Gene Xpert Diagnosis of TB Using Tracheal Aspirates From Intensive Care Unit (ICU) Patients

The recruitment status of this study is unknown because the information has not been verified recently.
Verified February 2012 by University of Cape Town.
Recruitment status was  Recruiting
Sponsor:
Information provided by (Responsible Party):
Keertan Dheda, University of Cape Town
ClinicalTrials.gov Identifier:
NCT01530568
First received: January 24, 2012
Last updated: February 9, 2012
Last verified: February 2012
  Purpose

Aim:

To evaluate the diagnostic utility and impact on patient outcomes of an automated PCR (Gene Xpert® MTB/RIF), in a group of patients with suspected pulmonary TB who are mechanically ventilated in ICU, using tracheal aspirates.

Hypothesis:

Gene Xpert is an accurate tool for the diagnosis of TB in the Intensive Care Unit and will impact on rates of treatment initiation and hospital stay.


Condition Intervention
Tuberculosis
Other: Xpert
Other: Smear

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single Blind (Caregiver)
Primary Purpose: Diagnostic
Official Title: A Randomised Control Trial of a Standardised and User-friendly Real-time PCR Assay for the Diagnosis of TB Using Tracheal Aspirates Obtained From Patients in the ICU

Resource links provided by NLM:


Further study details as provided by University of Cape Town:

Primary Outcome Measures:
  • Rates of TB treatment initiation [ Time Frame: 48 hours ] [ Designated as safety issue: No ]
    The proportion of patients on TB treatment in each arm will be compared longitudinally


Secondary Outcome Measures:
  • Mortality in ICU [ Time Frame: up to 2 months ] [ Designated as safety issue: No ]
    The time-specific proportion of patients who have died prior to discharge will be compared across arms

  • Duration of mechanical ventilation [ Time Frame: Up to 2 weeks ] [ Designated as safety issue: No ]
    The median Duration of mechanical ventilation will be compared between arms prior to discharge up to 2 weeks

  • ICU length of stay [ Time Frame: up to 3 months ] [ Designated as safety issue: No ]
    The median ICU length of stay will be compared up to 3 months


Estimated Enrollment: 150
Study Start Date: August 2010
Estimated Study Completion Date: April 2012
Estimated Primary Completion Date: April 2012 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Smear
Routine microbiology based diagnostics for TB
Other: Smear
This arm receives smear microscopy
Experimental: GeneXpert
Arm that will receive the Xpert test
Other: Xpert
This arm receives the GeneXpert test

Detailed Description:

Background Tuberculosis (TB) is a serious global public health emergency and there is a great need for the improvement of current diagnostic tools and the evaluation of newer and novel technologies for the rapid diagnosis of TB. The most common testing method for TB is sputum smear microscopy, which has remained largely unchanged in its sophistication and sensitivity. Smear microscopy detects around 50% of all active TB cases and is not capable of identifying drug resistance. Furthermore, even though culture is more accurate results are only available in several weeks. Treating patients empirically for TB exposes patients to the toxic side-effects of drugs, and if there is no response to treatment, raises the question of MDR-TB. These considerations apply to clinical decision-making in the ICU where TB is not infrequently encountered. A diagnosis of TB in this setting has important implications for drug-drug interactions, route of administration, and drug toxicity.

The Gene Xpert® system's MTB/RIF Assay, an on-demand molecular test for simultaneous detection of Mycobacterium tuberculosis (M.tb) and rifampicin (RIF) resistance, has recently been released. This is the only system that combines on-board sample preparation with real-time PCR [1]. Helb and colleagues developed and performed the first analysis of the Cepheid Gene Xpert System's MTB/RIF assay. They evaluated the diagnostic utility of the system using sputum samples and showed that the system was highly sensitive and simple-to-use [2]. A recent paper (NEJM, 2010, in press) that enrolled almost 2000 patients found Xpert to have a sensitivity of almost 90% in smear-negative TB. However, how the test will perform when using tracheal aspirates is unknown. It is also unclear whether the test will have any impact in the ICU where the decision to treat is often made clinically and empiric treatment is initiated. To address these questions we aim to obtain tracheal aspirates from about 120 mechanically ventilated patients with suspected TB from the Groote Schuur Hospital Intensive Care Unit. Tests will be conducted at the Lung Infection and Immunity Unit laboratory (Groote Schuur Hospital, Cape Town) to evaluate the diagnostic utility of the Xpert® MTB/RIF Assay in this group of patients. The expected study period will be 12 months.

  Eligibility

Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion criteria:

  1. Patients over 18 with suspected TB in the intensive care unit will be selected.
  2. Informed consent will be attained from the nearest relative through verbal explanation of the trial details, following which the relative will be required to sign a consent form if agreeable to participating in the study.
  3. Consent will be obtained retrospectively once the patient is liberated from mechanical ventilation
  Contacts and Locations
Please refer to this study by its ClinicalTrials.gov identifier: NCT01530568

Contacts
Contact: Grant Theron, PhD 0027216507718 grant.theron@uct.ac.za

Locations
South Africa
Groote Schuur Hospital, which operates within the Cape Town Central Health District of the Metro Region Recruiting
Cape Town, Western Cape, South Africa, 7925
Contact: Grant Theron, PhD    0027214047718    grant.theron@uct.ac.za   
Sponsors and Collaborators
University of Cape Town
Investigators
Principal Investigator: Keertan Dheda, PhD University of Cape Town
  More Information

No publications provided

Responsible Party: Keertan Dheda, Professor, University of Cape Town
ClinicalTrials.gov Identifier: NCT01530568     History of Changes
Other Study ID Numbers: TB Xpert ICU
Study First Received: January 24, 2012
Last Updated: February 9, 2012
Health Authority: South Africa: Human Research Ethics Committee

Keywords provided by University of Cape Town:
Intensive care, TB, tracheal aspirates, Gene Xpert

Additional relevant MeSH terms:
Tuberculosis
Mycobacterium Infections
Actinomycetales Infections
Gram-Positive Bacterial Infections
Bacterial Infections

ClinicalTrials.gov processed this record on April 17, 2014