According to the 1996 World Health Organization Report, at least 30 new
diseases, including AIDS, Ebola and Hepatitis C, have emerged over the past
20 years, while old infectious diseases such as tuberculosis, cholera,
malaria and diphtheria are coming back worldwide. Almost every month now in
the UK we hear reports on fresh outbreaks: Streptococcus, meningitis, E.
coli. Practically all the pathogens are resistant to antibiotics, many to
multiple antibiotics. Two strains of E. coli isolated in a transplant ward
outside Cambridge in 1993 were found to be resistant to 21 out of 22 common
antibiotics.(12) A strain of Staphylococcus isolated in Australia in 1990
was found to be resistant to 31 different drugs.(13) Infections with these
and other strains will very soon become totally invulnerable to treatment.
In fact, scientists in Japan have already isolated a strain of
Staphylococcus aureus that is resistant even to the last resort antibiotic,
vancomycin.(14)
Geneticists have now linked the emergence of pathogenic bacteria and of
antibiotic resistance to horizontal gene transfer - the transfer of genes
to unrelated species, by infection through viruses, though pieces of
genetic material, DNA, taken up into cells from the environment, or by
unusual mating taking place between unrelated species. For example,
horizontal gene transfer and subsequent genetic recombination have
generated the bacterial strains responsible for the cholera outbreak in
India in 1992,(15) and the Streptococcus epidemic in Tayside in 1993.(16)
The E. coli 157 strain involved in the recent outbreaks in Scotland is
believed to have originated from horizontal gene transfer from the
pathogen, Shigella.(17) Many unrelated bacterial pathogens, causing
diseases from bubonic plague to tree blight, are found to share an entire
set of genes for invading cells, which have almost certainly spread by
horizontal gene transfer.(18) Similarly, genes for antibiotic resistance
have spread horizontally and recombined with one another to generate
multiple antibiotic resistance throughout the bacterial populations.(19)
Antibiotic resistance genes spread readily by contact between human beings,
and from bacteria inhabiting the gut of farm animals to those in human
beings.(20) Multiple antibiotic resistant strains of pathogens have been
endemic in many hospitals for years.(21)
What is the connection between horizontal gene transfer and genetic
engineering? Genetic engineering is a technology designed specifically to
transfer genes horizontally between species that do not interbreed. It is
designed to break down species barriers and, increasingly, to overcome the
species' defence mechanisms which normally degrade or inactivate foreign
genes.(22) For the purpose of manipulating, replicating and transferring
genes, genetic engineers make use of recombined versions of precisely those
genetic parasites causing diseases including cancers, and others that carry
and spread virulence genes and antibiotic resistance genes. Thus the
technology will contribute to an increase in the frequency of horizontal
gene transfer of those genes that are responsible for virulence and
antibiotic resistance, and allow them to recombine to generate new
pathogens.
What is even more disturbing is that geneticists have now found evidence
that the presence of antibiotics typically increases the frequency of
horizontal gene transfer 100-fold or more, possibly because the antibiotic
acts like a sex hormone for the bacteria, enhancing mating and exchange of
genes between unrelated species.(23) Thus, antibiotic resistance and
multiple antibiotic resistance cannot be overcome simply by making new
antibiotics, for antibiotics create the very conditions to facilitate the
spread of resistance. The continuing profligate use of antibiotics in
intensive farming and in medicine, in combination with the commercial-scale
practice of genetic engineering, may already be major contributing factors
for the accelerated spread of multiple antibiotic resistance among new and
old pathogens that the WHO 1996 Report has identified within the past 10
years. For example, there has been a dramatic rise both in terms of
incidence and severity of cases of infections by Salmonella,(24) with some
countries in Europe witnessing a staggering 20-fold increase in incidence
since 1980.
That is not all. One by one, those assumptions on which geneticists and
regulatory committees have based their assessment of genetically engineered
products to be "safe" have fallen by the wayside, especially in the light
of evidence emerging within the past three to four years. However, there is
still little indication that the new findings are being taken on board. On
the contrary, regulatory bodies have succumbed to pressure from the
industry to relax already inadequate regulations. Let me list a few more of
the relevant findings in genetics.
We have been told that horizontal gene transfer is confined to bacteria.
That is not so. It is now known to involve practically all species of
animal, plant and fungus. It is possible for any gene in any species to
spread to any other species, especially if the gene is carried on
genetically engineered gene-transfer vectors. Transgenes and antibiotic
resistance marker genes from transgenic plants have been shown to end up in
soil fungi and bacteria.(25) The microbial populations in the environment
serve as the gene-transfer highway and reservoir, supporting the
replication of the the genes and allowing them to spread and recombine with
other genes to generate new pathogens.(26)
We have been assured that "crippled" laboratory strains of bacteria and
viruses do not survive when released into the environment. That is not
true. There is now abundant evidence that they can either survive quite
well and multiply, or they can go dormant and reappear after having
acquired genes from other bacteria to enable them to multiply.(27) Bacteria
co-operate much more than they compete. They share their most valuable
assets for survival.
We have been told that DNA is easily broken down in the environment. Not
so. DNA can remain in the environment where they can be picked up by
bacteria and incorporated into their genome.(28) DNA is, in fact, one of
the toughest molecules. Biochemists jumped with joy when they didn't have
to work with proteins anymore, which lose their activity very readily. By
contrast, DNA survives rigorous boiling, so when they approve processed
food on grounds that there can be no DNA left, ask exactly how the
processing is done, and whether the appropriate tests for the presence of
DNA have been carried out.
The survival of "crippled" laboratory strains of bacteria and viruses and
the persistence of DNA in the environment are of particular relevance to
the so-called "contained" users producing transgenic pharmaceuticals,
enzymes and food additives. "Tolerated" releases and transgenic wastes from
such users may already have released large amounts of transgenic bacteria
and viruses as well as DNA into the environment since the early 1980s when
commercial genetic engineering biotechnology began.
We are told that DNA is easily digested by enzymes in our gut. Not true.
The DNA of a virus has been found to survive passage through the gut of
mice. Furthermore, the DNA readily finds its way into the bloodstream, and
into all kinds of cell in the body.(29) Once inside the cell, the DNA can
insert itself into the cell's genome, and create all manner of genetic
disturbances, including cancer.(30)
There are yet further findings pointing to the potential hazards of
generating new disease-causing viruses by recombination between artificial
viral vectors and vaccines and other viruses in the environment. The
viruses generated in this way will have increased host ranges, infecting
and causing diseases in more than one species, and hence very difficult to
eradicate. We are already seeing such viruses emerging.
* Monkeypox, a previously rare and potentially fatal virus caught
from rodents, is spreading through central Zaire.(31) Between 1981-1986
only 37 cases were known, but there have been at least 163 cases in one
eastern province of Zaire alone since July 1995. For the first time,
humans are transmitting the disease directly from one to the other.
* An outbreak of hantavirus infection hit southern Argentina in December
1996, the first time the virus was transmitted from person to person.(32)
Previously, the virus was spread by breathing in the aerosols from
rodent excrement or urine.
* New highly virulent strains of infectious bursal disease virus (IBDV)
spread rapidly throughout most of the poultry industry in the Northern
Hemisphere, and are now infecting Antarctic penguins, and are suspected of
causing mass mortality.(33)
* New strains of distemper and rabies viruses are spilling out from
towns and villages to plague some of the world's rarest wild animals in
Africa:(34) lions, panthers, wild dogs, giant otter.
None of the plethora of new findings has been taken on board by the
regulatory bodies. On the contrary, safety regulations have been relaxed.
The public is being used, against its will, as guinea pigs for genetically
engineered products, while new viruses and bacterial pathogens may be
created by the technology every passing day.
The present situation is reminiscent of the development of nuclear energy
which gave us the atom bomb, and the nuclear power stations that we now
know to be hazardous to health and also to be environmentally unsustainable
on account of the long-lasting radioactive wastes they produce. Joseph
Rotblat, the British physicist who won the 1995 Nobel Prize after years of
battling against nuclear weapons, has this to say. "My worry is that other
advances in science may result in other means of mass destruction, maybe
more readily available even than nuclear weapons. Genetic engineering is
quite a possible area, because of these dreadful developments that are
taking place there."(35)
The large-scale release of transgenic organisms is much worse than nuclear
weapons or radioactive nuclear wastes, as genes can replicate indefinitely,
spread and recombine. There may yet be time enough to stop the industry's
dreams turning into nightmares if we act now, before the critical genetic
"melt-down" is reached.