The Coming Plague (112 page)
Authors: Laurie Garrett
When hospital-based amplification events occurred with enough frequency, they could lead to endemic nosocomial infection. In such cases the hospitals simply came to accept that newly emergent microbes, for example, drug-resistant bacteria, were permanent features of their environment, and the microbes frequently found their way into the general community. Such was the case for hepatitis B,
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vancomycin-resistant enterococci,
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respiratory syncytial virus,
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MRSA (methicillin-resistant staphylococci),
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MR
S
.
pneumoniae
and
S
.
epidermis,
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fluoroquinolone-resistant
Serratia
and
P
.
aeruginosa,
and a host of aminoglycosides-resistant bacterial species.
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vancomycin-resistant enterococci,
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respiratory syncytial virus,
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MRSA (methicillin-resistant staphylococci),
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MR
S
.
pneumoniae
and
S
.
epidermis,
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fluoroquinolone-resistant
Serratia
and
P
.
aeruginosa,
and a host of aminoglycosides-resistant bacterial species.
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In addition, the use of air conditioning or recirculation devices in otherwise airtight facilities has served to amplify airborne infections. Whether the setting was an airplane, nursing home, prison, or office building, the scenario was always the same: constant recirculation of the same air afforded small numbers of microbes enhanced opportunities to infect human beings. Examples include influenza,
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tuberculosis,
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Legionnaires' Disease,
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measles, and influenza.
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tuberculosis,
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Legionnaires' Disease,
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measles, and influenza.
Research into microbial ecology would help identify more amplifiers, as well as measures that could be taken to mitigate their effects. At Yale, Robert Shope was in 1993 trying to develop ways to spot zoonotic events along the frontiers of
Homo sapiens
encroachment upon rain forest areas. Harking back to his earlier years studying JunÃn and Oropouche in South America, Shope headed a team of scientists that was studying human residents of small islands in the Amazon River near Belém. Busily carving out farmland from the rain forest, they were being monitored by Shope's group for evidence of novel viruses in their bloodstreams.
Homo sapiens
encroachment upon rain forest areas. Harking back to his earlier years studying JunÃn and Oropouche in South America, Shope headed a team of scientists that was studying human residents of small islands in the Amazon River near Belém. Busily carving out farmland from the rain forest, they were being monitored by Shope's group for evidence of novel viruses in their bloodstreams.
Carol Jenkins of the Papua New Guinea Institute of Medical Research
headed up a similar effort in that country, following the health of people living in four comparable villages, two of which were employed in large-scale logging and deforestation efforts. Jenkins hoped to witness the emergence of newly recognized microbes or disease trends among the villagers most actively engaged in logging the previously pristine tropical forests.
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headed up a similar effort in that country, following the health of people living in four comparable villages, two of which were employed in large-scale logging and deforestation efforts. Jenkins hoped to witness the emergence of newly recognized microbes or disease trends among the villagers most actively engaged in logging the previously pristine tropical forests.
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Stanford University's Gary Schoolnick came up with another novel approach to monitoring disease emergence in Mexico. He set up a modest molecular epidemiology laboratory along the Mexico-Guatemala border and trained local residents how to spot unusual diarrhea cases and collect stool samples. The community straddled the Pan American Highway, the primary artery connecting North and South America. Every year millions of people journey from the remote regions of the Southern Hemisphere up the highway to jobs in the north. They carry their microbes with themâmicrobes Schoolnick hopes to spot as they make their way to the California and Texas borders.
In the microbe magnetsâthe world's urban centersâresearch is needed to determine which aspects of city life most amplify microbial spread. For example, how strong is the correlation between rising rat populations and disease? When, in 1992â93, New York City had a 70 percent jump in reported incidents of rats biting humans, was that a harbinger of coming disease? When city budget cuts led to radical reductions in rodent control programs, and rollbacks in garbage collection left steady supplies of would-be food lying about sidewalks protected only by plastic bags, could a surge in the rat population have been anticipated? Would a surge in disease follow? If New York City already had more than seven million rats in 1992, what was the threshold for a public health crisis? Ten million? Twenty million?
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Just how remote is the possibility that
Yersinia pestis
could acquire broad powers of antibiotic resistance, making the plague untreatable?
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Just how remote is the possibility that
Yersinia pestis
could acquire broad powers of antibiotic resistance, making the plague untreatable?
The same questions could be asked about unclean sewage, nonchlorinated drinking water supplies, the role of air pollution in enhancing human lung susceptibility to disease, the role of open water containers in promoting mosquito population growth, failures in urban vaccination programs, over-crowded housing, homelessness, and a plethora of other factors that affectâinverselyâthe quality of life for
Homo sapiens
and microbes.
Homo sapiens
and microbes.
Â
In 1991 Zambia became the first country to undergo a hopeful revolution. With the flick of a switch the University of Zambia Medical Library was on-line via satellite ground station to data bases in medical libraries in the United States and Canada. By the middle of 1993 eleven developing countries were connected to medical data bases in the wealthy world and to each other, via SatelLife. It was expected that six more developing countries would be on-line by the close of 1994.
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The SatelLife movement was the brainchild of Nobel Peace Prize winner Dr. Bernard Lown. Having led the International Physicians for the Prevention
of Nuclear War, Lown had developed a vast network of medical associates all over the world. And he recognized how desperately isolated physicians and scientists were in developing countries. A firm believer that “information is power,” Lown worked closely with Russian, Japanese, and Canadian colleagues to develop SatelLife. The Russian government launched a satellite for the program, the NEC Corporation of Japan provided the necessary equipment, and the International Development Research Centre of Canada came up with the funds.
of Nuclear War, Lown had developed a vast network of medical associates all over the world. And he recognized how desperately isolated physicians and scientists were in developing countries. A firm believer that “information is power,” Lown worked closely with Russian, Japanese, and Canadian colleagues to develop SatelLife. The Russian government launched a satellite for the program, the NEC Corporation of Japan provided the necessary equipment, and the International Development Research Centre of Canada came up with the funds.
For the first time, physicians in developing countries could consult colleagues in neighboring nations or medical libraries and data banks to help solve puzzling cases and alert one another to disease outbreaks.
So when multidrug-resistant gonorrhea surfaced in Mozambique in April 1993, Dr. Prassad Modcoicar sat before a computer and typed this message: “I would like to know if there are any published studies or current ongoing research about the efficacy of the antibiotic kanamycin in the treatment of acute gonorrhea in men.”
Modcoicar's message was carried by a ground-based satellite uplink to the SatelLife's orbiting satellite, which bounced his query back to satellite dishes in fifteen nations. In Lusaka, Zambia, Dr. M. R. Shunkutu saw the message and immediately transmitted to Modcoicar the results of a kanamycin study Subhash Hira had done in Lusaka in 1985. Before SatelLife went into operation, Modcoicar would have been obliged to either write letters to physicians in Europe and North America and wait interminable amounts of time for the results or simply experiment on his patients.
With SatelLife, Modcoicar instantly accomplished two tasks: he notified colleagues that he was seeing an outbreak of drug-resistant gonorrhea, and he found a solution for treatment of his patients. With plans to expand SatelLife into Asia and South America, the cheap, nongovernmental doctor-to-doctor service offered the real possibility of revolutionizing disease treatment and surveillance in the developing world. In the future, the kinds of satellite connections offered by SatelLife might also be used to relay information to public health planners all over the world that would allow them to be proactiveâto anticipate potential disease outbreaks. For example, El Niño-type climate shifts often begin in one part of the planet and then spread in a predictable pattern. The events are known to be responsible for ecological changes that heighten risks for emergences of cholera, malaria, nearly all arboviral diseases, and most diarrheal diseases, particularly in poorer countries. Advance climate warnings could go out by satellite, delivered in real time and designed specifically to alert physicians of coming changes that might be relevant to vector or microbe activity.
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Genetic data bases, such as the vast GenBank at Los Alamos National Laboratory in New Mexico or GenInfo at the U.S. National Library of Medicine, might also prove invaluable to scientists in developing countries. As PCR technology becomes more widely available, researchers working
in poor countries could be able to screen viruses and bacteria found in their patients and compare the strains to ones already archived in genetic data banks. If such technology were widely available, the result could be an avalanche of information on emerging strains of drug-resistant microbes, more virulent HIVs, even apparently new microbes.
in poor countries could be able to screen viruses and bacteria found in their patients and compare the strains to ones already archived in genetic data banks. If such technology were widely available, the result could be an avalanche of information on emerging strains of drug-resistant microbes, more virulent HIVs, even apparently new microbes.
At Harvard Medical School, Thomas O'Brien is trying to compile an international computerized data bank of genetic sequences for plasmids, transposons, phages, and resistance factors. Enhanced satellite communications systems that function independently from the frequently unreliable telephone systems of developing countriesâas is the case with SatelLife âcould allow for far more rapid monitoring, or at least reporting, of drug-resistance microbial activities worldwide.
Of course, such sophisticated systems are useless if no one acts on relayed information, or if there is no real primary medical system in a country. Without trained personnel and a functioning public health system it is almost inconceivable that anyone in a poor nation, or for that matter a poorly funded provincial department inside a rich nation, would be able to make use of GenBank or any such data base.
But no one in the belt-tightening world of the 1990s seemed much interested in contributing dollars, marks, or yen to the development of primary health infrastructures in countries like Armenia, Romania, Albania, Burma, or the Dominican Republic. The scale of the problem seemed too great, the payoff for donors too modest.
For every infectious disease, the preferred, easier option was vaccination. And by 1990 an estimated 70 percent of the world's children had been vaccinated against diphtheria, measles, pertussis, polio, tetanus, and tuberculosis. An estimated 130 million children were vaccinated every year in the developing world at a cost of about $1.5 billion.
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But experts were extremely dubious about the likelihood of expanding the vaccine market, developing new products, or using a newly developed vaccine in the midst of an emerging disease crisis. The phenomenal vaccination achievements of Merieux and the Brazilian government during the 1974 meningococcal bacteria epidemic may never be repeated. The reasons are numerous; they all boil down to money.
Pharmaceutical companies saw no profits in making vaccines intended for use by poor peopleâwho would pay for the products? AIDS was revealing the tremendous hurdles involved in tackling new microbes through immunization. The Swine Flu fiasco left the future of government-sponsored mass vaccination in doubt for reasons of litigation. Further, U.S. courts paid huge awards to alleged victims of contaminated vaccines.
By 1990 more than half of all vaccine manufacturers had pulled out of the business, and though biotechnology was pointing the way to exciting new possibilities for vaccine design, enthusiasm was less than lukewarm in corporate circles.
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“Serious deficiencies are extant,” D. A. Henderson said. “Vaccine production
for many vaccines is nowhere what is needed and resources for vaccine purchases are diminishing; vaccine quality control for locally produced vaccines is negligible to nonexistent; and surveillance, the foundation of disease control, remains seriously deficient and for many diseases, totally desert.”
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for many vaccines is nowhere what is needed and resources for vaccine purchases are diminishing; vaccine quality control for locally produced vaccines is negligible to nonexistent; and surveillance, the foundation of disease control, remains seriously deficient and for many diseases, totally desert.”
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Â
Ultimately, humanity will have to change its perspective on its place in Earth's ecology if the species hopes to stave off or survive the next plague. Rapid globalization of human niches requires that human beings everywhere on the planet go beyond viewing their neighborhoods, provinces, countries, or hemispheres as the sum total of their personal ecospheres. Microbes, and their vectors, recognize none of the artificial boundaries erected by human beings. Theirs is the world of natural limitations: temperature, pH, ultraviolet light, the presence of vulnerable hosts, and mobile vectors.
In the microbial world warfare is a constant. The survival of most organisms necessitates the demise of others. Yeasts secrete antibiotics to ward off attacking bacteria. Viruses invade the bacteria and commandeer their genetic machinery to viral advantage.
A glimpse into the microbial world, aided by powers of exponential magnification, reveals a frantic, angry place, a colorless, high-speed pushing and shoving match that makes the lunch-hour sidewalk traffic of Tokyo seem positively poky. If microbes had elbows, one imagines they would forever be jabbing neighbors in an endless battle for biological turf.
Yet there are times of extraordinary collectivity in the microbial world, when the elbowing yields to combating a shared enemy. Swapping genes to counter an antibiotic threat or secreting a beneficial chemical inside a useful host to allow continued parasitic comfort is illustrative of this microscopic coincidence.
An individual microbe's worldâits ecological milieuâis limited only by the organism's mobility and its ability to tolerate various ranges of temperature, sunlight, oxygen, acidity or alkalinity, and other factors in its soupy existence. Wherever there may be an ideal soup for a microbe, it will eagerly take hold, immediately joining in the local microbial pushing-and-shoving. Whether transported to fresh soup by its own micro motor and flagellae or with the external assistance of wind, human intercourse, flea, or an iota of dust makes little difference provided the soup in which the organism lands is minimally hostile and maximally comfortable.
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