HomeTable 1a. Epidemiological investigations reporting TB exposures in healthcare settings, linked to a health care worker index case
| Author, Ref, Year | Setting, Country | Index/Source Case Characteristics | Transmission (Yes/No) & Associated Risks | Study Population & Contact Investigation Details | TB/LTBI Screening & Testing | Transmission Outcomes |
|---|---|---|---|---|---|---|
| Acute Care Settings | ||||||
| Balmelli15 2014 |
Acute care hospital Switzerland |
Index: HCW from a high TB endemic region found to be infectious due to abrupt onset of productive cough, weakness, and malaise | No HCW did not undergo pre-employment TB screening; lack of baseline TST data limited HCW exposure assessments |
All HCW and patients in contact with index for any period of time in the 2 weeks before symptom onset | Questionnaire on demographics, risk factors and duration of contact with index case, 2 step TST, IGRA | Active TB cases linked to exposure event: None TST conversions linked to exposure event: 6 to 10/101 HCW and patient contacts (variability in 2 step TST and IGRA conversions) |
| Orenstein35 2013 | Acute care hospital Canada |
Index: HCW dx with active TB, assumed to be infectious for 6 months prior to diagnosis | No Delivery of care by a HCW with an active TB infection to Oncology and Palliative care patients |
All HCWs in contact with index case; all patient and family contacts | Not reported | Active TB cases linked to exposure event: None TST conversions linked to exposure event: 9/121 HCW contacts |
| Hazard13 2016 | Acute care hospital, nutritional service department employees United States |
Index: HCW with no patient contact | Yes Kitchen located in a confined basement of the facility with a dedicated exhaust system independent from healthcare facilities other ventilation systems |
All current and former (previous 6 months) staff (limited to kitchen) included in CI; Routine HCW TB screening identified a high frequency of TST conversions in nutritional service employees prompting a CI | Symptom questionnaire, 2 step TST, clinical assessment of contacts with previous positive TST results | Active TB cases linked to exposure event: 4 HCW contacts (nutritional service staff). 1 HCW was identified with MTB + sputum 4 years post exposure event, TST negative during CI and annual screening TST conversions linked to exposure event: 20/224 nutritional service staff contacts Index case confirmed by spoligotype and MIRU |
| Merte38 2014 |
Dental Clinic United States |
Index: HCW with active pulmonary TB, female, mid-40 yrs, known untreated LTBI, lived in a high TB endemic region, cough, fever, fatigue, weight loss; 4+ AFB, CXR indicative of infection | No Lack of baseline TST data limited HCW exposure assessments, HCW worked for approx. 6 months while infectious, |
HCW, patients, and household contacts of index; 462 patient contacts without previous documented TST | Symptom questionnaire, 2 step TST, clinical evaluation and CXR for contacts with previous positive TST results | Active TB cases linked to exposure event: None TST conversions linked to exposure event: 1/19 HCW contacts, 0/1 household contact |
| Romagnoli36 2012 | Acute care hospital, Neonatology unit Italy |
Index: HCW who worked at multiple healthcare facilities | Yes None reported |
All Patient in the maternity ward 3 months before the birth of the index case and 2 days after the last working day of the HCW with active TB | IGRA for newborn contacts > 12moa, and follow-up test at 3 moa; TST, CXR and clinical assessment for contacts with documented positive TST results | Active TB cases linked to exposure event: 1 Patient. dx. with pulmonary extra-pulmonary TB at 4 moa at another hospital TST conversions linked to exposure event: None Active TB cases matched by DNA finger printing |
| Long-term and Residential Care Settings | ||||||
| Khalil11 2013 | Long-term care and residential care facility Canada |
Index: HCW presenting with cough, fever, night sweats, and pleuritic chest pain; immigrant from an endemic region; Baseline TST at hire was documented to be negative Source case: Chart review suggests a resident with active TB may have been symptomatic up to 12 months prior to dx. |
Yes Patient care to residents; Baseline TST at hire available for 40% of staff; Ventilation in a tested dining room, common room, and most resident rooms <4 ACH |
Residents or staff (including volunteers) who shared indoor airspaces daily and/or >4 hr per week with index case; Family members or visitors who shared indoor airspaces for >2-4 hr per week with index case | 2 step TST, CXR for TST positive contacts, and suspicious CXR followed up with chest computerized tomography scan and sputum samples for culture; concentric circle approach to CI |
Active TB cases linked to exposure event: 3 resident contacts TST conversions linked to exposure event: 9/121 HCW contacts, 15/146 resident contacts, none among visitor and household contacts Active TB cases matched by genotyping |
| Mor37 2018 |
Nursing Home Israel |
Index: HCW from a high TB endemic region found to be infectious following productive cough, fever, malaise, weakness and loss of appetite | Yes Patient care to residents; HCW CXR abnormal but permitted to work at facility |
Resident and staff contacts of index case | Symptom screen interview, 2 step TST, concentric circle approach to CI | Active TB cases linked to exposure event: 1 HCW contact and 2 resident contacts TST conversions linked to exposure event: 26/68 resident contacts, 2/32 HCW contacts |
Table 1b. Epidemiological investigations reporting TB exposures in healthcare settings, linked to a patient or long-term care resident (patient) index case
| Author, Ref, Year | Setting | Index/Source Case Characteristics | Transmission (Yes/No) & Associated Risks | Study Population & Contact Investigation Details | TB/LTBI Screening & Tests | Transmission Outcomes |
|---|---|---|---|---|---|---|
| Acute Care Settings | ||||||
| Bucher17 2016 Freytag39 2016 A |
Acute care hospital Germany & United States |
Source: Patient. organ donor treated for TB 40+ years ago, no recent TB symptoms identified Index: Patient. 70 yrs, kidney organ recipient, clinical deterioration at 6 weeks post transplant Index: Patient. 60 yrs, liver transplant recipient, died from TB infection 15.5 months post transplant |
Yes Donor derived TB not considered among solid organ transplant recipients; AGMP and invasive medical procedures (e.g. surgical wound debridement, general anesthesia, endotracheal intubation) performed without airborne precautions |
Individuals cumulatively exposed to the index patient >40hrs or continuously for >8hrs | Not reported | Active TB cases linked to exposure event: 1 HCW contact. This HCW was excluded from the initial post exposure CI TST conversions linked to exposure event: Not Reported Active TB cases matched by WGS |
| de Perio23 2014 | Acute care hospital United States |
Index: Patient. with pulmonary TB, AFB positive, reported to have difficulty hearing (i.e. required close interactions to interpret communications) | Yes Delay in TB dx. and initiation of IPC measures; patient care (e.g. ED evaluation) performed without airborne precautions; NIOSH assessment identified issues with AIIR pressure sensor calibrations, ACH, direction of air flow and pressure differential (several AIIR did not meet CDC recommendation); doors between anteroom and hallways open when AIIR were occupied |
HCW with a TST conversion during outbreak year or self-reporting exposure to index patient; HCW exposures identified by shift records | TST, AFB, staff interviews | Active TB cases linked to exposure event: 1 HCW contact (nursing assistant); 1 household contact (spouse of index case) TST conversions linked to exposure event: 19/41 HCW contacts Report Active TB cases to be related |
| Grisaru-Soen14 2014 | Acute care Children’s hospital Israel |
Index: Patient. 26 day old premature infant with congenital TB, 5 day history of recurrent vomiting and respiratory failure at admission, mother originating from endemic region with suspect diagnosis for pulmonary TB | Yes Delay in TB dx. and initiation of IPC measures; AGMP and patient care (e.g. mechanical ventilation, bronchoalveolar lavage) performed without airborne precautions |
NICU PICU patients, staff, or visitors >24 in the same room as index case | TST contacts >5 years of age; physical examination for contacts <3 months of age; CXR; 2 step TST for adult contacts | Active TB cases linked to exposure event: 1 (mother of infant) TST conversions linked to exposure event: 3/35 staff contacts, 1/75 NICU & PICU patient contacts, 3/22 PICU visitors, 8/58 NICU visitors |
| Holden18 2018 | Acute care hospital, ER and ICU United Kingdom |
Index: Patient. 50 yrs, lower respiratory tract infection, history of sustained weight loss, productive cough at admission, marginally housed, CXR showed cavitation | Yes Delay in TB dx. and initiation of IPC measures due to misdiagnosis of pneumonia, AGMP and patient care performed without airborne precautions, Discontinuation of airborne precautions without considering symptoms after 14 days of anti-TB treatment. |
All HCW with >4hrs of contact with index Patient, HCW present during AGMP or in close proximity during invasive procedures; family members of HCW with active TB; concentric circle approach to CI |
Symptoms questionnaire, IGRA, CXR | Active TB cases linked to exposure event: 1 HCW contact. This HCW was excluded from the initial post exposure CI TST conversions linked to exposure event: 7/8 ICU HCW contacts Active TB cases matched by WGS |
| Jonsson24 2013 Kan40 2013A |
Acute care hospital Denmark |
Index: Patient. 50 yrs, HIV+, history of IDU, 6 week history of coughing and weight loss at admission, died at hospital | Yes Delay in TB dx. and initiation of IPC measures due to misdiagnosis of pneumonia, AGMP (e.g. bronchoscopy) and patient care performed without airborne precautions, discontinuation of airborne precautions without sputum analysis results, lack of baseline TST data limited HCW exposure assessments, socialization among ward patients, shared patient rooms, personal care assistance to roommate of index |
Initial CI was limited to HCW with major exposure to index patient, then expanded to include all HCW at the ward | TST, IGRA, CXR | Active TB cases linked to exposure event: 3 HCW contacts; 4 patient contacts. 1 HCW was excluded from the initial post exposure CI TST conversions linked to exposure event: 15/36 HCW contacts, 4/15 patient contacts, 5/7 social contacts. Some active TB cases matched by RFLP |
| Khatami34 2017 | Acute care Children’s hospital and pediatric operating room Australia |
Index: Patient. 12 yrs male; 5 day history of acute onset fever, dyspnea, cough, and malaise at admission; CXR abnormal | No Delay in TB dx. and initiation of IPC measures; AGMP and patient care performed without airborne precautions (e.g. daily chest physiotherapy, general anesthesiology, video-assisted thoracoscopic surgery, frequent blood collection, chest drain, central venous catheter insertion, bronchoalveolar lavage); shared patient rooms; lack of baseline TST data limited HCW exposure assessments |
HCW assessed to be close contacts of index case; patients who shared a room with the index case >8 hrs; concentric circle approach to CI | 2 step TST and IGRA, CXR and assessment at chest clinic for contacts with documented positive TST | Active TB cases linked to exposure event: None TST conversions linked to exposure event: Initial CI group 4/38 HCW contacts and expanded CI group 2/51 HCW contacts (physiotherapists and anesthesiologists) |
| Medrano12 2014 | Acute care hospital United States |
Index: Patient. mid 20 yrs, HIV+, history of being marginally housed, prison inmate admitted to hospital, died at hospital, previously infected and treated for another TB strain, PCR positive for MTB but no viable samples for genotyping Source: inmate from the same jail who shared the same holding cell for <10 hrs |
Yes Delay in TB dx. and initiation of IPC measures due to misdiagnosis of pneumonia; inadequate respiratory risk assessment at admission; patient often walked the halls of the hospital floor |
All HCW, correctional staff, patients, and visitors to the floor housing the index case NOTE: Routine HCW TB screening identified a high frequency of TST conversions prompting the CI |
TST, IGRA, TB symptom screen for contacts with documented positive TST results, CXR and sputum culture for symptomatic contacts | Active TB cases linked to exposure event: 3 HCW contacts (2 nurses and a social workers); 6 other hospital contacts (patients, visitors, correctional staff) TST conversions linked to exposure event: 87/318 of all hospital contacts; 23/30 HCW contacts (on the same floor as index case); 12/67 patient and visitor contacts Active TB cases (with positive culture results) matched by WGS |
| Townes41 2016 | Ambulatory care United States |
Index: Patient. at Rheumatology clinic on immunosuppressive medication, cough | No Delay in TB dx. and initiation of IPC measures due to misdiagnosis of pneumonia; inadequate respiratory risk assessment at clinic visit |
Anyone who shared the clinic airspace with index case >2hrs | Symptom assessment; 2 step TST and/or IGRA; CXR and symptom assessment for contacts with previous positive IGRA results | Active TB cases linked to exposure event: None TST conversions linked to exposure event: None among HCW and patient contacts; 7/17 community contacts |
| Long-term and Residential Care Settings | ||||||
| Harris22 2013 | Long-term care facility joined to an Acute care hospital United States |
Index: LTC resident 68 yrs, male with a history of laryngeal cancer, diabetes, hypertension, COPD, cerebrovascular accident, abnormal CXR 9 months prior to TB dx. | Yes Delay in TB dx. and initiation of airborne precautions; AGMP without airborne precautions (e.g. repeated mucus/secretion suction, routine tracheostomy care; re-insertion of tracheostomy tube); shared negative pressure room <2-3hrs ACH with airflow from index to secondary case; group dinning and recreation activities among LTC residents |
Resident/patient, visitor and staff contacts of index case in LTC (ventilator-dependent care and sub-cute care units); Hospital staff and patient contacts of index case | TST and IGRA, sputum sample culture, clinical assessment, CXR recommended for LTC contacts | Active TB cases linked to exposure event: 2 resident contacts (a roommate of index case, and a resident of a room across the hall from index at LTC site) TST conversions linked to exposure event: 7/64 patient or resident contacts, 5/239 HCW contacts (LTC staff). No TST conversions among hospital contacts Active TB cases matched by RFLP |
A-Companion articles. Articles identified as companion articles provide supplementary information about a specific epidemiological investigation. Where such articles exist, the additional information is included in the table.
Table 1c. Observational studies reporting on TB exposures in healthcare settings
| Author, Ref, Year | Setting, Country | Study Population | Transmission (Yes/No) & Associated Risks | Transmission Outcomes |
|---|---|---|---|---|
| Uppal20 2014 | Acute care hospital Canada |
All HCW, Patient and Visitor exposures to active TB cases (n = 15) at the hospital in 2011; Ten significant exposures identified among (n = 7) active TB infections | No Delay in TB dx. and initiation of airborne precautions; Advanced age, atypical presentation of TB infection, comorbid infections, errors in ordering and interpreting microbiological or CXR results |
Root cause analysis found 70% of the significant exposure incidents among active TB patients were linked to delay in TB dx. and initiation of airborne precautions No TST conversions among HCW following significant exposures identified |
| de Vries16 2017 | Not specified Netherlands |
HCW with TB identified in a national registry (n = 131), analysis of factors contributing to infection transmission from patients to HCW | Delay in TB dx. led to TB infection transmissions among 47% of HCW in the sample | 24% of TB cases (n = 32) in registry were categorized as transmissions in healthcare settings, between patients and HCW; majority linked to delays in TB dx. Roles of HCW infected with TB at the workplace were nurse (n = 15), medical doctor (n = 6), bronchoscopy assistant (n = 3), autopsy assistant (n = 3), medical equipment sterilisation assistant (n = 2), laboratory assistant (n = 1), pathology assistant (n = 1), and medical assistant (n = 1) |
| Muzzi21 2014 | Acute care hospital Italy |
HCW exposures (n = 388) to pulmonary and respiratory TB patients (n = 14) due to delayed dx. or airborne precautions | Patient comorbidities linked to delayed dx. cirrhosis, advanced cancer, chronic kidney disease, HIV and diabetes | TST conversions linked to exposure event: 3.7% (n = 9) of exposed HCW assumed TST negative at baseline (n = 255), were positive at 3 months post exposure by 2 step TST |
| Schepisi10 2015 | Various acute & outpatient healthcare settings Multiple countries |
HCW diagnosed with respiratory active TB (n = 177) among studies reporting confidence interval outcomes | Yes Medical procedures linked to transmission were tooth extractions and hemodialysis |
Meta-analysis estimated active TB among exposed individuals to be: 0.11% (95% Confidence Interval 0.04–0.21) for infants, 0.38% (95% Confidence Interval 0.01–1.60) for children, 0.09% (95% Confidence Interval 0.02–0.22) for adults and 0.00% (95% Confidence Interval 0.00–0.38) for HCWs. |
Abbreviations: TB, tuberculosis; LTBI, latent TB infection; HCW, health care worker; TST, tuberculin skin test; IGRA, interferon-gamma release assay; dx, diagnosis; CI, contact investigation; MTB, mycobacterium tuberculosis; MIRU, mycobacterial interspersed repetitive units; AFB, acid-fast bacillus; CXR, chest radiograph; Patient, patient; moa, months of age; DNA, Deoxyribonucleic acid; ACH, air changes per hour; AGMP, aerosol-generated medical procedure; WGS, whole genome sequencing; IPC, infection prevention and control; ED, emergency department; NIOSH, National Institute for Occupational Safety and Health; AIIR, airbone infection isolation room; CDC, Centers for Disease Control and Prevention; NICU, neonatal intensive care unit; PICU, pediatric intensive care unit; ER, emergency room; ICU, intensive care unit; HIV, human immunodeficiency virus; IDU, injecting drug user; RFLP, Restriction fragment length polymorphism; PCR, polymerase chain reaction; LTC, long-term care; n, number.
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