Alaska Tuberculosis Program Manual - Epidemiology - State of Alaska

In general, for the purposes of contact investigation, the infectious period is closed
when exposure to contacts has ended OR when all three of the following criteria are
met:
1. The index patient is receiving effective treatment (as demonstrated by
Mycobacterium tuberculosis susceptibility results) for at least two weeks.
2. The index patient has diminished symptoms.
3. The index patient has three (3) sputum-smears that are (-) for acid fast bacilli. 32,33
Take careful note of the following exceptions:
Multidrug-resistant TB (MDR-TB): MDR-TB can extend infectiousness if the
treatment regimen is ineffective.
Signs of infectiousness: Any index patient with signs of extended infectiousness
should be continually reassessed for recent contacts.
Susceptible contacts: Apply more stringent criteria for setting the end of the
infectious period if particularly susceptible contacts are involved. (HIV infection, child
under 5 years of age, immunosuppression, underlying disease processes).
Please consult the Alaska TB Program at 907-269-8000 when clearing
patients for travel or return to group settings.
Generally, a patient may be cleared to travel, return to a congregate living setting or
to any setting in which susceptible persons might be exposed all three of the
following criteria for noninfectiousness have been met: 34
1. Has been on antituberculosis therapy for at least two weeks;
2. Exhibits clinical improvement; and
3. Has at least three consecutive negative AFB sputum smear results from
sputum collected more than eight hours apart (with one specimen collected
during the early morning).
A L A S K A T U B E R C U L O S I S P R O G R A M M A N U A L Contact Investigation 11.22
Revised November 2012