a Animals positive for this organism among those tested with signs possibly associated with this disease.
b Animals positive for this organism among those tested during the intake examination.
FeLV, feline leukemia virus.
FIV, feline immunodeficiency virus.
c Disease that developed among the shelter animals while they were in residence in the shelter.
URTD, feline upper respiratory tract disease.
CIRD, canine infectious respiratory disease, also known as kennel cough.
d Could be treated in the future with additional resources.
One issue complicating the collection of surveillance data is the failure to reach a diagnosis. For this reason, some software programs enable shelters to retrieve both “diagnoses” and “clinical signs” (check your software). From a disease‐surveillance standpoint, a diagnosis is preferable, but since a specific diagnosis is often not possible in shelters, recording and monitoring important clinical signs can be helpful. An unusual frequency of diarrhea might prompt the collection and submission of samples for diagnostic testing and identify, for example, an outbreak of giardiasis. Sometimes, the level of uncertainty of diagnosis is incorporated into disease data. For example, some studies incorporate case descriptors such as “possible,” “probable” or “confirmed” or “presumptive” vs. “confirmed” for diagnoses and incorporate these levels into their analyses. It can be helpful to have data regarding both diagnoses and signs, particularly when diagnoses are suspect, or the shelter wishes to monitor disease severity. If both signs and diagnoses are collected, they should be in separate data fields to avoid double counting.
To achieve consistency of data recording among staff over time, shelters need written descriptions of each of the diseases they include in the surveillance system. Staff members require training regarding those definitions and the importance of adhering to them. For some diseases, this is relatively easy. A diagnosis of feline leukemia virus (FeLV), for example, is based on a positive result on a commercially available, validated test; for other diseases, such as canine infectious respiratory disease (also known as kennel cough or CIRD), defining cases is more difficult, as respiratory signs alone rarely establish a definitive diagnosis. In these instances, a “working definition” of the disease can be used (as is often true during outbreak investigations) or the incidence of certain clinical signs may be monitored. Despite the difficulty, if no attempt is made to standardize the grounds for a diagnosis or create a working definition, it is hard (if not impossible) to interpret changes in disease frequency. The key is to standardize as much as possible what staff diagnose as a particular disease or identify as a clinical sign. The definitions need not be perfect, only consistently applied.
The collection of the date of the first diagnosis is essential to mark the onset of each new case so that incidence measures can be calculated for specific time periods. For diseases that can occur more than once in an individual animal (e.g. upper respiratory tract infections), only the first episode during a particular timeframe is counted as a new or incident case. If the medical team has an interest in reoccurring illnesses, the rate of second occurrences can be calculated and reported separately. If second (or other) occurrences are monitored during a time period of interest, the denominator includes only animals with a first occurrence in that timeframe. Fortunately, since most animals do not reside in most shelters long enough to experience second infections of most diseases, the rate of second infections is usually ignored. An exception may be in sanctuaries.
3.2.4 Data Collection, Analysis, Interpretation, and Communication
Disease surveillance takes time and resources to do well. An effective surveillance program must be valued, planned, and well‐executed. Written protocols governing what, where, when, and by whom each component will be performed are essential.
Several staff members are usually involved in data collection during an animal's passage through the shelter system. For infectious disease surveillance, shelter intake (for denominators) and medical data (for numerators) are obviously needed, but data related to movement, outcomes, daily observations and other events could also be important to address questions that arise from surveillance. Quality and completeness of all relevant data are key components. Everyone involved with data collection must be trained and held accountable for providing good data. Without explicit protocols, staff may be unsure of how, what, when, and where to collect specific pieces of information.
How and by whom the data will be routinely analyzed should be clear. This includes the metrics (e.g. incidence, mortality) and subgroups of animals to monitor, the trends to track, and any other metrics that are important to the shelter's medical‐related goals.
Since disease risk frequently varies by age group, source (e.g. stray), and over time, separate incidence rates should be calculated for each of these factors. Data can contradict common beliefs. For example, after reviewing Figure 3.1, medical staff members were surprised that the incidence (or risk) of feline upper respiratory tract disease (URTD) was actually higher in the fall and winter months than in the spring and summer. Further analyses demonstrated that this was true among both kittens and adult cats. The staff
