Outbreak Basics. Alice Shumate, PhD Jason Mehr, MPH

Transcription

1 Outbreak Basics Alice Shumate, PhD Jason Mehr, MPH

2 Local Health Department (LHD) Roles and Responsibilities

3 LHD Preparation LHDs are required to respond to public health emergencies LHD must provide health care providers, NJDOH and the public with a contact in the event of an emergency 24 hours per day, seven days per week, including weekends and holidays Develop a preparedness plan Hold staff trainings at least once a year

4 Authority to Investigate This administrative code gives local health departments authority to investigate disease: a. The Red Book b. NJAC 52 c. NJAC 8:57 d. Title X

5 LHD Authority According to regulation, who has the ultimate jurisdiction in a municipality to investigate and report disease? a. Health Officers b. Disease investigators c. Public health nurses d. Animal control officers

6 Health Officer Authority [N.J.A.C. 8: ] Investigate the facts contained in disease report(s) Determine whether an outbreak exists Order testing of suspected cases Ascertain the source and spread of the infection Determine and implement appropriate control measures Prophylaxis if necessary Order isolation/quarantine

7 NJACCHO Performance Goals for Outbreak Tracking and Response 1. Immediately report all suspected outbreaks to the NJDOH. 2. Conduct an investigation of all suspected outbreaks within 24 hours of receipt of a report or notification. 3. Forward investigation summary reports to the NJDOH within 30 days of completion of the investigation. 4. Update the Red Book within 24 hours of change in personnel or contact information 1. 24/ by 3 (three contact persons with three contact methods) 5. Ensure that all outbreak response team personnel are properly trained.

8 Disease Reporting

9 Categories of Reportable Diseases in NJ Confirmed or Suspect Cases IMMEDIATELY Reportable to LHD Includes suspected outbreaks Reportable within 24 hours of diagnosis to LHD Reportable directly to NJDOH within 24 hours Report to NJDOH within 30 days of diagnosis/treatment

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11 Disease Reporting: Immediately Reportable An immediately reportable disease a. Must be reported to the health officer within 48 hours b. Should be lab confirmed before reported c. Must be reported to the health department within 24 hours d. Should be investigated by physicians to stop the spread e. None of the above

12 Who Reports What? Healthcare providers and administrators Clinical lab directors Veterinarians, animal control officers etc. Outbreaks must be reported, not just entered into Outbreaks must be reported, not just entered into CDRSS

13 Outbreak Investigation

14 What is an Outbreak? An outbreak is considered a. Less than the number of cases of disease normally experienced at a given time b. Usual occurrence of fdisease or any disease below background levels c. Higher cases of disease during the summer months d. Occurrence of disease that exceeds what is normal for that area

15 What is an Outbreak of Disease? Increase of disease in time or place Typically involves 2 or more cases but can vary by disease Can vary in magnitude and complexity Small, local cluster Larger, multistate

16 Disease Transmission Diseases can spread through various modes of transmission: Airborne Bloodborne Foodborne Person-to-person Vectorborne; and Waterborne

17 Labs, Providers, Vt Veterinarians i LHD State Department of Health

18 Steps to an Outbreak Investigation EARLY PHASE Make required notifications Brief the team/prepare for field work Confirm the suspected outbreak Verify the diagnosis Declare an outbreak Develop preliminary hypothesis Implement initial control & prevention measures Communicate with stakeholders MIDDLE PHASE Define cases Identify and track cases Interview cases Create line lists Describe the data Evaluate your hypothesis Adjust control & prevention measures LATE PHASE Declare outbreak over Report/communicate findings Review lessons learned

19 Step 1: Notify As soon as a suspected outbreak comes to attention notify NJDOH by phone no matter the time of day Remember: outbreak definition can vary As soon as possible share information with other relevant health officers/regional epidemiologists

20 Brief the Team and Prepare for Fieldwork Research disease in question Choose a team leader, develop an action plan for field personnel, gather supplies Review personal protection and ensure PPE provided Develop Incident Command Structure (ICS) if necessary Work with your HERC (Health Education Risk Communicator) to review and update your communication plan

21 Preparing for an Investigation: Personnel Consider the roles you need filled Leadership and expertise to inform team Don t forget about communications! Consider internal resources, state and neighboring jurisdictions, and others, such as Medical Reserve Corps Might need multiple investigation teams: ensure they are similarly balanced

22 Team Leader Most important responsibility: keep in constant communication Point of contact for NJDOH Review available information Specimen collection & transport methods Request assistance as needed Point of contact for team members

23 Preparing for an Investigation: Supplies Data collection forms Case investigation forms, line lists Disease reporting forms Maps Contact list Personal protective equipment Specimen collection supplies (who provides?) Collection kits Transport media Labels

24 Confirm the Outbreak Compare the current number of reported cases with: numbers from the previous weeks or months, or from a comparable period during previous years Other possible reasons for increase in cases: Changes in reporting procedures Revised case definition New diagnostic procedures Heightened awareness at the local or national level

25 Verify Diagnosis/Lab Testing Collect samples from suspect cases to submit for testing/get results from lab In most outbreaks, 2 or more lab confirmed cases confirms the outbreak Be careful to order the correct test!

26 Declare an Outbreak Notify NJDOH epidemiologist that the suspected outbreak has been confirmed Also give update regarding the preliminary investigation Brief your outbreak response team Prioritize the local health department s response and delegate duties and activities Maintain communication with the NJDOH

27 Communication between NJDOH and LHD Local Health: Continue daily to weekly contact regarding the status of the outbreak and intervention(s) Depends on the disease and situation Request support from NJDOH for additional lab testing, if needed Assess the need for NJDOH assistance NJDOH: Contact the local team leader periodically as needed Arrange conference e ce calls between ee local and state staff as needed Arrange for local assistance as requested

28 Develop Preliminary Hypothesis As information comes in, focus on a preliminary hypothesis to guide the investigation Information that can help includes: The nature of the disease Source of the agent Mode of transmission Potential exposures that caused the outbreak NOTE: You will revise your hypothesis based on the information you gather during the investigation.

29 Implement Initial Control and Prevention Measures Do not wait! Control measures vary by the host susceptibility, mode of transmission, and reservoir Be flexible: Control measures often change over the course of the investigation, and multiple approaches may be needed to stop transmission

30 Control Measure Determinants When determining which infection control measure(s) to implement, which of the following should be considered: C ti t a. Causative agent b. Reservoir c Mode of transmission c. Mode of transmission d. All of the above e. A & C only

31 Communicate with Stakeholders Not really a separate step Keep in constant contact Essential in controlling outbreak and getting up-todate case number If necessary, set up after hours contact number

32 Steps to an Outbreak Investigation EARLY PHASE Make required notifications Brief the team/prepare for field work Confirm the suspected outbreak Verify the diagnosis Declare an outbreak Develop preliminary hypothesis Implement initial control & prevention measures Communicate with stakeholders MIDDLE PHASE Define cases Identify and track cases Interview cases Create line lists Describe the data Evaluate your hypothesis Adjust control & prevention measures LATE PHASE Declare outbreak over Report/communicate findings Review lessons learned

33 Define Cases Case Definition- a standard set of criteria for deciding whether a person should be classified as having the disease and be included in your outbreak investigation. May Include: Clinical information about the disease Characteristics about the people who are affected Information about the location or place Specification of time during which exposure or onset occurred Outbreak case definition surveillance case definition Can be refined as time goes on Early working case definition iti might be very broad Can capture suspected/possible cases as well as confirmed and probable cases

34 Case Definition Classifications Confirmed: Verified case, usually through laboratory results Probable: A case that fits most of the typical clinical features of the disease but typically has no laboratory confirmation Suspect: A case that has some of the typical clinical features of the disease and has no laboratory verification Not a case: One that does not meet the outbreak case definition or working case definition

35 Case Definition Which of the following is a correct statement about a case definition? a. Case definitions may change as new/more information is learned during the public health investigation b. A working case definition is never the same as a surveillance case definition c. Cases should never be excluded in an outbreak, even if they are classified as Not a Case d. All of the above

36 Identify and Track Cases There are many ways to track down potential cases: Ask stakeholders (physicians, administrators, infection preventionists) to identify cases Review communicable disease registries Check with medical facilities and labs Conduct interviews within the population in question

37 Communicable Disease Reporting and Surveillance System (CDRSS) Secure, web-enabled, electronic disease reporting system Real time, 24/7 Patient-centric Available to all LHDs and acute care hospitals in NJ Tools Include: Detailed case management patient demographics disease signs, symptoms and risk factors laboratory data medical follow-up Outbreak management Contact tracing Surveillance Mapping/Graphs

38 Interview Cases Which of the following would be good information to collect from a case interview a. Travel History b. Symptom Onset c. Close Contacts d. Occupation e. All of the Above

39 Interview Cases Information to Collect: Demographics Occupation (especially important with person-toperson spread) Symptom onset, to calculate incubation and infectious periods Symptom type Duration of illness Travel history Contacts Disease specific risk factor information

40 Benefits of Case Interviews Contact patients with additional questions Notify patients of laboratory results Collect data for mapping, graphs Determine the population at risk Verify that the case definition has been met

41 Create Line Lists Line lists are created to keep track of cases and information from an outbreak Good way to organize important information pertaining to your case definition (Step 9) Constantly changing/revising Can include: Risk Factors, Clinical Information, Symptoms, Location, Onset Date etc.

42 Sample Line List

43 Describe Data Use data from your line list Describe the data in terms of Person Place Time Outbreak trend over time, geographic context, and affected populations Allows us to review and revise hypothesis, data collection plans, as relevant

44 Epi Curve: Your Best Friend 9 Influenza in Long Term Care Facility 8 NUMB BER OF CA ASES DATE OF ONSET

45 Epi Curve: Your Best Friend 9 Influenza in Long Term Care Facility 8 NUMB BER OF CA ASES DATE OF ONSET

46 Point-Source Exposure Num mber of Ca ases Days

47 Ongoing Exposure Num mber of Ca ases Days

48 Secondary Exposures (Repeated Primary Exposure) Num mber of Ca ases Days

49 Evaluate Hypothesis Two ways to test your hypothesis: 1. Compare with established facts- Sometimes the evidence is so strong a hypothesis doesn t need to be tested 2. Analytic Epidemiology Testing the hypothesis through case-control or cohort study

50 Analytic Epidemiology Used when the cause of the outbreak is less clear Quantifies the relationship between the exposures and the disease to find a causal link Different Types Case series Case-control study Cohort study

51 Case-Control Control Study Compares individuals with disease to those without disease, but that share a similar feature (location, particular exposure) Cases are picked by disease status first, with the outcome as the exposure(s) Retrospective in nature Relatively easy to conduct

52 Case-Control Control Study: Example A hospital in Atlantic County sees a huge upsurge in cases of GI illness after one weekend in July. Many ill persons mention having eaten takeout food from a popular deli near the beach. Your job: to determine the cause of the symptoms, and prevent further illness. How will you do it?

53 Case-Control Control Study: Example Cases (Ill) Controls (Well) Ate potato salad Didn t eat potato salad Total Total Testing for association between illness and exposure

54 Case-Control Control Study: Example Cases (Ill) Controls (Well) Ate potato salad Didn t eat potato salad Total Total Testing for association between illness and exposure Uses an odds ratio OR = (58/4)/(22/37) = 14.5/0.595 = 24.4 Persons who ate potato salad were 24 times more likely to become ill What else do you want to know?

55 Cohort Study Used to study a defined group of people Compares a group of people with a similar exposure to another group who do not share that exposure Here the cases are picked by exposure status, and the outcome is disease Can be retrospective or prospective in nature Generally more time consuming, more costly, but a more reliable study design

56 Cohort Study: Example You get a call about an increase in Serratia marcesans cases in an acute care hospital. The bacteria has been isolated from urine, blood, and sputum cultures among diseased patients. The increase in cases is most evident in the hospital s OR, which has 2 surgical suites (OR 1, OR 2). Upon interview, the hospital nursing staff in OR 1 mentioned that there has been recent construction to install new water pipes into OR 1 which may be the cause of the increase in cases. How can you test whether recent construction is How can you test whether recent construction is playing a role?

57 Cohort Study: Example Sick Well Total OR OR Total Testing for association between exposure and illness Uses relative risk

58 Cohort Study: Example Sick Well Total OR OR Total Testing for association between exposure and illness Uses relative risk RR = (33/187)/(15/178) = 0.176/0.084 = 2.10 How do you explain this to Hospital Administration?

59 Adjust Prevention and Control Measures The investigation progresses and narrows the source of disease Fine tune your prevention and control measures to fit with the updated information Do not wait to adjust for this step, this can be done throughout as new information comes in Evaluate effectiveness through surveillance

60 Steps to an Outbreak Investigation EARLY PHASE Make required notifications Brief the team/prepare for field work Confirm the suspected outbreak Verify the diagnosis Declare an outbreak Develop preliminary hypothesis Implement initial control & prevention measures Communicate with stakeholders MIDDLE PHASE Define cases Identify and track cases Interview cases Create line lists Describe the data Evaluate your hypothesis Adjust control & prevention measures LATE PHASE Declare outbreak over Report/communicate findings Review lessons learned

61 Declare the Outbreak Over When is an outbreak considered over? a. When you re over it b. No case is reported within one incubation period of the disease in question c. No case is reported within two incubation periods of the disease in question d. No case is reported within three incubation periods of the disease in question

62 Declare the Outbreak Over Outbreak is over when no case is reported within two incubation periods of the disease in question Can vary greatly by disease Allow for delays in reporting Consult with NJDOH if questions arise

63 Report and Communicate Findings Provide an oral briefing to your outbreak team; might have to include the media also Provide a written final report Summary of findings Actions taken to stop disease transmission Recommendations Must be submitted to NJDOH within 30 days of outbreak completion

64 Review Lessons Learned Take this time to look back on the investigation to see what went well and what needs to be improved upon Every new outbreak is a learning experience as every outbreak is different

65 Lessons Learned Which of the following would NOT be a good question to ask in reflecting on lessons learned from an outbreak? a. Which methods worked well? b. Who can we blame for all the problems we faced? c. What mistakes were made and how can they be prevented in the future? d. How successfully was the communication flow maintained? e. Who will be responsible for making sure the recommended e changes will be implemented? e

66 Steps to an Outbreak Investigation EARLY PHASE Make required notifications Brief the team/prepare for field work Confirm the suspected outbreak Verify the diagnosis Declare an outbreak Develop preliminary hypothesis Implement initial control & prevention measures Communicate with stakeholders MIDDLE PHASE Define cases Identify and track cases Interview cases Create line lists Describe the data Evaluate your hypothesis Adjust control & prevention measures LATE PHASE Declare outbreak over Report/communicate findings Review lessons learned

67 Example Outbreak Situations

68 Example 1: Outbreak of Illness in a Long-term Care Facility The call: Long-term care facility 3 of 47 residents ill on one unit Symptoms include vomiting, diarrhea, low grade fever What else do you want to know?

69 Example 1: Outbreak of Illness in a Long-term Care Facility Update: You reported to NJDOH and received guidance doc for LTC GI outbreaks Symptoms resolve in 1-2 days Now 18 of 47 residents, and 2 staff members on that unit, ill or recovered Stool samples from three residents come back positive for norovirus What should you do next?

70 Example 1: What Control Measures Should You Recommend? Require all staff to wear face masks Have staff clean facility with bleach Close dining room and other common areas Require staff to clean hands with sanitizer Post notices for family visitors Restrict new inpatient admissions Restrict resident diets to all-bran

71 Example 2: Illness in a Daycare Center The call: 4 children with fever, malaise, sore throat, and mouth ulcers. First case last week, then 3 additional cases this week What else do you want to know?

72 Example 2: Illness in a Daycare Center Updated information: Ill children from two different adjoining classrooms Currently ill children excluded from school Children have been diagnosed with coxsackievirus What should you do next?

73 Example 2: What Control Measures Should You Recommend? Exclude all cases from school until no fever/mouth sores Review good hand washing techniques with school Clean and disinfect all changing g tables, pay extra attention to cleaning before and after use Send notices home identifying the affected students Stress routine cleaning of toys, classrooms, nap areas, before snacks Close the daycare center until all cases have healed Refuse to change diapers

74 Example 3: Pneumonia in a Nursing Home The call: One case of pneumonia diagnosed by x-ray Urine antigen came back positive for Legionella Facility had a confirmed case of Legionella 3 years ago What else do you want to know?

75 Example 3: Legionella in a Nursing Home Updated Information: Case was severely compromised before diagnosis Case did not leave the facility at any point Facility recently underwent construction of patient wing What should you do next?

76 Example 3: What Control Measures Should You Recommend? Have the facility hire a water consultant with previous experience in Legionella remediation Have the facility take water samples of all faucets, showers, and any fountains in the building Send those samples to PHEL for analysis Have the facility use bottled water only for drinking Require the facility to be on active surveillance for new cases of pneumonia Recommend flushing to prevent dead legs in piping Tell the facility that if they conduct remediation there is no chance that Legionella can ever return to their facility Have the facility add in-line shower filters and remove aerators from sinks