Infection Surveillance
Public agencies take credit for the control of infectious
diseases achieved by reducing the microbial contamination of
food, air, and drinking water. Improved sanitation and personal hygiene
improved infection control. Infections such as typhoid and cholera
transmitted by contaminated water were major causes death prior to
the 20th century and were reduced dramatically by improved
sanitation. Smallpox was eliminated by vaccination and some the most
common endemic diseases continue to be controlled by vaccination.
Sad to say, the successes of the 20th century are not secure. Old
infections reappear in more virulent forms and new infections emerge
to challenge systems of control. Sustained attempts to develop
vaccines against major threats such as influenza, AIDS dengue and
malaria have limited or no success.
Biologists in the 21st century witness the processes
of evolution which are most rapid in bacteria and yeast cells. These
single-celled organisms are favored by geneticists since they
replicate in a matter of hours and evolving genetic changes occur
quickly. Bacteria acquire antibiotic resistance after repeated
exposure to antibiotics that kill susceptible bacteria, leaving the
resistant ones who eventually dominate the gene pool. Viruses evolve
most rapidly. New and more virulent mutations continue to be a
threat to human survival. Influenza viruses evolve so rapidly that
new vaccines have to be developed every year to immunize human
populations against infection with new variants of the virus.
Hein summarized current trends: "As the
world becomes smaller through global travel, we have learned that there are no
limits to how far, or how fast, infectious diseases can travel. We have seen
Legionnaires' disease spread through ventilation systems, HIV through
transfusion of unscreened blood, and numerous animal-to-human and air
travel-related infections. We are also seeing the
evolution of microbes, and some novel genetic mixes. Many new pathogens are
actually genetic mutations of older ones. Infectious diseases clearly represent
the Mendelian laws of survival, showing us that this field offers a continuum of
diverse challenges that have been difficult to predict
and sometimes difficult to control; this is unlikely to change. " (Ingrid
G. Hein . A 20-Year Look-Back: Two Steps Forward, One Step Back. Landmark
Developments in Infectious Diseases. www.medscape.com. October 20, 2015)
Bartlett wrote: "Predictions in this
field are particularly dangerous, on the basis of a history that is dense with
surprises in nearly all facets of the discipline. For example, Ebola was most
everyone's choice for medical story of the year for 2014, but this infection was
barely on the radar screen 1 year ago. The influenza vaccine recommended for the
current epidemic was created for the anticipated H1N1 strain, but the influenza
now causing widespread disease is largely the H3N2 strain. Chikungunya is hard
to pronounce and was rarely seen until the enormous epidemic in the Caribbean
that spilled over to the United States in returning travelers—and, more
worrisome, it achieved endemic transmission by mosquitoes in Florida. Antibiotic
resistance has been a notorious concern for more than a decade, but 2014 brought
federal legislation to address the problem, with a $1.1 billion price tag that came to most as a surprise.." (John G. Bartlett. Predictions for the
Field of Infectious Diseases for 2015. Medscape. Jan 29, 2015.)
My interest in infection surveillance and the lack thereof peaked
after I developed an airborne fungal infection. I used simple
microscopic techniques to diagnose my infection and invented a low
tech culture method that allowed me to monitor the infection. Most
of the physicians I encountered when I sought help to identify and
treat the fungal infection were not helpful. Indeed some were
remarkably stubborn in their ignorance and denial. I
encountered, for example, the spurious argument that the infection
has not been reported in BC before, therefore you can't have it.
There are several facts to acknowledge.
1. Infectious agents constantly evolve.
2 The distribution of infectious agents is always changing.
Planet wide events such as global warming, travel and the
shipment of goods and foods long distances connect all regions of
the planet. The idea of localized disease is obsolete.
Increasing populations and increasing urban density are ideal for
infection transmission. Transportation of people and goods all over
the world means that infections become worldwide in a matter of
days, not localized. I continue to meet physicians who think they
are living in the nineteenth century and refer to localized,
"endemic" infection.
Climate changes allow the migration and proliferation of vectors such as
mosquitoes that carry dengue, west nile virus, malaria, and yellow fever.
Other major diseases likely to spread with global warming are cholera,
filariasis and sleeping sickness. Fungi and bacteria are transported by wind,
water, animal vectors and by every mode of human transportation.
3. In Canada, medical awareness of diseases caused by fungi is
limited and prompt, accurate diagnosis is unlikely. Diseases that
are little known and are hard to diagnose become diseases that
"never occur around here."
4. Infection Surveillance systems are inadequate everywhere on
the planet. In Canada surveillance systems either don't exist
or if they do exist they are passive and disease-specific.
Communications among local physicians and public health services are
poor to non-existent. Canada lacks information-sharing. "New"
diseases will not be recognized quickly or treated effectively.
5. There are many different infections at work in every community
on any given day. The difficult task of identifying even common
infections is seldom undertaken by community physicians. Local
information about infections currently afflicting a community is
often not available.
Morse reported that concerns about the spread of infectious
diseases such as influenza or severe acute respiratory
syndrome (SARS), revealed the need for global early warnings and
rapid responses that did not exist. He stated: ”Although progress
has been made, many gaps remain. A number of the gaps can be
addressed through increased political will, improved resources for
reporting, improved coordination and sharing of information, raising
local doctors awareness, and more efficient triggers for action. The
increasing availability of communications and information
technologies worldwide offers new opportunities for reporting. “
[Health Affairs 26, no. 4 (2007): 1069–1077]
Influenza
Influenza surveillance has improved in recent years. In Canada,
FluWatch, a national influenza surveillance system, is coordinated
through the Centre for Infectious Disease Prevention and Control at
the Public Health Agency of Canada. Sentinel physicians collect
blood samples for influenza detection; participating labs can
accurately identify serotypes of the viruses which change within
months. The limitation has been that physicians and patients
remain ignorant of the infections prevalent in their own
communities.
In 2009 The emergence of a new H1N1 influenza virus created a frenzy of
misinformation and panic. TV news showed people wearing paper face masks, the
latest signal that the world is a dangerous place. While I have broadcast my
concern for many years that infection surveillance is inadequate and promoted a
new ethic of social responsibility, I found the frantic media reports about the
swine flu to be offensive if not absurd. Social responsibility means -- don't
spread infections you have acquired; if you are sick, stay at home.
Suddenly, quick tests for influenza were deployed worldwide and every news
organization broadcast daily influenza reports in a chaotic, confusing manner.
Individual examples of deaths from influenza were reported creating the false
impression that the swine flu was a new and deadly menace. Every year, for many
decades at least, thousands of people died from influenza infection but no-one
reported their fate. In previous years you had to be a dedicated researcher to
find morbidity and mortality reports to understand the severity of influenza
infection. Every year new variations of influenza virus spread thought the
world, but the modes of transmission, the rate and extend of spread were
scarcely known. Every year other viruses would spread widely with scarcely
any mention in the media and little international cooperation in the
identification of animal reservoirs and tracking of human to human transmission. In my
medical news blog I wrote "a brief review of the Swine Flu Scare of
2009 - a great pile of nonsense that seem to have overwhelmed even the most
cautious of scientists. This is not to argue that H1A1 viruses are innocuous,
but to develop a perspective on the relative threats of viruses in general and
to reveal that the evidence for swine flu as a special threat was lacking."
In the Northern hemisphere, viral epidemics cause up to 80% of all respiratory
illnesses. The most common infections are caused by six viral groups: rhinovirus
(RVs), respiratory syncytial virus, influenza virus, parainfluenza virus, corona
virus, and adenovirus. In one study of 285 children admitted to hospital with
lung infection, viruses were identified in 125 - respiratory syncytial virus
(107), influenza (9) and parainfluenza type 3 (9). Clinical and radiologic
diagnoses included bronchiolitis (127), interstitial pneumonia (47) and lobar
pneumonia (91).
