In response to my critique of recent trends toward over-reliance on
digital diagnoses, John Sherwood of the
University of Georgia (view article)
and Gerald Holmes et al of North Carolina State
University (view article) make three key points (in bold type), which I have
Holmes et al state that the use of digital images is only one of many
tools used in making a final diagnosis, but is not the sole source of
information used in making diagnoses. "At North Carolina State
University, digital images are typically accompanied by live
samples…," Holmes et al claim.
If this is indeed the case, and a sample is required to complete the
diagnosis, then it seems to me that digital imaging is a very nice but
extremely expensive accessory. However, a review of the web pages from the
University of Georgia and North Carolina State (the institutions that
employ Sherwood and Holmes et al, respectively) indicate that digital
images can be used as the sole source of information in developing a
diagnosis and management recommendation. "The agents then upload the
pictures to the World Wide Web. Scientists great distances away can
identify the problem and make a recommendation, usually via e-mail…It's
a reality that we can't have every specialist in every corner of the state
to help farmers" (view
page). And "…Samples can be submitted and diagnosed within 15
minutes in an emergency." Likewise, the North Carolina State University web page contains
the following comment on their Clinic page (view
page), "Handheld cameras and camcorders allow the county agent to
transmit digital pictures of the sample as well as the field distribution
providing a valuable overall picture of the problem. Digital image
transfer offers the opportunity for very rapid turnaround time."
There is no information on either of these web pages to indicate that a
sample is required for diagnosis, leaving the very certain message that
accurate diagnoses can be conducted using digital images alone. Whose
claims are we to believe?
Digital diagnoses offer an improvement over real-life diagnoses because of the deteriorated condition in which samples frequently arrive.
The argument presented by Sherwood is that digital images are at least
an improvement over making diagnoses from samples that are "…in the
mail or refrigerator for 3 days…" and Holmes et al claim that
digital "…images allow the diagnostician to preview the sample
before it arrives at the clinic (often in a deteriorated state)." Yet
I would have to question why, with the ready availability of overnight
shipment services that we currently enjoy, it is not possible for
diagnosticians to receive samples 24 hours after sampling occurs.
Webster's Seventh Collegiate Dictionary (1969) defines a straw man as a
"weak or imaginary opposition (as an argument or adversary) set up
only to be easily confuted." I am afraid that in their eagerness to
validate the use of digital diagnoses, Sherwood and Holmes et al have
resorted to the use of the proverbial "straw man" of
deteriorated samples-a situation that can be easily remedied through the
dissemination of proper shipping instructions (which could even be
provided electronically!)-only to allow them to knock it down.
Digital diagnoses provide the additional advantage of more rapid
diagnoses, increased availability of extension agents, and overall
better service to the public.
More rapid diagnosis is certainly an advantage, provided that the diagnosis is correct. However, it goes without saying that a speedy diagnosis that is wrong is at best of no value, and at worst, can result in the misuse or overuse of pesticides as well as serious crop losses due to the unchecked progress of disease, nutritional or other undiagnosed problems. How can we help avoid these problems? There is only one way, in my opinion, and that is to use all of the tools at our disposal-hands-on examination, background information from the grower or extension agent, digital images, etc.-to provide disease diagnoses that are as accurate as possible. This is particularly important because most of the samples that require input from plant pathologists are not easily diagnosed diseases such as powdery mildew-in most cases, extension agents and/or crop advisers can identify these diseases without our input and without the necessity of electronic diagnoses. Instead, it is the more complex, less easily diagnosed problems that we are more commonly called on to help resolve. Compaction, salinity stress, the presence of multiple pathogens, root diseases, and interactions with other biotic and abiotic factors are some of the more complex plant health problems that I typically receive in the lab. In these cases, a simple image of the plant or field will not provide the insights needed to make a responsible diagnosis and management recommendation. Even what may appear to be a simple disease commonly has many hidden factors that will influence the management of the problem. At PACE Consulting, we accept digital images and photographs to assist in a diagnosis but would never consider making a diagnosis based on the images of the plant or field alone.
We are not the only profession to be challenged by the ethics of using electronic communications for the purposes of conducting diagnoses and making recommendations. The American Medical Association recently developed a policy statement on the use of telecommunications for delivery of services which states: "Any telecommunication advisory service should employ certain safeguards to prevent misuse. For example, the physician responding to the call should not make a clinical diagnosis. Diagnosis by telecommunication is done without the benefit of a physician examination or even a face-to-face meeting with the caller. Critical medical data may be unavailable to the physician. Physicians who respond to callers should therefore act within the limitations of telecommunication services and ensure that callers understand the limitations of the services. Under no circumstances should medications be prescribed" (italics are mine).
It can be argued that this type of policy statement is even more important in the practice of plant pathology than in medicine. For although medical patients can decide whether or not to use the medication prescribed, the public does not get the opportunity to choose whether or not they consume food that, because of an incorrect diagnosis, has been unnecessarily treated with pesticides. As plant pathologists, we assume a great responsibility when we diagnose and provide treatment recommendations. For this reason, it is imperative that the APS address telecommunications for delivery of plant diagnostic services and the use of digital or photographic images in a fashion similar to that developed by the AMA.
I call upon the APS, the organization that provides stewardship for the profession of plant pathology, to begin a dialogue that will lead to development of guidelines for the responsible practice of plant pathology, including the role telecommunications and digital images in the development of diagnoses and recommendations. The confusion within our profession on this question indicates that leadership is called for. Now is the time for APS to step up to the plate.