Download Fumigation With a Combined Quaternary Ammonium Compound

Fumigation With a Combined
Quaternary Ammonium
Compound and 2 Alcohols
After Detection of Bacterial
and Fungal Air Bioburden
TO THE EDITOR—How best to evaluate
the effect of quaternary ammonium
compound–based products after detection of postflood bacterial and fungal air
bioburden remains uncertain. Thammasat University Hospital (Thailand)
closed after severe black-water flooding
in 2011; significant resources and costs
were associated with hospital closure,
reparations, and tiered reopening of select
units [1]. In addition, an infectioncontrol surveillance program was created
to optimize patient and healthcare worker safety [1]. After flood waters reached
a maximum 3-foot height between 14
October and 2 November 2011, hospital
units were inspected and reopened during
the interval from 2 November 2011 to
31 August 2012. An infection-control
protocol for cleaning and area decontamination was performed in accordance
with a checklist from the US Centers for
Disease Control and Prevention (CDC)
[2]. Despite thorough manual environmental cleaning, several units had high
bacterial and fungal air bioburden,
defined as measurements >500 colonyforming units (CFU)/m3 [1]. Special
area decontamination was then employed on all units that had subsequent
high bacterial or fungal air bioburden
after thorough manual environmental
cleaning, using a nontouch technique of
either a hydrogen peroxide vapor or a
quaternary ammonium compound–
based product [1].
Routine air sampling on a negativepressure hospital unit detected a high
bacterial and fungal air bioburden on 1
August 2012, despite special area decontamination with repeated manual cleaning (Table 1). We designed a fumigation
protocol, comprised of 2.5% isopropyltridecyl-dimethyl-ammonium (Umonium,
Huckert's International, Nivelles, Belgium),
1060
•
CID 2013:56 (1 April)
•
CORRESPONDENCE
according to the manufacturer's recommendation. After fumigation of the 4
patient rooms and the nursing station of
this unit, the air bioburden for bacteria and
fungi was monitored via passive air sampling using the settle plate method [3, 4].
Each sampling entailed 30-minute air exposure of two 90-mm Petri dishes containing sheep blood agar and Sabouraud
dextrose agar medium [3, 4]. The Petri
dishes were incubated and inspected on
day 5 for fungal quantification and identification in accordance with a standard
clinical microbiology method; total fungal
or bacterial bioburden <500 CFU/m3 was
the upper limit of normal [1, 4, 5]. The
number of fungal and bacterial colonies
expressed as CFU/m3 were estimated
using Koch sedimentation method according to Polish Standard PN 89/Z04008/08, per the following equation:
CFU/m3 = (the number of colonies on
the Petri plate × 1000)/(the surface area
of the Petri plate in cm2 × the time of
Petri plate exposure in minutes × 0.2) [6].
After fumigation, there was a clear reduction in both bacterial and fungal air
bioburden at 6 hours, day 1, and day 7.
There was a slightly increased air bioburden level of bacteria and fungi on
day 14 in some patient rooms, yet
these measurements were well below
500 CFU/m3 in all areas (Table 1). The
most common fungal species identified
were Penicillium, Aspergillus, Phialophora, and Syncephalastrum. No aerosolized bacteria were identified, and all
environmental surface cultures were
negative.
A prior report suggests that 2.5% quaternary ammonium–based compounds
have broad-spectrum disinfectant activity
for microorganisms on surfaces under
clean and dry experimental conditions [7].
The list of microorganisms eradicated
after environmental cleaning with 2.5%
quaternary ammonium–based compounds included Pseudomonas aeruginosa,
Escherichia coli, Staphylococcus aureus,
Candida albicans, Aspergillus niger,
Mycobacterium avium, Mycobacterium
terrae, poliovirus, adenovirus, hepatitis B
virus, and human immunodeficiency
virus [7, 8]. To date, our findings provide
the first report of an association of environmental cleaning with this agent and
eradication of aerosolized fungal bioburden. Although our study was limited to
air sampling, without initial environmental surface cultures, our data suggest
that fumigation with 2.5% quaternary
ammonium salt solution, combined with
isopropyl alcohol, benzalkonium chloride, and tridecyl ceteth alcohol pH 7, at
a concentration of 32 g per 100 mL, may
provide an alternative approach to reduce,
if not eradicate, bacterial and fungal air
bioburden in a closed hospital unit after
black-water flood exposure. Given the
relatively inexpensive capital cost of this
method, relative to other nontouch technologies, further studies that evaluate the
effectiveness and safety of this method
are needed in other at-risk settings.
Table 1. Serial Air Bioburden Measurements of Bacteria and Fungi in the Patient
Rooms and Nursing Station of a Hospital's Negative-Pressure Unit After Fumigation With
a Quaternary Ammonium Salt–Based Solution Combined With 2 Alcohols
Fungal Air Bioburden
(CFU/m3)
Bacterial Air Bioburden
(CFU/m3)
Duration After
Fumigation
PR 1
PR 2
PR 3
PR4
6 hours
NS
PR1
PR2
PR3
PR4
NS
840
660
580
680
900
534
553
585
536
556
Day 1
30
90
90
80
120
147
147
134
134
234
Day 7
Day 14
30
30
90
90
120
330
120
180
200
470
147
335
130
236
147
336
100
450
234
326
Abbreviations: CFU, colony-forming unit; NS, nursing station; PR, patient room.
Notes
Financial support. This work was supported
by the National Research University Project of
the Thailand Office of Higher Education Commission (to A. A.) and Infectious Diseases and
Infection Control Research Unit (to A. A.).
Potential conflicts of interest. L. M. M. is
an employee in WWEpidemiology, GlaxoSmithKline (GSK), and this work was conducted
pro bono and independently of GSK. All other
authors report no potential conflicts.
All authors have submitted the ICMJE Form
for Disclosure of Potential Conflicts of Interest.
Conflicts that the editors consider relevant to the
content of the manuscript have been disclosed.
Anucha Apisarnthanarak,1
Sunee Wongcharoen,1 and Linda M. Mundy2
1
Division of Infectious Diseases, Faculty of Medicine,
Thammasat University Hospital, Pathumthani,
Thailand; and 2GlaxoSmithKline, Collegeville,
Pennsylvania
References
1. Apisarnthanarak A, Khawcharoenporn T,
Mundy LM. Black-water floods and hospitalbased postflood mold investigation. Infect
Control Hosp Epidemiol 2012; 33:1285–6.
2. Centers for Disease Control and Prevention.
Checklist for infection control concerns when
reopening healthcare facilities closed due to
extensive water and wind damage. Available
at: http://emergency.cdc.gov/disasters/reopen_
healthfacilities_checklist.asp. Accessed 23
October 2011.
3. Andon BM. Active air vs. passive air (settle
plate) monitoring in routine environmental
monitoring programs. PDA J Pharm Sci
Technol 2006; 60:350–5.
4. Iwen PC, Davis JC, Reed EC, Winfield BA,
Hinrichs SH. Airborne fungal spore monitoring in a protective environment during hospital construction, and correlation with an
outbreak of invasive aspergillosis. Infect
Control Hosp Epidemiol 1994; 15:303–6.
5. Fromtling RA. Mycology. In: Murray PR, Baron
EJ, Jorgensen JH, Pfaller MA, Yolken RH, eds.
Manual of clinical microbiology. 8th ed. Washington, DC: ASM Press, 2003:1651–893.
6. Bhatia L, Vishwakarma R. Hospital indoor
airborne microflora in private and government-owned hospitals in Sagar City, India.
World J Med Science 2010; 5:65–70.
7. Conte M, Bagattini M, Trotra AM, Triassi M.
Assessment of the efficacy of Umonium38 on
multidrug-resistant nosocomial pathogens.
J Prev Med Hyg 2007; 48:50–3.
8. Raffo P, Salliez AC, Collignon C, Clementi
M. Antimicrobial activity of a formulation for
the low temperature disinfection of critical
and semi-critical medical equipment and surfaces. New Microbiol 2007; 30:463–9.
CORRESPONDENCE
•
CID 2013:56 (1 April)
•
1061
Correspondence: Anucha Apisarnthanarak, MD, Division of
Infectious Diseases, Faculty of Medicine, Thammasat University Hospital, Pathumthani, Thailand, 12120 (anapisarn@
yahoo.com).
Clinical Infectious Diseases 2013;56(7):1060–2
© The Author 2012. Published by Oxford University Press
on behalf of the Infectious Diseases Society of America. All
rights reserved. For Permissions, please e-mail: journals.
[email protected].
DOI: 10.1093/cid/cis1033
1062
•
CID 2013:56 (1 April)
•
Second, the authors interpret the data
to mean that untreated patients had less
severe disease. I disagree with this. Patients in the untreated group had a
shorter hospital stay, probably due to
the higher case fatality in this group.
Paradoxically, the authors interpret this
as an indication of less-severe disease.
CORRESPONDENCE