Disease Outbreaks Steps of Investigation Dr.Kedar Karki Steps of Investigation Steps of Investigation         Receiving Reports Confirming/Defining Cases Investigating Implementing Controls Managing Cases Managing Contacts Analyzing Effectiveness of Controls Reporting Step 1 Receiving Reports  Goals Protection Reduced exposure Limited spread What Illnesses are Reportable? Summary on N. C. Report Card: Bold Italics Within 24 Hours All Others Within 7 Days Who Must Report?     Physicians Medical and laboratory facilities Local health directors School principals and day care operators Immunity of Persons Who Report A person who makes a report pursuant to the provisions of the law shall be immune from any civil or criminal liability that might otherwise be incurred or imposed as a result of making that report. Confidentiality of Records All information and records, whether publicly or privately maintained, that identify a person who has AIDS virus infection or who has or may have a disease or condition required to be reported pursuant to the provisions of the law shall be strictly confidential... How Do You Insure that Reporting Occurs?    Encourage communication within healthcare community Build relationships with local providers Educate, educate, educate!!! Example: Reporting Pertussis  Bold italics Reportable within 24 hours of diagnosis (even suspicious of disease) . Step 2 Confirming and Defining Cases  Lab Confirmation test time method handling Appropriate Appropriate Appropriate Appropriate Confirming and Defining Cases  Case Definition Clinically compatible case: symptoms fit the clinical presentation of disease Confirmed case: clinically compatible and either lab confirmed or epi-linked Probable case: meets the clinical case definition and is not lab confirmed or epi-linked  Case Definition-continued Suspect case: person whose medical history and symptoms suggest infection Lab-confirmed case: one or more laboratory diagnosis methods present positive results Epi-linked case: patient has had contact with a diseased person Defining a Case  Gather disease specific information     Type of symptoms Duration of symptoms Exposure to someone with like symptoms Laboratory diagnostics Significance of Case Definition  If you don’t have lab results to confirm a case, use the case definition to see if the symptoms rise to a level of suspicion …or Or…..  If symptoms are intense and yet lab results show (perhaps a “false”) negative, you might still call it a case, based on case definition standards having been met Example: Pertussis...  Clinical Case Definition: Cough illness lasting at least 2 weeks with one of the following: Paroxysms of coughing … or Inspiratory “whoop” … or Post-tussive vomiting And without other apparent cause (as reported by health professional) Example: Pertussis...  Confirmed Case: An acute cough illness of any duration associate w/ B. pertussis isolation, …or A case that meets clinical case definition and is confirmed by PCR, …or A case that meets clinical definition and is epi-linked to a case confirmed by culture Example: Pertussis...  Probable Case: Meets clinical case definition, Is not lab confirmed, and Is not epi-linked to lab confirmed case. Step 3 Investigation  Local Health Director shall investigate... cases of communicable diseases and conditions reported to the local health director. Investigation  Determine if illness warrants investigation: Identify other similar cases previously or currently reported Determine if illness can be considered transmissible person to person. Investigation  Determine if reported case is one for which every case will be investigated Determine if reported case is similar to other reported cases   Determine if reported case is in a special high-risk population Investigation   Determine if diagnosis of illness has been made Determine if reported case has appropriate diagnostic labs, or meets case definition, or is epi-linked Investigation   Inform appropriate individuals and/or organizations of investigation activities Determine message to be relayed to individual and/or organization Example: Pertussis     Disease transmits person to person Every case is to be investigated Have you had other recent cases? Is this case epi-linked? Is this case or are contacts a high risk group? High Risk for Pertussis        Infants <1 year Close contact of infant Day care w/ young children Immunodeficient Health Care Worker-direct patient care Baby sitter Woman who is pregnant Step 4 Implementing Controls The local health director has the authority and responsibility to implement control measures to prevent the spread of reportable communicable disease... The Local Health Director has...  The authority to… Isolate  The authority to... Quarantine  Allcomply with control measures, including Persons... Shall submission to examinations, and tests, prescribed by the Commission subject to the limitations of G. S. 130A-148 Control of Communicable Diseases Manual (American Public Health Association) is codified in N.C. General Statutes as the requirements for control measures.  Do you really want to wait? Getting Started...     Report in a timely manner All facilities - hospitals, doctor’s office, school, college infirmary or child care nurse, report to local health department immediately Time is of the essence to interrupt the spread of disease Don’t wait for Lab confirmation Your Local Health Director Involve the Health Director early An Epi Team    Notify and involve early Many steps need to be taken in a short period of time Epi-Team is critical to meeting the needs Step 5 Managing Cases  Ensure that case is appropriately managed in order to prevent transmission of illness Managing Cases   Determine if still infectious-obtain lab confirmation While awaiting lab results, assume this is a case if illness meets case definition Follow guidelines in Control of CD Manual to: Require personal practices to prevent transmission Require medical treatments to prevent transmission  Example: Pertussis  Confirmatory LabsDFA (smear) Culture PCR (Polymerase Chain Reaction) Example: Pertussis   Isolate-remove from presence of young children/infants until case receives 5 days of minimum of 14-day Rx of antibiotic Without Rx with antibiotic, isolate for 3 weeks from cough on set Step 6 Managing Contacts   Identify individuals at risk of infection as a result of exposure to known source Ensure that contacts identified receive appropriate preventive treatment and that appropriate surveillance of contacts is conducted Managing Contacts    Determine if contact is susceptible to infection to which exposed Identify nature and duration of exposure Determine if exposure is likely to have resulted in transmission of agent Managing Contacts    Determine if contact is currently in another public health jurisdiction If so, inform appropriate public health authority Determine if contact is infected or ill. If so, manage as case Inform contact about a) exposure b) incubation period c) Signs/symptoms d) Seek medical attention and contact public health authority if becomes ill Managing Contacts-continued Determine if contact should be placed under active surveillance  Follow guidelines for contact management in Control of CD Manual or current CDC recommendations  Example: Pertussis    Inadequately immunized household contacts <7 years should be excluded for 21 days after last exposure or until received 5 days of 14 day treatment of antibiotic Immunize by guidelines A 14-day course of erythro. For household and close contacts regardless of vaccine Hx and age Step 7 Analyze Effectiveness of Controls   Determine if there are any additional cases which meet clinical and/lab criteria of case definition If additional cases identified, determine if onset occurred after last date cases should have occurred-? controls Analyze Effectiveness of Controls    If case occurred beyond last date cases should have occurred, determine if case resulted from exposure to or acquired from 1) original source 2) any original contacts Assess application of controls Determine if changes in investigation or management of cases or contacts should have occurred Step 8 Reporting the Event   Call Regional Immunization Consultant as soon as case reported to LHD Complete surveillance form required for reportable disease