This document discusses case-based scenarios addressing transmission-based and isolation precautions for various infectious diseases, particularly measles, mumps, and meningococcemia. It highlights key guidelines for healthcare providers on patient isolation, vaccine administration, and the necessary precautions to prevent airborne and droplet transmission of infections. The document includes specific case examples to illustrate the application of these isolation protocols in emergency settings.

1. Case-based Discussions on
Transmission-based and
Isolation Precautions
Arthur Dessi E. Roman, MD FPCP FPSMID
Moderator
Laarni D. Canceran, RN
Co-Moderator
@gonnabedess

2. Disclosures
• CME Lectures for UniLab, Terumo, MSD, Sanofi
Pasteur, Zuellig and J&J
• No identified conflict of interest for this lecture

4. Main Reference
Siegel JD, Rhinehart E, Jackson M, Chiarello L, and the
Healthcare Infec<on Control Prac<ces Advisory CommiBee,
2007 Guideline for Isola<on Precau<ons: Preven<ng
Transmission of Infec<ous Agents in Healthcare SeJngs.
Available from
hBps://www.cdc.gov/infec<oncontrol/guidelines/isola<on/
Last update: April 2019

5. Case 1
Brian, 9/M was admitted for fever and rash of 2 days
duration. He was brought by his caretaker who is
unaware of his vaccination status. There was
associated with coryza, cough and yellowish sputum.
On PE, RR 32 T=28℃ BP 90/60, auscultation revealed
coarse bilateral crackles. There were postauricular
lymphadenopathies. There was generalized
maculopapular rashes that are non-blanching.

7. Question
What will you do for this patient upon consultation at
the Emergency Room?
A. Send home and place on home isolation.
B. Transfer to isolation room while waiting for
admission.
C. Maintain on single bed at least 1m from other
patients while awaiting results of diagnostic tests.
D. Close the curtains and advise the patient to wear an
N95 mask.

8. Measles
• Incubation period of 10-12 days (US CDC)
• Airborne transmission with a basic reproduction
number (R0) of 12-18.1
1. Guera FM et al. The basic reproducHon number (R0) of measles: a systemaHc review. The Lancet InfecHous
diseases. 17(12): PE420-E428, DECEMBER 01, 2017
Measles R0
18

9. Who should take care of
[suspected] measles cases?
• Susceptible healthcare personnel (HCP) should not
enter room IF immune care providers are available.
• Exclude susceptible healthcare personnel.

10. Measles: Evidence of Immunity
Atleast one (1) of the following:
• Written documentation of adequate vaccination:
• One (1) or more doses of a measles-containing vaccine administered on or
after the first birthday for preschool-age children and adults not at high risk
• Two (2) doses of measles-containing vaccine for school-age children and
adults at high risk, including college students, healthcare personnel, and
international travelers
• Laboratory evidence of immunity (Rubeola IgG+)
• Laboratory confirmation of measles (in the past)
• Birth before 1957 (may not be applicable in the Philippines)
Healthcare providers should not accept verbal reports of vaccination without
written documentation as presumptive evidence of immunity.
hPps://www.cdc.gov/measles/hcp/index.html

11. What to do with exposed
susceptibles?
Give post-exposure vaccine within
72 hours
or immune globulin within 6
days when available

12. What to do with exposed
susceptibles?
• If MMR vaccine is not administered within 72 hours of
exposure as PEP, MMR vaccine should still be offered at
any interval following exposure to the disease in order
to offer protection from future exposures.
• Do not administer MMR vaccine and IG simultaneously,
as this practice invalidates the vaccine.
• People who receive MMR vaccine or IG as PEP should
be monitored for signs and symptoms consistent with
measles for at least one incubation period.

13. Question
A nurse who had a history of measles vaccina5on
was assigned to take care of Brian. She insists on not
wearing an N95 mask because she “trusts” her
immune system. Do you agree with her?
A. Yes
B. No
C. I don’t know.

14. What PPE should be worn?
Regardless of presumptive immunity
status, all healthcare staff entering
the room should use respiratory
protection consistent with airborne
infection control precautions
(use of an N95 respirator or a respirator with
similar effectiveness in preventing airborne
transmission)

15. Measles: Patient placement
• Single-patient rooms are always indicated for patients
placed on Airborne Precautions
• Preferred: AIIR (Airborne infection isolation room)
• Monitored negative pressure relative to the surrounding area
• 12 air exchanges per hour for new construction and renovation and 6 air
exchanges per hour for existing facilities
• Air exhausted directly to the outside or recirculated through HEPA
filtration before return
• In the absence of AIIR (i.e. due to limited engineering resources like
physician offices:
• Provide surgical mask to the patient
• Maintain in a single private room (e.g., office examination room) with the
door closed, and providing N95 or higher level respirators

16. Question
What will you do for this patient upon consultation at
the Emergency Room?
A. Send home and place on home isolation.
B. Transfer to isolation room while waiting for
admission.
C. Maintain on single bed at least 1m from other
patients while awaiting results of diagnostic tests.
D. Close the curtains and advise the patient to wear an
N95 mask.

17. Question
What will you do for this pa1ent upon consulta1on at
the Emergency Room?
A. Send home and place on home isola1on.
B. Transfer to isola/on room while wai/ng for
admission.
C. Maintain on single bed at least 1m from other
pa1ents while awai1ng results of diagnos1c tests.
D. Close the curtains and advise the pa1ent to wear an
N95 mask.

18. Measles Transmission
• Measles virus can remain infectious in the air and on
contaminated surfaces for up to two (2) hours after an infected
person leaves an area.
• Infected people are considered contagious from about five
days before the onset of rash to four (4) days afterwards.
• Measles is maximally contagious during the prodromal phase
which lasts for 2–4 days and is characterized by intense
coughing.
https://ecdc.europa.eu/en/measles/facts/factsheet

19. Suspected Measles
Siegel JD, Rhinehart E, Jackson M, Chiarello L, and the Healthcare Infection Control Practices Advisory Committee, 2007 Guideline for Isolation
Precautions: Preventing Transmission of Infectious Agents in Healthcare Settings https://www.cdc.gov/infectioncontrol/guidelines/isolation/index.html

20. Varicella
Siegel JD, Rhinehart E, Jackson M, Chiarello L, and the Healthcare Infection Control Practices Advisory Committee, 2007 Guideline for Isolation
Precautions: Preventing Transmission of Infectious Agents in Healthcare Settings https://www.cdc.gov/infectioncontrol/guidelines/isolation/index.html

21. Case 2
Lea, 13/F consults your clinic for 3 day history of
preauricular pain and fever. She was sent home from
school and referred to you fur further assessment.
The pain is severe. This is associated with malaise
and anorexia. On PE, she was not febrile (since the
night before).

22. Photo from https://www.theherald-news.com/lists/2018/12/11/5ebed2540919441385ea56a75c98571e/index.xml

23. Mumps
• Caused by Mumps rubulavirus
• Transmitted by respiratory droplets and saliva
• Average incubation period of 16 to 18 days
• Mumps R0 = ~41
1 Edmunds WJ, Gay NJ, Kretzschmar M, Pebody RG, Wachmann H; ESEN Project. European Sero-epidemiology Network. The pre-
vaccination epidemiology of measles, mumps and rubella in Europe: implications for modelling studies. Epidemiol Infect. 2000;125(3):635–
650.

24. Question
She is a graduating student and cannot afford to miss
any days off school. She is very anxious about
returning to school. When can you clear her to go
back?
A. She is afebrile already. She can go back to school
anytime.
B. She can return to school 5 days after the onset of
parotitis.
C. She can return to school 9 days after the onset of
parotitis.
D. She can return to school 5 days after resolution of all
symptoms (i.e. pain, fever, or parotid enlargement)

25. Updated Recommendations for
Isolation of Persons with Mumps
Data on mumps viral isolation available from eight small studies (median
number of subjects=16; range 1-46)
Timing Virus isolation rate
6-7 days before parotitis 17%
2-3 days before parotitis 40%
1 day before 86%
Day of parotitis 78%
1 day after 81%
2-3 days after 49%
4-5 days after 40%
6-7 days after 17%
MMWR. October 10, 2008 / 57(40);1103-1105

26. Updated Recommendations for
Isolation of Persons with Mumps
1. Bitsko RH, Cortese MM, Dayan GH, et al. Detection of RNA of mumps virus during an outbreak in a population
with a high level of measles, mumps, and rubella vaccine coverage. J Clin Microbiol 2008;46:1101--3.
2. Okafuji T, Yoshida N, Fujino M, et al. Rapid diagnostic method for detection of mumps virus genome by loop-
mediated isothermal amplification. J Clin Microbiol 2005;43:1625--31.
Timing Virus isolation rate
<3 days after parotitis 35%
4-22 days after parotitis none
A study from Japan, examining viral load during the course of natural infection,
found that viral load decreased substantially during the first 4 days after illness
onset and was extremely low thereafter

27. Updated Recommendations for
Isolation of Persons with Mumps
MMWR. October 10, 2008 / 57(40);1103-1105
• The scientific evidence indicates that, although mumps virus can be isolated
from saliva or respiratory secretions 5 or more days after parotitis onset,
viral load decreases rapidly during the 4 days after onset of parotitis.
• Therefore, the risk for transmission after 5 days is considered low on the
background of a relatively low R0.
• Besides, a longer isolation period of 9 days likely would result in less
compliance and more cost and not produce any substantial decrease in
mumps transmission.

28. Question
She is a graduating student and cannot afford to miss
any days off school. She is very anxious about
returning to school. When can you clear her to go
back?
A. She is afebrile already. She can go back to school
anytime.
B. She can return to school 5 days after the onset of
parotitis.
C. She can return to school 9 days after the onset of
parotitis.
D. She can return to school 5 days after resolution of all
symptoms (i.e. pain, fever, or parotid enlargement)

29. Question
She is a graduating student and cannot afford to miss
any days off school. She is very anxious about
returning to school. When can you clear her to go
back?
A. She is afebrile already. She can go back to school
anytime.
B. She can return to school 5 days after the onset of
parotitis.
C. She can return to school 9 days after the onset of
parotitis.
D. She can return to school 5 days after resolution of all
symptoms (i.e. pain, fever, or parotid enlargement)

30. Case 3
• A meningococcemia suspect is admitted inside the
isolation room of your emergency (hospital is 120
kms away from RITM). There are purpuric rashes
over his back and he is on a single inotrope. Your
hospital is full. You are trying to coordinate transfer
to RITM when the admitting called up the ER and
informed you that there is one vacant bed in a
triple ward room. Currently, there are 2 patients
with DHF admitted in the triple ward room.
• After a few minutes, a patient with MDRTB with
concomitant pneumonia was brought in and
intubated for respiratory distress.

31. Question
What are you going to do with the meningococcemia
suspect?
A. Pursue transfer to RITM.
B. Keep patient inside the isolation room at the ER.
C. Transfer to the triple room.
D. Create a make-shift tent.

32. Meningococcemia
Siegel JD, Rhinehart E, Jackson M, Chiarello L, and the Healthcare Infection Control Practices Advisory Committee, 2007 Guideline for Isolation
Precautions: Preventing Transmission of Infectious Agents in Healthcare Settings https://www.cdc.gov/infectioncontrol/guidelines/isolation/index.html

33. Droplet Precautions
Droplet transmission is, technically, a form of contact
transmission, and some infectious agents
transmitted by the droplet route also may be
transmitted by the direct and indirect contact routes.
Siegel JD, Rhinehart E, Jackson M, Chiarello L, and the Healthcare Infection Control Practices Advisory Committee, 2007 Guideline for Isolation
Precautions: Preventing Transmission of Infectious Agents in Healthcare Settings https://www.cdc.gov/infectioncontrol/guidelines/isolation/index.html

34. Droplet Precautions
• However, in contrast to contact transmission, respiratory
droplets carrying infectious pathogens transmit infection
when they travel directly from the respiratory tract of the
infectious individual to susceptible mucosal surfaces of the
recipient, generally over short distances, necessitating facial
protection.
Siegel JD, Rhinehart E, Jackson M, Chiarello L, and the Healthcare Infection Control Practices Advisory Committee, 2007 Guideline for Isolation
Precautions: Preventing Transmission of Infectious Agents in Healthcare Settings https://www.cdc.gov/infectioncontrol/guidelines/isolation/index.html

35. Caution on Droplet Precautions
• Historically, a distance of ≤3 feet
around the patient is designated as
the area of defined risk
• Using this distance for donning masks
has been effective in preventing
transmission of infectious agents via the
droplet route.
• No routine recommendations for use
of goggles or face shield.
Siegel JD, Rhinehart E, Jackson M, Chiarello L, and the Healthcare Infection Control Practices Advisory Committee, 2007 Guideline for Isolation
Precautions: Preventing Transmission of Infectious Agents in Healthcare Settings https://www.cdc.gov/infectioncontrol/guidelines/isolation/index.html

36. Caution on Droplet Precautions
However, studies on emerging diseases such as smallpox and
SARS suggest that droplets from patients with these two
infections could reach persons located 6 feet or more from
their source
Siegel JD, Rhinehart E, Jackson M, Chiarello L, and the Healthcare Infection Control Practices Advisory Committee, 2007 Guideline for Isolation
Precautions: Preventing Transmission of Infectious Agents in Healthcare Settings https://www.cdc.gov/infectioncontrol/guidelines/isolation/index.html
Factors that affect the distance travelled by droplets
• Velocity and mechanism by which respiratory droplets are
propelled from the source
• Density of respiratory secretions
• Environmental factors such as temperature and humidity

37. Caution on Droplet Precautions
• Thus, a distance of ≤3 feet around the patient is best viewed
as an example of what is meant by “a short distance from a
patient” and should not be used as the sole criterion for
deciding when a mask should be donned to protect from
droplet exposure.
Siegel JD, Rhinehart E, Jackson M, Chiarello L, and the Healthcare Infection Control Practices Advisory Committee, 2007 Guideline for Isolation
Precautions: Preventing Transmission of Infectious Agents in Healthcare Settings https://www.cdc.gov/infectioncontrol/guidelines/isolation/index.html
Based on these considerations, it may be prudent to don a
mask when within 6 to 10 feet of the patient or upon entry into
the patient’s room, especially when exposure to emerging or
highly virulent pathogens is likely.

38. Droplet Precautions
If it becomes necessary to place patients who require Droplet
Precautions in a room with a patient who does not have the same
infection:
• Avoid placing patients on Droplet Precautions in the same room
with patients who have conditions that may increase the risk of
adverse outcome from infection or that may facilitate
transmission (e.g., those who are immunocompromised, have or
have anticipated prolonged lengths of stay).
• Ensure that patients are physically separated (i.e., >3 feet apart)
from each other. Draw the privacy curtain between beds to
minimize opportunities for close contact
• Change protective attire and perform hand hygiene between
contact with patients in the same room, regardless of whether
one patient or both patients are on Droplet Precautions

39. Airborne precautions
• Unfortunately, for airborne transmission, only AIIR is recommended.
• Use temporary portable solutions (e.g., exhaust fan) to create a
negative pressure environment in the converted area of the facility.
Discharge air directly to the outside, away from people and air
intakes, or direct all the air through HEPA filters before it is introduced
to other air spaces
• Once the patient leaves, the room should remain vacant for the
appropriate time, generally one hour, to allow for a full exchange of
air.
Siegel JD, Rhinehart E, Jackson M, Chiarello L, and the Healthcare Infection Control Practices Advisory Committee, 2007 Guideline for Isolation
Precautions: Preventing Transmission of Infectious Agents in Healthcare Settings https://www.cdc.gov/infectioncontrol/guidelines/isolation/index.html

40. Airborne Precautions
• Instruct patients with a known or suspected
airborne infection to wear a surgical mask and
observe Respiratory Hygiene/Cough Etiquette.
• Once in an AIIR, the mask may be removed; the
mask should remain on if the patient is not in an
AIIR.
Siegel JD, Rhinehart E, Jackson M, Chiarello L, and the Healthcare Infection Control Practices Advisory Committee, 2007 Guideline for Isolation
Precautions: Preventing Transmission of Infectious Agents in Healthcare Settings https://www.cdc.gov/infectioncontrol/guidelines/isolation/index.html

41. Question
What are you going to do with the meningococcemia
suspect?
A. Pursue transfer to RITM.
B. Keep patient inside the isolation room at the ER.
C. Transfer to the triple room.
D. Create a make-shift tent.

42. If you will admit the patient
to the ward…
• Make sure the distance with other patients is more than 3 feet.
• Load antibiotics as soon as possible.
• Provide curtain barriers/ dividers if possible.
• Provide mask for all the patients inside the room.
• Make sure hand hygiene facility is accessible to all.
• Change protective attire after contact with meningo patient.
• Provide trash bins beside meningo patient.

43. Case 4
A 53/male on NIV for impending respiratory distress
is inside the isolation room of your ICU for 7 days.
He is being treated for pneumonia. Six weeks prior
to admission, he was diagnosed with PTB (smear+)
and started on HRZE 4 tabs OD. His latest sputum
culture grew pan-sensitive Klebsiella pneumonia for
which he is being Ceftriaxone (D8). His latest CXR
showed partial regression of RLL infiltrates but he is
unable to tolerate O2 support via NC.

44. Question
The MICU ROD called you up today referring a patient for
possible admission at the ICU. The case is that of an SJS-TEN
for IVIg infusion whom he wants to be admitted in the
isolation room for protective isolation. What are you going to
do?
A. Request for sputum AFB x 3 for the TB patient. Transfer
out if negative already.
B. Transfer TB patient out and admit SJS-TEN patient after
terminal cleaning ASAP since patient has been on several
weeks of anti TB already.
C. No need to admit SJS-TEN in an isolation room.
D. Send tissue GS/CS from skin lesion. If with growth, may
not admit patient to isolation room.

45. Competing priorities when
determining the appropriate room
placement for patients:
• Reason for admission
• Patient characteristics: age, gender, mental status
• Staffing needs
• Family requests
• Psychosocial factors
• Reimbursement concerns

46. Patient Placement
When there are only a limited number of single-patient
rooms, it is prudent to prioritize them for:
1. Patients who have conditions that facilitate transmission
of infectious material to other patients
e.g. draining wounds, stool incontinence, uncontained secretions
2. Those who are at increased risk of acquisition and adverse
outcomes resulting from HAI
e.g., immunosuppression, open wounds, indwelling catheters,
anticipated prolonged length of stay, total dependence on
HCWs for activities of daily living
Siegel JD, Rhinehart E, Jackson M, Chiarello L, and the Healthcare Infection Control Practices Advisory Committee, 2007 Guideline for Isolation
Precautions: Preventing Transmission of Infectious Agents in Healthcare Settings https://www.cdc.gov/infectioncontrol/guidelines/isolation/index.html

47. Tuberculosis
Discontinue precautions only when patient on effective
therapy is improving clinically and has 3 consecutive
sputum smears negative for acid-fast bacilli collected on
separate days (MMWR 2005; 54: RR-17 Guidelines for
Preventing the Transmission of Mycobacterium
tuberculosis in Health-Care Settings, 2005)
https://www.cdc.gov/mmwr/preview/mmwrhtml/rr5417a1.htm accessed September 2018)

48. Question
The MICU ROD called you up today referring a patient for
possible admission at the ICU. The case is that of an SJS-TEN
for IVIg infusion whom he wants to be admitted in the
isolation room for protective isolation. What are you going to
do?
A. Request for sputum AFB x 2 for the TB patient. Transfer
out if negative already.
B. Transfer TB patient out and admit SJS-TEN patient after
terminal cleaning ASAP since patient has been on several
weeks of anti TB already.
C. No need to admit SJS-TEN in an isolation room.
D. Send tissue GS/CS from skin lesion. If with growth, may
not admit patient to isolation room.

49. Question
The MICU ROD called you up today referring a patient for
possible admission at the ICU. The case is that of an SJS-TEN
for IVIg infusion whom he wants to be admitted in the
isolation room for protective isolation. What are you going to
do?
A. Request for sputum AFB x 2 for the TB patient. Transfer
out if negative already.
B. Transfer TB patient out and admit SJS-TEN patient after
terminal cleaning ASAP since patient has been on several
weeks of anti TB already.
C. No need to admit SJS-TEN in an isolation room.
D. Send tissue GS/CS from skin lesion. If with growth, may
not admit patient to isolation room.

50. (JP) Thank you (En)
Arigatou (Ro)