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3/5/2020 I have nothing The Nuts and Bolts of an Outbreak Investigation to disclose. Robert Kosnik, MD Professor of Medicine, Medical Director, Occupational Health Services March 5, 2020 Investigation Fundamentals Angiosarcoma of the Liver

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3/5/2020 1

The Nuts and Bolts of an Outbreak Investigation

Robert Kosnik, MD

Professor of Medicine, Medical Director, Occupational Health Services March 5, 2020

I have nothing to disclose.

Investigation Fundamentals

 Case (Definition)  Exposure  Association

Angiosarcoma of the Liver

Disease: Angiosarcom a

Exposure: Vinyl Chloride

Association: Veteran em ployees w ith at least 1 2 years of experience & w orked as “pot cleaners”

I nitially observed by John Creech MD, the plant physician, w ho realized through careful history-taking that they w orked in the sam e departm ent of the plant.

Block BJ, “Angiosarcom a of the Liver Follow ing Vinyl Chloride Exposure”,
  • JAMA. 1974; 229(1): 53-54.
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3/5/2020 2

What is an Outbreak

 An outbreak or an epidem ic is the
  • ccurrence of more cases of disease

than expected in a given area or among a specific group of people over a particular period of time. Usually, the cases are presumed to have a common cause or to be related to one another in some way.

What is a Cluster

 A cluster is an aggregation of cases in

a given area over a particular period without regard to whether the number

  • f cases is more than expected.
 This aggregation of cases seems to be

unusual, but frequently the public (and sometimes the health agency) does not know the denominator.

Bradford Hill Criteria

 Strength of association  Consistency across studies  Specificity  Temporality  Biological gradient (dose-response)  Biological plausibility

Steps of an Outbreak Investigation

 Confirm the diagnosis  Determine the existence of an outbreak  Identify and count cases  Orient the data in terms of person, place,

and time

 Develop and test hypotheses  Plan for more systematic studies  Implement and evaluate control measures  Communicate findings
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SLIDE 3

3/5/2020 3 JOHN SNOW AND THE BROAD STREET PUMP: 150 YEARS OF EPIDEMIOLOGY

By John Snow - Published by C.F. Cheffins, Lith, Southhampton Buildings, London, England,

Diagnosis Outbreak Identify cases Data (Time, Place) Hypothesis Plan study Implement Evaluate Communicate

Issues Unique to Occupational Outbreak Investigations

 Workplace access  “Healthy participant” effect

 Current vs. former workers  Employed vs. contingent workers

 Exposure assessment  Competing interests

A skewing of data in randomized medical studies that occurs when healthy participants are less likely to drop out of the study than sicker patients. Wikipedia

Potential Investigators

 Clinicians  Academic researchers, consultants  Local and state health departments  Occupational Safety and Health

Administration (OSHA)

 National Institute for Occupational Safety and

Health (NIOSH)

Potential Stakeholders

 Industry  Labor  Government  Insurers  Suppliers  Downstream users
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Epidemiologic Steps of an Outbreak Investigation

Prepare for field work

Establish the existence of an outbreak

Verify the diagnosis

Construct a working case definition

Find cases systematically and record information

Perform descriptive epidemiology

Develop hypotheses

Evaluate hypotheses epidemiologically

As necessary, reconsider, refine, and re-evaluate hypotheses

Compare and reconcile with laboratory and/ or environmental studies

Implement control and prevention measures

Initiate or maintain surveillance

Communicate findings

Principles of Epidemiology in Public Health Practice, Third Edition An Introduction to Applied Epidemiology and Biostatistics

Skin Disorder in Electronic Store

An outbreak of skin disorders was noted by the primary care physician responsible for the health care of 52 employees in an electronics store. The cases occurred after termite treatment of the store, and the breakdown of the air‐conditioning system in several areas in the store. Investigations were initiated to allay worker concern that the chemicals used for termite treatment (in particular, arsenic trioxide) were responsible for the outbreak. 9 of the 52 workers were found to have heat rash (miliaria rubra). 21% (7) of workers who worked in non‐air‐conditioned areas had heat rashes, as compared to 11% (2) of workers who worked in air‐conditioned work zones. 2 workers had contact dermatitis due to exposure to greaseless lubricant, and 8 other workers had a non‐work‐related skin disorder. Indoor wet bulb globe temperature index measurements in the non‐air conditioned areas were within threshold limit values, but ventilation in these areas was very poor. 2 environmental samples had non‐detectable limits of arsenic.

Contact Derm atitis, Koh, D; Volum e 3 2 , I ssue 6 , June 1 9 9 5 , Pages 3 2 7 -3 3 0

How to Respond to an Outbreak: When in the Midst

  • f that Outbreak

Infectious Agent Specific Definitions

 Method of Transmission  Case, Contact, Contact of Contact  Self-Monitoring for Symptoms  Level of Isolation (Social Distancing)  Type of Quarantine (Movement Restrictions)  Type of Exposure – Protected or Unprotected
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Transmission of an Infectious Agent

RESOLUTION SYMPTOMS INCUBATION

EXPOSURE DIAGNOSIS

Time ## Days

## Days

PRODROME

Transmission of an Infectious Agent

RESOLUTION SYMPTOMS INCUBATION

EXPOSURE DIAGNOSIS

Time ## Days

## Days

PRODROME INFECTIVITY

Transmission of an Infectious Agent

INFECTIVITY HCW A EXPOSURE RESOLUTION SYMPTOMS INCUBATION

EXPOSURE DIAGNOSIS HCW B

EXPOSURE

HCW C

EXPOSURE Time ## Days

## Days

PRODROME

Transmission of Small Pox

INFECTIVITY HCW A EXPOSURE

RESOLUTIO N SYMPTOMS INCUBATION EXPOSURE DIAGNOSIS HCW B

EXPOSURE

HCW C

EXPOSURE Time 12 Days

1 - 4 Days 21 Days

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Transmission of Pandemic Influenza

INFECTIVITY HCW A EXPOSURE RESOLUTION SYMPTOMS INCUBATION

EXPOSURE DIAGNOSIS HCW B

EXPOSURE

HCW C

EXPOSURE Time 24 – 72 hours

0 Days

PRODROME

3 Days

Transmission of SARS CoV - 1

INFECTIVITY HCW A EXPOSURE

RESOLUTIO N SYMPTOMS INCUBATION EXPOSURE DIAGNOSIS HCW B

EXPOSURE

HCW C

EXPOSURE Time 4 - 10 Days

0 Days ?? Days

Transmission of SARS CoV - 2

INFECTIVITY HCW A EXPOSURE

RESOLUTIO N SYMPTOMS INCUBATION EXPOSURE DIAGNOSIS HCW B

EXPOSURE

HCW C

EXPOSURE Time 14 Days

0 Days ?? Days

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Emergency Operations Sars CoV - 1

EMPLOYEE HEALTH UNIT – SARS EXPOSURE RUBRIC No Known Exposure Exposure Within the Past 10 Days Contact2 Case3 No Contact Contact of Contact1 Unprotected4 / Breach of Protection 7 Protected5 No Symptoms Return to Work Return to Work  Send Home  Quarantine for 10 days  Kit with 2 masks  Maintain contact with EHU  EHU Call Public Health Return to Work  Under the care of a physician Fever > 38C Send to ER Notify ICP Fever > 38C Send to ER Notify ICP Fever > 38C Send to ER Notify ICP Symptoms Malaise OR Myalgia OR Headache OR Cough OR Shortness of Breath One symptom return to work For two or more symptoms consult EHU / ER Malaise OR Myalgia OR Headache OR Cough OR Shortness of Breath For One symptom return to work For two or more symptoms consult EHU / ER  Refer to ER for evaluation as a case If staff not a case just a contact,  quarantine for 10 days  Kit with 2 masks  Maintain contact with EHU  EHU call Public Health Malaise OR Myalgia OR Headache OR Cough OR Shortness of Breath One symptom return to work For two or more symptoms consult EHU / ER Under the care of a physician
  • 1. A Contact of Contact is someone who came into contact with a quarantined individual. Eg. Spouse of a quarantined contact from Scarborough Grace Hospital
  • 2. A contact is someone who came into contact is a case. This may be:
 A) a known diagnosed case, suspect or probable, B) travel to an affected area, C) attendance at an institution designated by Public Health. (See Toronto Public Health – Fact Sheet) or otherwise designated by Public Health, D) breach of Infection Control Precautions for suspect and probable cases as well as persons under investigation. For individuals who visited, worked or were a patient at an affected or designated health care institution, please get the following:  A) date of contact(s), B) location of contact, C) if available the contact name.
  • 3. A case is someone who meets the case definition from Health Canada for a suspect or probable case of SARS.
  • 4. An Unprotected Contact is someone who came into contact with a case less than 2 days prior to the onset of symptoms in the case. Eg. Contact on Monday for a case
with symptoms starting on Wednesday.
  • 5. A Protected Contact is someone who came into contact with known case who was wearing proper protective equipment, including mask, gloves, gown and goggles. A)
Fully assess the extent of the protection. B) Identify the case, location and contact telephone number (if Possible). C) Review symptoms each day for the 10 day period.
  • 6. Off work for 2 to 10 days past the end of the symptoms, maintain usual contact with manager, call the EHU 864.5013, follow the usual back to work guidelines.
  • 7. The Infection Control Practitioner MUST BE NOTIFIED about ALL cases of breach in infection control protocol as well as ALL individuals with a fever over 38C.

SARS Screening

TABLE - Breakdown of Exposure in staff evaluated by the Em ployees' H ealth U nit Exposure Status SA RS 1 SAR S 2 Total No Exposure 841 884 1725 Exposed 133 405 538

TABLE - Breakdown of SMH staff who were not exposed to SARS No Exposure SARS 1 SARS 2 Total Symptoms Only 764 841 1605 Contact of Contact 77 43 120

SMH SARS Quarantine

TABLE - Breakdown of Hospital Positions that were Quarantined. QUARANTINED SARS 1 SARS 2 Total Registered Nurses 36 161 197 Physicians 7 17 24 Residents 20 28 48 CLM / NP / Case Managers 2 4 6 Environmental Assistants 3 17 20 Clinical Assistants 6 24 30 Clerical Assistants 3 9 12 Allied Health Staff* 5 21 26 Medical Imaging 1 28 29 Other 49 94 143 Totals 133 405 538

* Allied Health Staff includes physiotherapists, occupational therapists, pharmacists, and respiratory technicians
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SARS Contacts of Contacts

SARS 1 - March 9th to April 25th, 2003 Number of First Encounters per Day

5 10 15 20 25 C o nt o f C o nt 3 6 2 4 10 10 9 7 3 1 8 1 2 1 3 2 C o ntacts 1 1 1 9 8 7 7 9 9 14 11 16 1 4 11 1 1 1 1 3 1 1 3 2 2 0/ 3 21 / 3 2 2/ 3 2 3/ 3 2 4/ 3 2 5/ 3 2 6/ 3 2 7/ 3 2 8/ 3 2 9/ 3 3 0/ 3 31 / 3 1/ 4 2/ 4 3/ 4 4/ 4 5/ 4 6/ 4 7/ 4 8/ 4 9/ 4 10 / 4 11 / 4 12 / 4 13 / 4 14 / 4 15 / 4 16 / 6 17 / 6 18 / 4 19 / 4 2 0/ 4 21 / 4 2 2/ 4 2 3/ 4 2 4/ 4 2 5/ 4

SARS - Overall Fit Test Results

Mask Type versus Test Result

81.2 65.2 62.0 54.7 78.0 45.3 500 1000 1500 2000 2500 Number of Tests 40 50 60 70 80 90 100 Percent Pass 2145 467 269 163 188 91 Fail 497 249 165 135 53 110 Pass Rate 81.2 65.2 62 54.7 78 45.3 3M 8210 3M 7048 3M 1870 MSA FR200 Duckbill 3M 8110 Staff experiencing clinical symptoms due to prolonged use
  • f respirators were evaluated in
the Employee Health Unit Some common complaints: aggravation of asthma (increased use of medication), shortness of breath, skin problems, runny nose, coughing One individual experienced allergic reaction despite respirator being deemed hypoallergenic (this case was treated twice in Emergency) Questionnaires were developed for skin and asthma problems focusing on an increase in symtpoms * Included the following symptoms when wearing N95: runny nose, shortness of breath Respiratory Ski n

♥

Oth er* Asthma Cough SO B Othe r SARS 1 7 4 SARS 2 20 2 15 10 16 1 16 Questionnaire 29 12

Prolonged Wearing of N95 Respirators

Position Total Registered Nurses 128 Registered Respiratory Care Pratitioners 17 Clinical Coordinator – RT 1 Physiotherapist 2 Clinical Leader Manager 1 Environmental Assistants 10 Clinical Assistants 11 Clerical Assistants 3 Clinical Nurse Educator 1 Clinical Pharmacy Specialist 1 Coordinator 2 Facility Housekeeper 1 Nurse Specialist Educator 1 Technologist 1 Chaplain 1 Total 181 128 17 11 10 5 10 15 20 25 30 35 40 45 50 Count START Team Positions Registered Nurse Reg Resp Care Practi Clinical Asst Env Asst Clerical Asst Physiotherapists Breakdown of the Members of the START Team cleared by the Employees’ Health Unit This activity involved the development of a SARS pre-placement medical evaluation form for completion by staff prior to undertaking an assignment on the START team. It focused on the following: 1) conditions that are known to have an adverse result if SARS is contracted, 2) current medications and 3) current symptoms. The forms were completed during training and reviewed by the Medical Director, Employee Health Unit. The completed forms were retained in the occupational health file of the employee.

SARS Start - Team

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Working in an Outbreak

 Be informed  Be watchful  Be involved  Be decisive  Be transparent

References

Kreiss K, Cummings KJ. Occupational disease and injury. In: Rasmussen SA, Goodman RA, eds. The CDC Field Epidemiology Manual, 4th Edition. New York: Oxford University Press, 2019. www.cdc.gov/eis/field-epi- manual/index.html. CDC’s Epidemic Intelligence Service. https://www.cdc.gov/eis/index.html.

Page 36

The Nuts and Bolts of an Outbreak Investigation

Q’s

A’s

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Examples of Investigations

 Key points will be discussed through

presentation of several workplace investigations conducted by the presenter and others.

MULTIPLE CHOICE QUESTIONS

  • 1. Which of the following

indicates an outbreak?

  • A. A substantial increase in the incidence of a disease

among workers at a facility. B. A cluster of a novel disease in a workplace. C. Multiple cases of different rare lung diseases among co- workers. D. A substantial increase in the incidence of an occupational disease after more sensitive surveillance is introduced. E. A and B. F. All of the above.

  • 2. Which of the following is

true?

  • A. Non-disclosure agreements may limit investigators’ ability

to share findings with a wider audience.

  • B. NIOSH recommendations are enforceable in states with

federal OSHA plans.

  • C. Health departments do not have authority to conduct

workplace investigations.

  • D. OSHA is the federal agency best positioned to investigate

novel disease outbreaks. E. B and D.

  • F. All of the above.
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  • 3. Which of the following can

be used in an occupational

  • utbreak investigation?

A. Case-control study. B. Retrospective cohort study. C. Industrial hygiene assessment. D. Experimental study. E. A and C. F. All of the above.

UC San Francisco UC San Francisco