Biosafety Implications of GeneXpert MTB/RIF assay: Experience of the National Tuberculosis Reference Laboratory , Lagos Nwokoye N, Onubogu CC, Nwadike PO, Abiodun AT, Tochukwu NE, Ejezie CO, Onwuamah CK, Gidado M, Elom E, Idigbe OE Presenter Nwokoye Nkiru

Introduction Tuberculosis (TB) is an airborne infection that is transmitted primarily via aerosol Occupational transmission of TB has been demonstrated among health care workers (Kehinde et al., 2011) Test methods that involve aerosol-generating procedures expose testing personnel to high risk of TB infection. The Genexpert MTB/RIF (Xpert) assay has been described as a point-of-care test that can be performed outside the biosafety cabinet. Sample reagent (SR) contains compounds that effectively kill the TB bacilli (Banada et al. 2012)

Introduction… Worrisome issues What if the sample reagent fails to Kill theTB bacilli? What if the substandard sputum cup leaks and releases the bacilli? What if the released bacilli are not the susceptibleTB but MDR or even XDR-TB?

Objective To assessing the killing effect of the sample reagent on tubercle bacilli. Methodology The study investigated 604 patients that were referred to the National Tuberculosis Reference Laboratory, Nigerian Institute of Medical Research (NIMR), Lagos, between January and December 2012. Categories of patients enrolled included presumptive drug resistant-TB (DR-TB) cases and HIV positive patients showing symptoms of TB. GeneXpert assay and TB culture were done as per standard protocol

Findings and implications Result Implication Table 1: MTB and Rifampicin resistance detection by Xpert assay Xpert characteristics Frequency (%) MTB detected 164(27.2) MTB not detected 440(72.9) Rifampicin resistance detection Resistance detected 68(41.5) Resistance not detected 95(57.9) Indeterminate 1(0.6) High prevalence of Rifampicin resistant TB High MDR-TB prevalence among the study population

Table 2: MTB detection by Xpert based on HIV-status Findings and implications... Table 2: MTB detection by Xpert based on HIV-status MTB detection HIV status Negative Positive Total Negative 174(39.5%) 82(50.0%) 226(42.4%) Positive 240(54.6%) 54(32.9%) 294(48.7%) Unknown 26(5.9%) 28(17.0%) 54(8.9%) Total 440(100.0%) 164(100.0%) 604(100.0%) Implication Increased detection of MTB among the HIV-positive patient smear microscopy has reduced sensitivity in HIV –positive patient (onubogu et al., 2012; Oludiran et al., 2008) Xpert is a Veritable tool for TB diagnosis in HIV co-infected patients

Findings and implications... Table 3: Growth inhibition by Xpert sample reagent (SR) Growth on LJ without SR(control) Growth on LJ with SR Negative Positive Total Negative 123(100.%) 65(82.3%) 188(93.1%) Positive 0(0.0%) 14(17.7%) 14(6.9%) Total 123(60.9%) 79(39.1%) 202(100.0%) p = 0.00007 Implications Xpert SR was unable to kill all the TB bacilli after 15 mins of incubation Processing involves aerosol generating procedures, Sputum cups are not leak proof, N95 respirator is not worn Following national policy, laboratory personnel performing Xpert assay has 17.7% chances of being exposed to live TB bacilli

Recommendations National policy on diagnosis of DR-TB should be reviewed to accommodate Use of leak proof, screw capped sputum container for processing of xpert specimens Processing of xpert samples in a well ventilated laboratory Use of N95 respirator when handling known or suspected DR-TB specimens (screw cap sputum cup) N95 respirator

Conclusion Xpert is a veritable tool for TB diagnosis particularly in HIV co- infected patients Following national policy, laboratory personnel performing Xpert assay has 17.7% chances of being exposed to live TB bacilli. National policy on DR-TB diagnosis should be reviewed to avert upsurge of laboratory acquired DR-TB References Kehinde AO, Baba A, Bakare RA, Ige OM, Gbadeyanka CF, Adebiyi OE (2011). Pulmonary tuberculosis among health care workers at two designated DOTS Centers in urban city of Ibadan, Nigeria. Indian J Med Res 133: 613-617 Onubogu CC, Nwokoye NN, Kunle-Ope CN, Raheem TY, Igbasi UT, Tochukwu N, et al. (2012). Sensitivity of direct smear microscopy for the diagnosis of TB in high HIV prevalent population . Scientific Research and Essay 7: 593-597 Oludiran KA, Eziuka OR, Mayowa IO, Ajani BR, kikelomo O (2008). Bacteriology of childhood tuberculosis in Ibadan, Nigeria: A five-year review. Trop. Med. Health 36: 127-130. Banada P, Sivasubramani SK, Blakemore R, Boehme C, Perkin MD, Fennelly K, Alland D(2010). Containment of bioaerosol infection risk by the Xpert MTB/RIF assay and its applicability to point-of-care settings, J. Clin. Microbiol. 48:3551–3557.

References Kehinde AO, Baba A, Bakare RA, Ige OM, Gbadeyanka CF, Adebiyi OE (2011). Pulmonary tuberculosis among health care workers at two designated DOTS Centers in urban city of Ibadan, Nigeria. Indian J Med Res 133: 613-617 Onubogu CC, Nwokoye NN, Kunle-Ope CN, Raheem TY, Igbasi UT, Tochukwu N, et al. (2012). Sensitivity of direct smear microscopy for the diagnosis of TB in high HIV prevalent population . Scientific Research and Essay 7: 593-597 Oludiran KA, Eziuka OR, Mayowa IO, Ajani BR, kikelomo O (2008). Bacteriology of childhood tuberculosis in Ibadan, Nigeria: A five-year review. Trop. Med. Health 36: 127-130. Banada P, Sivasubramani SK, Blakemore R, Boehme C, Perkin MD, Fennelly K, Alland D(2010). Containment of bioaerosol infection risk by the Xpert MTB/RIF assay and its applicability to point-of-care settings, J. Clin. Microbiol. 48:3551– 3557.

TB Healthy scientist Shutting TB out THANK YOU