TB-425_Infectious_Period_Calculation_April_2020v2.pdf

Publication # TB-425 Revised 4/2020 Page 1 of 2

TUBERCULOSIS INFECTIOUS PERIOD CALCULATION SHEET

This calculation sheet is designed to estimate the time a client with suspected or confirmed tuberculosis (TB) disease is capable of transmitting TB to others. Identifying the infectious period establishes a point in time to focus contact investigation efforts including evaluating exposed persons at risk of progressing to TB infection or disease.

Patient’s name: _______________________________ Date of birth: ________________

Completed by: ________________________________ Title: _______________________

Phone #: _____________________________________ Date completed: _____________

Table 1. Estimating the Date of Symptom Onset Symptom Yes No Duration Onset Date

Cough Cough with blood Weight loss Night sweats Chest pain Loss of appetite Fever Chills Other (i.e., shortness of breath & fatigue)

Table 2. Estimating the Beginning of the Infectious Period

A. Criteria B. Estimated Start of Infectious Period

Select any of the following based on criteria met by client in Column A

C. Infectious Period Start Date

Select earliest date of symptom onset listed in Table 1

TB

Symptoms

Positive AFB Sputum or other respiratory specimen

Cavitary

CXR

Yes Yes Yes Three (3) months before symptom onset or first positive finding consistent with TB disease (e.g.

abnormal chest radiograph) whichever is longer.

Yes Yes No

Yes No No

No Yes Yes Three (3) months before first positive finding consistent with TB

No No No Four (4) weeks before date of suspected diagnosis

Source: Adapted from MMWR. 2005; 54 (No. RR-15)

Publication # TB-425 Revised 1/2017 Page 1 of 2

TUBERCULOSIS INFECTIOUS PERIOD CALCULATION SHEET

This calculation sheet is designed to estimate the time a client with suspected or confirmed tuberculosis (TB) disease is capable of transmitting TB to others. Identifying the infectious period establishes a point in time to focus contact investigation efforts including evaluating exposed persons at risk of progressing to TB infection or disease.

Patient’s name: _______________________________ Date of birth: ________________

Completed by: ________________________________ Title: _______________________

Phone #: _____________________________________ Date completed: _____________

Table 1. Estimating the Date of Symptom Onset Symptom Yes No Duration Onset Date

Cough Cough with blood Weight loss Night sweats Chest pain Loss of appetite Fever Chills Other (i.e., shortness of breath & fatigue)

Table 2. Estimating the Beginning of the Infectious Period

A. Criteria B. Estimated Start of Infectious Period

Select any of the following based on criteria met by client in Column A

C. Infectious Period Start Date

Select earliest date of symptom onset listed in Table 1

TB

Symptoms

Positive AFB Sputum or other respiratory specimen

Cavitary

CXR

Yes Yes Yes Three (3) months before symptom onset or first positive finding consistent with TB disease (e.g.

abnormal chest radiograph) whichever is longer.

Yes Yes No

Yes No No

No Yes Yes Three (3) months before first positive finding consistent with TB

No No No Four (4) weeks before date of suspected diagnosis

Source: Adapted from MMWR. 2005; 54 (No. RR-15)

Publication # TB-425 Revised 4/2020 Page 2 of 2

Table 3. Estimating the End of the Infectious Period (Release from Respiratory Isolation) for clients with drug susceptible TB

A. Criteria B. Check (√) when criteria is met

C. Infectious Period End Date Type the date the selected criteria in Column A was met.

When patient has

POSITIVE AFB

sputum smear at diagnosis

1. Three (3) consecutive negative AFB sputum smears, collected in 8 to 24 hour intervals (one should be an early morning specimen)

2. Symptomatic improvement

3. Effective multi-drug therapy for tuberculosis for at least the equivalent of two weeks given as directly observed therapy (DOT)

4. Completely adherent with DOT

When patient has three consecutive

NEGATIVE AFB

sputum smears at diagnosis and has never had a positive sputum specimen

1. Three (3) consecutive negative AFB sputum smears, collected in 8 to 24 hour intervals (one should be an early morning specimen)

2. Symptomatic improvement

3. Multi-drug therapy for tuberculosis for at least 5 days given as DOT

4. Completely adherent with DOT

5. Drug resistance is not suspected or confirmed

Date on Table 2, Colum C Date on Table 3, Colum C

TB PREVENTION AND CARE RECOMMENDATIONS BASED ON ESTIMATED

INFECTIOUS PERIOD

• Implement home-based respiratory isolation for clients adherent to medical treatment.

• House clients in a negative pressure air-borne infection isolation room (AIIR) room if in a congregate setting (e.g. hospital, nursing home, jail, homeless shelter) or seek an alternative facility if an AIIR is not available.

• Request a “medical hold” for the client if transfer to a congregate setting without an AIIR is anticipated during the infectious period.

• Monitor the general medical and mental health of the client and ensure he or she has the opportunity to make health needs, including possible side effects from the TB regimen, known on a daily basis.

• Focus TB contact investigation efforts on identifying and screening persons exposed to the client during the infectious period.

• Discontinue respiratory isolation when the infectious period ends.

• Consult with a TB expert to determine when clients suspected or known to have drug resistant TB may be released from isolation.

5. Drug resistance is not suspected or confirmed

Source: Adapted from MMWR. 2005; 54 (No. RR-12)

Estimated Infectious Period: From _________________ to ____________________

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