1 Detection and Response to Infectious Disease Outbreaks H5N1 as a case-study Daniel S. Miller MD, MPH International Influenza Unit U.S. Department of Health Human Services

2 Detection Requires timely and quality information to be collected at local levels by trained personnel about possible occurrence of severe acute respiratory illness Requires rapid reporting to a more central authority for epidemiologic assessment, investigation, and possible response by specifically trained personnel Requires adequate laboratory capabilities to identify or confirm H5N1

3 Case Investigation Objectives Confirm or exclude H5N1 virus infection Reduce morbidity and mortality through rapid identification, isolation, treatment, clinical management of cases and follow-up of contacts Reduce further spread of H5N1 virus infection through identification of exposure sources and implementation of control measures Determine if cases or cluster of cases represent the beginning of a potential pandemic

4 Overview of the Steps of a Case Investigation  Pre-Investigation  Planning the Response  Investigation  Case definitions  Specimen collection  Case finding  Interviewing  Contact identification  Post-Investigation  Evaluate performance  Data collection  Data management  Data analysis  Assessing transmission  Reporting  Writing a summary report

5 When to Initiate Investigations? Cases of severe acute respiratory infection with a possible link to AI Any case meeting WHO suspect, probable or confirmed case definition. SARI cases in workers in poultry industry Association with sick or dying poultry or wild birds History of travel within the last 10 days to an area or region known to have circulating avian influenza Photo: Tony Mounts, CDC

6 Triggers without H5N1 Link Cases in Health Care Workers who care for patients with SARI or pneumonia Clusters of 2 or more SARI cases in a 2 week period –2 people in a family –Cases in a small geographic area –Cases with social or occupational connection Increases in cases at a hospital compared to the same time in previous years Change in the epidemiology of cases

7 Poultry events: excessive deaths Rumors from informal data sources – news media – information hotlines Other Triggers for Investigation Photo: Diane Gross, CDC

8 Pre-Investigation: Plan the Response Convene rapid response team (RRT) Possible roles and responsibilities –Team leader –Epidemiologists –Medical officer –Veterinary officer –Laboratory scientist –Communications specialist –Logistician –Data Manager Photo: Tim Uyeki, CDC

9 An important resource for H5N1 case investigations

10 WHO Suspected Case Exposures: Close contact (within 1 meter) with a person who is a suspected, probable, or confirmed H5N1 case; –caring for, speaking with, or touching Exposure to poultry or wild birds or their remains or to environments contaminated by their feces in an area where H5N1 infections in animals/humans have been suspected/confirmed in the last month –handling, slaughtering, defeathering, butchering, preparation for consumption) Consumption of raw or undercooked poultry products Close contact with a confirmed H5N1 infected animal other than poultry or wild birds –e.g. cat, dog, or pig Handling samples (animal or human) suspected of containing H5N1 virus in a laboratory or other setting.

11 Why is Case Finding Important?  Identify all possible cases in a community  Treat affected persons, determine exposure sources, and prevent further transmission  May provide information about potential human-to-human transmission  Obtain information on cases related in time and location to other cases or clusters

12 Active Case Finding Attempt to identify additional cases beyond known cases and close contacts –Persons who may have been exposed to the same H5N1 source as the case –Persons with bird/animal exposures or healthcare workers caring for H5N1 patients –Persons with unexplained acute lower respiratory infection with fever or persons who died of an unexplained acute respiratory illness

13 How to Find Cases Active case finding:  Refer/obtain respiratory specimens for H5N1 testing from suspected cases  Refer suspect cases for medical care Cases should be sought in the area where a case has occurred  Consider house-to-house searches, visits to health care facilities, private practitioners, traditional healers, laboratories Photo: Diane Gross, CDC

14 How to Find Cases Passive case finding:  Routine surveillance  Rumor hotlines Public information messages in the affected communities  Can be “enhanced” with refresher trainings etc…

15 Enhanced Surveillance  Enhance routine surveillance in areas where H5N1 cases live or where animal outbreaks are occurring  Consider active surveillance in hospital in-patient units and emergency rooms; traditional healers, private practitioners, private laboratories; active surveillance of health care workers, persons exposed to birds/animals  Duration of enhanced surveillance is a minimum of 2 weeks after the last human H5N1 case is identified (2 incubation periods)  Enhanced surveillance may need to be maintained for longer periods if H5N1 poultry outbreaks are not controlled

16 What is Contact Tracing? The identification and diagnosis of persons who may have been in close contact with an infected individual during the infectious period

17 Risk Stratification: Based on Exposures High risk exposure –(e.g. household or close family contacts) Moderate risk exposure –(e.g. other exposed persons who were not wearing appropriate PPE) Low risk exposure –(e.g. unexposed persons or those wearing appropriate PPE) * WHO Rapid Advice Guidelines on pharmacological management of humans infected with avian influenza A (H5N1) virus

18 Why Use Risk Stratification? Helps prioritize limited human and non- human resources Provides a rational a priori explanation for who will, and will not, receive limited resources. Is used in the World Health organization’s recommendations on post-exposure antiviral chemoprophylaxis

19 Monitoring and Managing Contacts Actively monitor (daily) contacts for signs of illness for 7 days after exposure to a case or to infected birds –Encourage self-health monitoring –Instruct to report onset of symptoms –Visit or phone daily to monitor for illness –Refer contacts with fever and respiratory illness to medical care, isolation, treatment; obtain respiratory specimens for H5N1 testing Request voluntary home quarantine of all contacts for 7 days post exposure Consider antiviral chemoprophylaxis, if available

20 Prioritize Contact Identification If number of contacts is large, focus on: –Contacts of probable and laboratory confirmed H5N1 cases –Contacts with prolonged close exposures to a suspected H5N1 case (e.g. household contacts sharing the same sleeping and eating space, persons providing bedside care)

21 Inform ‘Those who Need to Know’ Local Level: who is responsible for submitting H5N1 case reports? When should this be done? National Level: who needs to be updated on the progress of the investigation and receive the final report on number of H5N1 cases? Who is responsible for assuring that this occurs? International Level: Probable, and confirmed H5N1 cases should be reported immediately to WHO. The Ministry of Health will be responsible for notifying WHO.

22 Prevention and Control Activities Animal health: implementation of culling, disinfection, surveillance, poultry vaccination Infection control –Isolation of suspected and confirmed cases –PPE, proper infection control precautions Treatment of ill patients Contact tracing –Antiviral chemoprophylaxis of high-risk groups –Active surveillance of contacts for illness –Voluntary quarantine of well contacts Implementation of active surveillance and enhanced case finding

23 Why communicate the findings? A document for action -Control and prevention measures To share new insights To obtain national and international resources Documents the investigation To assist other nations districts or countries with investigation Inform the public -Prevents future outbreaks

24 Infection Control Measures All interventions should be used in combination with infection control measures including: –Hand hygiene –Cough etiquette –Environmental cleaning –Personal protective equipment such as face masks

25 Non-pharmaceutical interventions (NPIs) –Measures other than vaccines and antivirals that may reduce the risk of transmission of influenza to individuals and communities –NPIs can be implemented at borders, or at the level of the community and the individual What are NPIs?

26 Examples of NPIs PurposePotential NPI Limit spread across borders Travel screening and entry/exit restrictions Reduce spread within national/local populations Social distancing; quarantine of exposed; isolation Reduce an individual person's risk Personal protective measures (e.g., masks) Communicate risk to the public Public health communication campaign

27 Other Definitions I Isolation –Separation or restriction of movement of persons ill with an infectious disease in order to prevent transmission to others Quarantine –Restriction of persons who are not ill but presumed exposed, usually in the home or a designated facility Social Distancing –Measures to increase the space between people and decrease the frequency of contact among people

28 Other Definitions II Infection Control –Hygiene and personal measures to reduce the risk of transmission of an infectious agent from an infected person to uninfected persons Containment –Efforts undertaken to confine early cases of pandemic influenza to a geographic area or population Mitigation –Efforts undertake to lessen the impact of pandemic influenza on the community Cluster –A laboratory confirmed index case and at least one laboratory confirmed epidemiologically-linked case

29 During the first few months after a pandemic begins: –Vaccine made from a pandemic strain will probably not to be available –Antivirals may be insufficient in quantity, ineffective and/or difficult to distribute in a timely way In many countries of the world, it may be some time before either vaccine or antivirals are available in sufficient quantity Why are NPIs being considered?

30 What are the Goals of Community-based NPIs? 1. Delay disease transmission and outbreak peak 2. Decompress peak burden on healthcare infrastructure 3. Diminish overall cases and health impacts Daily Cases # 3 Days since First Case Pandemic outbreak with no intervention Pandemic outbreak With intervention # 2 # 1