Just as humans and animals can be infected with viruses, so too can bacteria. Bacteriophages, also called "phages", are a group of viruses which infect and kill bacteria. They were co-discovered by Frederick Twort and Félix d'Herelle between 1915 and 1917. Although they remained part of medical practice in the former Soviet republic of Georgia, research on them was largely abandoned in the West. This was due to the overwhelming success of antibiotics.
After their mainstream introduction in 1945, antibiotics proved to be one of the cornerstones of modern medicine. With them came massive improvements in surgery and the treatment of infections. What were once life-threatening conditions became routinely curable, while entirely new medical procedures were made possible. The average global life expectancy rose from 45 years in 1945 to 67 years by 2000.
Though hoped to be a final end to infection and bacteria, antibiotics were never destined to last. Through the gradual process of evolution, bacteria over the years developed resistance to treatments, necessitating the continual creation of new formulas. While always pushing the danger back temporarily, each successive generation of antibiotics created a more resistant and hardy population of bacteria. The misuse of antibiotics, not being prescribed properly or used too frequently and for too long, made the problem even worse.
From the late 20th century onwards, this trend accelerated dramatically. MRSA, for example, saw 50% incidence of resistance by the year 2000. Genes began appearing in the DNA of various bacteria that were completely immune to even the most modern antibiotics.*
These trends have continued to the present day. As the supply of effective antibiotics becomes exhausted, a global public health disaster appears to be looming. Alongside this, poor financial investment in antibiotics research has only exacerbated the situation. Major pharmaceutical companies are losing interest in the antibiotics market, because these drugs are not as profitable as those for treating chronic (long-term) conditions and lifestyle issues. The pipeline of new antibiotics is drying up.
Though the situation is nearing crisis level,* new breakthroughs are being made in the field of biology. The most promising is the development of bacteriophage therapy. Viruses that infect and kill bacteria - while not posing any danger to animals or humans - could become an effective alternative to antibiotics.**
Due to their extreme abundance (10 million are in a millilitre of seawater), genetic engineering is not required either. Treatments can be made with a cocktail of the appropriate phages, taken in pill or liquid form. The phages carry genetic material, enclosed in an outer protein capsid. Upon locating and landing on a bacterium, this DNA is injected like a mosquito bite, where it then starts to reproduce itself. Soon, the bacterium is teeming with new phages that burst forth, destroying the bacterium from within.
At present, most research into phage therapy is focussed on the treatment of animals for agriculture, but success in that area could encourage new policies and regulations allowing its widespread use in human health. This method, it is hoped, may succeed in replacing antibiotics in many instances, enabling a wide variety of medical procedures to continue as before.
Slightly further into the future, the emergence of medical nanobots - microscopic machines programmed to travel inside the body - may replace phage therapy itself. A true end to bacterial infection would then be in sight.
are developing 3D "bio-printers", a cutting-edge technology
that will allow the creation of synthetic human tissue on demand. In
the future, these machines could be used to print entire replacement
organs, as well as being available for cosmetic procedures.*
When will cancer be cured?
There are more than 200 types of cancer. In 2007, they caused about 13% of all human deaths worldwide (7.9 million). Below is a graph showing 15 of the most common cancers in the USA, their five year survival rates, and current trends extrapolated into the future. This ignores possible major events or breakthroughs that could radically alter these trends, such as a technological singularity, or global disaster. It is simply intended to provide a current overview of progress and a visual representation that combines all of the major cancer types in one single, long-term graph.
As can be seen, there is considerable variation in survival rates. However, the next few decades are likely to see cures emerging for a number of cancers, with potentially every cancer eradicated by 2200 AD. With information technology becoming an ever larger part of medicine, researchers are gaining the ability to literally rewrite the software of biology. More targeted therapies, DNA sequencing, nano-medicine, robotic surgery and various other techniques may lead to a Moore's Law-style effect with exponential improvements in survival rates.
Some of these individual cancer types are covered in more detail on our timeline. This graph is based on the latest data from the National Cancer Institute, with 2008 being the most recent year available for five-year survival rates. Click on the graph to view a larger version.
advances in stem cell research could provide a method of regenerating
sensory cells within the inner ear. Humans are born with 30,000 cochlear
and vestibular hair cells per ear. Unlike many animal species, they
are unable to regenerate these if they are damaged. However, experiments
with mice have shown that stem cells - along with reprogrammed fibroblasts
- can be induced into creating replacement hair cells. If this process
could be replicated in people, it could one day fully restore hearing.
Scientists believe this could be achieved in a decade or so.*
patient's own skin as a source of stem cells would mean that the replacements
are a perfect genetic match for their body, avoiding issues of immune
rejection. This form of therapy could also enable a variety of other
ailments to be treated, such as balance disorders and tinnitus.
the next few decades, it may be possible for humans to regrow lost limbs.
Scientists recently discovered a gene known as P21. This blocks cell
cycle progression in the event of DNA damage, preventing cells from
dividing and potentially becoming cancerous. By temporarily switching
off this gene, adult mammalian cells can be induced to behave like regenerative
embryonic stem cells.
treatments are developed, these would be applied transiently during
the healing process and only locally at the wound site, minimising any
side effects. Further
into the future, spinal cords and even damaged brains may be capable
of being regenerated.*
degeneration is the leading cause of blindness in people aged 65 and
older. In 2010, following clinical trials, it became possible to treat
this condition using a miniature telescope implanted in the eye. Consisting
of two lenses within a small glass tube, this works like a telephoto
zoom lens. It combines with the cornea to project a magnified image
of whatever the wearer is looking at over a large part of the retina.
Only the central portion of the sufferer's vision is damaged by the
disease, so magnifying the image on the eye allows the retinal cells outside the macula to detect light, refocus it, and redirect
the information to the brain.*
resonance imaging (MRI) is a medical imaging technique, most commonly
used in radiology to visualise detailed internal structure and limited
function of the body.
MRI scanners are so bulky that they fill entire rooms.* Scans typically require 30 minutes to create. They are also highly expensive:
upwards of a million dollars for a state-of-the-art model, with each
individual scan costing hundreds of dollars.
2050s, experts believe that portable, handheld MRI scanners will be
available.* This new generation
of machines will have supersensitive atomic magnetometers - able to
detect the tiniest magnetic fields - replacing the huge doughnut-shaped
magnets that are currently used. Hi-res, 3D imaging of internal structures
and brain activity would be possible in real-time video, using devices
no bigger than a camera.
be accompanied by a hundredfold decrease in cost.* Healthcare programs in developing countries will benefit particularly
is a mosquito-borne infectious disease of humans, caused by eukaryotic
protists of the genus Plasmodium. It is widespread in tropical
and subtropical regions, including much of Sub-Saharan Africa, Asia
and the Americas. This disease results from the multiplication of malaria
parasites within red blood cells, causing symptoms that typically include
fever and headache - in severe cases progressing to coma, and death.
Malaria is responsible for over 2.2% of all deaths worldwide. Each year,
there are more than 225 million cases, killing 781,000 people.
vaccine that offers long-term, high levels of protection has yet to
be developed. However, recent advances in gene research may offer new
hope from a different angle. In 2010, scientists in the USA successfully
engineered the first malaria-resistant mosquito. By introducing a gene
that modified the insect's gut, the malaria parasites were prevented
from developing. This gene also reduced the insects' lifespan.*
advance was made in 2011, when a gene modified against malaria was successfully
spread throughout a whole population of mosquitoes. This was achieved
in just a small number of generations. Inserting the gene produced an
enzyme which split the mosquito DNA in two. The cell's repair machinery
then used this gene as a "template" when repairing the cut.
As a result, the gene was preserved and copied, with all sperm produced
by a male mosquito subsequently carrying copies of it. In other words,
all its offspring would have the gene.*
future, it is conceivable that widespread deployment of such a technology
could result in the disease being largely eradicated from the world.
Exactly how long this would take is unclear. There would also be concerns
arising from the use of genetically modified organisms. In the coming
years, however, once the risks have been assessed and the moral zeitgeist
has moved forward, it seems highly likely that malaria will be consigned
to the history books.
as genetic modification and research into a vaccine, "mosquito
lasers" are being developed. These could be utilised in hospitals
and other health-sensitive buildings, zapping the insects before they
even land on people.*
robots - measuring just a few nanometres across - are expected to be
developed in the mid-2020s.* These tiny machines will be available for a variety of medical uses.
Their size will enable them to reach places in the human body that were
simply inaccessible before or too delicate for conventional instruments
to operate on.
coming years, the most important breakthroughs will be in the treatment
of cancer. Using nanobots, it will be possible to detect tumours earlier
than ever before and to target them with far more precision. In the
2030s, 90% of cancers may be cured as a result of this. Even patients
who would previously have been classed as terminally ill could routinely
be saved. Monitoring of heart conditions, neurological disorders and
many other illnesses would also improve dramatically. Combined with
enormous strides in stem cell research, this would create a new generation
of medical treatments reaching a whole new level of sophistication and
themselves will be built on a molecule-by-molecule basis, via positionally-controlled
diamond mechanosynthesis and diamondoid nanofactories. Each robot will
propel itself using tiny motors and will come equipped with microscopic
sensing, guidance and communication devices.
of 2011, it is already possible to grow individual tissues, tendons
and cartilages from stem cells. By 2020, scientists expect to have fully
characterised how every part of the heart works - enabling them to grow
complete replacements for use in transplants.*
for external donors will be eliminated, and since the organ will be
genetically matched to the patient, there will be no chance of rejection.
Natural, living tissue is also far more flexible, sophisticated and
efficient than artificially built components - so this new treatment
will offer radical hope to millions of people affected by cardiovascular
disease. Around 15m people currently die each year from heart-related
benefits could be huge. A significant percentage of healthcare costs
are attributable to organ failure, the recurring treatments for chronic
diseases and their subsequent complications. This new regenerative medicine
will effectively provide a cure, rather than ongoing treatment. Direct
healthcare costs of organ replacement and associated care are currently
over $350 billion globally (about 8 percent of global healthcare spending).
may be developed in the 2020s: lungs, livers, kidneys, spleens, stomachs
and sexual organs could all be made available by the end of the decade.
Internal organ failure will gradually become a thing of the past.
with new vitrification techniques* (allowing organ banking without damage from ice crystal formation),
this will be a major step towards longevity extension.
the near future, doctors will no longer have to use a needle and thread
to seal wounds. Pen-shaped devices are being developed that can do the
job using lasers, in combination with a blood protein called albumin.
Heated at just the right temperature, this forms a natural "glue"
after the skin has cooled down. Using this method allows a wound to
be stronger, water-tight, and less likely to scar than traditional stitches.*
been demonstrated in mice, bioengineered tooth regeneration may soon be
available for humans. Using a combination of stem
cells, scaffold material and signaling molecules, a fully functional
and living tooth could be regrown in around two months - complete with
roots, inner pulp and outer enamel.
dental implant therapies have required pre-existing high quality bone
structures for supporting the artificial implants. Full reconstruction
of natural, healthy teeth in patients without adequate bone support
will therefore be possible. Fillings and dentures will become obsolete
as a result, improving the health and well-being of many millions of
10"It's going to be an incredible tool. Fifty years down the road,
there could be small handheld MRI devices - like the tricorder in the
Star Trek television series - that enable us to see signals from molecules,
and there will be patterns for different diseases." See Thinking outside the box on MRI, Medical Physics Web: http://medicalphysicsweb.org/cws/article/research/30780
Accessed 17th October 2009.