Latent Tuberculosis Infection
Conditions
Keywords
Interferon-gamma release assay
Brief summary
The present study was to evaluate the usefulness of a whole-blood interferon-r release assays (IGRAs) as diagnostic tool of the latent tuberculosis infection for healthcare workers.
Interventions
OTHER1-step tuberculin skin test (TST) and blood sampling
In only new healthcare workers, the 1-step TST and quantiFERON-TB Gold In-Tube test were performed.
Sponsors
Samsung Medical Center
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
SCREENING
Masking
NONE
Eligibility
Sex/Gender
ALL
Healthy volunteers
No
Inclusion criteria
* doctors and nurses newly hired at Samsung Medical Center between February, 2008 and November, 2008.
Exclusion criteria
* Non-applicable
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Annual Incidence of Tuberculosis Infection Among Newly Employed Doctors and Nurses in Korea | QFT-IT test was performed at enrollment and repeated at point of one year after enrollment. So, the length of timw which from the start of the first test of very first participant to the end of second test of very last participant is 2 years. | The participants performed QuaniFERON-TB Gold In-Tube test (QFT-IT test). Annual infection of tuberculosis infection was evaluated with the conversion of QFT-IT test through annual check up of QFT-IT test. The definitions for QFT-IT test conversion was based on the CDC definition (Baseline IFN-r \< 0.35 IU/ml and follow-up IFN-r ≥ 0.35 IU/ml). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Negative Conversion Rate in Follow-up QuantiFERON-TB Gold In-Tube Test (QFT-IT Test) After Treatment of Latent Tuberculosis Infection (LTBI) | 3 months after LTBI treatment | The percentage of participants with negative conversion in follow-up QFT-IT test after LTBI treatment, out of those who had QFT-IT test conversion after one year of employment and agreed to undergo treatment for LTBI according to our recommendation Participants with QFT-IT test conversion were recommended for LTBI therapy using 3 months of daily isoniazid and rifampicin, which was the regular treatment for LTBI in our institution. The QFT-IT test was repeated after LTBI therapy. Negative conversion was defined as baseline IFN-r ≥ 0.35 and follow-up IFN-r \< 0.35 IU/ml. |
Countries
South Korea
Participant flow
Recruitment details
The study participants were doctors and nurses who were newly hired in 2008 at the Samsung Medical Center, a 2,000-bed referral hospital in Seoul, Korea.
Participants by arm
| Arm | Count |
|---|---|
| New Healthcare Workers a baseline 1-step tuberculin skin test (TST) and baseline QuantiFERON-TB Gold In-Tube test were performed in the new healthcare workers.
After oner year, serial QFT-IT testing was performed for all participants, except for those who had left the hospital. | 322 |
| Total | 322 |
Withdrawals & dropouts
| Period | Reason | FG000 |
|---|---|---|
| Overall Study | Lost to Follow-up | 47 |
Baseline characteristics
| Characteristic | New Healthcare Workers |
|---|---|
| Age Continuous | 24 years |
| Region of Enrollment Korea, Republic of | 322 participants |
| Sex: Female, Male Female | 274 Participants |
| Sex: Female, Male Male | 48 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | — / — |
| other Total, other adverse events | 0 / 0 |
| serious Total, serious adverse events | 0 / 0 |
Outcome results
Primary
Annual Incidence of Tuberculosis Infection Among Newly Employed Doctors and Nurses in Korea
The participants performed QuaniFERON-TB Gold In-Tube test (QFT-IT test). Annual infection of tuberculosis infection was evaluated with the conversion of QFT-IT test through annual check up of QFT-IT test. The definitions for QFT-IT test conversion was based on the CDC definition (Baseline IFN-r \< 0.35 IU/ml and follow-up IFN-r ≥ 0.35 IU/ml).
Time frame: QFT-IT test was performed at enrollment and repeated at point of one year after enrollment. So, the length of timw which from the start of the first test of very first participant to the end of second test of very last participant is 2 years.
Population: Of the 322 healthcare workers (HCWs), 275 (85%) underwent repeat QuantiFERON-TB Gold In-Tube test (QFT-IT test) after 1 year of employment; the 47 participants who had resigned were excluded. Two participants with indeterminate results on the baseline QFT-IT test were excluded from the analysis.
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| New Healthcare Workers | Annual Incidence of Tuberculosis Infection Among Newly Employed Doctors and Nurses in Korea | 57 number of new cases per 1000 person/year |
Secondary
Negative Conversion Rate in Follow-up QuantiFERON-TB Gold In-Tube Test (QFT-IT Test) After Treatment of Latent Tuberculosis Infection (LTBI)
The percentage of participants with negative conversion in follow-up QFT-IT test after LTBI treatment, out of those who had QFT-IT test conversion after one year of employment and agreed to undergo treatment for LTBI according to our recommendation Participants with QFT-IT test conversion were recommended for LTBI therapy using 3 months of daily isoniazid and rifampicin, which was the regular treatment for LTBI in our institution. The QFT-IT test was repeated after LTBI therapy. Negative conversion was defined as baseline IFN-r ≥ 0.35 and follow-up IFN-r \< 0.35 IU/ml.
Time frame: 3 months after LTBI treatment
Population: Thirteen participants agreed to undergo treatment for latent tuberculosis infection and completed 3 months therapy.
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| New Healthcare Workers | Negative Conversion Rate in Follow-up QuantiFERON-TB Gold In-Tube Test (QFT-IT Test) After Treatment of Latent Tuberculosis Infection (LTBI) | 15 Percentage of participants |