Welcome to the National Healthcare Safety Network
or NHSN Hot Topic Session. This presentation will
provide you with updates to reporting on Bloodstream
Infection or BSI definition changes for 2015.
This presentation focuses on changes to 2015
Protocol for BSI. The full protocol is available on the
NHSN website. You should review the Hot Topic on
definitional changes prior to reviewing any protocol.
This webinar contains guidance for properly applying
new rules and definitions for date of event, Repeat
Infection Timeframe, or RIT, and secondary
bloodstream attribution period, all of which are
used during BSI surveillance for NHSN reporting.
A short webinar can be found at cdc.gov/nhsn/training.
So, why update the BSI definitions for 2015? The
Center for Medicare and Medicaid Services or CMS
quality improvement programs, along with state
mandates, have prompted careful review of criteria for
Healthcare Associated Infections, or HAIs, and other
reportable events. CDCs assessment of NHSN,
coupled with feedback from system users and subject
matter experts, have led to important changes in
definitions, criteria, and business rules. These
updates aim to increase consistency in reporting,
update surveillance definitions, and streamline
secondary BSI reporting.
Neither the Laboratory Confirmed Bloodstream
Infection LCBI criteria, nor the Mucosal Barrier Injury
MBI LCBI, have any criterion changes for 2015.
Let's look at what's new. Surveillance definitions for
specific types of infections have been updated to
reflect current practices, and may affect when a BSI is
attributed to another primary site. New changes are
detailed in the Hot Topic Definitions presentation.
Please review for clarity.
Date of event is updated to reflect the date when the
first element used to meet the criterion occurs for the
first time in the seven-day infection window. Gap days
are no longer used to determine fulfillment of infection
criteria. Instead, the NHSN infection window is used
to make this determination. The NHSN infection
window is defined as the seven-day period during
which all site-specific infection criterion must be met.
It includes the day the first positive diagnostic test
included as part of the site-specific infection criterion
was obtained, and the three calendar days before and
three calendar days after. Diagnostic tests could
include the laboratory specimen collection date,
imaging test date, procedure or exam date, physician
diagnosis, or initiation of treatment.
Here is an example of how to identify the infection
window, and set the date of event. The blood culture
on day thirteen sets the center point of the infection
window. The infection LCBI2 definition is met, and
hospital day eleven is the date of event. The date the
first element, fever, is used to meet the LCBI2 criterion
occurs for the first time within the seven-day infection
window period.
Let's now move on to the next definition, Secondary
BSI Attribution Period. This is the period in which a
positive blood culture must be collected to be
considered secondary to a primary site infection.
This period includes the infection window period
combined with the RIT. This period is 14 to 17 days,
depending on the date of event. Note that a primary
BSI does not have a Secondary BSI attribution period.
Let's look at this symptomatic UTI, or SUTI example.
The date of event for this SUTI is hospital day 11. The
secondary BSI attribution period encompasses both
the infection window period and the RIT. In this
example the BSI attribution period is 15 days in
length. This includes the 14 days of the RIT and one
additional day of the infection window period. The
length of the secondary BSI attribution period depends
on the date of event. It is, however, never greater than
17 days.
Secondary BSIs may be attributed to a primary site
infection if either of the following is true: the positive
blood culture pathogen matches at least one
organism found in the site-specific infection culture
used to meet the primary site infection criterion
OR
The positive blood culture is an element used to meet
the primary site infection criterion.
Let's return to the SUTI example. A blood culture with
a collection date on hospital day 18, a day that is
included in the secondary BSI attribution period, is
positive with a pathogen that matches at least one
organism found in the urine culture. Therefore, the final
determination is a SUTI with a secondary BSI,
pathogen E.coli, and date of event day 11.
Appendix one, Secondary BSI infection guide should
continue to be used to determine appropriate
attribution of secondary BSIs. Remember, primary
site-specific criteria, as defined in the CDC NHSN
surveillance definitions for specific types of infection,
Chapter 17, must be met first in order apply the
Secondary BSI guidance. The first guidance to
consider is whether there is at least one matching
organism for both the blood and the site-specific culture.
If the blood and site-specific cultures do NOT match,
but the positive blood culture is an element used to
meet the primary site infection criterion, then the BSI
is considered secondary to the primary site-specific infection.
If the site-specific criteria does NOT use the blood
culture as an element to meet the criteria and the
organisms do not match, then a primary BSI must be
identified. Logical pathogens have been removed from
the protocol and are not considered. Also recall that
the site-specific infection would only be reported if it is
a part of your facilities plan and, or, required by your state.
Use this algorithm to assist in making determinations.
Remember that both the site specific criteria and
LCBI criteria must be met in order to consider a blood
stream infection as secondary to another primary source.
The final topic is the assignment of pathogens when
reporting infections to NHSN.
If additional pathogens are identified within a RIT and
found to be associated with the event, those
pathogens are added and a new infection is not
reported. In 2015, for some infection types there are
pathogen exclusions. For example, certain designated
organisms are not available for meeting the infection
criteria for UTI& pneumonia definitions. Pathogens
excluded from specific infection definitions also
cannot be assigned as secondary BSI pathogens for
those types of infections. Excluded pathogens must
be attributed to either a secondary BSI for another
site-specific infection, or a primary
BSI. For more details related to excluded pathogens,
refer to the UTI and Pneumonia Hot Topic
presentations.
So let's look at these two pathogen assignment rules.
In this example, a urine culture is collected on day 18
which is within the SUTI repeat infection timeframe. A
new pathogen, Enterococcus, is identified. Because
the culture was collected within the SUTI repeat
infection timeframe and Enterococcus is an eligible
pathogen, it is assigned to the originally reported
SUTI. Additionally, a blood culture collected during
the SUTI secondary BSI attribution period, hospital
day 14, was found to be positive with pathogens E.coli
and C. albicans. Because C. albicans is an excluded
pathogen for the UTI definition, it cannot be assigned
as a secondary BSI to the SUTI. Instead, other primary
sources for the C. albicans BSI must be considered
according to the secondary BSI guide. If another
site-specific infection is not identified for which the
BSI can be secondary, then the BSI meets criteria for
a primary LCBI. Note the date of event for the primary
BSI, hospital day 14, is also the date of the positive blood
culture. This is day one of the 14 day RIT for the
primary BSI. During this timeframe no new primary BSI
is reported. The final determination represented on
this slide is a SUTI with a secondary BSI. Pathogens
include E.coli and Enterococcus and the date of event
is hospital day 11. Additionally, an LCBI has been
identified with pathogen C. albicans and the date
of event is day 14.
Another concept to discuss relates to the assignment
of a pathogen to more than one infection source.
Depending on federal, state, and local, reporting
requirements, a secondary BSI pathogen may be
assigned to two different primary site infections, for
example a UTI and an IAB infection.
In this example, a pathogen is assigned as a secondary
BSI pathogen to two different primary infection sites, UTI
and non-surgical IAB. Two primary site infections have
been identified and a blood culture collected on Day
17, which is within both the SUTI and the non-surgical
IAB secondary BSI attribution period, has a matching
pathogen to both primary site infections. Therefore
both primary sites are reported to have a secondary
BSI. The final determination is a SUTI with secondary
BSI, pathogen E.coli, date of event hospital day 11
and a non-surgical IAB with secondary BSI, pathogen
E.coli, date of event hospital day nine.
Let's look at another scenario. A SUTI is identified
with hospital day 11 as the date of event. On hospital
day 17, a blood culture is positive for E. coli, matching
the SUTI pathogen. In accordance with the secondary
BSI guide in appendix one, the BSI is determined to be
secondary to the SUTI. Note the blood culture
collection on hospital day 17 also occurred within the
RIT of a primary BSI. E.coli pathogen is assigned to
the LCBI. The result is identification of an LCBI with
pathogens Staph aureus and E. coli, and a date of
event on hospital day nine.
In conclusion, familiarize yourself with the new
terminology and definitions before applying protocols.
Identify your infection window and set your date of
event to determine your RIT. If a another primary
infection source is considered for a BSI, then the site-
specific definition must be met and Secondary BSI
guidance must be applied before calling a BSI
secondary to another primary source. Apply the
pathogen assignment guidance as needed.
This concludes the NHSN Hot Topic update focusing
on reporting changes for BSI protocol. Additional
resources can be found on the NHSN website. For
other questions, please contact: NHSN user Support
at NHSN@CDC.gov.