DOCUMENTION OF ANTIBIOGRAMS WITH WHONET - USE IN ANTIBIOTIC POLICY

1. DOCUMENTION OF ANTIBIOGRAMS WITH WHONET - USE IN ANTIBIOTIC POLICY
Dr.T.V.Rao MD
What is an antibiogram?
•Antibiograms are important tools for health care professionals involved in prescribing empiric
antibiotics for suspected bacterial infections. These tools utilize microbiologic data from patient
specimens from a nursing facility to estimate the ward- or facility-wide prevalence of antibiotic
susceptibilities for common bacterial pathogens. They are also an important component of
monitoring trends in antimicrobial resistance within different areas of a facility.
Hospitals use antibiograms as part of their infection control measures to classify types of bacteria
found in cultures, to identify patterns of antibiotic susceptibility in those bacteria, and to track
changes in antibiotic susceptibility over time. Hospitals use these cumulative antimicrobial
susceptibility test data reports to determine the most appropriate agents for initial empirical
antimicrobial therapy and to target efforts to reduce inappropriate antibiotic use
an antibiogram is the result of an antibiotic sensitivity test, a laboratory test for the sensitivity of an
isolated bacterial strain to different antibiotics. It is by definition an in vitro sensitivity, but the
correlation of in vitro to in vivo sensitivity is often high enough for the test to be clinically useful.
Cumulative antibiograms provide local susceptibility and resistance information to aid clinicians in
making informed empiric therapeutic choices while waiting for susceptibility results of a patient's
isolate. However, many bacteria are known to be resistant to several classes of antibiotics, and
treatment is not so straightforward. This is especially the case in vulnerable patients, such as
patients in the intensive care unit. When these patients develop a hospital-acquired pneumonia,
more hardy bacteria like Pseudomonas aeruginosa are potentially involved. Treatment is then
generally started on the basis of surveillance data about the local pathogens probably involved. This
first treatment, based on statistical information about former patients, and aimed at a large group of
potentially involved microbes, is called empirical treatment. Additionally, antibiograms can identify
trends in emerging resistance patterns, which might otherwise go unnoticed. Many laboratories rely
on the software provided with their commercial antimicrobial susceptibility testing, I was using
WHONET org for many years with predictable results for forecasting trends, and WHONET is a free
Windows-based database software developed in 1989 by the World Health Organization (WHO). The
software is used in laboratories worldwide for the management and analysis of microbiology
laboratory data with a special focus on the analysis of antimicrobial susceptibility test results. This
software will analyse the culture results of your nursing home facility and supply you with the
susceptibility results for your antibiograms.
As you will learn through the tutorials, you will need to define the data fields from your database
(Culture Date, Organism, etc.) so that WHONET can understand them
Identification Number = Resident ID
Sex = Sex
Date of Birth = Birthdate
Location = Room
Department = Floor*
Specimen number = Culture ID

2. Specimen Date = Collection Date
Specimen Type = Source
Using WHONET to Find Percent (%) Susceptibilities
As with Backlink, the WHONET Tutorials are very helpful. In particular, the two "Data Analysis"
tutorials will be helpful for finding the percent (%) susceptibilities that will go into the antibiogram.
Below are a few tips for Data Analysis in WHONET that should make creating and updating the
antibiogram easier. These are covered in more detail in the tutorials, but there are many options for
data analysis and the steps below will make creating the antibiogram easiest:
1. After opening "Data Analysis" in WHONET, select "Analysis type." A box will open with options.
◦For "Analysis type," select "% RIS and test measurements."
◦For "Report format," choose "Summary."
◦Under "Antibiotics" leave "All antibiotics" selected. This will give you percent (%) susceptibility for
all antibiotics that have susceptibility results.
◦Select "OK."
2. Select "One per patient?" in the top right corner. Another box will open with options. ◦At the top,
under "Include which result in the analysis of each species?" select "By patient."
◦Then select "First isolate only." This will ensure that you are only analyzing the first isolate found for
each resident, so results are not biased by residents with recurring infections by the same organism.
◦Click "OK."
3. Under "Organisms," select all the organisms that have been found in cultures at your facility.
4. Under "Data files," select the Text file that you created from your culture data.Organism =
Organism
In addition to making and updating the antibiogram, you can use WHONET to answer more specific
infection control questions. For example, you could analyze a specific organism. Or you can select
"Isolates" when setting up data analysis to set more specific criteria for your results (for example, to
look at only one floor or one ward). See the WHONET and BacLink Tutorials for more detailed
information.
HELPS TO MAKE US BETTER ANTIBIOTIC POLICY
Why should you develop and use an antibiogram at your nursing facility?
•Antibiograms encourage responsible use of antibiotics throughout facilities. Prescribing clinicians—
physicians, nurse practitioners, and physician assistants—can consult these tools before initiating
empiric antibiotic therapy, which may improve outcomes among patients with infections.
•Antibiograms are a good way to detect changes in resistance patterns for an entire facility or for
locations within a facility.
•Antibiograms can be inexpensive to develop and maintain. The results are easily accessible to
health care providers.

3. What should you know before you decide to use an antibiogram?
•Antibiograms are not generalizable to different nursing facilities; they can be useful tools for
guiding empiric therapy and monitoring antibiotic susceptibility trends within a specific facility.
•Selection of empiric therapy in a particular patient should not be based solely on an antibiogram. A
patient's particular infection history, including past antimicrobial use, must also be considered.
•Antibiograms only capture the aggregate proportion of susceptible isolates for a given organism-
antibiotic combination. They do not provide the prevalence resistance to multiple antibiotics.
•Antibiograms provide guidance for empiric antibiotic use in patients, but other factors including
patient characteristics and prevalence of other risk factors should be incorporated when making
therapeutic decisions
IT IS ESSENTIAL ALL DIAGNOSTIC MICROBIOLOGY LABORATOREIS SHOULD MAKE SCEITIFIC
DOCUMENTATION WITH WHONET SOFTWARE
ALL THE MICROBIOLOGISTS SHOULD LEARN TO USE AND DOCUMENT THE ANTIBIOGRAMS AS
WITH THE SIMPLE CLICK OF A MOUSE WE CAN WATCH TRENDS OF ANTIBIOTIC RESISTANCE AT
OUR HOSPITALS
IT WILL MAKE US TO IMPRESS MANY CLINICIANS TO INCORPORATE MATTERS IN ANTIBIOTIC
POLICY
Ref Concise Antibiogram Toolkit Using WHONET to Create Your Antibiogram Agency for Health care
Research and quality
Dr.T.V.Rao MD, Clinical Microbiologist, Freelance writer