Infectiousness

1
Infectiousness

• Number of tubercle bacilli expelled into air
  determines patient's infectiousness
• factors include
• Site of disease
• Severity of disease
• Frequent coughing (or cough-inducing procedure)
• Presence of AFB on sputum smear
• Status of treatment
• Age
• Drug resistance

2
Infectiousness (2)

• Patient considered non-infectious when all are
  true
• gt 2 weeks of adequate therapy
• Significant clinical improvement
• Three consecutive negative sputum smears
  collected on three different days

3
Infectiousness (3)

• Monitoring patients
• Many patients become non-infectious within 24
  weeks of treatment
• Patient who is not clinically improving
• may not be taking all prescribed drugs
• may have drug-resistant TB

4
Infection Control

• Infection control
• TB can be spread in
• homes
• worksites
• group living facilities
• healthcare facilities
• High-risk environments small or crowded rooms
  and poorly ventilated areas
• Infection control procedures and policies that
  monitor and try to control the spread of TB

5
Infection Control (2)

• A. Infection control (cont)
• Goals of infection control program early
  detection, isolation, and treatment of persons
  with infectious TB
• Isolation physical separation of infectious
  patients from others to prevent or limit
  transmission of disease
• Isolation room special room designed and
  equipped to prevent the spread of TB droplet
  nuclei

6
Infection Control (3)

• B. Three types of infection control
• Administrative controls reduce risk of exposing
  uninfected persons to persons with infectious TB
• written policies and guidelines on detecting,
  evaluating, and isolating suspected TB cases
• health workers educated and trained to prevent
  spread of TB
• regular screening and TSTs for health workers

7
Infection Control (4)

• B. Three types of infection control (cont)
• Engineering controls prevent the spread and
  reduce number of infectious droplet nuclei
• ventilation systems maintain negative pressure
  in isolation and sputum induction rooms
• HEPA filters remove droplet nuclei from air
• UV lamps
• - kill tubercle bacilli
• - specially placed to avoid harming skin or eyes

8
Infection Control (5)

• B. Three types of infection control (cont)
• Personal respiratory protection
• personal respirators special masks worn by
  health workers to filter out droplet nuclei
• advantages
• - can greatly reduce exposure
• - can help patient understand seriousness of
  infectiousness

9
Infection Control (6)

• B. Three types of infection control (cont)
• disadvantages
• - can make patient feel stigmatized
• - can jeopardize confidentiality if worn in
  public
• - can make communication difficult

10
Surveillance

• Definition ongoing collection and analysis of
  health data for public health programs
• First step identify suspected or confirmed TB
  cases
• Routine case reporting
• Healthcare provider or institution must report a
  suspected or confirmed TB case to public health
  authority

11
Surveillance (2)

• Active case finding
• Contact investigation
• Reviewing lab and pharmacy records
• Regular networking with staff in other settings
  who serve clients at high risk for TB
• Surveillance data
• Keeps track of places and groups affected by TB
• Allows appropriate interventions to be planned
  and conducted

12
Case Management

• A. Definition
• Primary responsibility for coordinating patient
  care to ensure that medical, psychological, and
  social needs are met
• Assignment of individual or team to be primarily
  responsible for patient's care

13
Case Management (2)

• B. Goals of TB case management program
• Make patient non-infectious
• Promptly start effective treatment
• Prevent disease from getting worse
• Identify and remove barriers to adherence
• Provide patient with information on TB and its
  treatment
• Identify individuals who may have been exposed
  and are at risk for infection
• Identify and address other health and/or related
  needs

14
Case Management (3)

• C. Role of case manager or team is to assure
  that
• 1. Patient is educated about TB and its treatment
• 2. Therapy is appropriate, continuous, and
  completed
• 3. Patient's ongoing status and response to
  therapy is monitored until treatment is complete
• 4. Contacts are identified, evaluated, referred,
  and monitored

15
Case Management (4)

• C. Role of case manager or team is to assure
  that (cont)
• 5. Other urgent health and social needs are
  addressed
• 6. Staff have adequate knowledge and skills, and
  a professional, caring attitude
• 7. Communication is maintained among all health
  and social service providers

16
Case Management (5)

• D. Steps in case management
• 1. Receive case report and decide on urgency
  (1 day)
• 2. Contact care provider (13 days)
• 3. Initial contact with patient by home visit or
  in hospital (37 days)
• 4. Ongoing visits during patient's treatment (at
  least monthly)
• 5. Follow-up on completion of treatment
  activities
• 6. Conduct contact investigation to prevent
  spread of TB disease

17
Risk Assessment

• A. What influences the infectiousness of a
  patient?
• Laryngeal or pulmonary TB
• Sputum smear-positive
• Cavitary disease on chest radiograph
• Cough
• Positive culture for M. tb

18
Risk Assessment (2)

• B. What environments are high-risk for TB
  transmission?
• Small or crowded rooms
• Poorly ventilated areas
• Areas without air-cleaning systems
• High-risk sites correctional facilities,
  shelters, nursing homes, and hospitals

19
Risk Assessment (3)

• C. What type of exposure increases a contact's
  risk for TB transmission?
• Frequent time spent with patient during
  infectious period
• Close physical proximity to patient during
  infectious period

20
Contact Investigation

• A. Contact investigation
• Procedure for identifying people ("contacts")
  exposed to infectious person
• Contacts are evaluated for LTBI and TB disease,
  and given treatment, if needed
• Important for stopping transmission of TB
  infection and disease
• B. "Index patient" or "index case" person
  initially reported to health department with
  suspected or confirmed TB

21
Contact Investigation (2)

• C. Contact investigation not performed if
• Extrapulmonary TB (not infectious)
• Index patient is young child (rarely infectious)
• If young child has TB infection or disease,
  source case investigation is conducted to find
  source of transmission

22
Contact Investigation (3)

• D. Contact investigation involves 3 types of
  places
• 1. Household or residence
• 2. Work or school
• Leisure or recreational environments
• E. Use concentric circle approach to identify
  and evaluate contacts in order of priority

23
Concentric Circle Approach
Household/Residence Environment
Other-than-close
Lower Priority
Close Contacts
High Priority
Close Contacts
Index Patient
Close Contacts
Lower Priority
Lower Priority
High Priority
High Priority
Other-than-close
Other-than-close
Leisure/Recreation Environment
Work/School Environment
24
Contact Investigation (4)

• Social networking
• Social networking strategy used if concentric
  circle approach is not adequate for identifying
  contacts
• Focuses on groups with connections in patient's
  life that promote disease transmission,
  including
• drug use
• common sex partners
• common gathering places

25
Contact Investigation (5)

• Social networking (cont)
• Cluster interview another technique to identify
  contacts
• definition planned interview with someone
  knowledgeable about index patients activities
• person may reveal possible places of transmission
  that patient is reluctant to disclose

26
Contact Investigation (6)

• Cluster interview another technique to identify
  contacts (cont)
• may widen or narrow investigation and help to
  confirm or disprove patient's statements
• only Health Officer or his/her designee, with
  explicit approval of index patient, can breach
  confidentiality

27
Contact Investigation (7)

• Nine steps in contact investigation
• Determining period of infectiousness review
  patient's medical record
• Interviewing patient
• Field investigation visiting patient's home,
  work, etc.
• Risk assessment analyzing information about
  infectious period, environmental characteristics,
  and exposure to determine who is most at risk for
  TB transmission
• Decision about priority of contacts

28
Contact Investigation (8)

• Evaluation of contacts for LTBI and TB disease
• Everyone TST and medical histories
• Immunocompromised persons and children lt 4 years
  chest radiograph, regardless of TST results
• Person with symptoms and/or TST reaction
  classified as "positive" chest radiograph and
  sputum exam
• Contacts with no TST reaction re-test
  1012 weeks after exposure to infectious TB
  patient is broken

29
Contact Investigation (9)

• Treatment and follow-up for contacts
• Positive TST reaction and no evidence of TB
  disease usually LTBI treatment
• Immunocompromised persons and young children with
  no TST reaction
• begin LTBI treatment until second TST
• if second TST shows no reaction, stop treatment
• in some cases, treatment may continue

30
Contact Investigation (10)

• Positive sputum or chest radiograph suggesting
  active TB begin treatment for TB disease
  immediately
• Decision about whether to discontinue or expand
  testing
• Test in order of priority, using concentric
  circle approach

31
Contact Investigation (11)

• Decision about whether to discontinue or expand
  testing (cont)
• Screen next group of contacts if evidence of
  recent transmission found in first group
• high infection rate
• TB infection in young child
• documented TST conversion
• secondary case of TB disease

32
Contact Investigation (12)

• Evaluation of contact investigation activities
• Analyze contact investigation results to
  determine if appropriate contacts were
  identified, located, evaluated, and treated

33
Adherence

• Definition following recommended course of
  treatment by taking all prescribed medications
  for entire time necessary
• Consequences of not adhering to treatment
• Increases drug-resistant TB
• Contributes to ongoing transmission
• Leads to prolonged illness, disability, and
  possibly death

34
Adherence (2)

• Why is adherence so challenging?
• Patient no longer feels sick, but must continue
  medication
• Lack of TB knowledge
• Personal or cultural beliefs about TB
• Forgetfulness
• Lack of access to healthcare
• Language barriers

35
Adherence (3)

• Why is adherence so challenging? (cont)
• 7. Poor relationship(s) with health worker(s)
• 8. Cultural barriers between patient and health
  worker(s)
• 9. Lack of motivation
• Medication side effects
• Complex regimen

36
Adherence (4)

• Why is adherence so challenging? (cont)
• Competing priorities (housing, access to drugs,
  etc.)
• Conflicts with work and school schedules
• Other medical conditions and medications

37
DOT

• Definition
• Health worker or other designated individual
  watches patient swallow every dose of prescribed
  TB drugs
• ATS and CDC recommend every patient be considered
  for DOT

38
DOT (2)

• DOT tasks
• Check for side effects
• Verify medication
• Watch patient take pills
• Document visit

39
DOT (3)

• Who can deliver DOT?
• TB program personnel (usually)
• Staff at other healthcare settings
• Other responsible persons
• NOT family members

40
DOT (4)

• Where is DOT delivered?
• Clinic or other healthcare facility
• Patients home
• Patients workplace
• School
• Public park, restaurant, or other agreed-upon
  location

41
DOT (5)

• Can we reliably predict who will be non-adherent
  to treatment?
• NO!
• Anyone can be non-adherent, regardless of
• Social class
• Educational background
• Age group
• Gender
• Ethnicity

42
DOT (6)

• Which patients are highest priority for DOT?
• Drug-resistant TB
• Prior treatment failure
• HIV-positive
• Homeless
• Substance users
• Children/adolescents
• Foreign-born, recent arrivals, or anyone with
  language barriers

43
DOT (7)

• Which patients are highest priority for DOT?
  (cont)
• 8. Persons with mental/physical disabilities
• 9. Patients failing on therapy
• Patients who give reason to doubt adherence
• Patients on intermittent therapy

44
Review Questions

• What are three factors that can determine the
  infectiousness of a TB patient?
• Describe each of the following types of infection
  control
• Administrative controls
• Engineering controls
• Personal respiratory protection

45
Review Questions (2)

• Which of the following is NOT a major step
  involved in TB case management?
• Contact patients care provider
• Train staff about infection control
• Home or hospital visit with patient
• Contact investigation

46
Review Questions (3)

• Which of the following groups should receive high
  priority for targeted testing?
• Close contacts of persons known or suspected to
  have TB
• Foreign-born persons from areas that have high
  rates of TB
• Residents and employees of high-risk settings
  (correctional facilities, nursing homes, mental
  institutions, homeless shelters, etc.)
• All of the above

47
Review Questions (4)

• Name three of the nine steps involved in a
  contact investigation
• What are four reasons a patient might be
  non-adherent to his/her TB treatment?
• Explain the role of DOT in patient adherence
• List three groups of TB patients who are the
  highest priority to receive DOT