1 hospital preparedness and h1n1 2009 influenza khachornsakdi silpapojakul md prince of songkla...
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Hospital Preparedness and H1N1 2009 influenza
Khachornsakdi Silpapojakul MD
Prince of Songkla University
Hat yai, Songkla, Thailand
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What ???
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Swine influenza
Influenza as a disease of pigs was first recognized during the Spanish influenza pandemic of 1918–1919. Veterinarian J. S. Koen was the first to describe the illness,observing frequent outbreaks of influenza in families followed immediately by illness in their swine herds,and vice versa.
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Why important ?????
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Country Cases Deaths
MEXICO 4174 80
U.S.A 6552 9
CANADA 805 1
JAPAN 345 0
SPAIN 133 0
UK 122 0
PANAMA 76 0
Total 12515 91 (0.7%)
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Pandemics?
the three important criteria for a new pandemic influenza virus—ie, the ability to replicate in human beings and the absence of antibodies to the virus in the human population at large. The third criterium is the potential to rapidly spread from man to man.
8Drugs 2001;61:263-83
Hemagglutinin
Neuraminidase
M2 ion channel
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H5N1 Avian influenza
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Human influenza A receptor = SAα2,6-linked
Avian influenza A receptor = SAα2,3-linked
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Avian SAα2,3-linked receptors = red Human SAα2,6-linked receptors = green
Nasal mucosa Sinus Bronchus
bronchiole
Alveoli
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Why are pigs important regarding pandemics ???
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Avian SAα2,3-linked receptors = red Swine SAα2,6-linked receptors = green
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Pigs are thought to have an important role in interspecies transmission of influenza, because they have receptors to both avian and human influenza virus strains.
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Why important ?????
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Pandemics
the three important criteria for a new pandemic influenza virus—ie, the ability to replicate in human beings and the absence of antibodies to the virus in the human population at large. The third criterium is the potential to rapidly spread from man to man.
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Swine flu: Mortality??
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Country Cases Deaths
MEXICO 4174 80
U.S.A 6552 9
CANADA 805 1
JAPAN 345 0
SPAIN 133 0
UK 122 0
PANAMA 76 0
Total 12515 91 (0.7%)
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EID 2006;12: 15-22
Case fatality rates were >2.5%, compared to <0.1% in other influenza pandemics.
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High school A with 2,686 students and 228 staff members.
April 23–24, a total of 222 students got ill.
During April 26–28, 44 (86%) of 51 specimens collected were tested positive at CDC for S-OIV,
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Median age = 15 years (range: 14–21 years).
All were students,
The only adult was a teacher aged 21 years.
None of the 44 patients reported recent travel to California, Texas, or Mexico.
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Further enhanced surveillance among all students, staff members, and family members of persons at high school A indicated widespread influenza-like symptoms, with hundreds of students and many staff members reporting symptoms that met the case definition for ILI.
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Several students participating in the on-line survey (none of whom had confirmed S-OIV) reported travel to Mexico during the week before April 20; an undetermined number were symptomatic at the time of survey participation.
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Swine flu: Morbidity??
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N Engl J Med 2009;361:1-10
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Severe Swine Flu: Who ???
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Of the 22 hospitalized patients for whom data were available, 4 (18%) were children under the age of 5 years, and 1 patient (4%) was pregnant. Nine patients (41%) had chronic medical conditions.
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Severe Swine Flu: Old age???
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March 1–April 30,2009
1,918 suspected cases
286 probable cases 97 confirmed cases 7 died
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EID 2006;12: 15-22
Case fatality rates were >2.5%, compared to <0.1% in other influenza pandemics.
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Probable Scenario of Pandemic Influenza Outbreak.
What?
When?, How long?
Where?
Who?
Why?
How?
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Where shall they begin?
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First wave of influenza epidemic: In the community
Where & Who?
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School absentee
Pediatric pneumonia
ER visits
Adult pneumonia
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High school A with 2,686 students and 228 staff members.
April 23–24, a total of 222 students got ill.
During April 26–28, 44 (86%) of 51 specimens collected were tested positive at CDC for S-OIV,
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Cough ( 43 patients [98%]),
Subjective fever (42 [96%]),
Fatigue (39 [89%]),
Headache (36 [82%]),
Sore throat (36 [82%]),
Runny nose (36 [82%]),
Chills (35 [80%]),
Muscle aches (35 [80%]).
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Nausea (24 [55%]),
stomach ache (22 [50%]),
diarrhea (21 [48%]),
shortness of breath (21 [48%]), and
joint pain (20 [46%])
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Second Wave of Epidemic: ? in the Hospitals
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Nosocomial transmission was the primary acceleration of SARS infections accounting for 72% of cases in Toronto, 41% of cases in Singapore and 55% of probable cases in Taiwan.Ref.: Booth CM et al. JAMA 2003;289:2801-9
James L et al. Publ Health 2006;120:20-26
CDC. MMWR 2003;52:461-6
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A ProMED-mail post
<http://www.promedmail.org>
Date: 2 May 2009
From: Oliver Schmetzer
Human to human transmission, Germany
According to the press release of the president Juerg Hacker of the German health institute (Robert-Koch-Institute) from 2 May 2009:
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“The 2nd suspected human-to-human infection has been confirmed. In addition to the 42-year-old nurse, the 38-year-old patient which shared the room with the initial in Mexico infected 37-year-old man has been tested positive for A/H1N1…..”
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Where in the hospital did the outbreak occur?
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EID 2004;10:782-788
Thirty- one cases of SARS occurred after exposure in the emergency room of the National Taiwan University Hospital.
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Crit Care Med 2005;33:S53-S60
Four hospitals had major nosocomial outbreaks of SARS. Three of these outbreaks occurred in ICUs.
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“Within 18 hrs of presentation, the patient was admitted to the ICU and 3 hrs later was placed in an isolation room.This 21-hr period of unprotected contact led to128 cases of SARS resulted from transmission of the virus within this hospital. (42% HCWs, 28% patients or visitors, and 30% household contacts).”
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73 ICU beds were closed during various phases of the SARS outbreak, representing38% of the tertiary-care university medical–surgical ICU beds and 33% of the community ICU beds in Toronto.
Ref.: Booth CM & Stewart TE. Crit Care Med 2005;33:S53-S60
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How long shall the epidemic last???
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Singapore: James L et al. Publ Health 2006;120:20-6
69Taiwan: EID 2004;10:777-781
70Beijing: EID 2004;10:25-31
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EID 2004;10:771-776
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SARS and Critical Care: Lessons Learned
“the most important of which is preparedness. We were not prepared for SARS, nor did we have a systemwide critical care communication strategy in place..... the most important limitation in the response to SARS was the absence of a coordinated leadership and communication infrastructure. BoothCM,Stewart TE. Severe acute respiratory syndrome and critical care medicine:The Toronto experience. Crit Care Med 2005;33:S53-S60
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“Noah's ark was built before the rain.”
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Personnels Preparedness:Keywords
Education &Training
Maximize Their Safety
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Hospital Staffs Education
Routes of transmission
Handwashing
How to don and how to remove personal protective gears
Wear N95 masks at meetings and briefings in the hospital.
Limit social interactions.
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Personnels Education Team
= ICNs
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Personnels Preparedness:Keywords
Education &Training
Maximize Their Safety
(Handwashing & Masks)
(Tamiflu prophylaxis)
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Exit the patient’s room: What to do?
“the first pair of gloves was removed, followed by the hair net, the face shield, and the second pair of gloves; next, hands were washed with quick-drying antiseptic solution, and the gown was carefully removed; then the hands were washed again before the staff member left the room. In the hallway, hands were washed, goggles removed and disposed of, hands washed again, respirators removed, hands washed, and finally, a new N95 respirator was donned.”
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EID 2004;10:280-6
Infection control training <2 hours was a significant independent risk factors for SARS infection.
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Respiratory Viruses Transmission: How?
Possible Modes of Spread
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Hand-to-hand transmission of rhinovirus colds. Gwaltney JM Jr et al. Ann Intern Med 1978 Apr;88(4):463-7
Virus on donors' hands was transferred to recipients' fingers during 20 of 28 (71%) 10-second hand-contact exposures. These findings support the concept that hand contact/self-inoculation may be an important natural route of rhinovirus transmission.
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Aerosol transmission of rhinovirus colds.Dick EC et al. J Infect Dis 1987; 156:442-448
“(donors) and susceptible men (recipients) who played cards together for 12 hr. In three experiments the infection rate of restrained recipients (10 [56%] of 18), who could not touch their faces and could only have been infected by aerosols, and that of unrestrained recipients (12[67%] of 18), who could have been infected by aerosol, by direct contact, or by indirect fomite contact, was not significantly different (chi 2 = 0.468, P = .494). …These results suggest that contrary to current opinion, rhinovirus transmission, at least in adults, occurs chiefly by the aerosol route.”
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Modes of transmission of respiratory syncytial virus. Hall C:J. Pediatr 1981;99:100-103
The first group, called "cuddlers".These staff wore gowns but no mask or gloves. The second group, called "touchers," touched with ungloved hand surfaces likely to be contaminated with the baby's secretions when the infant was
out of the room. They then gently rubbed the mucous membranes of their nose or eye, The third group, called "sitters," was exposed to an infected baby by sitting at a
distance of >1.8 m from the bed. They wore gowns and gloves, but no masks. Only the cuddlers and touchers became infected, which suggests that routes that require close or direct contact with infectious secretions and self-inoculation were the major or most effective means of transmission.
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3 possible mechanisms
1. Contacts (Direct or Indirect (Fomites)self-inoculation after touching
contaminated surfaces
2. Droplets or large particles>5 microns particlesclose person-to-person contact at a distance of < 0.9 m (3 feet)
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3 Possible Modes of Spread
3. small-particle aerosols (airborne) < 3-5 microns generated by coughing or
sneezing traverse distances > 1.8 m such as occur with measles,
varicella, and sometimes influenza
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Effectiveness of measures to prevent SARS
A case-control study in 5 Hong Kong hospitals
241 non-infected and 13 infected staffs
about use of mask, gloves, gowns, and hand-washing
Ref. : Seto WH et al.Lancet2003;361:1519-20
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Effectiveness of measures to prevent SARS
Results: 69 staffs who reported use of all four
measures were not infected. Fewer staff who wore masks (p=0·0001), gowns (p=0·006), and washed their hands (p=0·047) became infected compared with those who didn't, but stepwise logistic regression was significant only for masks(p=0·011).
Ref. : Seto WH et al.Lancet2003;361:1519-20
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Front line of defence: Screening area & ER
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Screening:
WHO ???
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N Engl J Med 2009;361:1-10
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Of 178 patients,
145 (82%) reported recent travel to Mexico, and
four (2%) reported travel to the United States.
Among those who had not traveled to Mexico, 17 (52%) reported contact with a returning traveler from Mexico.
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Country Cases Deaths
MEXICO 4174 80
U.S.A 6552 9
CANADA 805 1
JAPAN 345 0
SPAIN 133 0
UK 122 0
PANAMA 76 0
Total 12515 91 (0.7%)
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EID 2004;10:771-776
Tent assessment clinic was constructed within 1 week. It contained eight negative-pressure isolation rooms built with pipe framing and plastic walls and ceilings. Areas for clerical work, registration, and changing personal protective equipment were also created. Other components included an area for case review, a lead-lined x-ray room, and an x-ray viewing room.
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Emergency Department and SARS Assessment Clinic
North York General Hospital, Toronto
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Emergency Department and SARS Assessment Clinic
North York
General Hospital, Toronto
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T= Triage area and body temperature screening station, C = Cardiopulmonary resuscitation area, L = Low-risk area for patients with fever or cough, H = High-risk area for suspect and cases of SARS.
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“Our ER continued to operate efficiently throughout the critical period, even when the other 2 emergency departments in this city of 3 million people were shut down.”
“No secondary or tertiary transmission has been discovered.”
“less than 1% of patients seen actually had SARS”
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EID 2004;10:777-781
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Screening area: Essential Elements
One way traffic
Waiting area (each seat >3 feet apart, mask and portable alcohol-based hand washing for everybody)
Triage area
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CPR areaLow risk areaHigh risk areaX-ray areaSputum collection areaArea for changing personal protective equipment??? Portable toilets
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Traffic Control: ? SARS Police
Security ensured that unauthorized persons did not enter the hospital; a security staff member, with a nurse, escorted SARS patients on transports between departments, logging the date, time, and persons involved in the transfer.
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Identification tagsSecurity and traffic officersRecorder & record forms (logging the date, time, and persons involved, ?? computerized )Back-up consultants for ambiguous cases.
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EID 2004;10:210-216
Adverse Effects of setting up a fever clinic
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EID 2004;10:777-781
Officials either constructed or retrofitted existing facilities to create SARS evaluation centers (i.e.,“Fever Clinics”) ...in both Toronto andTaiwan, no transmission was reported in these facilities.
Fever Clinics
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1. Toll free.2. 52 physicians,(6 hr. shift) between 8 a.
m. and 10 p.m. daily3. 86% of Teipei residents knew of the
project from television.
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Objectives of fever hotline:1.Aimed at reduce clinic visits by the “worried well,” 2. Prepared the potential cases before going to see the doctors.3. Prepared the transportation of potential patients..
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During June 1 to 10, a total of 11,228 calls were made
Of the 4,000 telephone numbers dialed, 2,999 numbers were invalid, unanswered, or refusals.
Persons were advised to seek further medical evaluation in 28% (n = 3,100) of calls.
Only 18 were identified as being at high risk for SARS.
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How to tranport febrile patient to the hospital???
Dedicated ambulance service for SARS cases were set up during the 2003 outbreak of SARS in Singapore.
James L et al. Publ Health 2006;120:20-26
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121SARS Ward, Taiwan. EID 2004;10:1187-1194
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Tai DYH. Ann Acad Med Singapore 2006;35:368-73
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Resources
Personnels
Equipments
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Patient: Nurse Ratio
At the beginning of the outbreak, the ratio was approximately 4–5 patients per nurse, a potentially dangerous ratio that could lead to transmission. During SARS II, the ratio was 1:1 if the patient was on oxygen requiring hourly monitoring and 2:1 for more stable patients. In the ICU, the ratio was two nurses per patient,
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Patient: Physician Ratio
The patient-to-physician ratio was 5–10 SARS patients per physician. (including emergency department physicians, general internists, family physicians, surgeons, and anesthesiologists)
One infectious disease consultant was assigned to each SARS ward, and one also covered the SARS ICU for a ratio of 20to 30 SARS patients per infectious disease consultant.
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Shortage of hospital personnels
Up to 40% of the workforce will not be available due to personal illness, illness in a family member, providing care for children at home due to school closure or due to anxiety leading to work avoidance.
US Department of Health and Human Services. HHS pandemic influenzaplan; November 2005. http://www.hhs.gov/pandemicflu/plan/pdf/
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Martinello RA. Preparing for avian influenza. Current Opinion in Pediatrics 2007, 19:64–70
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Hospital personnels
Up to 40% of the workforce will not be available due to personal illness, illness in a family member, providing care for children at home due to school closure or due to anxiety leading to work avoidance.
US Department of Health and Human Services. HHS pandemic influenzaplan; November 2005. http://www.hhs.gov/pandemicflu/plan/pdf/
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????Dedicated Avian Flu Care Team ???
“Facilities may find it useful to create dedicated teams of clinical and ancillary staff to limit the number of persons interacting with potentially contagious patients and to assure appropriate use of infection control precautions.”
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Hospital personnels
“First Avian Flu Care Teams”
ER & ICU
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??? Avian flu caregivers dormitory???
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Use the new non-suction oxygen mask with highly efficient Virus Filters attached
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Intubation: ?When?
if an oxygen flow over 15Liter/min or a frequency of over 30 breaths/min is still not able to maintain oxygen saturation.
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Is wearing a surgical mask acceptable?
Answer: No. Recent research has shown that many surgical masks do not do a good job of removing all TB bacteria. Some surgical masks fit so poorly that they provide very little protection from any airborne hazard.Only NIOSH-certified respirators should be worn for TB protection. A surgical mask is not a respirator.
NIOSH. A respiratory protection guide for heathcare workers 1995 pp.5
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138Powered Air Purifying Respirators (PAPRs)
139Powered Air Purifying Respirators (PAPRs)
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PAPRs with loose-fitting facepieces, hoods, or helmets have <4% inward leakage under routine conditions. Therefore, a PAPR might offer lower levels of face-seal leakage than nonpowered, half-mask respirators.
European Committee for Standardization. Respiratory protective devices: filtering half masks to protect against particles—Requirements,testing, marking. Europaishe Norm 2001;149.
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Filter
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Beware! :The filter on the expiratory end should be changed if its flow resistance has increased > 3cmH2O.
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Caution!: Pay attention to filters which may have an influence on the function of some ventilators.
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In the inspiratory limb of the circuit the Virus filter is placed on the entrance of Humidifier.
In the expiratory limb of the circuit the Virus filter is placed on the exit of the isolation system.
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Personnels Preparedness:Keywords
Education &Training
Maximize Their Safety
(Handwashing & Masks)
(Tamiflu prophylaxis)
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Organisms Infection Disease Death . . .
1 2 3
Pre-exposure Prophylaxis?
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Viruses from 13 (20%) of 64 patients have been tested for resistance to antiviral medications.
All exhibited IC50 values characteristic of oseltamivir- and zanamivir-sensitive influenza viruses.
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NYC Department of Health and Mental Hygiene (DOHMH) is recommending treatment with oseltamivir for:
1) hospitalized persons with suspected, severe febrile unexplained respiratory illness pending testing for swine influenza, or
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2) patients with mild (uncomplicated) influenza-like illnesses and underlying conditions (such as, chronic cardiovascular or renal disorders or immunosuppression) that increase the risk for more severe illness because of influenza.
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DOHMH is recommending treatment for any patient with mild (uncomplicated) influenza-like illnesses permissively only if started within 48 hours of symptom onset.
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Prophylactic Tamiflu???
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JAMA 2001;285:748
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Participants: Three hundred seventy-seven index cases(ICs), 163 (43%) of whom had laboratory confirmed influenza infection, and 955 household contacts (aged >12 years) of all ICs (415 contacts of influenza-positive ICs).
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Interventions: Household contacts were randomly assigned by household cluster to take 75 mg of oseltamivir (n=493) or placebo (n=462) once daily for 7 days within 48 hours of symptom onset in the index case. The index cases did not receive antiviral treatment.
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Results: In contacts of an influenza-positive index case, the overall protective efficacy of oseltamivir against clinical influenza was 89% for individuals (95% CI, 67%-97%; P<.001) .
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NEJM 1999;341:1336
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Design:Placebo controlled, double-blind trials at different U.S. sites during the winter of 1997–1998.
Methods:1559 healthy, nonimmunized adults were randomly assigned to receive either oral oseltamivir (75 mg given once or twice daily, for a total daily dose of 75 or 150 mg) or placebo for six weeks during a peak period of local influenza virus activity. The primary end point with respect to efficacy was laboratory-confirmed influenza-like illness.
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Results:For culture-proved influenza, the rate of protective efficacy in the two oseltamivir groups combined was 87 percent (95 percent confidence interval, 65 to 96 percent). The rate of laboratory-confirmed influenza infection was lower with oseltamivir than with placebo (5.3 percent vs. 10.6 percent, P<0.001).
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Lancet 2004; 364: 759–65
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“We identified a neuraminidase mutation in viruses isolated from nine (18%) of the 50 oseltamivir-treated patients. On day 5 or 6, the level of virus shedding was reduced in 18 of 19 patients without resistant viruses and in four of six with resistant viruses.”
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Consider antiviral prophylaxis for all health-care personnel, regardless of their vaccination status, ifthe outbreak is caused by a variant of influenza virus that is not well matched by the vaccine.
CDC’s GUIDELINES AND RECOMMENDATIONSInfection Control Guidance for the Prevention and Control of Influenza in Acute-Care Facilities. ( February 8, 2007)
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Prophylactic Tamiflu???
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Antiviral prophylaxis is being recommended for
1) health-care workers who provided care to patients with suspected swine influenza without using appropriate personal protection,or
2) asymptomatic household or other close contacts of ill persons of suspected swine influenza who are at higher risk for complications of influenza or are health-care workers themselves.
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Personnels Vaccination???
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6 additional cases.
Cases 1&2 : an adolescent girl aged 16 years and her father aged 54 years went to a clinic with acute respiratory illness. The father had received seasonal influenza vaccine in October 2008; the daughter was unvaccinated. Both had self-limited illnesses.
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Case 4: A woman aged 41 years with an autoimmune disease was hospitalized because of fever, headache, sore throat, diarrhea, vomiting, and myalgias.She recovered and was discharged on April 22. The woman had not been vaccinated against seasonal influenza viruses.
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N Engl J Med 2009;361:1-10
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Surveillance & Data Collection Team
In-patients surveillance: When a new SARS case was diagnosed in a hospital, the hospital initiated active contact tracing of all HCWs, inpatients and visitors who may have had contact with the case. HCWs, and or other patients with unprotected exposure were further quarantined.
.
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“Discharged patients were kept under telephone surveillance for a further 10 days.Those who was unwell and required hospital admission, was re-admitted to TTSH and managed as a suspect SARS until SARS was actively excluded.”
Disharged Patients
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Hospital staffs surveillance:
Daily telephone- monitoring record of all hospital staffs who had contact with SARS patients.
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Sick personnel
Staff with a fever were not allowed to work and required to stay at home or in their dormitory and limit social contact.
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Psychological Team
At NYGH, we put together a SARS psychological team (including social workers, psychiatric crisis nurses, psychiatrists, and infectious disease specialists) that developed a plan to manage the psychological impact on patients and staff..
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Public information team
TV or radio “SARS Channel”
Daily briefing of the situation. Education ( eg. handwashing, not going to work or school if they had a fever etc.)
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Resources
Personnels
Equipments
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Equipments:
Even in Singapore, N95 masks were of limited supply therefore HCWs wore them throughout the hospital and re-used them for about a week. Thus far, this behaviour did not result in further SARS infection. James L et al. Publ Health 2006;120:20-26
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Home-made respiratory mask
Dato VM et al. EID 2006;12:1033-1034
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Research Team
“Research is imperative during such an outbreak, particularly for a new disease… The ethics board was prompt in attending to required approvals, often a lengthy process.”
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System Thinking and Lobby Team
BoothCM,Stewart TE. Severe acute respiratory syndrome and critical care medicine:The Toronto experience. Crit Care Med 2005;33:S53-S60
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Establishing a Ministerial Committee and SARS Task Force. consisted of members from the Ministries of Health, Foreign Affairs, Home Affairs, Defence,Education, Environment, Transport and the Ministry of Information & Communications
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Examples of public issues to be decided.
?Laws amendment regarding quarantine.
Incoming travellers
(prohibit?,screening?, quarantine?)
International agreement
(exchange of data & aids)
?Schools & Hospitals closure.
?Mass prophylaxis
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System Thinking and Lobby Team
Important issues that were considered by this group included the following: whether to create “SARS hospitals”
BoothCM,Stewart TE. Severe acute respiratory syndrome and critical care medicine:The Toronto experience. Crit Care Med 2005;33:S53-S60
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EID 2004;10:25-31
Through June 2003, a total of 2,521 patients with probable cases of SARS were hospitalized in Beijing. The outbreak peaked during the 3rd and 4th weeks in April, when hospitalizations for probable SARS exceeded 100 cases for several days,
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.
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Local shortages of isolation rooms, intensive care facilities, and hospital beds were addressed by dispatching specially equipped ambulances to transfer SARS patients to designated facilities. An anticipated shortage of hospital beds for care and isolation of SARS patients prompted authorities to construct a new 1,000-bed hospital in 8 days.
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Centralized Influenza Hospital???
Singapore:Tan Tock Seng Hospital (TTSH) was designated as the SARS Hospital on 22nd March 2003. All suspect SARS cases throughout Singapore island were immediately referred for assessment and further management to TTSH.
James L et al. Publ Health 2006;120:20-26
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Canceling elective surgeries and preserve the care of emergent patients (such as trauma, cardiac, neurosurgery, and transplant)...... Such a responseappears to require a regionalizedapproach or systemwide thinking to thedelivery of critical care.
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Co-ordination between SARS Hospital and other hospitals:
The general public were informed to seek medical care at other hospitals for emergency and specialized care.
In order to have the capacity to absorb the cases diverted from TTSH, other hospitals reduced their elective operations and admissions.
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SARS in Singapore: Role of Internet
SARSWeb for all hospitals:
Updated list of SARS and home quarantine cases and their contacts (family members and healthcare workers)
To facilitate identification of suspect cases of SARS
Need password
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Public Health Team, Torontoa mobile public health outbreak management team.
“swift contact tracing and the quarantine of persons identified as having had unprotected exposure to a SARS patient”
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JAMA 2001;285:748
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EID 2005;11:278-282
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“Most of the quarantined persons were confined to their homes for 10–14 days.”
“Public health nurses would bring the quarantined persons 3 meals everyday and sometimes helped them with odd jobs such as washing clothes or taking care of pets.”
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SARS quarantine: Singapore Style
A Singapore security agency installed an electronic picture (ePIC) camera at the home of each contact.
Quarantined persons were required to stay at home for 10 days and to minimise interaction with other people.They were called on thetelephone daily to make sure that they did not break the quarantine and were well. They had to appear in front of the ePIC camera each time they were called. James L et al. Publ Health 2006;120:20-26
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Airport screening???
Aircrews should notify airport officials regarding febrile passengers before landing.
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Entry Screening???
EID 2004;10:1900
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Thermal Scanner????
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Entry Screening???
Data from a worldwide survey indicate that among 72 patients with imported probable or confirmed SARS cases, 30 (42%) had onset of symptoms before or on the same day as entry into the country and symptoms developed in 42 patients (58%) after entry.
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In Taiwan, incoming travelers from affected areas were quarantined; probable or suspected SARS was diagnosed in 21 (0.03%) of 80,813. None of these 21 was detected by thermal scanning when they entered Taiwan.
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BMJ 2005;331:1242–3
“Entry screening is unlikely to be effective in preventing or delaying an epidemic resulting from the importation of SARS or influenza.”
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The most important disease vector
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In Flight Transmission of SARS?
EID 2004;10:1900
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In Flight Transmission of Flu?Human to human transmission, Germany
A ProMED-mail post <http://www.promedmail.org>
Date: 3 May 2009 From: "Oliver Schmetzer" <[email protected]> [Edited] Update, 3 May 2009
In addition to the 2 human-to-human transmissions in Bavaria, the infection of a couple in Frankfurt/Oder in Brandenburg has been confirmed to be A/H1N1. The couple was infected on a flight from Mexico likely by the confirmed case in Hamburg.
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Closing down airports????
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PLoS Med 3(10): e401.DOI: 10.1371/journal.pmed.0030401
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PLoS ONE 2(5): e401. doi:10.1371/journal.pone.0000401
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a 90%, 99% or 99.9% reduction in importedinfections might delay the peak of the US pandemic by 1.5, 3, or 6 weeks, respectively
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??? Mass prophylaxis with oseltamivir ???
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NEJM 1999;341:1336
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Design:Placebo controlled, double-blind trials at different U.S. sites during the winter of 1997–1998.
Methods:1559 healthy, nonimmunized adults were randomly assigned to receive either oral oseltamivir (75 mg given once or twice daily, for a total daily dose of 75 or 150 mg) or placebo for six weeks during a peak period of local influenza virus activity. The primary end point with respect to efficacy was laboratory-confirmed influenza-like illness.
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Results:For culture-proved influenza, the rate of protective efficacy in the two oseltamivir groups combined was 87 percent (95 percent confidence interval, 65 to 96 percent). The rate of laboratory-confirmed influenza infection was lower with oseltamivir than with placebo (5.3 percent vs. 10.6 percent, P<0.001).
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??? Mass prophylaxis with oseltamivir ???
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Antiviral prophylaxis of household members is effective in reducing cumulative attack rates by at least one third but requires an antiviral stockpile large enough to treat 46% or 57% of the population for the moderate and high transmissibility scenarios, respectively.
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No intervention Prophylaxis Quarantine
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Hospital Preparedness and Avian influenza
Khachornsakdi Silpapojakul MD
Prince of Songkla University
Hat yai, Songkla, Thailand
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SARS: PSU Experience
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Organisms Infection Disease Death . . .
1 2 3
?
Conceptual Framework
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Respiratory Viruses Transmission: How?
Possible Modes of Spread
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Hand-to-hand transmission of rhinovirus colds. Gwaltney JM Jr et al. Ann Intern Med 1978 Apr;88(4):463-7
Virus on donors' hands was transferred to recipients' fingers during 20 of 28 (71%) 10-second hand-contact exposures. These findings support the concept that hand contact/self-inoculation may be an important natural route of rhinovirus transmission.
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Aerosol transmission of rhinovirus colds.Dick EC et al. J Infect Dis 1987; 156:442-448
“(donors) and susceptible men (recipients) who played cards together for 12 hr. In three experiments the infection rate of restrained recipients (10 [56%] of 18), who could not touch their faces and could only have been infected by aerosols, and that of unrestrained recipients (12[67%] of 18), who could have been infected by aerosol, by direct contact, or by indirect fomite contact, was not significantly different (chi 2 = 0.468, P = .494). …These results suggest that contrary to current opinion, rhinovirus transmission, at least in adults, occurs chiefly by the aerosol route.”
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Modes of transmission of respiratory syncytial virus. Hall C:J. Pediatr 1981;99:100-103
The first group, called "cuddlers".These staff wore gowns but no mask or gloves. The second group, called "touchers," touched with ungloved hand surfaces likely to be contaminated with the baby's secretions when the infant was
out of the room. They then gently rubbed the mucous membranes of their nose or eye, The third group, called "sitters," was exposed to an infected baby by sitting at a
distance of >1.8 m from the bed. They wore gowns and gloves, but no masks. Only the cuddlers and touchers became infected, which suggests that routes that require close or direct contact with infectious secretions and self-inoculation were the major or most effective means of transmission.
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3 possible mechanisms
1. Contacts (Direct or Indirect (Fomites)self-inoculation after touching
contaminated surfaces
2. Droplets or large particles>5 microns particlesclose person-to-person contact at a distance of < 0.9 m (3 feet)
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3 Possible Modes of Spread
3. small-particle aerosols (airborne) < 3-5 microns generated by coughing or
sneezing traverse distances > 1.8 m such as occur with measles,
varicella, and sometimes influenza
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Darin Areechokchai, C. Jiraphongsa, Y. Laosiritaworn, W. Hanshaoworakul, M. O'Reilly
Investigation of Avian Influenza (H5N1) Outbreak in Humans --- Thailand, 2004
MMWR Morb Mortal Wkly Rep. 2006;55 (Suppl 1):3-6.
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OR (95% CI)
Dead poultry around the house 5.6 (1.5-20.7)
Being =< 1m. away from dead poutry 13.0 (1.6-19.3)
Direct Touching of sick poultry 5.6 (1.5-20.7)
Direct Touching of dead poultry 29.0 (2.7-306.2)
Plucking poultry 14.0 (1.3-152.5)
Hx of contact with H5N1 patients 0.9 (0.2-4.4)
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Transmission of Influenza Viruses
Seasonal Influenza in
Humans
Avian Influenza in Humans
Droplet Yes Probably (human to human)
Airborne Rare Unknown
Contact Yes Yes (bird to human)
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Patients H5N1 HCWs Infection Disease Death
1y 2y 3y
Screening
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Patients H5N1 HCWs Infection Disease Death
1y 2y 3y
Screening
Handwashing
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Published: 9 February 2007
BMC Infectious Diseases 2007, 7:5 doi:10.1186/1471-2334-7-5
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Patients H5N1 HCWs Infection Disease Death
1y 2y 3y
Screening
Handwashing
Mask for the patient
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Efficiency of surgical masks in ‘sneezing’ experiments. Madsen PO & Madsen RE. AJS 1967;114:41
Type of masks Efficiency
Polypropylene 98.8%
Polyester & Rayon 98.4%
Glass fibers 97.3%
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Measuring the speed of the wind from the mouth with an ultrasonic anemometer.
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Compared with the airspeed without masks, all three masks reduced thespeed to less than 1/10.
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% spore recovered
No mask (n=8) 24.6%
American Hospital masks (n=8)
-conventionally worn 24.2%
-taped masks 0.00%
3M masks (n=8)
-conventionally worn 30.9%
-taped masks 0.00%
Ref.:Pippin DJ et al. J Oral Maxillofac Surg 1987;45:319
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Patients H5N1 HCWs Infection Disease Death
1y 2y 3y
Screening
Handwashing
Mask for the patient
Mask for personnel
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Effectiveness of measures to prevent SARS
A case-control study in 5 Hong Kong hospitals
241 non-infected and 13 infected staffs
about use of mask, gloves, gowns, and hand-washing
Ref. : Seto WH et al.Lancet2003;361:1519-20
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Effectiveness of measures to prevent SARS
Results: 69 staffs who reported use of all four
measures were not infected. Fewer staff who wore masks (p=0·0001), gowns (p=0·006), and washed their hands (p=0·047) became infected compared with those who didn't, but stepwise logistic regression was significant only for masks(p=0·011).
Ref. : Seto WH et al.Lancet2003;361:1519-20
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