Program Three: "Dangerous Friends and Friendly Enemies"

Life in a Contaminated World (Part 8 of 10)

In underdeveloped countries, poor conditions increase the risk of disease and scarce medical resources make harder to treat disease properly. Witness how a strain of Hanta virus in Argentina evolves to pass between humans without an intermediate host.

 

Transcript

 

{Title: Life in a Contaminated World}

Narrator, Lillian Lehman:
Tegucigalpa, Honduras in Central America. Perhaps the poorest country in the Americas. Many people here, and other developing countries, live in conditions that the industrialized world left behind many years ago. Germaine Hanquet is a physician with the international agency Doctors without Boarders. She has worked in Africa, and is now working in Honduras.

Doctor, Germaine Hanquet: In developing countries, the major problem, is that the environmental. The water supply, the sanitation conditions, the level of hydrogen, the level of education. The level of nutrition of the people. In general the living conditions of the people are poor, and this is favoring the spread of those infectious disease.

Narrator, Lillian Lehman: Inadequate nutrition, and constant exposure to dangerous microbes, can weaken the immune system. Worldwide fifty thousand people a day, die of infectious diseases, such as, typhoid, tuberculosis, cholera, yellow fever, and malaria. Infectious diseases are the world's biggest killers.

Doctor, Germaine Hanquet: Most of them, you can prevent them, you can treat them, you can act on them. Its not like for cancer, or chronic disease, for which you can't do much. But infectious diseases, it's really something that you can act on. In developing countries in Africa, and Honduras, most of the disease are infectious. So that is really what I meet most, children are dying. Hola, hola, buenas tardes. Buenas tardes señoras. Cómo están?

Mother holding baby: Bien.

Doctor, Germaine Hanquet: I really love this work, I feel my job is really useful, where you are really needed, where you find a lot of diseases, that you can treat it, you can prevent, which you can really do something for.

Narrator, Lillian Lehman: At the time of Germaine Hanquet's arrival in Honduras, there was a cholera epidemic, a bacterial disease common in developing countries.

Doctor, Germaine Hanquet: It was a acute diarrheal disease, which kill fifty percent of the people, which are infected, if nothing is done. And its so easy to save those people. And if you treat them well, only one percent would die, maximum.

Narrator, Lillian Lehman: The infectious diseases most problematic here are well understood. The strategist to control them have been known for years. Sadly they still run rampant. With so many diseases flourishing here, if Hantavirus surfaced it would probably be diagnosed as pneumonia, or more likely go unrecognized. The best defense, prevention, should be applied to all microbial threats.

Doctor, Germaine Hanquet: I think those new disease that are emerging, or re-emerging like Hantavirus. They appear, first you don't know who is causing them, then you don't know, which is a reservoir. You really have to do the entire work around it. To really find, where it is coming from, and how can we do to prevent it. You never know in advance, how big the problem will be, look at AIDS, it started by a few cases. And now it is a disease which affects the entire world.

Narrator, Lillian Lehman: Germaine Hanquet is a frontline warrior in the fight against infectious disease. The battle she wages every day could easily affect us thousands of miles away.

Doctor, Germaine Hanquet: It's clear that infectious disease they do not have borders. They do not respect borders. Nowadays people are moving so much from one country to another country, every country is at risk almost of every disease.

Narrator, Lillian Lehman: The largest problems are presented by infectious diseases, which are easily transmitted. As deadly as Hanta is, it kills a small number of people, when compared to other infectious diseases such as Cholera. Why? Because Cholera can be easily transmitted through contaminated water. What would happen if the Hantavirus evolved, and found a way to infect people as readily as Cholera?

{Title: The Enemy Changes Strategy}

{Guitar tango music.}

Narrator, Lillian Lehman: Buenos Aires, Argentina is a sophisticated city. It has one of the highest standards of living in Latin America. Three hours away is the peaceful community of Pergamino. Here modern farming methods have transformed wide pampas into a fertile bread basket. The Hanta outbreak in New Mexico, had happened over five thousand miles away, and the treat appeared to have long passed. For the local residents, it was a shock to discover Hanta appearing in their surrounds without warning in a deadly new form. Dr. Delia Enria is a physician, and microbiologist expert on viral diseases. At the National Institute for Human Viral Illness in Pergamino, she noticed unusual symptoms in some patients. She didn't know it was a Hantavirus. Through the internet, she received a c.D.C. Report about the virus. Since the nineteen ninety three outbreak, of Hantavirus in New Mexico, there had been about two hundred cases, in twenty nine states. The C.D.C report triggered the memory of a patient, Delia Enria had treated with similar symptoms. She paid a visit to her former patient, Oscar Michetti. At the time of his illness Oscar Michetti had not tested positive for any known pathogen. She wanted to know how he had gotten sick.

Doctor, Delia Enria: You are a detective. You are following, step by step, uh, what we call an hypothesis.

Patient, Oscar Michetti: Pasaba más o menos de noche, cuando salía afuera de la pieza.


Doctor, Delia Enria: He said that he was going to die. The description of his symptoms, coupled with the kind of farming chores that Oscar Michetti was doing before he got sick, pointed towards a Hantavirus. In September nineteen ninety six, Dr. Enria's fears were confirmed. In the quiet resort town of Bariloche, in southern Argentina, four people became ill with flu like symptoms. They were short of breath, and their lungs filled up with fluid, tests sent to the c.D.C. proved that the killer was another new strain of Hantavirus. Over fifty percent of those stricken died rapidly. The outbreak caused panic. Something was happening that had not happened in the United States. People who came in contact with victims also came down with the disease. A reporter covering the story suddenly got sick and died. A doctor who had treated patients in Bariloche became sick. He traveled one thousand miles to Buenos Aires to see a specialist. The specialist got sick. The specialist's wife got sick. All three died. Delia Enria suspected person to person transmission something that had never occurred with any Hantavirus outbreak. This would mean the virus had changed, becoming capable of jumping from human to human. If this was the case, the virus would spread easier and faster.

{Woman Singing In Spanish}

Narrator, Lillian Lehman: At the hospital in Pergamino, Dr. Enria had another case.

Doctor, C.J. Peters: I got a call from, ah Dickie Enria at the Institute for Virology in Pergamino, and she wanted to talk about the issues around human to human transmission. Well, I figured that that was probably just a fantasy.

Narrator, Lillian Lehman: Facing skepticism about her person to person transmission hypothesis, Delia Enria was determined to find the source of the virus. She and her colleagues set traps in the area where the recent victim lived, even if it had evolved to be contagious from one person to another, the starting point, the original source still had to be a rodent. Not all rodents carry the virus, but in field work, they protect themselves as if all mice were deadly. This one had no trace of the Hantavirus.

Doctor, C.J. Peters: The Argentines organized a team. A couple of us went down to work with them. We began to set up a series of hypotheses about the way these people were getting infected. And we had a long list, and we went through the list, and we were able just to draw a line through each, uh, each hypothesis, until we were left with person to person transmission. Not supposed to happen with Hantaviruses.

Narrator, Lillian Lehman: Person to person transmission of the virus could have meant rapid infection of nearby Buenos Aires, or beyond. A neighbor, a relative anyone could have passed the virus. Avoiding rodents would not prevent the disease.

Doctor, C.J. Peters: The virus diseases that have been able to come into humans, cause problems, and be transmissible from human to human are the diseases that we know we have to watch out for.

{woman singing in spanish}

Narrator, Lillian Lehman: Yet, in the case of this Hantavirus, the disease mysteriously vanished at least for now, almost as quickly as it had appeared. Ironically, although the virus changed strategy its mode of transmission, it was still reaching a dead end. Either the virus kills its human host, or the host kills the virus before it can be transmitted. Humans are not a good host for Hantavirus, yet.

Doctor, C.J. Peters: You can look at that as half full, or half empty. Well it only killed a few hundred people, why are we worried about it? Or you can look at it, from the point of view that, it killed a few hundred people, and what's the next time bring? What about the genetic variability that's inherent in these viruses? Could they take off? Well, we don't know. And we better find out.

{Title: Life in a Contaminated World}

Narrator, Lillian Lehman: Research into Hantavirus, continues. When Hanta surfaced in nineteen ninety three, it was identified fairly quickly.

Unkown man 1: Is that number twenty one?

Unkown man 2: Twenty one, right.

Unkown man 1: Okay.

Narrator, Lillian Lehman: But cases keep appearing, throughout the Americas, and there is still no vaccine, or cure for the disease. So far the strain found in Argentina has been the only one capable of jumping for person to person. It is believed that Hantavirus has been dangerous for thousands of years. Periodically emerging, and re-emerging, in outbreaks. But now we have learned to recognize it.

Doctor, Delia Enria: I am completely sure this is the tip of the ice berg. Once we begin looking better for these viruses we will find new surprise. We will find that they are causing disease, that we are not able to recognize yet.

Narrator, Lillian Lehman: Scientist now theorize that Hantavirus arrived in the Americas a long time ago. Rodents, carrying some form of the virus, probably migrated millions of years ago, across an ancient ice bridge, which once connected Asia, and the Americas. Why are we just finding it now?

Scientist, Terry Yates: There are several major things, in my opinion, that are, are changing our relationship with microbes, and pathogenic organisms of different kinds. Climate change, and changing human land use patterns.

Scientist, Stanley Falkow: Now what's happened in modern times, is shown by the Hantavirus, is that human populations have gotten bigger, and bigger, and bigger, and we suddenly come in contact with creatures we ordinarily didn't before.

Narrator, Lillian Lehman: Since the detection of Hantavirus in New Mexico, eighteen other previously unknown strains of Hanta have been discovered in the Americas. Some fear this is only the beginning.

Scientist, Stanley Falkow: We still have not encountered many of the microorganisms that are out there in nature, and the more we encroach in the environment, and the more different living things that we effect, and indeed the species that we wipe out. Every time that this happens, we really effect the microbial balance of the world. In ways we, we can't understand. We are destined to live in a contaminated world. We are not going to live in a sterile environment. The evolution of our interaction between microbes and humans, is in a constant state of flux. And so I think that, we will, as we have in the past, constantly be surprised by new kinds of interactions that we will view as disease, and the microbes will view as survival.

Narrator, Lillian Lehman: Understanding the relationship between humanity, microbes, and the environment, is a scientific challenge for the coming decades. Using this understanding to fight microbial disease, is not only a scientific problem, but a social, and economical one as well. The dance with microbes has lasted as long as we've existed, while some are dangerous, most are not. We are locked in an embrace of cause and effect, with the microbial world. We do something and they change, then we change, and so it will continue. For as long as there is life.

(Transcript provided by Tyler Anderson)

 

 

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