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Immunology, Infectious Disease, Microbiology, Public Health, Research, Stanford News

Paradox: Antibiotics may increase contagion among Salmonella-infected animals

Paradox: Antibiotics may increase contagion among Salmonella-infected animals

cattleMake no mistake: Antibiotics have worked wonders, increasing human life expectancy as have few other public-health measures (let’s hear it for vaccines, folks). But about 80 percent of all antibiotics used in the United States are given to livestock – chiefly chickens, pigs, and cattle – at low doses, which boosts the animals’ growth rates. A long-raging debate in the public square concerns the possibility that this widespread practice fosters the emergence of antibiotic-resistant bugs.

But a new study led by Stanford bacteriologist Denise Monack, PhD, and just published in Proceedings of the National Academy of Sciences, adds a brand new wrinkle to concerns about the broad administration of antibiotics: the possibility that doing so may, at least  sometimes, actually encourage the spread of disease.

Take salmonella, for example. One strain of this bacterial pathogen, S. typhimurium, is responsible for an estimated 1 million cases of food poisoning, 19,000 hospitalizations and nearly 400 deaths annually in the United States. Upon invading the gut, S. typhimurium produces a potent inflammation-inducing endotoxin known as LPS.

Like its sister strain S. typhi (which  causes close to 200,00o typhoid-fever deaths worldwide per year), S. typhimurium doesn’t mete out its menace equally. While most get very sick, it is the symptom-free few who, by virtue of shedding much higher levels of disease-causing bacteria in their feces, account for the great majority of transmission. (One asymptomatic carrier was the infamous Typhoid Mary, a domestic cook who, early in the 20th century, cheerfully if unknowingly spread her typhoid infection to about 50 others before being forcibly, and tragically, quarantined for much of the rest of her life.)

You might think giving antibiotics to livestock, whence many of our S. typhi-induced food-poisoning outbreaks derive, would kill off the bad bug and stop its spread from farm animals to those of us (including me) who eat them. But maybe not.

From our release on the study:

When the scientists gave oral antibiotics to mice infected with Salmonella typhimurium, a bacterial cause of food poisoning, a small minority — so called “superspreaders” that had been shedding high numbers of salmonella in their feces for weeks — remained healthy; they were unaffected by either the disease or the antibiotic. The rest of the mice got sicker instead of better and, oddly, started shedding like superspreaders. The findings … pose ominous questions about the widespread, routine use of sub-therapeutic doses of antibiotics in livestock.

So, the superspreaders kept on spreading without missing a step, and the others became walking-dead pseudosuperspreaders. A lose-lose scenario all the way around.

“If this holds true for livestock as well – and I think it will – it would have obvious public health implications,” Monack told me. “We need to think about the possibility that we’re not only selecting for antibiotic-resistant microbes, but also impairing the health of our livestock and increasing the spread of contagious pathogens among them and us.”

Previously: Did microbes mess with Typhoid Mary’s macrophages?, Joyride: Brief post-antibiotic sugar spike gives pathogens a lift and What if gut-bacteria communities “remember” past antibiotic exposures?
Photo by Jean-Pierre

Chronic Disease, Health Costs, Infectious Disease, Research

Despite steep price tag, use of hepatitis C drug among prisoners could save money overall

Despite steep price tag, use of hepatitis C drug among prisoners could save money overall

pills-384846_640There’s nothing free about the revolution that’s shaking up hepatitis C treatment. A slew of newer drugs, including sofosbuvir, are nearly eliminating the virus with fewer side effects than the old standbys, pegylated interferon and ribavirin, which had limited effectiveness and caused fatigue, nausea and headaches. But at a cost of $7,000 a week, it seems obvious they are more expensive.

Not necessarily, however, says Jeremy Goldhaber-Fiebert, PhD. Working with colleagues including former Stanford graduate student Shan Liu, PhD, Goldhaber-Fiebert developed a model that examines the overall costs and benefits of treating hepatitis C with sofosbuvir rather than the traditional drugs in prisons. Prisoners are more likely than those in the general population to be infected with hepatitis C, a virus that attacks the liver, because it can be transmitted through intravenous drug use and unclean tattoos.

The researchers found that the high upfront cost saves money in later years by reducing the number of liver transplants and other more invasive treatments needed. In accordance with standard practices, this  study examined the overall societal cost without accounting for the source of the money. For example, the prison system’s are more likely to spend more money upfront, although savings might be recouped by Medicaid or other private insurers several decades later. From our release:

“Overall, sofosbuvir is cost-effective in this population, though its budgetary impact and affordability present appreciable challenges,” said Goldhaber-Fiebert,who is also a faculty member at Stanford’s Center for Health Policy/Center for Primary Care and Outcomes Research, which is part of the university’s Freeman Spogli Institute for International Studies.

Goldhaber-Fiebert called hepatitis C a “public health opportunity.”

“Though often not the focus of health-policy research, HCV-infected inmates are a population that may benefit particularly from a highly effective, short-duration treatment,” he said.

The research appears in this week’s Annals of Internal Medicine.

Previously: Fortune teller: Mice with ‘humanized’ livers predict HCV drug candidate’s behavior in humans, A primer on hepatitis C and For patients with advanced hepatitis C, benefits of new drugs outweigh costs
Photo by stevepb

Ebola, Global Health, Infectious Disease, Patient Care, Stanford News, Surgery

How to keep safe while operating on Ebola patients

How to keep safe while operating on Ebola patients

surgical instrumentsAmid the Ebola crisis, two U.S. surgeons with a combined 30 years of working in developing countries have stepped forward to help disseminate well-defined protocols for operating on any patient with the virus or at-risk of having contracting the virus.

In an op-ed piece published today in the San Jose Mercury News, the two surgeons first ask, then answer, their own question: “Why should anyone care about surgery and Ebola? Ebola is a virus.” Their answer is that patients still have accidents. They still need things like appendectomies and C-sections and treatment for gunshot wounds.

The piece points to shocking news reports like those of 16-year-old Shacki Kamara, a patient in Sierra Leone who died of gunshot wounds to his leg during the Ebola quarantine of West Point, Liberia because people were afraid to operate on him. The growing fear of operating on anyone suspected of having contracted the Ebola virus, which is transmitted by bodily fluids, is a flashback to the early days of the AIDS crisis when operating room personnel and physicians often declined to treat patients, said Stanford surgeon Sherry Wren, MD, who co-authored the op-ed with Johns Hopkins surgeon Adam L. Kushner, MD, founder and director of Surgeons OverSeas. The two wrote:

With supportive medical care, patients may survive an Ebola infection. Without surgery for severe trauma, obstructed labor, a strangulated hernia, or a perforated ulcer, some patients may die. The moral dilemma is overwhelming. How does one operate on a patient infected with Ebola, yet at the same time protect the surgical staff?

Last week, the two came together to write an Ebola surgery protocol and send it to a number of surgical organizations, and the largest one – the American College of Surgeons – immediately accepted and posted it on their website. The response to the new guidelines was immediate and overwhelming, Wren said. In Africa, 10 countries have since adopted the protocol. Press articles on the guidelines have also appeared around the world, including in the New York Times and Washington Post and on Al Jazeera. Wren told me in a phone interview that she was both a bit surprised and overwhelmed by the reaction:

I’ll tell you, it was amazing. I’ve seen very few things in surgery go that fast. There was a need to start the discussion. It was never my intent to be the definitive Ebola expert. I’ve never seen a case of Ebola in my life. We expanded existing  CDC guidelines for prevention of transmission of other infections such as HIV and hepatitis and then added common sense from years of  experience operating.

Both Wren and Kushner acknowledged the “unsung heroes” who bravely choose to treat Ebola patients and stress the importance of working to keep them as safe as possible by increasing the availability of supplies of protective gear especially in West Africa and working toward increased training for health care workers. As they state in their op-ed:

 The management of Ebola is new to many clinicians in the United States and elsewhere. We hope to see more training, protocols and personal protective supplies to lower risks to surgical staff and patients. Just as surgery is a necessary part of a functioning health system, surgery must be part of the discussion during this time of Ebola; otherwise, the death toll will not only include those unfortunate to have died from the virus but also those unlucky to have developed a treatable surgical condition in this time of Ebola.

Previously: Experience from the trenches in the first Ebola outbreak, Ebola: A look at what happened and what can be done, Paul Farmer: We should be saving Ebola patients, Ebola panel says 1.3 million cases possible, building trust key to containment and Should we worry? Stanford’s global health chief weighs in on Ebola
Photo by Badly Drawn Dad

Ebola, Events, Global Health, Infectious Disease

Experience from the trenches in the first Ebola outbreak

Experience from the trenches in the first Ebola outbreak

512px-Ebola_virus_emNoted infectious disease expert Donald Francis, MD, PhD, was “a quiet doctoral student” at Harvard when he was called in to fly into the remote bush of southern Sudan in 1976 to help with one of the world’s first documented outbreaks of Ebola. The federal Centers for Disease Control and Prevention dispatched him for a two-week assignment that stretched into two months, as he saw villages demolished by the virus and helped bury some 274 bodies, he told a group of 70 science writers earlier this week in San Francisco.

Like today’s epidemic in West Africa, most people who contracted the disease were caregivers, either at home or at the make-shift tent hospital, or people assisting at funerals, where bodies were literally dripping with blood, he said. A single drop contains many thousands of viral particles, so all it took was a simple scratch of the nose with a contaminated finger to become infected.

Remarkably, none of his team members became infected, though they took risks, including storing viral samples in unsafe vials, and flying in and out of the treatment area when they were supposed to be in quarantine, he said.

Unlike today’s epidemic, the outbreak burned itself out because it took place in the remotest of areas.

“This was a very good place to control an outbreak – very rural, very isolated,” said Francis, co-founder and executive director of Global Solutions for Infectious Diseases.

Francis is the former director of the CDC’s AIDS Laboratory Activities and was among the first to suggest that AIDS was caused by an infectious agent. He has worked in epidemics around the world and helped eradicate smallpox from Sudan, India and Bangladesh before he became involved in the AIDS epidemic.

But his early work was in Ebola. During that first outbreak in Sudan, his five-member team worked with local nurses, some of whom were sickened by the virus but recovered. “I had patients who were so sick that the whole skin of their feet would slough off,” he said. And though the survivors were in a weakened state, losing as much as 20 percent of their body weight, they were determined to continue caring for their fellow villagers, he said.

He said today’s epidemic in West Africa presents a number of “worrisome challenges,” as it is occurring in a part of the world beset by political and social chaos.

“You have social chaos, socio-economic lack of resources, and hospitals that are just set up for transmission of the virus,” he said.

He said Ebola “can be controlled, but once it becomes so broad (as is currently the case), you lose that capability.” He expressed little hope that the current epidemic could be contained anytime soon: “I expect it will play out very badly for at least a year.”

Previously: Ebola: A look at what happened and what can be done,  Dr. Paul Farmer: We should be saving Ebola patients, Ebola panel says 1.4 million cases possible, building trust key to containmentShould we worry? Stanford’s global health chief weighs in on Ebola and Biosecurity experts discuss Ebola and related public health concerns and policy implications
Photo by CDC/ Dr. Frederick A. Murphy

Ebola, Global Health, In the News, Infectious Disease

Ebola: A look at what happened and what can be done

Ebola: A look at what happened and what can be done

As of September 28, the World Health Organization (WHO) estimates that, so far, more than 7,100 people have been infected with and more than 3,300 have died from the Ebola virus. These estimates of what has happened are almost certainly far too low; the estimates of what will happen are terrifyingly high. The current Ebola epidemic may well become the worst human disaster in this century. And we are not doing enough about it.

Ebola is unlikely to become a major problem in the developed world. But… it seems increasingly likely that hundreds of thousands, and quite possibly millions, of men, women, and children will be struck down by this ghastly plague

What happened?

Researchers will be trying to answer that question for years. This is the 24th known outbreak of Ebola virus disease since it was first recognized in 1976. All of the other outbreaks burned themselves out quickly, after between one and 425 people had been infected. Over nearly 40 years, fewer than 2,500 people are known to have become infected and fewer than 1,500 to have died. The outbreaks were all in Central Africa; they killed people in scattered villages, with few Western connections and fewer Western media on site.

However, the current outbreak started in West Africa, not Central Africa. I suspect this change in location will prove to be the key change, not so much in how it has affected human responses but how it has affected human susceptibility. Yes, the health infrastructures in Guinea, Liberia, and Sierra Leone were very poor (and are now far worse), but they were no worse than those in the Democratic Republic of Congo, South Sudan, or Uganda, the sites of most of the earlier outbreaks. But the lands where this outbreak start are more densely populated and better connected. Instead of burning out in one or two villages, hidden away in dense jungle, the virus spread from village to village, from village to town, and eventually from town to city. When it hit Monrovia, the slum-ridden, million-person capital of Liberia, an explosion was probably inevitable. (It has recently begun to expand in Freetown, the capital of Sierra Leone, as well as Conakry, the capital of Guinea.)

The growth of the epidemic has brought with it the growth of terror and the destruction of already tenuous trust, both in governments and in modern health care. It has also brought death from other, treatable conditions that cannot now be treated in health care systems that Ebola has collapsed. It has brought restricted transportation and supplies and, as a result, in some places, sharply higher food prices. It may eventually bring, in spots, starvation.

Recriminations have already started. Why didn’t the West provide powerful help in March 2014, when the epidemic (already about a year old) began to be noticed? Or why hasn’t Western science, expensively pursuing the latest “me too” drug for common Western conditions, produced a treatment, cure, or vaccine for Ebola? These critiques seem too harsh. No previous epidemic has ever ballooned like this one, even in Central Africa. And the chance of an epidemic outside those traditional regions, let alone in the West, appeared remote.

And while some have pointed fingers at the West, others have focused on the behavior of the affected West African populations. Much has been made of their reluctance to abandon traditional methods of burying their dead, their lack of trust in modern medicine, and even their physical attacks on health care workers. But before blaming the victims for their poor infection control measures, put yourself in their shoes. A five year old – perhaps your five year old – is feverish and vomiting. She is crying and holding her arms out to you for comfort, for help. In West Africa you would not have the chance to telephone for an ambulance, with well-protected professionals to treat the child. Touching her could kill you. But what would it do to you – what would it make of you – to ignore her? As Benjamin Hale wrote in Slate, Ebola is a fantastically cruel disease, turning against us our own compassion, care, and love.

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Cancer, Infectious Disease, Pediatrics, Research, Stanford News

Summer’s child: Stanford researchers use season of birth to estimate cancer risk

Summer’s child: Stanford researchers use season of birth to estimate cancer risk

Four_seasons

One of the hardest parts of unraveling childhood cancers is understanding what causes them. In recent years, evidence has been mounting that cancer and many other chronic diseases begin early in life – and perhaps even in utero. To untangle some of these early causes of cancer in children and young adults, Stanford epidemiologist and family physician Casey Crump, MD, PhD, is partnering with researchers at Lund University in Sweden, a working relationship was set up by Marilyn Winkleby, PhD, MPH, professor emeritus of medicine here. The team is using Sweden’s national registries for birth certificates and medical records to track how factors during gestation and soon after birth – called perinatal factors – affect cancer risks.

Because Sweden has a national health care system, it’s relatively easy to track the course of illness in individuals. By comparison, the U.S.’s health care system is fragmented across dozens of health care providers and insurers, so getting medical records for a single person that might span decades is a much more difficult prospect.

Crump’s team is focusing on cancers that are common in childhood and early adulthood: brain tumors, leukemia and lymphoma among them. Two papers published earlier this year examine how the time of year a child is born affects cancer risk. The most recent, published ahead of print in April in the International Journal of Cancer, examined whether the season of birth was linked to the risk of developing either Hodgkin’s lymphoma or non-Hodgkin’s lymphoma later in life. Crump explained:

Lymphomas are among the most common cancers in childhood but the causes are still largely unknown. It’s been hypothesized that infectious exposures, such as Epstein Barr virus and others may play an important role, but it’s still unclear what the critical age window of susceptibility might be. We had an opportunity to use season of birth from birth records as a proxy for infectious exposures in the first few months of life, and see the relationship between that and subsequent risk of Hodgkin’s and non-Hodgkin’s lymphoma – following these people from birth through childhood and on into young adulthood.

The researchers found that children born in spring or summer had a higher risk of developing non-Hodgkin’s lymphoma later in life compared to kids born in winter. The team didn’t find any similar seasonal pattern for risk of Hodgkin’s lymphoma. The results lend additional support to the “delayed exposure hypothesis.” Children born in spring or summer may not be exposed to critical pathogens during a critical early period of immune system development, leaving them vulnerable later in life. Children born in the fall or winter, by comparison, do get that important exposure at just the right time. Crump was quick to note that season of birth provides only a rough estimate of these exposures, since the team didn’t have accurate measures of exposures to Epstein Barr or other viruses, but he also added that these results “shed additional light on possible pathways of risk that may contribute to the development of non-Hodgkin’s lymphoma.”

A similar study published in January in the International Journal of Epidemiology found that children born in spring and summer had a higher chance of developing melanoma later in childhood or early adulthood. The team hypothesized that spring and summer babies are exposed to more UV radiation in warm summer months in the first few months of life – an exposure that fall and winter babies are less likely to have.

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Ebola, Events, HIV/AIDS, Infectious Disease, Public Health, Stanford News

Dr. Paul Farmer: We should be saving Ebola patients

Dr. Paul Farmer: We should be saving Ebola patients

The photo says it all: A very slender, ailing man sits on the floor with his head bent, completely alone in the dark in what used to be an Ebola treatment center in West Africa.

Paul Farmer, MD, PhD, the brilliant physician and humanitarian, flashed the photo on a screen to a rapt Stanford audience last Friday to show the emaciated state of health care systems in West Africa, incapable now of treating the most basic ailments.

Every time someone dies, it’s a failure to diagnose and deliver the imperfect tools we have

“The primary determinant of outcomes is the strength of health care systems. And if this is what ETU’s (Ebola Treatment Units) look like, there are going to be a lot of fatalities,” he told the crowd of some 400 people at Stanford’s Graduate School of Business. “We should be saving most of these patients. Every time someone dies, it’s a failure to diagnose and deliver the imperfect tools we have.”

But this vast inequity in care need not exist, said Farmer, MD, PhD, a Harvard professor. He pointed to examples from his own experience, in which he and the group he co-founded, Partners in Health, helped build robust health systems in Haiti and more recently, Rwanda, saving thousands of lives.

Farmer started working in Haiti while he was a student at Harvard Medical School nearly 30 years ago. In 1998, during the peak of the AIDS epidemic there, he established the HIV Equity Initiative, which relied on community health workers to visit the homes of patients daily to check on their status and ensure that they took their antiretroviral and/or tuberculosis medications. The approach proved remarkably successful, as people rose from their deathbeds to return to normal, functioning lives.

More recently, after the 2010 quake in Haiti, his group helped to build a medical center and teaching hospital in rural Haiti; he showed a photo of the modern, expansive new facility to the Stanford audience, which applauded the work.

“This is what I think of for rural Liberia, rural Sierra Leone,” he said. “This is not rocket science. Just think what we could do if we had a lot of help with systems and partners. It just requires sticking with some of these problems for a long time.”

Previously: Ebola panel says 1.4 million cases possible, building trust key to containmentExpert panel discusses challenges of controlling Ebola in West Africa, Should we worry? Stanford’s global health chief weighs in on Ebola and Biosecurity experts discuss Ebola and related public health concerns and policy implications

CDC, In the News, Infectious Disease, Neuroscience, Pediatrics

Stanford experts offer more information about enterovirus-D68

Stanford experts offer more information about enterovirus-D68

Below is an updated version of an entry that was originally posted on Sept. 26.

SONY DSCLast week, the California Department of Public Health confirmed that the season’s first four cases of enterovirus-D68 respiratory illness had been found in the state, three in San Diego County and one in Ventura County, with more expected to surface. As of Sept. 29, this makes California one of 40 states across the nation to be affected by EV-D68.

Health officials in Colorado are now investigating a handful of cases of paralysis in children there; the paralysis began a few weeks after respiratory illness and appears to be connected to EV-D68. Since the same virus was tentatively linked to paralysis cases in California children earlier this year, California officials are monitoring the situation closely.

Below, Yvonne Maldonado, MD, service chief of pediatric infectious disease at Lucile Packard Children’s Hospital Stanford, answers additional questions about the respiratory symptoms caused by this virus. Keith Van Haren, MD, a pediatric neurologist who has been assisting closely with the California Department of Public Health’s investigation, also comments on neurologic symptoms that might be associated with the virus.

Enteroviruses are not unusual. Why is there so much focus from health officials on this one, EV-D68?

Maldonado: The good news is that this virus comes from a very common family of viruses that cause most fever-producing illnesses in childhood. But it’s been more severe than other enteroviruses. Some hospitals in other parts of the country have had hundreds of children coming to their emergency departments with really bad respiratory symptoms. The fact that it’s been so highly symptomatic and that there has been a large volume of cases is why it has gotten so much attention.

Van Haren: It’s important to remember that most children and adults who are exposed to enteroviruses don’t get sick at all. A smaller percentage come down with fever and/or respiratory symptoms, as Dr. Maldonado has described. And as far as we can tell, it’s only a very, very small number of children, if any, who get paralysis, typically affecting one arm or leg. The Centers for Disease Control and the California Department of Public Health are still investigating to try to determine conclusively whether EV-D68 is causing neurologic symptoms, such as paralysis.

What do we know about the course of possible neurologic symptoms of EV-D68 and their potential treatments?

Van Haren: We’re still learning about the possible neurologic symptoms and how we might treat them. To start, we have a growing suspicion that EV-D68 may be associated with paralysis. In the patients we’ve seen with paralysis, progression of weakness appears to stop on its own, and recovery of strength is very slow and usually incomplete.

Which groups are most at risk?

Maldonado: Children with a history of asthma have been reported to have especially bad respiratory symptoms with this virus. It can affect kids of all ages, from infants to teens. So far, only one case has been reported in an adult, which makes sense because adults are more likely to have immunity to enteroviruses. We do worry more about young infants than older children, just because they probably haven’t seen the virus before and can get worse respiratory symptoms with these viral infections.

Van Haren: We don’t yet know who is most at risk for paralysis or other neurologic symptoms, but we are studying this carefully to find out why some children get sick and some do not. So far, it seems that the children who have been affected by paralysis were generally healthy prior to their illness.

What is the treatment for EV-D68?

Maldonado: There is no treatment that is specific to the virus. At home, parents can manage children’s fevers with over-the-counter medications, make sure they drink lots of fluids to avoid dehydration, and help them get plenty of rest. For children who are very ill, doctors will check for secondary illnesses such as bacterial pneumonia, which would be treated with antibiotics, and may hospitalize children who need oxygen or IV hydration to help them recover.

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Ebola, Global Health, Infectious Disease, Patient Care, SMS Unplugged

The hand-sanitizer dilemma: My experiences treating patients in Uganda

The hand-sanitizer dilemma: My experiences treating patients in Uganda

Ugandan hospital - smallSMS (“Stanford Medical School”) Unplugged is a forum for students to chronicle their experiences in medical school. The student-penned entries appear on Scope once a week; the entire blog series can be found in the SMS Unplugged category.

A thick green glob landed on my scrub top at the same time that the first drop of sweat rolled down the small of my back. I tried not to grimace and discretely walked over to the hand-sanitizer dispenser. But like every other hand sanitizer I had tried, this one was empty. Yesterday I had also discovered that the only bathroom in the hospital had no toilet paper. It was 7 AM, and I would be using my pocket toilet-paper stash to clean off sputum from the hacking patient that apparently all the doctors knew to avoid standing in front of. The day was off to a good start.

How, I wondered as we continued rounding, did doctors respond to this dilemma – having to care for patients without being able to fully protect themselves – when they were in health centers treating Ebola. I tried not to think about what I would tell my parents if I developed rare infectious symptoms in a few days. We were in Uganda, countries away from the Ebola outbreak, but there were still plenty of infectious agents we could and probably were exposing ourselves to.

Just as I was wracking my brain for the names of the bacteria and viruses that might be deadly, I noticed one of the doctors rest his hand on a patient’s shoulder. And it dawned on me that the real dilemma was not about what I, who had access to the best medical care, might pick up, but rather about what I might pass from patient to patient.

It’s ironic that in the U.S., patients have to remind doctors to reach out and touch their shoulder or hand at an appropriate time – to make patients feel that the doctor connects with them on a human level. Yet here in Uganda, the  doctors know when to reach out to their patients, they know how to talk to the patient’s family. My clinical-skills professors would love to see this.

But if the hand-sanitizer dispenser was empty for me, it was empty for the  Ugandan doctors as well. We were told as first-year medical students that we would fail our “Practice of Medicine” final if we forgot to sanitize our  hands upon entering our standardized patient’s room. So what were we to do when we had more than twenty patients in one room, each with at least two family members, and no hand sanitizer for anyone? How many of these dozens  of people were walking around with my hacking patient’s sputum on them as  well?

The doctors certainly could be spreading infectious agents. But given the proximity of patients on the wards, those very same infectious agents had likely already been spread between the patients overnight – before we even arrived that morning. I couldn’t help but wonder which was more important to the patients who had a 50 percent chance of survival: to feel that their doctor was treating them as a human being or to increase their chance of survival by a negligible margin? How big or small would the margin introduced by the doctor’s touch have to be to tip the scale one way or another?

Before I could finish thinking through my ethical dilemma, we left the ward to scrub in for surgery. There I found the only working hand-sanitizer dispenser.

Natalia Birgisson is a second-year student at Stanford’s medical school. She is half Icelandic, half Venezuelan and grew up moving internationally before coming to Stanford for college. She is interested in neurosurgery, global health, and ethics. Natalia loves running and baking; when she’s lucky the two activities even out.

Photo of Ugandan hospital by Natalia Birgisson

Clinical Trials, History, Immunology, Infectious Disease, Research

Stanford scientists strive to solve centuries-old puzzle: Why are young children so vulnerable to disease?

Stanford scientists strive to solve centuries-old puzzle: Why are young children so vulnerable to disease?

512px-Gabriël_Metsu_-_The_Sick_Child_-_WGA15091

Several months ago, Stanford immunologist Mark Davis, PhD, went for a stroll in Union Cemetery in Redwood City, Calif. (not far from the Stanford campus). Graves there date from the Civil War-era and Davis, who’s currently immersed in a study of childhood immunity, was intrigued.

“In the early years, you see entire families — mom, dad, and then a whole bunch of children’s headstones,” Davis told me. “It really brought home to me how differently we live now that we just take for granted a kid will survive and grow up.”

Vaccines arrived and childhood survival rates soared. Yet young children remain much more vulnerable to infectious diseases than adults. Why?

Davis and his team think vaccines trigger a set of changes that strengthens children’s immune systems — allowing them to ward off diseases they haven’t even heard of before. That’s why the researchers are conducting a group of studies, all focused on revealing new details about the immune system’s response to the flu vaccine. They need participants, particularly young children who have never received a flu vaccine before. They also need older children and twins. All participants will receive a licensed flu vaccine that will help protect from influenza this coming winter.

Davis and colleagues plan to investigate the children’s development of two types of immune cells — memory T and B cells — that are specialized to recognize certain foreign invaders. Interestingly, adults have T cells that spot diseases they’ve never been exposed to, such as HIV, Davis said. Yet newborns lack these specialized cells, leaving them vulnerable to infection.

“Somewhere between birth and adulthood we see the appearance of these memory T cells without having the particular disease,” Davis said. “It’s a real puzzle.”

Davis suspects that routine vaccines and infections may spur the development in children of a broad spectrum of memory T cells, ones that recognize all sorts of diseases. One study plans to follow children for several years, perhaps revealing how, and when, the children develop a full compliment of these memory T cells, Davis told me.

The studies are possible thanks to the development of new analytical techniques, according to virologist and immunologist Harry Greenberg, MD, who is working with Davis on the influenza studies.

“We’ve been studying influenza for half a century, but these new assays developed in the last five years offer hope we can develop better ways of protecting more people,” Greenberg told me.

More information about the flu vaccine studies and the Stanford-LPCH Vaccine Program is available here or (650) 498-7284.

Becky Bach is a proud graduate of the UC Santa Cruz Science Communication Program (go Banana Slugs!) and a science-writing intern at the Office of Communications and Public Affairs.

Previously: Q&A about enterovirus-D68 with Stanford/Packard infectious disease expert, Gut bacteria may influence effectiveness of flu vaccine and Side effects of childhood vaccines are extremely rare, new study finds
Photo by Gabriel Metsu

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