MedTech I.Q.

The Cutting Edge of Medical Technology Content, Community & Collaboration

Forecasting and Early Warning for Infectious Disease Crises: A Critical Component to Preparedness

Infectious Disease Crises and
Disasters: Statement of the Problem


Any country, including the United States, is exposed to the world's
infectious disease traffic through the air transportation and commerce
grid. Whether infectious disease hazards emerge locally or are
introduced from abroad, pre-event situational awareness is essential for
rapid identification of risk and preemptive mitigation.

Drawing from years of operational biosurveillance experience, this post
discusses the concept of integrated infectious disease warning systems and
the sociology of warning that may enable the
realization of an "intelligent" network of healthcare systems.

A Tale of Two Cities: SARS in Vancouver and Toronto

Pre-sensitization is an important psychological process triggered by
effective warning systems. Cues provided to medical staff to consider
the non-routine in their differential diagnosis can mean the difference
between negligible and serious impact to hospital operations from an
unexpected infectious disease.

During the emergence of SARS in 2003, two cities in Canada were impacted
in dramatically different ways, the result of a difference in pandemic
preparedness. SARS-infected travelers had returned to both Vancouver
and Toronto from the original Hotel M cluster before the first publicly
announced global alert by the World Health Organization on March 12,
2003.

Because of the volume of direct, non-stop air traffic from China to
Vancouver and rising threat of H5N1 avian influenza, the British
Columbia Centre for Disease Control (BCCDC) had initiated an aggressive
pandemic preparedness program prior to the emergence of SARS. They
established an electronic communications system to rapidly disseminate
advisories to healthcare providers in the province. They also adopted
best practices in public communication of emergency warning through
proactive issuance of advisories about "atypical pneumonia" ahead of the
WHO announcements on February 20th. These advisories were repeated
multiple times on February 24, 28, and March 12th. This prompted local
hospitals to conduct reviews and assessments of their infection control
procedures ahead of the ultimate arrival of the Vancouver index patient
on March 7th. The risk associated with this patient was immediately
recognized, and proper infection control procedures were implemented
immediately. In summary, a total of 5 cases were identified, 4 of which
were imported. It is believed this proactive warning and preparedness
posture protected the Vancouver area from further transmission and
compromise of their medical grid.

In Toronto, there was no comparable organization to the BCCDC that
coordinated preparedness activities for the province. Information
sharing was fragmented among multiple local health boards and hospitals.
On March 7th, Toronto's index case appeared and was not flagged as a
potential risk to staff and the facility itself. This patient remained
for 18 hours in the emergency department on a nebulizer. He was not
placed into isolation for 21 hours. By March 12th, the day of the WHO
global alert, 14 patients in Toronto had become infected through 4
generations of spread. Three hospitals were severely compromised due to
infection control-related ICU closure and need to treat healthcare
workers who were infected. In summary, a total of 247 cases and 43
fatalities were reported. Three of these cases were imported. The
medical grid and the economy of Toronto was severely impacted.

In their conclusion, the Canadians offered Pasteur's quote as a warning
to others: "Chance favors only the prepared mind."

The Case of the 2009 H1N1 Influenza
Pandemic


The United States Veteran Affairs recently published a study examining
successful detection of the 2009 H1N1 influenza pandemic that followed
the deployment of the ESSENCE syndromic surveillance system, which uses
ICD-9 billing codes to provide anomalous signal detection for a wide
variety of infectious diseases and their associated syndromes. The
study revealed success in providing detection of the increase in cases
across several ICD-9 codes. The authors did not provide insight into
how the information was used operationally to guide decision-making
during the crisis, however. This has long been a challenge to disease
surveillance systems: utilization of actionable information to guide
response during an infectious disease crisis.

Warning of the pandemic to CDC and WHO was provided through open source
information analysis and social networking, as was reporting of
subsequent operational strain observed in laboratory diagnostic
capacity, intensive care units (with specific emphasis on the use of
ECMO in adults), emergency departments, and so on. Social media
analysis revealed different sectors of the medical and paramedical
community experiencing true operational strain versus crisis anxiety.
These points highlight the broader variety of information needed to
assess the potential and live impact of infectious disease events.

Infectious Disease Hazards and Hospital
Vulnerability


While the more dramatic rare, high consequence infectious disease crises
are usually quoted when discussing infectious disease surveillance,
these events must be placed into context with the full range of risk
events and a consideration of what is most commonly observed. The
impact of infectious disease hazards does not become manifest unless
there is an intersection with indigenous vulnerability. This
vulnerability relates not only to availability of well-trained and
supplied medical care providers but also their access to early warning
information and situational awareness, knowledge, and effective
management of public expectation for uninhibited access to a given
standard of medical care.

Here we use a heuristic model to illustrate different types of
infectious disease events. This heuristic model capitalizes on the
classic features of a true crisis:

* Unexpected;
* Abrupt in appearance;
* Minimal forewarning;
* High level of uncertainty in information;
* Locally unfamiliar infectious agent;
* High mortality;
* Plainly visible and debilitating clinical features;
* Affects children,fetuses, or pregnant mothers
* Perception of no countermeasures

It is important to note the driver of a "crisis" being described as such
(especially by the media) strongly relates to uncertainty. Effective
warning systems combat uncertainty.

Category 0: The unreported infectious
disease event.


Daily, routine infectious diseases are handled at this level, and
provision of warning about these diseases is not deemed 'relevant'.
Non-routine infectious disease may also manifest as an unreported
infectious disease event, implying the "astute clinician" in the local
community network has not raised the concern something unusual was
observed in the clinic, and nothing unusual was noted in local public
health information feeds. This is the bleeding edge limitation of
disease surveillance, where the first case of unusual infectious disease
is often missed.

Typical examples include a case of influenza-like illness, non-specific
rash, or uncomplicated febrile illness seen by a healthcare provider.

Category 1: The reported infectious
disease event.


The typical Category 1 infectious disease event reported by a community
reflects a sensitivity to public health or medical significance.
Occasionally reporting reflects a sensational aspect of the disease in
question such as "flesh-eating" Streptococcal infection. This typically
appears in media reports. No other significant features indicative of
immediate public health or medical infrastructure impact, public
anxiety, or civil unrest triggered by the event are noted. Examples
include report of a chickenpox outbreak, limited norovirus outbreak, or a
single case of methicillin-resistant Staphylococcus aureus (MRSA).

Category 2: The infectious disease
event associated with routine organized response.


These events often reflect locally well-known diseases that nevertheless
generate a demand for organization-level time-sensitive action. This
action is local routine.

Examples include routine community action for seasonal diarrheal disease
in undeveloped countries or seasonal influenza in developed countries.
It is important to note non-routine infectious disease may present as a
Category 2 event, particularly when it shares similar clinical features
with routine disease. The classic example is the appearance of
pandemic influenza in the context of normal seasonal influenza, as was
observed in April 2009 with pandemic H1N1, where similarity in clinical
presentation masks the evolution of a crisis. Early indicators were
difficult to distinguish because the level of impact had not reached
"critical mass" to allow social recognition of the event as a threat.
Indeed, it is highly likely pandemic H1N1 was transmitting in Mexico
well before April 2009, undetected. Thus, the non-routine may present
as routine.

Category 3: Infectious disease event
associated with non-routine organized response.


Category 3 events are essentially the beginnings of a community crisis.
The operational definition of a crisis we are working from is the
following:

An infectious disease event becomes a
crisis when there is a recognized requirement for time-sensitive,
non-routine organization-level decisions that may affect a local
community’s activities of daily living. It is more common such
decision-making falls within the organizational roles and responsibility
of a public health institution than a public or private hospital or
individual healthcare provider. This becomes a community level
decision-making activity in countries where there is no public health
capacity.


It is important to note Category 3 events may be associated with
organized response features without significant broader social
disruption, as evidenced in a Category 4 event.

Examples of this type of event include a new vaccine-drifted influenza
type A variant that appeared before an updated vaccine could be made
available to the public. Another example is the 1999 introduction of
West Nile virus to the United States, after recognition of the event to
represent a public health threat. In this category it becomes important
to understand the differences between organized response seen in public
health versus medical care such as that provided by a hospital.
Monitoring both is crucial.

Category 4: infectious disease event associated with social disruption

Category 4 events highlight when organized response has occurred, yet
significant social disruption has been documented. The operational
definition of social disruption we are working from is the following:

Social disruption [of community vital processes] refers to the process
where a community moves from a given level of integration towards
disintegration.

Coleman’s (1966) original theory of community integration proposed
“vital processes” of a community that “keep it alive as a community and
prevent its disorganization”. These processes included:

- Work
- Education of children
- Religiously related activities
- Organized leisure activities
- Unorganized social play of children and adults
- Voluntary activities for charitable or other purposes
- Treatment of sickness, birth, death (healthcare)
- Buying and selling of property
- Buying consumable goods (food, etc.)
- Saving and borrowing money
- Maintenance of physical facilities (roads, sewers, water, light)
- Protection from fire
- Protection from criminal acts

It is well recognized infectious disease events may impact a community
to the point of straining various aspects of these vital processes.
Category 4 events may be associated with significant strain of multiple
community vital processes without inducing community disintegration,
which is the indication of a Category 5 event.

Examples of Category 4 events include the 1957, 1968, and 2009 influenza
pandemics and the introduction of Chikungunya to India in 2006.

Category 5. Infectious disease event associated with disaster indicators

The operational definition of a disaster we are working from is the
following:

An infectious disease crisis becomes a
“disaster” when crisis mode decision making by public health officials
or institution fails to control the situation, either from an
informational or response perspective and substantial social disruption
associated with features of community disintegration occurs as a result.


This is the typical modern day end-point of social strain experiences
when cultural protections fail and individuals of a community physically
abandon their dwellings or those vital processes necessary for
community integration. The concepts of integration and disintegration
are not absolute: each community is associated with a given balance of
factors that promote integration and disintegration. Disasters tip this
balance towards disintegration. This concept therefore encompasses more
than simply public health response capacity but a broader social
context.

Category 5 infectious disease events are classically observed as the
so-called "panic evacuations", which is a misnomer. Observations for
years has instead suggested people migrate out of an area of perceived
high threat in a manner that attempts to preserve the family unit and
other close social ties. It is often observed these individuals attempt
to return to their homes. Thus, a Category 5 event typically
represents transient community disintegration.

Examples include outbreaks of Ebola hemorrhagic fever in Africa,
occasional abrupt appearances of cholera in IDP camps in Africa, and
measles in Africa. We have also seen the 2009 H1N1 influenza pandemic
induce Category 5 conditions among indigenous peoples in South America.
The key is the intersection between the infectious disease event and
violation of cultural protections to the point of inducing community
disintegration.

Perspective

The relative frequency of Category 0 - 6 events ranges from common to
exceedingly rare. What are highly disruptive events in some countries
are not in the United States owing to a difference in medical and public
health capabilities and indigenous knowledge. Declared crises such as
the appearance of West Nile virus in the New York City area in 1999 may
quickly become a matter of routine, owing to adaptation of knowledge and
acceptance of what can and cannot be done to mitigate the risk.

Hospital Vulnerabilities

The urban hospital facility and its referring satellite clinics does not
function in isolation from the local community environment. The
hospital-local community is also connected to distant communities,
domestic and foreign, by way of air traffic, commerce, and cultural
diaspora.
These are the levels are at which events typically get handled, which
require distinct (yet integrated) approaches:

1. Patient-medical care provider

Most infectious disease hazards are adequately handled on a daily basis
at the patient-medical care provider level. However, as highlighted
earlier, occasional infectious disease events required a more concerted
organized and time-sensitive response. The vulnerability is the
potential for exposure by an unrecognized infectious disease hazard such
as MDR-TB to unsuspecting staff.

2. Unit or department level

Some infectious disease issues become unit or department-level
challenges such as Clostridium difficile, Vancomycin-resistant
Enterococcus (VRE), or Methicillin-Resistant Staphylococcus aureus
(MRSA). It can be argued the cost and staffing to address organized
response towards these issues has become routine in many hospitals.
Admission to the hospital of a case of previously unrecognized MDR- or
XDR-TB may incur non-routine protocols to perform contact tracing and
staff exposure assessments. In a more extreme and rare example, the
admission of unrecognized SARS cases to an intensive care unit in
Toronto results in closure of that unit, with a resultant ripple effect
throughout the hospital (explained below).

3. Hospital level

Some of the vulnerabilities identified at the unit or departmental level
become a persistent hospital-wide challenge. Examples include
Clostridium difficile and Vancomycin-resistant Enterococcus (VRE).

Some of the hospital units function as critical nodes within the
facility. For example, excession of bed capacity in the intensive care
unit directly affects the emergency department's ability to ingest
critically ill patients. The intensive care unit consists of highly
specialized medical personnel who are not easily replaced if an
unrecognized serious infectious disease exposure occurs. Demands for
specialized care above and beyond what is typically utilized in the unit
such as ECMO during the 2009 H1N1 pandemic may further compromise the
unit's ability to be agile in the face of a threat.

4. Hospital-community level

Untoward outcomes in the hospital are associated with community
relations challenges in the form of risk communication and avoidance of
unnecessary social outcry.

Here the overall objective is to recognize the hazards, vulnerabilities,
and the overlap between them as a function of risk. The majority of
risk, as explained, is generally handled routinely at the individual
patient-medical care provider level, however other challenges have crept
their way into the unit and multiple-unit levels of the hospital and
now are routinely addressed to varying levels of success.
An important consideration for the hospital is the concept of adaptive
fitness, otherwise known as resilience over time. Here the thoughtful
question becomes, how resilient is the hospital now and how resilient
will it be in the future as hazards and vulnerabilities evolve over
time. Resilience is, as explained above, not just a consideration for
the hospital facility itself by all of its components, satellite
clinics, staff, the local community it operates in, and those distant
communities it is connected to. This leads to the realization of the
"intelligent hospital".

Warning systems are a key component of preparedness, which contributes
to positive adaptive fitness for the medical system over time.

Views: 26

Comment

You need to be a member of MedTech I.Q. to add comments!

Join MedTech I.Q.

Comment by Eric K. Noji, M.D. on July 11, 2010 at 2:39pm
You're the best.

© 2024   Created by CC-Conrad Clyburn-MedForeSight.   Powered by

Badges  |  Report an Issue  |  Terms of Service