African Journal of
Microbiology Research

  • Abbreviation: Afr. J. Microbiol. Res.
  • Language: English
  • ISSN: 1996-0808
  • DOI: 10.5897/AJMR
  • Start Year: 2007
  • Published Articles: 4829

Full Length Research Paper

Evaluation of gene xpert assay and microscopic examination for detection of Mycobacterium tuberculosis in sputum at Port Harcourt, Nigeria

Confidence Kinikanwo Wachukwu
  • Confidence Kinikanwo Wachukwu
  • Department of Medical Laboratory Science, Rivers State University, Nkpolu-Oroworukwo, Port Harcourt, Rivers State, Nigeria.
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Stella Paulinus Okwelle
  • Stella Paulinus Okwelle
  • Department of Medical Microbiology, University of Port Harcourt Teaching Hospital, Choba, Rivers State, Nigeria.
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Easter Godwin Nwokah
  • Easter Godwin Nwokah
  • Department of Medical Laboratory Science, Rivers State University, Nkpolu-Oroworukwo, Port Harcourt, Rivers State, Nigeria.
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Ollor Amba Ollor
  • Ollor Amba Ollor
  • Department of Medical Laboratory Science, Rivers State University, Nkpolu-Oroworukwo, Port Harcourt, Rivers State, Nigeria.
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  •  Received: 25 August 2017
  •  Accepted: 14 December 2017
  •  Published: 14 April 2018

Abstract

The re-emergence and increase in the prevalence of tuberculosis cases and multidrug resistant strains is of public health concern. The conventional Acid Fast Bacilli detection tool is weak in the current disease trend especially in children, patients with human immunodeficiency virus (HIV) and low bacterial load. The aim of this research was to assess effectiveness of the Gene Xpert MTB/RIF assay and Microscopy in detectiing Mycobacterium tuberculosis (MTB) in sputum samples in Port Harcourt metropolis. A total of two hundred sputum samples were collected from tuberculosis (TB) suspected patients visiting the antiretroviral and directly observed short treatment clinics at Braithwaite Memorial Specialist Hospital, Port Harcourt and University of Port Harcourt Teaching Hospital, Choba. These samples were investigated to compare and evaluate the detection of M. tuberculosis using Gene Xpert MTB/RIF assay and microscopy. Results revealed that 20% (40/200) of the samples were positive for MTB. Ages 31 to 40 years had 55 samples with ten positive MTB while ages < 10 years had the least number of specimens and one MTB detected.  Out of 200 samples analyzed, the percentage positive was 20% while 80% was negative for MTB.  Ages < 10 years did not show any AFB positive smear whereas ages 31 to 40 years had 10 positive AFB smears. One hundred and four individuals were people living with HIV, ninety six were negative for HIV; fifteen individuals were positive for HIV as well as MTB (co-infection) and no individual that was co-infected had Rifampicin resistance. There is a significant difference in the detection of MTB across PLHIV and negative persons using AFB microscopy and Gene Xpert technique. It can be concluded that the gene xpert MTB/RIF assay is highly sensitive (98%) with a p-value of < 0.001 and specific in the detection of MTB and Rifampicin Resistance in sputum, and its use in health institutions should be encouraged to reduce exposure and spread of the disease as well correct treatment.

Key words: Gene xpert, tuberculosis, Mycobacterium tuberculosis/Rifampicin (MTB/RIF), sputum, microscopy.