The paediatric ward informs you of a child admitted last night with a maculopapular rash. The child is currently in a single room; however, the staff are requesting you review the type of infection control precautions required. There is no history of contact with measles, mumps or rubella, however, the child has never been immunized. Clinically the child has a dry cough, coryza and a pink maculopapular rash – the parents are unsure of where the rash started. The paediatrician suspects measles or rubella.
Case Two Questions:
1. What are your recommendations regarding infection control precautions for this child?
Suspected measles=airborne precations.
Patients with suspected measles should be placed under airborne precautions (Lautenbach, p. 57).
Airborne precautions “prevent disease transmission by aerosols containing droplet nuclei or contaminated dust particles” (Lautenbach, p. 57). Droplet nuclei are less than 5um in size and may remain suspended in the air allowing them to migrate for long periods of time.
The patient is already in a private room but should be in an airborne infection isolation room, AIIR, which is a private room with negative air pressure and at least 6 air exchanges per hour (preferrably 12). Room air being exhausted directly outside or through a high efficiency particulate air, HEPA, filter. The room door should be kept closed at all times. (Lautenbach, p. 57).
Patient transport: a surgical mask should be worn by the patient.
Visitors and staff entering the room: wear a respirator. The N95 mask filters out 95% or particles.
Suspected rubella=droplet precautions
Droplet precautions “prevent the transmission of micro-organisms by particles larger than 5um. Droplets are produced when the patient talks, coughs, or sneezes. (Lautenbach, p.58.)
The patient should also be placed on contact precautions to prevent spread of disease from contaminated surfaces (Lautenbach, p. 59). Measels mode of transmission is through “airborne by aerosol and droplet spread, direct contact with nasal or throat secretions of infected persons; less commonly by articles freshly soiled with nose and throat secretions.” (BCCDC, 2014). Healthcare workers should gown and glove when entering the room and change gloves if touching materials with high concentration of micro-organisms.
Considering the patient has a rash that is not yet known to be rubella or measles it is best to place the patient in the more extensive and encompassing precautions – airborne isolation with contact precautions until a definite diagnosis can be made (Lautenbach, p. 59).
Once definitive diangosis is made, isolation precaution continuation and removal will follow CDC guidelines for the pathogen-specific illness (Lautenbach, p. 59).
2. What laboratory tests would help in the diagnosis and why is it important to confirm your suspicions?
Lab tests for measels:
- Submit a nasopharyngeal swab and urine sample for measles virus isolation and PCR testing.
- isolation of measles virus from an appropriate clinical specimen
- detection of measles virus RNA
- seroconversion or a significant (e.g. fourfold or greater) rise in measles IgG titre by any standard serologic assay between acute and convalescent sera
- positive serologic test for measles IgM antibody using a recommended assay in a person who is either epidemiologically linked to a laboratory-confirmed case or has recently travelled to an area of known measles activity.
- Epidemiologically-linked: • Clinical illness (fever≥ 38.3oC and cough, coryza or conjunctivitis and generalized maculopapular rash for at least 3 days) in a person with an epidemiologic link to a laboratory-confirmed case. (BCCDC, 2014)
Lab tests for rubella:
- “Nasopharyngeal or throat swab specimens and/ or urine should be taken for virus isolation. Virus may be isolated 1 week before to 2 weeks after rash onset” (BCCDC, 2014)
- isolation of rubella virus from an appropriate clinical specimen
- detection of rubella virus RNA
- seroconversion or a significant (i.e., fourfold or greater) rise in rubella IgG titre by any standard serologic assay between acute and convalescent sera
- detection of rubella IgM antibody using a recommended assay in a person with an epidemiologic link to a laboratory- confirmed case or who has recently travelled to an area of known rubella activity
- Epidemiologically-linked: Clinical illness (fever and rash, and at least one of the following: arthralgia/arthritis, lymphadenopathy, conjunctivitis) in a person with an epidemiologic link to a laboratory confirmed case (BCCDC, 2014)
Importance of confirming suspicions:
Due to infectious nature of disease, morbidity and mortality confirming cases promplty is of great importance. “Investigate all confirmed, probable, and suspect cases of measles within 24 hours”. For rubella “Confirming the diagnosis is particularly important in pregnant women, cases who have contact with pregnant women, suspected cases of CRS, and during outbreaks.” (BCCDC, 2014) as the virus has significant implications on the developing fetus.
Case reporting to the following is necessary along with contact tracing for tratment and containment of the outbreak.
- Complete the individual case report in iPHIS (Integrated Public Health Information System)/ Panorama or PARIS.
- Public health action, including contact management, may commence at any level of the case definition, including for a suspect case.
- Inform the local Medical Health Officer and initiate control measures immediately.” (BCCDC, 2014)
- Viral detection methods (e.g., RT-PCR followed by sequencing) enable a definitive diagnosis, allow the laboratory to distinguish vaccine virus type from wild virus type
- DNA viral testing can determine if there are single or multiple genotypes of virus circulating in a community.
- Genotyping of the virus is helpful in understanding transmission patterns
- Genotying faciliates outbreak investigation when there is no epidemiological links between cases because such results can indicate whether the origin of the virus is the same or different. (CDC, 2014)
- “Clinical diagnosis of rubella is challenging and may be inaccurate because symptoms and signs are not unique to this disease. ” (BCCDC, 2014). The virus has significant implications on the developing fetus therefore confirming a case is crucial for the pregnant woman and her GP to make informed decisions regarding pregancy care and carrying the fetus to term (BCCDC, 2014)
3. How would you perform a risk assessment to determine the extent of contact tracing for possible exposed individuals?
Risk Assessment: “An evaluation of the interaction of the health care provider, the client/patient/resident and the client/patient/resident environment to assess and analyze the potential for exposure to infectious disease.” (PIDAC pdf, p12)
“The risk of transmission of microorganisms between individuals involves factors related to:
the client/patient/resident infection status (including colonization)
the characteristics of the client/patient/resident
the type of care activities to be performed
the resources available for control
the health care provider immune status.” (PIDAC pdf p.24)
I would start by determine if correct PPE was used and protocols followed as soon as measles or rubella was suspected. Determine at first encounter, if any staff were not yet following appropriate precautions (this would be prior to suspicion of rubella or measles). Consider all unimmunized staff, patients, and visitors waiting in ER, hallways, elevators at the time this patient was brought in and then transferred to the paediatric unit. Then all unimmunized hospital staff, patients, visitors within this suspected infected patient’s air space prior to the patient being place place in a negative pressure room and under correct isolation precautions for rubella/measles. (PIDAC pdf, p40)
Contact tracing would then extend beyond the hospital into the community (the child’s school, church, community/rec centre, library etc) for all unimmunized potentially exposed individuals – ensure these individuals get tested to contain outbreak.
Post exposure follow-up:
“ identification of exposed staff
assessment and immunization history
post-exposure prophylaxis and follow-up including:
collection and analysis of exposures
a program for prompt response to sharps injuries16, 77
policies to deal with spills and staff exposure to blood or body fluids
education regarding preventive actions that may be put into place to improve practices and prevent recurrence.” (PIDAC pdf, p64)
4. What is the difference between Airborne and Droplet Precautions? What is a bioaerosol?
Airborne Precautions “prevents disease transmission via aerosols containing droplet nuclei or contaminated dust particles.” (Lautenbach p. 57.) Droplet nuclei are particles less than 5um and may remaining suspended in the air for long periods. Airborne precautions therefore consist of a negative pressure, single patient room with at least air exchanges per hour exhausted to the outside or through HEPA filters and room doors must be closed. N95 or portable respirators must be worn by those entering the room and the patient must wear a surgical mask on transport outside the room. (Lautenbach, P57, Table 6-3)
Droplet precautions “prevent the transmission of microorganisms by particles larger than 5um”, produced when the patient talks, coughs or sneezes or during certain procedures. (Lautenbach p. 58) Droplet precautions consist of a single patient room where the door may remain open. Surgical or isolation mask must be worn by those entering the room and the patient must wear a surgical or isolation mask if transported outside the room. (Lautenbach, P57, Table 6-3
Bioaerosols: are “Small droplet of moisture that may carry microorganisms. Aerosols may be light enough to remain suspended in the air for short periods of time, allowing inhalation of the microorganism.” (PIDAC, p. vii)
5. You are asked to provide an education session to the staff on Infection Control Precautions. What principles would you use in your approach to planning and carrying out the session?
Adults learn best when convinced of the need for knowing the information. Often a life experience or situation stimulates the motivation to learn” (medscape article)
Therefore provide relevance, emphasizes how what the group is learning will help protect them as well as their patients.
“former experiences can assist the adult to connect the current learning experience to something learned in the past. ” (Russel, 2011).
Draw on the group’s experiences, have them give examples of past cases they have used various infection control methods relevant to this suspected measles/rubella case. Eg. Have any of them cared for a patient in a negative pressure room? When was the last time they cared for a patients under droplet precautions?
Facilitate the learning group process:
“The learner participates completely in the learning process and has control over its nature and direction.
It is primarily based upon direct confrontation with practical, social, or personal problems.
Self-evaluation is the principal method of assessing the progress or success.” (Medscape article)
Engage the group with a practically relevant trial runs by having them set up an infection control room for droplet precautions, a negative pressure room etc. have them volunteer ideas and critique the scenarios.
Understand there are different learning styles amongst the group: kinaesthetic, auditory and visual. Teach to all these styles. Provide hands-on activities such as the scenarios above for the kinaesthetic learners, use the visual aides (infection control signs/posters with steps on) for the visual learners and discuss material with repetitions during the session for the auditory learners. (Russel, 2011).
1. Lautenbach, E., Woeltje, K., and Malani, P. 2010. Practical HealthcareEpidemiology, 3rd ed.
2. BCCDC. (2014). Communicable Disease Control Manual Chapter 1 – Management of Specific Diseases Measles. Section 6.1 Laboratory Testing. http://www.bccdc.ca/resource-gallery/Documents/Guidelines and Forms/Guidelines and Manuals/Epid/CD Manual/Chapter 1 – CDC/MeaslesSeptember2014.pdf
3. BCCDC. (2014). Communicable Disease Control Manual Chapter 1 – Management of Specific Diseases Rubella. Section 6.1 Laboratory Testing. http://www.bccdc.ca/resource-gallery/Documents/Guidelines and Forms/Guidelines and Manuals/Epid/CD Manual/Chapter 1 – CDC/RubellaSeptember2014.pdf
4. Provincial infectious diseases advisory committee (PIDAC). (2012). Routine practices and additional precautions in healthcare settings. http://www.publichealthontario.ca/en/eRepository/RPAP_All_HealthCare_Settings_Eng2012.pdf
5. Russell, SS. (2011). An overview of adult learning processes. http://www.medscape.com/viewarticle/547417_print
- Lautenbach, E., Woeltje, K., and Malani, P. 2010. Practical HealthcareEpidemiology, 3rd ed.
- Airborne precautions – p. 57
- Droplet and contact precautions – p.58
- Common virus work ups – chicken pox, MMR, paro, Hep A, flu, TB – p. 292
Infection control structure and activities:
- Kristina A. Bryant, Anthony D. Harris, Carolyn V. Gould, Eve Humphreys, Tammy Lundstrom, Denise M. Murphy, Russell Olmsted, Shannon Oriola and Danielle Zerr (2016). Necessary Infrastructure of Infection Prevention and Healthcare Epidemiology Programs: A Review. Infection Control & Hospital Epidemiology. https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0899823X15003335
Weekly schedule and activities of an infection control professional
- Archer, Joanne. (2012). Orientation Program for Infection control professionals. https://www.picnet.ca/wp-content/uploads/01-Introduction.pdf
- BCCDC. (2014). Communicable Disease Control Manual Chapter 1 – Management of Specific Diseases Measles. Section 6.1 Laboratory Testing. http://www.bccdc.ca/resource-gallery/Documents/Guidelines and Forms/Guidelines and Manuals/Epid/CD Manual/Chapter 1 – CDC/MeaslesSeptember2014.pdf
- BCCDC. (2014). Communicable Disease Control Manual Chapter 1 – Management of Specific Diseases Rubella. Section 6.1 Laboratory Testing. http://www.bccdc.ca/resource-gallery/Documents/Guidelines and Forms/Guidelines and Manuals/Epid/CD Manual/Chapter 1 – CDC/RubellaSeptember2014.pdf
- Russell, SS. (2011). An overview of adult learning processes. www.medscape.com/viewarticle/547417_print
Provincial infectious diseases advisory committee (PIDAC). (2012). Routine practices and additional precautions in healthcare settings.
Outbreak Investigation: Lautenbach ch. 12 p. 145.
- Provincial Infection Control Network of British Columbia. (2012). PICNet BC Clostridium difficile infection toolkit and clinical management algorithm. https://www.picnet.ca/wp-content/uploads/Toolkit-for-Management-of-CDI-in-Acute-Care-Settings-2013.pdf
- Lautenbach ch19, p. 220
outbreak definition: sets the parameters or conditions for when an outbreak is declared. Includes person, place and time as it defines those individuals who will be counted as a case.
1. in the text:
- Chapter 9 “Molecular Typing Systems”
- Chapter 17 “Control of Gram-Positive Multidrug-Resistant Pathogens” p. 197
- Chapter 18 “Control of Antibiotic-Resistant Gram-Negative Pathogens”
- Chapter 19 “Clostridium difficile Infection” in the Lautenbach textbook.
2. PICNet BC. (2014). PICNet BC Toolkit for the Management of Carbapenemase producing Organisms (CPO) at https://www.picnet.ca/wp-content/uploads/PICNet-CPO-Toolkit-2015.pdf.
3. PICNet. (2013). Antibiotic Resistant Organisms Prevention and Control Guidelines for Healthcare Facilities. Retrieved from: https://www.picnet.ca/wp-content/uploads/PICNet_ARO_Guidelines_March2013.pdf
Various infection control guidelines PICNET: https://www.picnet.ca/guidelines/
PICNet. (2011). Respiratory Infection Outbreak Guidelines for Healthcare Facilities. https://www.picnet.ca/guidelines/
Ambulatory care settings
- Chapter 27 “Infection Control in the Outpatient Setting” – p. 392
- Chapter 23 “Exposure Workups” – p. 291
- Center for disease control and prevention (2016). Prevention Strategies for Seasonal Influenza in Healthcare Settings Guidelines and Recommendations. https://www.cdc.gov/flu/professionals/infectioncontrol/healthcaresettings.htm
- Influenzan (flu) Infection Control in Health Care Facilities documents hm pg https://www.cdc.gov/flu/professionals/infectioncontrol/index.htm
World Health Organization. WHO guidelines on hand hygiene in health care. Geneva; 2009. http://apps.who.int/iris/bitstream/10665/44102/1/9789241597906_eng.pdf
Vertical and Horizonal approaches to ARO management:
Goldmann, Donald A., Perl, Trish M., Septimus, Edward., Weinstein, Robert A., and Yokoe, Deborah S. (2014). Infection Control and Hospital Epidemiology. http://www.jstor.org/stable/pdf/10.1086/676535.pdf
Health Canada and the Public Health Agency of Canada. (2016). Guidelines on Public Engagement. Obtained from: http://www.healthycanadians.gc.ca/publications/health-system-systeme-sante/guidelines-public-engagement-publique-lignes-directrice/alt/pub-eng.pdf
Human Factors engineering:
- What is Human Fators and why is it important to patient safety. Accessed Mar1, 2017 from http://www.who.int/patientsafety/education/curriculum/who_mc_topic-2.pdf
Employee Health and Occupational Medicine – text ch24, p. 319
Needle stick injury:
BCCDC. (2016). Blood and Body Fluid Exposure Management. http://www.bccdc.ca/resource-gallery/Documents/Guidelines%20and%20Forms/Guidelines%20and%20Manuals/Epid/CD%20Manual/Chapter%201%20-%20CDC/CPS_CDManual_BBFExpManage.pdf
Sharps injury prevention
CDC. (2008). Workbook for designing, implementing and evaluating a sharps injury prevention program. https://www.cdc.gov/sharpssafety/pdf/sharpsworkbook_2008.pdf
Contruction and renovation:
- Chapter 34 “Infection Control Issues in Construction and Renovation” in Lautenbach. p. 439
- Public health Agency of Canada. (2001). Construction-related Nosocomial Infections in Patients in Health Care Facilities. http://www.collectionscanada.gc.ca/webarchives/20071124025823/http://www.phac-aspc.gc.ca/publicat/ccdr-rmtc/01vol27/27s2/index.html
- PICNet. (2012). Orientation program for Iinfection Control Professionals Module 10 “Construction and Renovation”. https://www.picnet.ca/wp-content/uploads/10-Construction-Renovation.pdf
- BCCDC. 2004. Communicable disease control Varicella zoster. http://www.bccdc.ca/resource-gallery/Documents/Guidelines%20and%20Forms/Guidelines%20and%20Manuals/Epid/CD%20Manual/Chapter%201%20-%20CDC/Epid_GF_VaricellaZoster_July04.pdf
- Government of Canada. 2016. Canadian Immunization guide. https://www.canada.ca/en/public-health/services/publications/healthy-living/canadian-immunization-guide-part-4-active-vaccines/page-24-varicella-chickenpox-vaccine.html#p4c23a4
You are the infection control practitioner in a new, 400 bed community hospital with a six-bed adult and a six-bed paediatric intensive care unit. You have been asked to assist in establishing an Infection Control program and deciding its priorities.
Case One Questions:
1. What will be the structure of your infection control program? To whom do you think the program should report and why?
The structure should be in the form of a committee (Lautenbach, p. 403) with committee memebers holding hospital leadership positions which will enable them to provide insight, opinions and affect necessary change.
The infection control comittee should report to the facility’s medical board or medical advisory committee and/or senior management (Lautenbach, p 403).
Infection control committees composed of 8-12 members serve a single health care facility such as a hospital or long term care facility. Infection control committees composed of 15-25 members serve a health care region. (Lautenbach, p. 403)
An infection control committee is multidisciplinary with representatives from senior faclity management, the physcian group and nursing. Members from crital care, the surgical department, general medicine, the microbiology lab, pharmacy, occupational health, central processing, housekeeping and the local public health department should also be included (Lautenbach, p. 403).
The infection control program should report to their chair. The committee chair should be a physican leader for greatest effect. in best case scenario the chair is the hospital epidemiologist. With the committee reporting to a physician lead and hopefully a physician epidemiologist team lead, the infection control program is best supported to gain access to resources needed and to perform as efficiently as possible without being blogged down by leaders who do not fully understand the immplications of unmanaged infection control issues.
2. List key activities of your infection control program. Would these activities change if you were based in a long-term care institution? Why or why not?
- hand hygiene audits
- outbreak management: Acute event response, including outbreak investigation
- staff and patient education
- staff disease prevention/vacciation clinics
- review of ongoing infection control measures
- Performance improvement to reduce HAI
- Reporting of HAI to the Centers for Disease Control and Prevention’s National Healthcare Safety Network as well as entities required by law (Bryant et al, 2016)
In long term care less acute issues arise, patient turnover decreased. The majority of staff are less educated therefore increased staff education and hand hygiene audits so that principals do not get overlooked due to “home -like” or more casual setting.
3. Using a table, outline your idea of a typical week for an infection control practitioner (you do not have to account for every hour of the day, but rather blocks of time or percentage of time dedicated to activities). Briefly discuss the rationale behind your time allotments.
Monday: 30% walk through of work area assigned/30% site surveillance/30% review isolation cases
Tuesday: 30% Staff education/ 30% walk through of work area assigned/30% review isolation cases
Wednesday: 30% walk through of work area assigned/30% site surveillance/30% review isolation cases
Thursday: 30% hand hygiene audits/ 30% review staff vaccination programs/ 30% site surveillance
Friday: 30% walk through of work area assigned/30% site surveillance/30% review isolation cases. (Archer, 2012).
Reviewing patients on isolation is essiential to infection prevention and control therefore should be given priority each day to stay on top of new cases. Educating staff and ensuring appropate precautions are being followed is also central to the role yet can be addressed through regular site surveillances and key components of education can be re-itterated once weekly with addition sessions as needed.
4. Would the percentage of time spent during your work week change if you were in a long-term care institution. Why or why not?
Yes it would change. LTC is less acute, less patient turnover, therefore more time could be spent on staff education, hand hygiene audits and surveillance than reviewing infection control and isolation cases as there would be fewer.
5. Where do you think Infection Prevention and Control should ‘fit’ operationally in relation to the Quality and Safety Program in a hospital?
Infection control should fit under epidemiology and within the hospital administration framework along with hospital quality management department, “care-managed entities, regulatory and accrediting agencies, lawmakers and public accountability “(Lautenbach, p. 43). Infection control must fit into this framework because “multidisciplinary collaborations are essential to instigate innovative preventative research, identify new applications for old prevention strategies, maximize synergy among the broad array of professionals engated in quality promotion effortsm minimize overlap and conserve scarse resources” (Lautenbach, p. 43)
6. What is the institutional role of Infection Prevention and Control in terms of Quality and Patient Safety initiatives?
“Healthcare-associated infections are an important measure or quality” (Lautenbach, p. 42). Hospital epidemiology and infection prevention and control must demonstrate compliance with evidence based standards and reduce incidence of nosocomial infections. With that comes insitutional pressure for infection, prevention and control teams to be clearly accountable to Quality and Patient safety. (Lautenbach, p. 42)
1. Lautenbach, E., Woeltje, K., and Malani, P. 2010. Practical HealthcareEpidemiology, 3rd ed.
2. Kristina A. Bryant, Anthony D. Harris, Carolyn V. Gould, Eve Humphreys, Tammy Lundstrom, Denise M. Murphy, Russell Olmsted, Shannon Oriola and Danielle Zerr (2016). Necessary Infrastructure of Infection Prevention and Healthcare Epidemiology Programs: A Review. Infection Control & Hospital Epidemiology. https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0899823X15003335
3. Archer, Joanne. (2012). Orientation Program for Infection control professionals. https://www.picnet.ca/wp-content/uploads/01-Introduction.pdf
One of the patients in your long-term care facility has a positive smear for Acid Fast Bacilli from a sputum sample. This gentleman resides in a four-bed ward and has been actively coughing blood-tinged sputum for the last two weeks following what appeared to be a flu-like illness. He is of Chinese descent and his family states that he has never been known to be exposed to tuberculosis. A rapid diagnostic test is done which confirms that the organism is indeed M.tuberculosis
Case Eight Questions:
1. How is the diagnosis of active tuberculosis made? Compare and contrast traditional culture methods versus newer rapid tests.
Diagnosis of active TB may be made with the use of “acid-fast bacilli on smear microscopy and/or culture of Mycobacterium tuberculosis, or…amplification and detection of M. tuberculosis complex (MTBC) nucleic acids using nucleic acid amplification tests (NAATs).” (Public Health Agency of Canada, PHAC, 2013).
Traditionally a chest X-ray was used in a TB diagnosis however an X-ray alone cannot provide conclusive diagnosis. Currently, a microbiologic testing is needed for conclusive diagnosis (PHAC, 2013).
In addition to NAAT, microscopic smear, and M. tuberculosis bacterial culture (in liquid and solid media), sputum samples should be collected. Minimum 3 samples collected a minimum 1 hour apart are needed (PHAC, 2013). If TB is suspected, three fluorescent smears should be tested. In new TB patients (with positive smear test) should have at least one respiratory specimen tested with a public health agency validated or approved NAAT (PHAC, 2013).
Traditional culture vs newer rapid testing:
Chest X-ray – has a sensitivity of only 70% – 80% for the diagnosis of active TB based on abnormal presentations and only 10% of HIV infected patients will score positive TB chest X-rays (PHAC, 2013).
Acid fast bacilli on smear microscopy – The most widely used rapid test.
The benefits of smear microscopy:
- identifies the most infectious TB patients
The draw backs of smear microscopy:
• Sensitivity is modest and variable (20%-80%) depending upon the type of specimen, patient population, stain used and the experience of the microscopist. Thus, multiple sputum smears are recommended to increase the overall sensitivity and yield. Sensitivity is higher for respiratory than for nonrespiratory specimens, particularly body fluids.
• In low TB incidence settings, smear microscopy has lower specificity – a positive smear could be due to nontuberculous mycobacteria (NTM).
• Smear microscopy has lower sensitivity in childhood TB and extrapulmonary disease, especially in HIV-infected people.
• Smear microscopy cannot be used to determine drug resistance.” (PHAC, 2013)
Media Culture of M. Tuberculosis – “Mycobacterial culture, using both solid and liquid media, is considered the gold standard for diagnosis, and the use of broth-based culture methods for DST is the standard of practice in North America” (PHAC, 2013).
The benefits of culture:
- further use of culture isolates for molecular epidemiology using DNA fingerprinting.
- Culture can be performed on all specimen types.
The draw backs of culture:
- results typically take 2-8 weeks, depending on the culture method used and the number of MTBC bacteria in the inoculum.
Nucleaic acid amplification test (NAAT)
The benefits of NAAT:
- enables multi-drug resistant TB strain detection (unlike the other testing methods).
- specificity of the commercial NAAT is very high in all specimens (90%-100%)
- sensitivity of commercial NAATs to detect TB is high (>95%) in sputum smear-positive samples (PHAC, 2013)
The drawbacks of NAAT:
- inaccessible to the poorer regions and remote areas in the world
- sensitivity is lower (50%-70%) when smear-negative/culture-positive specimens are tested.
- sensitivity is also lower in extrapulmonary specimens.
- a negative NAAT result should not be used to rule out TB, especially in paucibacillary forms of TB (i.e. smear-negative and extrapulmonary TB).
- requires sophisticated laboratory infrastructure and highly skilled technicians
- The risk of contaminating the test site with amplified DNA requires stringent quality control procedures and a specific infrastructure to limit contamination (PHAC, 2013)
2. What should be done for the patient and his roommates? Assuming he attended activities/procedures outside his room during his stay – would you follow the other patients?
This patient should be placed in a single room and placed on airborne infection isolation in a negative pressure room (Lautenbach, p. 335). If that is not possible place each patient on airborne and contact precautions seeing as the patient has been coughing for 2 weeks in this shared space in close to his other roomates/patients. It is important to note that “If appropirate facilites for isolation of potentially infectious patients are not available on-site, an agreement should be in place to faciliate prompt transfer of such patients to alternate facilites” (Lautenbach, p354)
Yes I would follow and closely monitor all patients, visitors and staff who were in this patient’s proximity, tracing back contacts over the 2 weeks he was coughing. All contacts who were potentially exposed should undergo comprehensive tuberculin skin testing (Lautenbach, p. 335)
Lautenbach, p. 354, states that long term care facilities need to monitor for:
- skin test conversions among residents and staff
- identify and promptly evaulate patients with pulmonary symotoms or radiologic findings consistent with tuberculosis
- immediately isolate patients with potential of proven pulminary tuberculosis
- trace exposed patients and staff
- initate prophylactic isoniazid therphy
3. What advice will you give to the staff in terms of their follow-up and protection? What are the Canadian recommendations regarding initial and routine screening of hospital staff for tuberculosis?
Follow-up and protection:
- Staff should use N95 respirators when caring for the infected patient in his negative pressure room (Lautenbach, p335)
- UV germicial irradiation of all potentially exposed contact surfaces should be undertaken to prevent infection spread via those surfaces (Lautenbach, p. 335)
- Potentially exposed patients and staff should be tested for TB based on risk assessment and CDC guidelines (Lautenbach, p. 322).
- Staff with underlying immunocompromising conditions should be discouraged from caring for the patient with TB.
- Seeing as this patient’s family state he has not been known to be exposed to tuberculosis, nosocomial or cummunity acquired infection should be suspected and with that suspcision an immediate investigation should be undertaken and active, corrective steps should be implemented (Lautenbach, p. 325)
- Consulation with public health official and experts in healthcare epidemiology and infection control should occur
- based on the risk assessment, appropriate administrative, environmental and respiratory protection policies to prevent occupational exposure to and nosocomial transmission from the infectious or potentially infectious individual should put be in place (Lautenbach, p. 335).
Initial and routine screening:
“Prior to admission and employment all residents and employees of these facilities are to be assessed for their risk of tuberculosis.” (PICNET, p9).
- Patients under 60 years – tuberculin skin test. Chest x-ray for those with a positive tuberculin reaction. (PICNET, p9)
- Patients 60 years and over – chest x-ray only. Where there is difficulty obtaining a chest x-ray prior to or at the time of admission a normal chest x-ray completed within one year preceding admission for asymptomatic residents is acceptable (PICNET, p9).
For staff “The occupational medicine, hospital epidemiology and institutional biosafety programs should work together to establish effective ongoing tuberculosis prevention and management program” (Lautenbach, p. 320).
- new employees should receive intradermal Mantoux skin testing unless they have the employee has prior documentation of active TB, previous positive skin test, and/or completion of therapy for infection (Lautenback, p. 320).
- The whole blood interferon-y release assay could also be used, however discordant results have been reported between this and the skin test. (Lautenbach, p320)
4. What should be done for the patient and his roommates? Assuming he attended activities during the day, should you follow the rest of the patients on the ward?
note question 2 is very similiar therefore see it for answer.
5.Do you think this represents primary or reactivation tuberculosis? Justify your answer and explain what primary and reactivation tuberculosis means.
Considering that the family states this patient has not been knowingly exposed to TB we might consider sources for his infection. That said this patient is elderly, in long term care and would have few avenues of contracting a novel TB infection, with a weakened immune system dormant TB may reactive.
“All residents entering long term care facilities should have a baseline diagnosis test for LTBI performed… unless they are documented to have had a positive result previously” (Lautenbach, p. 338). We can hope we would have a TB test indicating the patient’s status upon admission.
If this patient’s infection represents a primary infection then potential sources he was exposed to need to be investiaged, such as staff, family members, visitors and patients.
Given age and accompanying immunocompromising factors along with the rigorous testing of all newly admitted patients and newly employed staff it is most probably that this patient has reactivation TB. However without knowing this patient’s TB immunity status prior to admission it is also possible the patient could have acquaried a primary infection from travelling family members or staff newly infected, other patients with re-activation (who also have been assumed to simply have a flu-like illness thus far). The results of the outbreak investigation and testing of patients and staff in the facility along with the patient’s TB test admission results would be needed to answer this question for certain.
From U.S. CDC Guidelines for the investigation of contacts of persons with infectious Tuberculosis the following data needs collecting in order to proceed with an thorough answer to this question:
“Multiple factors are relevant to a contact investigation, including the following: • history of previous exposure to TB,
• history of previous TB disease and treatment,
• anatomical sites of TB disease,
• symptoms of the illness,
• date of onset,
• chest radiograph results,
• other results of diagnostic imaging studies,
• diagnostic specimens that were sent for histologic or bac- teriologic analysis (with dates, specimen tracking num- bers, and destinations),
• current bacteriologic results,
• anti-TBchemotherapyregimen(withdates,medications, dosages, and treatment plan),
• results from HIV testing,
• the patient’s concurrent medical conditions (e.g., renal failure implies that a renal dialysis center might be part of the patient’s recent experience),
• other diagnoses (e.g., substance abuse, mental illness, or dementia) that impinge directly on the interview, and
• identifying demographic information (e.g., residence, employment, first language, given name and street names, aliases, date of birth, telephone numbers, other electronic links, and next-of-kin or emergency connections).” (MMWR, 2005)
Primary tuberculosis: the “first infection by Mycobacterium tuberculosis, typically seen in children but also occurs in adults, characterized in the lungs by the formation of a primary complex consisting of small peripheral pulmonary focus with spread to hilar or paratracheal lymph nodes; may proceed to cavitate or heal with scarring or may progress.” (Farlex, 2012).
Reactivation tuberculosis: is “a form of secondary tuberculosis that recurs as a result of the activation of a dormant endogenous infection. Causes of the reactivation may include loss of immunity, hormonal changes, or poor nutrition.” (Mosby’s, 2009).
6. What infection control measures would you have implemented if this had been non-tuberculous Mycobacterium?
Non-tuberculin mycobacterium are opportunistic organisms affecting immunocompromized and immunocompetent patients with a broad spectrum of virulence (Ryu, Koh and Daley, 2016). The most common Mycobacterial species causing infection are Mycobacterium avium complex (MAC), M. abscessus complex (MABC) and M. kansasii (Ryu, Koh and Daley, 2016).
Due to variable virulence, airborne, droplet (airborne covers this) and contact precautions should be implemented until lab results return identifying strain. From there a treatment plan can be drawn up according to the specific strain. Note that though mode of infection is difficult to identify, infiection via ingestion, inhalation or implantation (Johnson and Odell, 2014). Sources of infection such as probable inhalation of aerosoled droplets small enough to enter lung alveoli are the source of pulmonary NTM. Non-tubuculosis Mycobacterium exist in water and soil proving the patient’s general environment could also be a source of infection(Johnson and Odell, 2014).
However, identification of Mycobacterium organisms in pulminary specimen culture does not always indicate active infection (Johnson and Odell, 2014). That said it is difficult to treat and recurrences of infection due to the original organism is common (Johnson and Odell, 2014) and long courses of antibiotic treatment are necessary.
Mycobacterium are aerobic, non-motile bacterial that have lipid rich, hydrophobic cell walls much thicker than other bacterial strains (Johnson and Odell, 2014). The thick cell walls pose infection control obstacles as it enables the bacterium resistance to disinfectants, antibiotics and heavy metals (Johnson and Odell, 2014). Non-tubuculosis mycobacterium (NTM) are associated with biofilms which promote it’s antibiotic and disintectant resistant properties. NTM are hydrophobic and readily aeorsolize from water, they are also quite resitant to high temperatures and low pH posing further sterilization and infection control challenges (Johnson and Odell, 2014).
Water systems such as those in general hospital, hemodialysis and dental centers have high rates of Mycobacterium colonization (Johnson and Odell, 2014) so methods of sterilizing water should be assessed by infection control if the facility’s water supply proves contaminated.
7. What is MDR? XDR? What are the treatment and Infection Control implications?
MDR stands for Multi-drug resistant.
XDR is extensively drug-resistant TB. “XDR TB is a rare type of multidrug-resistant tuberculosis (MDR TB) that is resistant to isoniazid and rifampin, plus any fluoroquinolone and at least one of three injectable second-line drugs (i.e., amikacin, kanamycin, or capreomycin). MDR TB is caused by an organism that is resistant to at least isoniazid and rifampin, the two most potent TB drugs.” (CDC, 2013).
Treatment and Infection Control implications:
- XDR TB is resistant to the most treatment options
- the limited, remaining treatment options are less effective (30-50%), have more side effects, and are more expensive.
- HIV infected patients or those with other immunocompromizing conditions are at far greater risk of contracting TB and XDR TB
- Co-infected TB and HIV patients have a far higher mortality rates than others once TB is contracted. (CDC, 2013)
XDR TB is on the rise globally and is more common in patients who:
- Have HIV
- Do not take their TB medicine regularly
- Do not take all of their TB medicines as prescribed by their doctor
- Develop re-activation TB
- Reside in or have immigrated from areas of the world where drug-resistant TB is common
- Have spent time with someone known to have drug-resistant TB disease (CDC, 2013)
1. Lautenbach, E., Woeltje, K., and Malani, P. 2010. Practical HealthcareEpidemiology, 3rd ed.
2. Johnson, M. M., & Odell, J. A. (2014). Nontuberculous mycobacterial pulmonary infections. Journal of Thoracic Disease, 6(3), 210–220. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3949190/
3. Public Health Agency of Canada. (2013). Canadian Tuberculosis Standards. 7th ed. Accessed April 16 from http://www.respiratoryguidelines.ca/tb-standards-2013
4. Ryu, Y. J., Koh, W.-J., & Daley, C. L. (2016). Diagnosis and Treatment of Nontuberculous Mycobacterial Lung Disease: Clinicians’ Perspectives. Tuberculosis and Respiratory Diseases, 79(2), 74–84. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4823187/
5. PICNET. (2011). Residential Care Infection Prevention and Control Manual. Accessed April 17, 2017 from https://www.picnet.ca/wp-content/uploads/PICNet_Residential_Care_Manual_2011.pdf
6. Elsevier. (2009). Mosby’s Medical Dictionary, 9th edition.
7. Farlex. (2012). Farlex Partner Medical Dictionary.
8. Department of health and human services centers for disease control and prevention. (2005). Guidelines for the investigation of contacts of persons with infectious Tuberculosis. Accessed April 18, 2017 from https://www.cdc.gov/mmwr/pdf/rr/rr5415.pdf
9. CDC. (2013). Extensively Drug-Resistant Tuberculosis (XDR TB). Accessed April 18, 2017 from https://www.cdc.gov/tb/publications/factsheets/drtb/xdrtb.htm
You were informed by one of the patient service managers that one of her staff (a 26 year-old female) has just been diagnosed by her family practitioner as having chicken pox. She works on the general paediatric ward and her last day of work was three days ago, the same day the rash developed. The nurse had worked with three patients in adjacent rooms for five days prior to her last day of work, although she had been giving break relief to other nurses throughout that period. The unit has twelve patients on the one wing. The children range from age 2 to 13.
Case Seven Questions:
1. What precautions should be taken, if any, to protect patients on the ward? Would you recommend prophylactic therapy for any of the patients? Justify your response
Seeing as the nurse diagnosed with chicken pox has potentially been in contact with all patients on the ward through covering break relief as well as caring for the own patients it would be a sensible to test all twelve of the patients for their Varicella IgG antibody titer to determine immune status to chicken pox (Lautenbach, p. 293).
Children without immunity should be immunized as per BCCDC guidleines. Children who cannot be immunized as a result of the following should be closely monitored:
- “a life-threatening reaction to a previous dose of chickenpox vaccine, or any component of the vaccine including neomycin or gelatin
- an immune system weakened by disease or medical treatment;
- a blood transfusion or received other blood products within the past 12 months;
- active untreated tuberculosis” (HealthlinkBC, 2017)
Considering that we do not yet know if the nurse was infected by a patient at work it would be advisable to put all patients on airborne precautions to prevent possible further spread from one patient to others until lab results come back (Lautenbach, p.301).
Noting that children routinely receive their first dose of the chicken pox vacine at age 12 months and the second and final dose between the ages of 4 and 6 years (BCCDC, 2017) the patients on the pediatric unit who have not received the varicella vaccine at all or those who have not yet completed their second dose of the vaccine are especially at risk and should be monitored closely for symtoms.
The incubation period for Varicella Zoster is 14-16 days with a range of 10-21 days) and up to 28 days in persons who have received the VZIG (Lautenbach, p 293).
Infected individuals are infectious 1-2 days before and shortly after rash appears which was when the nurse was working prior to developing a rash.
Until lab results return on our 12 patient’s immune titres for varicella zoster it is best to treat all patients is nonimmune. “nonimmune patients who have been exposed to chicken pox should be placed under airborne precautions from day 10 through day 21 after their initial exposure (or through day 28, if the person is immunocompromized or received varicella zoster immunoglobulin)” (Lautenbach, p. 301)
Therefore, patients should remain on airborne precautions for 21 days unless they hae received the VZIG, then should remain on precautions for 28 days.
Would prophylactic therapy be recommended? Varicella zoster can cause “severe morbidity and mortality…in immunocompromized individuals” (Gnann, 2007). The virus is also associated with a “much greater mortality in patients with impaired cell-mediated immune response ” (Gnann, 2007). Therefore if these criteria fit any of the 12 pediatric patients their exposure could have dire consequences. “The outcomes of varicella and herpes zoster, especially in immunocompromised patients have been dramatically improved by safe and effective antiviral drugs” (Gnann, 2007).
In immunocompromized pediatric patients with varicella zoster, IV acyclovir reduced the frequency of VZV pneumonitis from 27% down to zero (Gnann, 2007).
In our exposed patients close monitoring and IV acyclovir intiated at the first sign of infection, switching to oral antiviral therapy when the patient is afebrile and no new lesions have appeared. (Gnann, 2007)
Lautenbach, p. 293 states for prophylaxis of “non-immune immunocompromised persons, consider giving VZIG within 96 hours after exposure.
If lesions develop the patient(s) should be placed on both airborne and contact precautions. The varicella zoster or disseminated zoster virus and shingles may be spread through:
- “face-to-face contact with infected person for 5 minutes of more without wearing a respirator,
- direct contact with vesicle fluid without wearing gloves,
- continueous household contact
- direct contact with vesicle fluid without wearing gloves” (Lautenback p. 293)
2. What, if any, infection control measures should be considered for the hospital workers?
Health care workers in theory should have been vaccinated at or prior to employment however based on the fact that our 26 year old pediatric nurse has just developed varicella zoster we cannot assume any of the workers have their Varicella vacinations. I would start by obtaining the vaccination status of all the hospital workers for varicella. Lautenbach, p. 293 states for “susceptible HCW, consider giving Varicella virus vaccine within 3 days after exposure to prevent or modify infection, giving the vcaccine does not change the work restirctions”.
So far as infection control measures relating to Varicella zoster exposed healthcare workers are at risk of infection unless the worker has serologic evidence of immunity or has documentation of recieving 2 doses of the varicella vaccine (Lautenbach, p. 293). For those without immunity to varicella zoster work restritcitons after exposure are as follows:
- Day 1-7, no restrictions
- Day 8 of first (or single ) exposure through day 21 of last exposure the healthcare workers “must not work or must not have direct patient contact and must work only with immune persons away from patient-care areas” (Lautenbach, p. 293).
- For health care workers who receive VZIG work is restricted through day 28.
- Infected healthcare workers may return to work after lesions are dry and crusts.
3. What are the tests available to confirm a diagnosis of chicken pox? Is laboratory confirmation always necessary – why or why not?
Varicella zoster is confirmed by:
- “isolation of the varicella virus from an appropriate clinical lab specimen
- significant rise in serum varicella varicella IgG antibody by any significant serological assay
- presence of clinical illness in any person who is epidemiologically linked to a confirmed case.
- Note: a clinical illness is characterized by rash with rapid evolution of macules to papules to vesicles to crusts with all stages simultansiously present. Lesions are superficial and may appear is crops.” (BCCDC, 2004)
Given that Varicella zoster cases can be confirmed in persons with presence of illness who are epidemiologically liked to confirmed cases, laboratory confirmation is not always necessary.
4. How effective is Varicella zoster vaccination in children? In adults? What are the potential complications?
A long term pediatric study of the vaccine effectiveness found the vaccine to be 90% effective (Baxter et al, 2013). ). The Baxter et al. study found that cases that did develop occurred early after the first dose of vaccine, symptoms were mild. They found that no child developed Varicella after the second and final dose of the vaccine. (Baxter et al, 2013).
However BCCDC states “The efficacy of a single dose of varicella-containing vaccine is about 94% in children. With a second dose, efficacy is about 98%.” (BCCDC, 2017).
“In healthy children 12 months to 12 years of age, a single univalent varicella vaccine dose results in a seroconversion rate of 98% at 4 to 6 weeks after vaccination, with antibodies persisting in 98% at 5 years and 96% at 7 years after vaccination. A second dose of a univalent varicella vaccine in children produces an improved immunologic response that is correlated with improved protection.” (Canadian immunization guide, p. 24)
“In adults and adolescents 13 years of age and older, 2 vaccine doses administered 4 to 8 weeks apart result in seroconversion rates of 99% at 4 to 6 weeks after the second dose, with persistence of antibodies 5 years later in 97% of vaccine recipients.”(Canadian immunization guide, p.24).
“The estimated vaccine effectiveness 10 years following the receipt of 2 doses of univalent varicella vaccine is estimated at over 98% against any varicella disease and 100% against severe varicella.” (Canadian immunization guide, p.24).
In older adults aged 60 or over the shingles vaccine is recommended to prevent recurrence of shingles as the immune system weakens with age. “however anyone 50 years of age and older can get the vaccine. Only 1 dose is needed for protection.” (Healthlink BC: Shingles vaccine)
Possible complications and side effects: “Reactions to univalent varicella vaccine are generally mild and include injection site pain, swelling and redness in 10% to 20% of recipients. A low-grade fever has been documented in 10% to 15% of vaccine recipients. A varicella-like rash occurs at the injection site or is generalized in 3% to 5% of vaccine recipients after the first dose. The rash usually appears within 5 to 26 days after immunization. As varicella-like rashes that occur within the first 2 weeks after immunization may be caused by wild-type virus (varicella virus circulating in the community” (Canadian immunization guide)
5. This nurse, as the case turns out, is pregnant and delivers the day following her visit to her family practitioner. The baby is admitted to the neonatal intensive care unit. What measures should be taken?
Measures to be taken for the infected nurse:
“Persons are contagious from 5 days (but usually 1 to 2 days) before onset of rash until all lesions have crusted.” (BCCDC, 2004) so contact precautions are necessary during care.
The nurse is at high risk for complications of Varicella zoster due to the fact that she became infected while preganant as has now just delivered (BCCDC, p.4). Our next step to protect this high risk patient is to “provide immunoprophylaxis with either Varicella Zoster Immune Globulin (VZIG) or varicella vaccine.”
Measures to be taken for the infant:
Lab tests to determine if the infant has contracted varicella zoster. In this case the infant is epidemiologically linked to a confirmed case through the mother, however isolating the virus in the infant from an appropriate clinical specimen or testing “Significant rise in serum varicella IgG antibody level by any standard serologic assay” (BCCDC, p.2) will help guide treatment.
Page two of BCCDC Varicella zoster guideline states “Children exposed to varicella-zoster virus in utero during the second 20 weeks of pregnancy can develop inapparent varicella and subsequent zoster early in life without having had extrauterine varicella.” so continued monitoring will be necessary.
“Varicella infection can be fatal for an infant if the mother develops varicella from 5 days before to 2 days after delivery.” (BCCDC, p2) in our case the mother contracted Varicella zoster, developing a rash 5 days before delivery placing the infant in this high risk category.
Considering that the vaccine is offered to children 12 months of age or older, this infant is not elligible(BCCDC, 2017). “Varicella zoster immune globulin (VZIG) given within 96 hours of exposure may prevent or modify disease in susceptible close contacts of cases.” (BCCDC, 2004). Our infant fits into the timeline criteria to be given VZIG for management of this viral infection as the infant is a newborn whose mother developed varicella disease 5 days before delivery. (BCCDC, 2004).
The newborne should be on contact and airborne precautions while in treatment in NICU (Lautenbach, 2010)
1. BCCDC. 2017. Chicken pox (Varicella) Vaccine. Accessed April 3, 2017 from http://www.bccdc.ca/health-info/immunization-vaccines/vaccines-in-bc/chickenpox-varicella-vaccine
2. Healthlink BC. 2017. Chicken pox (Varicella) Vaccine. Accessed April 3, 2017 from https://www.healthlinkbc.ca/healthlinkbc-files/chickenpox-vaccine
3. Lautenbach, E., Woeltje, K., and Malani, P. 2010. Practical HealthcareEpidemiology, 3rd ed.
4. Gnann, Jr, JW. 2007. Antiviral Therapy of Varicella-zoster virus infections. Human Herpesviruses: Biology, Therapy, and Immunoprophylaxis. Accessed April 3, 2017 from https://www.ncbi.nlm.nih.gov/books/NBK47401/
5. BCCDC. 2004. Communicable disease control Varicella zoster. Accessed April 5, 2017 from http://www.bccdc.ca/resource-gallery/Documents/Guidelines%20and%20Forms/Guidelines%20and%20Manuals/Epid/CD%20Manual/Chapter%201%20-%20CDC/Epid_GF_VaricellaZoster_July04.pdf
6. Baxter, R, Ray, P, and Tran, T et al. 2013. Long term effectivenss of Varicella vaccine: a 14-year prospective cohort study. Pediatrics. Vol 131, Issue 5 accessed April 6, 2017 from http://pediatrics.aappublications.org/content/131/5/e1389.short
7. Government of Canada. 2016. Canadian Immunization guide. Accessed April 6, 2017 from https://www.canada.ca/en/public-health/services/publications/healthy-living/canadian-immunization-guide-part-4-active-vaccines/page-24-varicella-chickenpox-vaccine.html#p4c23a4
8. HealthlinkBC> 2017. Shingles Vaccine. Accessed April 6, 2017 from https://www.healthlinkbc.ca/healthlinkbc-files/shingles-vaccine
Positive pressure room: Air will flow out of the room instead of in, so that any airborne microorganisms (e.g., bacteria) that may infect the patient are kept away.
Negative pressure room: a ventilation system that generates negative pressure to allow air to flow into the isolation room but not escape from the room, as air will naturally flow from areas with higher pressure to areas with lower pressure, thereby preventing contaminated air from escaping the room.