history

DSCN0895 cropped and resizedIn the nearly 70-year history of the Centers for Disease Control and Prevention (CDC) only three disasters called for an “all hands on deck,” Level 1 emergency response – Hurricane Katrina in 2005, the H1N1 pandemic of 2009 and the Ebola epidemic of 2014. This Ebola epidemic – the largest one in history – was the first assignment for Christopher Hsu, MD, PhD, from the Epidemic Intelligence Services (EIS) officer training program at the CDC.

As an EIS officer in the Division of High-Consequence Pathogens and Pathology at CDC, Hsu investigates and studies deadly and exotic pathogens like chikungunya, monkeypox, rabies and Ebola.

Given Hsu’s work on disease at CDC, I was surprised to learn that the topic of his prestigious three-year fellowship at Stanford was cancer, not infectious disease. I asked Hsu about this and what it’s like working on the largest Ebola epidemic in the world. He summed it up this way: “I get to work with very deadly and interesting diseases. I travel, see new cultures and am immersed in my work. I’m not just studying the disease; I’m in the jungle, studying the disease where it began with the people from that region. It’s a great honor to be in that position.”

Hsu’s switch from studying cancer to investigating infectious disease sounds drastic, but it wasn’t much of a stretch, he explained. Hsu earned a PhD in veterinary pathobiology studying interspecies disease transmission before he began studying cancer at Stanford. “I enjoyed the work, but I also recalled some savvy advice a mentor once said to me, ‘you excel where your passion lies.’ I realized I lacked the fire in the belly.”

DSCN0828 cropped and resized-2When Hsu told his peers and mentors at Stanford he wanted to study infectious disease, Philip Pizzo, MD, former dean of the medical school and a specialist in oncology and infectious diseases, supported his decision. “I am very grateful to him,” Hsu said. “He probably doesn’t realize this, but he was a huge influence on where I am today after Stanford.”

Two years later, Hsu and his cohort of EIS officers, affectionately nicknamed “the Ebola Class,” learned the 2014 Ebola outbreak had just been classified as a Level 1 emergency. CDC Director Tom Frieden, MD, MPH, visited Hsu’s class and personally asked them to take up the call to work on Ebola. Hsu’s cohort was a mix of physicians, nurses, veterinarians, and scientists with specialties ranging from malaria to violence prevention, but after Frieden’s visit, their professional interests no longer mattered. “We decided we were all working on Ebola in some capacity,” Hsu said.

Many of the EIS officers in Hsu’s Ebola class have completed one or two 30 to 90-day deployments to prevent and control Ebola in West African countries with widespread transmission (Guinea, Liberia and Sierra Leone), or in one of the other countries where Ebola occurred in the past. Hsu describes his disease fieldwork as part detective work and part disease control. “I investigated who was sick, what their symptoms were and who had contact with them,” Hsu said.

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In the News, Infectious Disease, Nutrition, Pediatrics

Raw milk still a health hazard, says Stanford doctor

Raw milk still a health hazard, says Stanford doctor

MoooooooIn spite of looser regulations around the sale of unpasteurized milk, it’s still unsafe to drink. That’s the message from Stanford pediatric infectious disease expert Yvonne Maldonado, MD, who is quoted in a new story on Today.com about the relaxation of raw-milk regulations in West Virginia and Maine.

In the United States, each state writes its own rules for in-state sales of raw milk, and they vary — a lot. Until last week, West Virginia required all dairy products sold in the state to be pasteurized, or heated briefly to kill germs. The state’s new laws allow for “cow shares,” in which individuals can pay to share ownership of a cow in exchange for some of the cow’s unpasteurized milk. Maine, meanwhile, is considering relaxing its license regulations on farmers who sell milk directly to consumers. (Other states take different approaches, ranging from entirely banning raw milk sales to allowing it in retail stores.)

Raw-milk aficionados claim that unpasteurized dairy products are safe and have health benefits.

Not so fast, says Maldonado, who was the lead author of the American Academy of Pediatrics’ 2013 policy statement discouraging the consumption of raw milk. In the Today.com story, she explains:

“People want to be more responsible for their sustainable environment and what they are putting into their bodies but they conflate the two issues because natural doesn’t always equal healthy,” says [Maldonado].

… “Our recommendations are evidence-based and there is no scientific evidence that drinking raw milk is better than drinking pasteurized milk and milk products,” says Maldonado, an infectious disease expert and pediatrician at Lucile Packard Children’s Hospital. “But we do see a very large number of diseases and illnesses from raw milk and raw milk products and the infections can be just horrible,” causing diarrhea, fever, cramps, nausea and vomiting, and some may even become systemic.

Previously: Stanford pediatrician and others urge people to shun raw milk products and Stanford study spoils hopes that raw milk can aid those who are lactose-intolerant
Photo by Steven Zolneczko

Global Health, Health Policy, Infectious Disease

“Made-in-India” vaccine could save thousands of children

"Made-in-India" vaccine could save thousands of children

5559524166_510ebb57a0_zIndia reached a milestone this week with the introduction of a novel rotavirus vaccine, the first vaccine designed entirely in the developing world. The vaccine is not only safe and effective, but also affordable; the manufacturer, Bharat Biotech, has pledged to make it available for $1 to governments in low-income countries.

The vaccine, known as ROTAVAC, will be used to fight a disease that kills 80,000 children a year in India alone. On a global scale, rotavirus, which causes severe diarrheal disease, is responsible for some 450,000 childhood deaths and 2 million hospitalizations.

The vaccine was developed through a unique partnership supported by the Indo-U.S. Vaccine Action Program, which was chaired until recently by Harry Greenberg, MD, senior associate dean for research at the School of Medicine. Greenberg was a lead inventor of the first-generation vaccine for rotavirus.

“The ROTAVAC project is a beautiful example of the great power of team science,” Greenberg told me. “The vaccine is a culmination of a very large and disparate group of people and organizations, all working together for a common goal: to produce a safe, effective and affordable vaccine to prevent severe, rotavirus-associated diarrhea in Indian children.”

During a three-day visit to India in January, U.S. President Barack Obama and Indian Prime Minister Narendra Modi had praised the “highly successful collaboration” that lead to the development of the vaccine. Prime Minister Modi was on hand for ceremonies Monday announcing the launch of the vaccine, which the Indian government will make available in public clinics across the country.

The vaccine originated from a weakened strain of rotavirus that was isolated from an Indian child in the mid-1980s. It went through a long development process which included investigators from 13 institutions and culminated in a randomized, double-blind clinical trial involving nearly 6,800 infants in India. The results, published in the Lancet in 2014, showed it was as effective as two other licensed, commercial oral rotavirus vaccines.

The vaccine was developed with support from the National Institutes of Health and the U.S. Centers for Disease Control and Prevention, among others.

“The impact of this vaccine to improve child survival is enormous,” said Roger Glass, MD, PhD, director of the Fogarty International Center at the NIH. “Our groups at the CDC and NIH are proud to be an integral part of this longstanding and enormously successful collaboration with our Indian colleagues.”

Previously: President Obama and Indian Prime Minister praise partnership that led to rotavirus vaccine, Life-saving dollar-a-dose rotavirus vaccine attains clinical success in advanced India trial and Trials, and tribulations, of a rotavirus vaccine
Photo by The Bill and Melinda Gates Foundation

Chronic Disease, Immunology, Infectious Disease, Neuroscience, Research, Stanford News

ME/CFS/SEID: It goes by many aliases, but its blood-chemistry signature is a giveaway

ME/CFS/SEID: It goes by many aliases, but its blood-chemistry signature is a giveaway

signature

It’s the disease that dare not speak its name without tripping over one of its other names. Call it what you will – chronic fatigue syndrome (CFS), myalgic encephalomyelitis (ME) or its latest, Institute of Medicine-sanctioned designation, systemic exertion intolerance disease (SEID). It’s very real, affecting between 1 million and 4 million people in the United States alone, according to Stanford infectious-disease sleuth Jose Montoya, MD, who has closely followed more than 200 SEID patients for several years and done extensive testing on these patients in an effort to find out what’s causing their condition.

Different authorities have quoted different numbers regarding those with SEID. The name-calling and number-assigning squishiness stems from the fact that beyond its chief defining symptom – overwhelming, unremitting exhaustion lasting for six months or longer – it’s tough to pin down. Additional symptoms can range from joint and muscle pain, incapacitating headaches or food intolerance to sore throat, lymph-node enlargement, gastrointestinal problems, abnormal blood-pressure or hypersensitivity to light, noise or other sensations.

Research into the hows and whys of SEID has been plagued by the inability to establish any characteristic biochemical or neuroanatomical underpinnings of the disorder. Although many viral suspects have been interrogated, no accused microbial culprit has been indicted. To this day, there are no valid laboratory tests for diagnosing SEID.

But a burst of insight into SEID’s physiological substrate came only months ago when Stanford neuroradiologist Mike Zeineh, MD, PhD, working with patients from Montoya’s registry, found that they shared a pattern of white-matter loss in specific parts of the brain. The discovery drew a great deal of attention in the press as well as the CFS community. (See our news release about that study for details.)

Now a high-profile, multi-institution team including Montoya has published a study in Science Advances showing yet another physiological basis for a diagnosis of SEID: a characteristic pattern, or “signature,” consisting of elevated levels of various circulating immune-signaling substances in the blood.

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Cancer, Evolution, Genetics, Infectious Disease, Microbiology, Research, Stanford News

Bubble, bubble, toil and trouble – yeast dynasties give up their secrets

Bubble, bubble, toil and trouble - yeast dynasties give up their secrets

yeasty brew

Apologies to Shakespeare for the misquote (I’ve just learned to my surprise that it’s actually “Double, double, toil and trouble“), but it’s a too-perfect lead-in to geneticist Gavin Sherlock’s recent study on yeast population dynamics for me to be bothered by facts.

Sherlock, PhD, and his colleagues devised a way to label and track the fate of individual yeast cells and their progeny in a population using heritable DNA “barcodes” inserted into their genomes. In this way, they could track the rise and fall of dynasties as the yeast battled for ever more scarce resources (in this case, the sugar glucose), much like what happens in the gentle bubbling of a sourdough starter or a new batch of beer.

Their research was published today in Nature.

From our release:

Dividing yeast naturally accumulate mutations as they repeatedly copy their DNA. Some of these mutations may allow cells to gobble up the sugar in the broth more quickly than others, or perhaps give them an extra push to squeeze in just one more cell division than their competitors.

Sherlock and his colleagues found that about one percent of all randomly acquired mutations conferred a fitness benefit that allowed the progeny of one cell to increase in numbers more rapidly than their peers. They also learned that the growth of the population is driven at first by many mutations of modest benefit. Later generations see the rise of the big guns – a few mutations that give carriers a substantial advantage.

This type of clonal evolution mirrors how a bacterium or virus spreads through the human body, or how a cancer cell develops mutations that allow it to evade treatment. It is also somewhat similar to a problem that kept some snooty 19th century English scientists up at night, worried that aristocratic surnames would die out because rich and socially successful families were having fewer children than the working poor. As a result, these scientists developed what’s known as the “science of branching theory.” They described the research in a paper in 1875 called “On the probability of extinction of families,” and Sherlock and his colleagues used some of the mathematical principles described in the paper to conduct their analysis.

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Big data, Genetics, Global Health, Infectious Disease, Research, Science

The benefit of mathematical models in medicine

The benefit of mathematical models in medicine

1024px-Free_range_chicken_flockTheoretical modeling sounds like it has, at best, a distant connection to the day-to-day concerns of medical professionals who care for or research the needs of patients. But when I spoke recently with Noah Rosenberg, PhD, a population geneticist at Stanford and editor of the scientific journal Theoretical Population Biology, he pointed out that modeling can offer distinct benefits to those in medical fields like epidemiology and genetics.

“We see a lot of occasions in public discussions of areas like the spread of epidemics, the demography of aging populations, and big data analysis in genomics where part of the backdrop arises from theoretical population biology work,” Rosenberg said. “We hope to spread the word that there is a place for the kinds of theoretical and mathematical insights that can contribute to those important topics.”

Rosenberg noted that papers in the journal often span the divide between mathematics and biology, but they have a few things in common. In an editorial he published last month in the journal, Rosenberg describes an ideal study for the journal – namely that first, “the mathematical work is motivated by a genuine problem in biology, and there’s a need for theory to resolve the problem,” he said. Secondly, the mathematical work is substantial enough that it uncovers new potential relationships or new explanations for a phenomenon, and lastly, that the advances contribute to our understanding of biology – though some of the best papers in the field can also have a big impact on the field of mathematics, too.

When I asked him to talk about what that would mean for studies that touch on health research, he pointed me to a couple of fascinating papers. One is a paper by Shai Carmi, PhD, and colleagues that explains a new way to look at shared DNA strands between people in order to understand their relatedness and the amount of overlap in their genomes. This has implications for how we think about “the way in which genes descend within families, including genes that may be related to a disease.” It’s one of the journal’s most downloaded papers, Rosenberg told me.

The second is a study by Maciej Boni, PhD, and colleagues that incorporates how decisions that poultry farmers in Southeast Asia make about market conditions might affect the spread of avian influenza in their flocks. When avian flu is identified in a region, poultry flocks are usually culled. It’s an interesting example of how human behavior can affect disease dynamics.

Rosenberg noted that the studies and models that are able to incorporate human behavioral patterns are among the most interesting that he sees. Nailing down how people’s decisions affect the course of an outbreak is notoriously difficult, but like the avian influenza paper demonstrates, mathematical models make it possible to explore the consequences of different assumptions about these decisions.

Rosenberg says that it’s even possible to make mathematical models of cultural practices (like deciding not to immunize your children) and how they spread among groups of people. One public laboratory this interaction is currently playing out in is the measles outbreak that got its start at Disneyland in December. The outbreak topped 100 cases nationwide, mostly among families that refuse to vaccinate their children. “It’s the intersection between human behavior and dynamics of disease,” he said. “Putting those together in a mathematical model to predict what might happen is the kind of work that appears in Theoretical Population Biology.”

Previously: Stanford physician Sanjay Basu on using data to prevent chronic disease in the developing world and Facebook app models how viruses spread through human interaction
Photo by Woodley Wonderworks

Immunology, Infectious Disease, Public Health, Research

Is honey the new antibiotic?

Is honey the new antibiotic?

3535805377_807788e3e1_z…Well, not quite. But recent research shows that honey does have infection-fighting properties surprisingly similar to the common antibiotic ampicillin. And even more importantly, honey worked just as well against bacteria that had developed a resistance to ampicillin, which is good news as the medical community raises awareness about antibiotic resistance.

The study, which was recently published in PLOS ONE, compared the effects of Canadian honey and ampicillin on E. coli bacteria. The most common kind of antibiotics – beta-lactams, which includes ampicillin – work by destroying the cell wall of a bacterium. This prohibits the bacterium from surviving, growing, and reproducing. In the experiment, the researchers used scanning electron microscopy to visualize the changes in the bacterial cultures’ cell structures. They saw that honey and ampicillin had similar effects on the shapes of the E. coli, that they affected it to a similar degree, and that honey had equal effects on normal and antibiotic-resistant E. coli.

As reported on the PLOS blog:

While scientists have yet to confirm the exact compounds responsible, the results of the above study support the idea that honey and ampicillin may have similar antibacterial efficacies, with possibly different mechanisms of attack.

But before you start smothering your toast with gooey goodness each morning or adding heaping spoonfuls to your tea, keep in mind that more research is needed to better understand the potential for honey’s medicinal use.

Previously: A look at our disappearing microbes
Photo by bionicgrrl

Events, Immunology, Infectious Disease, Microbiology, Public Health

A look at our disappearing microbes

A look at our disappearing microbes

8146322408_5312e9deb2_zCould obesity, asthma, allergies, diabetes, and certain forms of cancer all share a common epidemiological origin? NYU microbiologist Martin Blaser, MD, thinks so – he calls these “modern plagues” and traces them to a diminished microbial presence in our bodies, caused by the overuse of antibiotics and the increased incidence of caesarian sections.

I attended a recent public lecture sponsored by UC Santa Cruz’s Microbiology and Environmental Toxicology department, during which the charismatic Blaser cited statistics about antibiotic use in childhood. Alarmingly, American children receive on average seventeen courses of antibiotics before they are twenty years old, taking a progressively bigger toll on their internal microbial ecosystems. We also have an unprecedented rate of c-sections – at nearly 33 percent. Babies delivered this way are deprived of contact with their mothers’ vaginal microbes, which in vaginal deliveries initiates the infant’s intestinal, respiratory, and skin flora. Breastfeeding has implications for beneficial bacterial transfer, too.

It’s not news that antibiotics are being overused – Stanford Medicine hosts an Antimicrobial Stewardship Program dedicated to this cause, and the CDC has been hosting a campaign for awareness about appropriate antibiotic use for several years, including their use in farm animals. (Seventy to eighty percent of antibiotic use takes place on farms to promote growth – that is, not for veterinary reasons.)

Overuse leads to antibiotic resistance, a serious problem. Meanwhile, research by Blaser and others – notably Stanford microbiologist David Relman, MD – has shown that abundant bacterial and viral life is essential to healthy bodies, and that imbalances in the microbial ecosystems that inhabit our gut play an important role in the chronic diseases of the modern age. Blaser said he is concerned that we’re going down a path where each generation has fewer and fewer species of microbes; part of his research is to compare human gut biodiversity in different parts of the globe, and people in remote areas of New Guinea have far more variety than those in Western nations.

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Global Health, Health Policy, In the News, Infectious Disease

President Obama and Indian Prime Minister praise partnership that led to rotavirus vaccine

President Obama and Indian Prime Minister praise partnership that led to rotavirus vaccine

Barack_Obama_talks_with_Narendra_ModiDuring his three-day visit to India, President Barack Obama issued a joint statement with Indian Prime Minister Narendra Modi praising the “highly successful collaboration” that led to the availability of a newly developed Indian rotavirus vaccine, which is expected to save 80,000 children in India alone each year.

The vaccine was developed with support from the Indo-U.S. Vaccine Action Program, co-chaired since 2009 by Harry Greenberg, MD, senior associate dean for research at the Stanford School of Medicine. Greenberg was the lead inventor of the first-generation vaccine for rotavirus, a severe diarrheal disease that kills between 300,000 and 400,000 children each in the developing world.

“This is the VAP’s biggest accomplishment to date,” Greenberg told me from Taiwan, where he is attending a conference. “The program really helped support the development of a new safe and effective rotavirus vaccine from the start to finish. And it’s the first time ever that a new vaccine was developed in a less developed country by and for that country and became licensed.”

The vaccine initiative, funded by the U.S. Public Health Service and the Indian government, was created in 1987 to help advance the development of new vaccines of importance to India. The NIH manages research grants in the United States for the vaccine program.

“The VAP has been the most successful, continuous program we have with India,” Roger Glass, MD, PhD, director of the NIH’s Fogarty International Center, wrote in an email from India to top NIH officials. “It’s amazing to me that this little research project on rotavirus with Harry Greenberg and George Curlin (former deputy director of NIH’s Division of Microbiology and Infectious Diseases) has turned into a real product that is being launched and will be used.”

A low-cost version of the vaccine, known as Rotavac, is being manufactured in India and was launched into the marketplace on Jan. 23, Greenberg said. It was the result of an unusual team effort involving diverse multinational groups of investigators from 13 institutions seeking to create a vaccine that was not only safe and effective, but also affordable enough for use in India and other low-income countries, Greenberg said. The Indian government is negotiating to purchase the vaccine for public distribution. The vaccine also will compete in the private market against at least two other commercially available vaccines.

In the joint statement, the two world leaders pledged continued support for the vaccine program, and Greenberg, who recently stepped down from his chairmanship, made an argument for now focusing the attention of the vaccine partnership on respiratory syncytial virus (RSV), a potentially serious lung disease that is prevalent in children in India and in other regions as well.

“RSV is an incredibly important pediatric pathogen all over the world, and there is now potential for great progress,” Greenberg said. “I suggested to VAP that it think about RSV as a new target for research. It has a huge public impact and it may well be that there are great advances to be made in the near future. I think that idea resonated with the people. We will see.”

Previously: Life-saving dollar-a-dose rotavirus vaccine attains clinical success in advanced India trial and Trials, and tribulations, of a rotavirus vaccine
Photo courtesy of The White House

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