Molecular test for chlamydia and gonorrhoea used at point of care in remote primary healthcare settings: a diagnostic test evaluation.

OBJECTIVES: A new molecular test for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) (GeneXpert CT/NG) has been demonstrated to be as accurate as conventional nucleic acid amplification tests (NAAT), but performance has not been evaluated in routine primary care, performed at the point of care by clinicians. We aimed to examine its diagnostic performance when used by clinicians in remote community health services in Australia with high prevalences of CT and NG infection. The trial was registered with the Australian and New Zealand Clinical Trials Registry (#12613000808741) METHODS: At 12 health services, training was provided to 99 clinicians in the use of the GeneXpert CT/NG assay who tested specimens from all patients undergoing STI screening. Specimens were also sent in parallel for conventional laboratory-based NAATs and the concordance of results was evaluated. RESULTS: Clinicians conducted 2486 tests: CT concordance was 99.4% (95% CI 99.1 to 99.7) with a positive concordance of 98.6% (95% CI 95.9 to 99.7) and negative concordance of 99.5% (95% CI 99.1 to 99.8); NG concordance was 99.9% (95% CI 99.7 to 100.0) with a positive concordance of 100.0% (95% CI 97.5 to 100.0) and negative concordance of 99.9% (95% CI 99.7 to 100.0). CONCLUSIONS: In this first study reporting routine point-of-care use of GeneXpert CT/NG by primary care clinicians, we found excellent concordance with conventional NAATs. The use of the GeneXpert CT/NG at the point of care could potentially transform management and control of these infections in many endemic settings, including low/middle-income countries.

Detection of Neisseria gonorrhoeae and Chlamydia trachomatis from pooled rectal, pharyngeal and urine specimens in men who have sex with men.

OBJECTIVES: Screening of men who have sex with men (MSM) for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) requires sampling from anorectal and pharyngeal sites in addition to urogenital sampling. Due to the cost of testing multiple anatomical sites individually testing of pooled specimens has potential merit. The Cepheid GeneXpert CT/NG assay (GeneXpert), which also has potential for point-of-care nucleic acid testing in the sexual health clinic, has not been assessed for pooled specimen testing. METHODS: We prospectively compared GeneXpert testing of pooled pharyngeal and rectal swabs with urine samples to standard of care testing of individual specimens from 107 participants using the Roche cobas 4800 CT/NG assay (cobas) for CT and NG in high-risk MSM attending an inner city sexual health clinic. RESULTS: We found testing of pooled pharyngeal, rectal and urine samples by the GeneXpert to have 100% agreement for NG and 94% overall agreement for CT when compared with individual specimen testing by cobas. For CT testing, 14 cases were detected for both tests, 4for cobas only, 2 for GeneXpert only and 89 participants were negative for both tests. CONCLUSIONS: Pooled specimen CT and NG testing by the GeneXpert was accurate when compared with single specimen testing and has potential for screening MSM for CT and NG. The role of pooled specimen testing with the GeneXpert as a point-of-care nucleic acid test in MSM requires further investigation.

Mycobacterium chimaera colonisation of heater-cooler units (HCU) in Western Australia, 2015: investigation of possible iatrogenic infection using whole genome sequencing.

Following the reported link between heater-cooler unit (HCU) colonisation with Mycobacterium chimaera and endocarditis, mycobacterial sampling of all HCUs in use in Western Australia was initiated from August 2015, revealing M. chimaera colonisation in 10 of 15 HCUs. After M. chimaera was isolated from a pleural biopsy from a cardiothoracic patient who may have been exposed to a colonised HCU, a whole genome sequencing investigation was performed involving 65 specimens from 15 HCUs across five hospitals to assess if this infection was related to the HCU. Genetic relatedness was found between the 10 HCU M. chimaera isolates from four hospitals. However the M. chimaera isolate from the cardiothoracic patient was not genetically related to the HCU M. chimaera isolates from that hospital, nor to the other HCU isolates, indicating that the HCUs were not the source of the infection in this patient.

Pandemic influenza (H1N1) 2009 pneumonia: CURB-65 score for predicting severity and nasopharyngeal sampling for diagnosis are unreliable.

BACKGROUND: From the first case reports of pandemic influenza (H1N1) 2009 it was clear that a significant proportion of infected individuals suffered a primary viral pneumonia. The objective of this study was twofold; to assess the utility of the CURB-65 community acquired pneumonia (CAP) severity index in predicting pneumonia severity and ICU admission, and to assess the relative sensitivity of nasopharyngeal versus lower respiratory tract sampling for the detection of pandemic influenza (H1N1) CAP. METHODS: A retrospective cohort study of 70 patients hospitalised for pandemic influenza (H1N1) 2009 in an adult tertiary referral hospital. Characteristics evaluated included age, pregnancy status, sex, respiratory signs and symptoms, smoking and alcohol history, CURB-65 score, co-morbidities, disabling sequelae, length of stay and in-hospital mortality outcomes. Laboratory features evaluated included lymphocyte count, C-reactive protein (CRP), nasopharyngeal and lower respiratory tract pandemic influenza (H1N1) 2009 PCR results. RESULTS: Patients with pandemic (H1N1) 2009 influenza CAP differed significantly from those without pneumonia regarding length of stay, need for ICU admission, CRP and the likelihood of disabling sequelae. The CURB-65 score did not predict CAP severity or the need for ICU admission (only 2/11 patients admitted to ICU had CURB-65 scores of 2 or 3). Nasopharyngeal specimens for PCR were only 62.9% sensitive in CAP patients compared to 97.8% sensitivity for lower respiratory tract specimens. CONCLUSIONS: The CURB-65 score does not predict severe pandemic influenza (H1N1) 2009 CAP or need for ICU admission. Lower respiratory tract specimens should be collected when pandemic (H1N1) 2009 influenza CAP is suspected.