Module 6 Contact Investigations for Tuberculosis Page 12 of 40 |
The Period of Infectiousness | |
Determining the period of
infectiousness can help focus the contact
investigation efforts on those persons who were
exposed while the patient was
infectious. The beginning of the infectious period is usually estimated by determining the date of onset of the patient's symptoms (especially coughing). |
The period of infectiousness is the time period during which a person with TB disease is capable of transmitting M. tuberculosis. Determining the period of infectiousness can help focus the contact investigation efforts on those persons who were exposed while the patient was infectious. There is no universal, well-established method to determine the period of infectiousness. The beginning of the infectious period is usually estimated by determining the date of onset of the patient's symptoms (especially coughing). Sometimes when it is difficult to obtain a reliable history from the patient about the onset of symptoms, the beginning of the infectious period is estimated to be earlier than the onset of symptoms. Estimating the period of infectiousness should be done by clinical and supervisory staff after a complete assessment of the information available. |
The period of infectiousness
ends when symptoms have improved, the patient
has been receiving adequate treatment for at
least 2 to 3 weeks, and the patient has had
three consecutive negative sputum smears from
sputum collected on different days.
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The period
of infectiousness ends when all the
following criteria are met:
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Table 6.2
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Study Question
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