Mycobacterium Tuberculosis Lineage 7

Tuberculosis (TB) has been a significant cause of illness and death among humans for centuries. In 2014, the World Health Organization estimated that there were 9 million new cases and 1.5 million deaths resulting from TB, of these, 95% of the cases and deaths occur in high TB burden countries.

About the project

A recent genotyping study of Mycobacterium tuberculosis (M. tuberculosis) isolates among pulmonary tuberculosis patients in Ethiopia showed the presence of high level of diversity of strains among the 237 M. tuberculosis isolates (Yimer et al. 2013 ). Among others, the Tuscany (T), Central Asia Spoligotype (CAS), Unclassified (U), Haarlem (H) and Latin American Mediterranean strains were identified. The most exciting finding in this study was the identification of a considerable proportion of Spoligo-International-Type (SIT) 910 and SIT 1729 strains. Only a few of these strains are included in the database to date. The high proportion of SIT 910 and SIT 1729 strains may suggest an increase in the importance of these lineages in the transmission of TB in Ethiopia, and possibly in the neighboring countries.

Currently, there is an ongoing discussion among international TB experts whether the SIT 910 and SIT 1729 identified in this study belong to a new lineage; tentatively termed “lineage seven”. Our hypothesis is that the M. tuberculosis lineages SIT 910 and SIT 1729 are associated with different clinical features and transmission pattern compared to other lineages.

Objectives

  1. To characterize the predominant strains of M. tuberculosis circulating in Ethiopia, South Sudan and Sudan
  2. To investigate the association of the M. tuberculosis lineages with transmissibility of infection, clinical outcome and severity of disease
  3. To assess cross border transmissions of TB in Ethiopia, South Sudan and Sudan

Publications

  • Yimer SA, Norheim G, Namouchi A, Zegeye ED, Kinander W, Tønjum T, Bekele S, Mannsåker T, Bjune G, Aseffa A, Holm-Hansen C. Mycobacterium tuberculosis lineage 7 strains are associated with prolonged patient delay in seeking treatment for pulmonary tuberculosis in Amhara Region, Ethiopia. J Clin Microbiol 2015; 53:1301-9.

Background

This is a prospective cohort study involving pulmonary and extra pulmonary (TB meningitis and TB lymphadenitis) patients. Study participants will be recruited from selected health facilities in Ethiopia, Sudan and South Sudan. Structured questionnaire will be used to collect sociodemographic and clinical data, In addition, sputum, cerebrospinal fluid and lymph node aspirate, plasma and serum samples will be collected from the study participants. Various laboratory analyses: Culture, drug susceptibility testing, spoligotyping, MIRU-VNTR typing and full genome sequencing will be performed.  Proteomic and lipidomic analyses will also be performed using mass spectrometry .

Financing

  • Helse Sør-Øst

Cooperation

  • Oslo University Hospital
  • Norwegian Institute of Public Health
  • Armaur Hansen Research Institute in Addis Ababa, Ethiopia
  • Regional State Health Bureaus in Ethiopia: Amhara, Benshangul Gumuz and Gambella
  • Epidemiological Laboratory (Epi Lab) in Khartoum, Sudan
  • Ministry of Health in South Sudan

Start - finish

2013-2016

Tags: Global South
Published Apr. 20, 2015 1:10 PM - Last modified May 31, 2016 3:03 PM

Contact

Project leader

Tone Tønjum

Participants

  • Abebe Yimer Solomon
  • Tone Tønjum
  • Gunnar Aksel Bjune
  • Dominique A Caugant
  • Dr Carol Holm-Hansen, Norwegian Institute of Public Health
  • Dr Gunnstein Norheim, Norwegian institute of Public Health
  • Dr Abraham Aseffa, Armauer Hansen Research Institute
  • Dr Markose Abebe, Armauer Hansen Research Institute
  • Professor Asma Elsony, Epidemiological laboratory (EpiLab), Khartoum, Sudan
  • Dr Richard Lako, Ministry of Health South Sudan
  • Ms Zebideru Zewde, Amhara Regional State Health bureau, Ethiopia
Detailed list of participants