Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Clinical Trial
. 2019 Apr 12;14(4):e0206334.
doi: 10.1371/journal.pone.0206334. eCollection 2019.

Insights into the genetic diversity of Mycobacterium tuberculosis in Tanzania

Liliana K Rutaihwa  1   2   3 , Mohamed Sasamalo  1   2   3 , Aladino Jaleco  1   2 , Jerry Hella  1   2   3 , Ally Kingazi  3 , Lujeko Kamwela  1   2   3 , Amri Kingalu  4   5 , Bryceson Malewo  4   5 , Raymond Shirima  4   5 , Anna Doetsch  1   2 , Julia Feldmann  1   2 , Miriam Reinhard  1   2 , Sonia Borrell  1   2 , Daniela Brites  1   2 , Klaus Reither  1   2 , Basra Doulla  4   5 , Lukas Fenner  1   2   6 , Sebastien Gagneux  1   2
Affiliations
Clinical Trial

Insights into the genetic diversity of Mycobacterium tuberculosis in Tanzania

Liliana K Rutaihwa et al. PLoS One. .

Abstract

Background: Human tuberculosis (TB) is caused by seven phylogenetic lineages of the Mycobacterium tuberculosis complex (MTBC), Lineage 1-7. Recent advances in rapid genotyping of MTBC based on single nucleotide polymorphisms (SNP), allow for phylogenetically robust strain classification, paving the way for defining genotype-phenotype relationships in clinical settings. Such studies have revealed that, in addition to host and environmental factors, strain variation in the MTBC influences the outcome of TB infection and disease. In Tanzania, such molecular epidemiological studies of TB however are scarce in spite of a high TB burden.

Methods and findings: Here we used SNP-typing to characterize a nationwide collection of 2,039 MTBC clinical isolates representative of 1.6% of all new and retreatment TB cases notified in Tanzania during 2012 and 2013. Four lineages, namely Lineage 1-4 were identified within the study population. The distribution and frequency of these lineages varied across regions but overall, Lineage 4 was the most frequent (n = 866, 42.5%), followed by Lineage 3 (n = 681, 33.4%) and 1 (n = 336, 16.5%), with Lineage 2 being the least frequent (n = 92, 4.5%). We found Lineage 2 to be independently associated with female sex (adjusted odds ratio [aOR] 2.14; 95% confidence interval [95% CI] 1.31 - 3.50, p = 0.002) and retreatment cases (aOR 1.67; 95% CI 0.95 - 2.84, p = 0. 065) in the study population. We found no associations between MTBC lineage and patient age or HIV status. Our sublineage typing based on spacer oligotyping on a subset of Lineage 1, 3 and 4 strains revealed the presence of mainly EAI, CAS and LAM families. Finally, we detected low levels of multidrug resistant isolates among a subset of 144 retreatment cases.

Conclusions: This study provides novel insights into the MTBC lineages and the possible influence of pathogen-related factors on the TB epidemic in Tanzania.

PubMed Disclaimer

Conflict of interest statement

Sebastien Gagneux used to be an editorial member of PLOS ONE while Lukas Fenner is currently an editorial member of PLOS ONE. However, this should not alter authors' adherence to all the PLOS ONE policies on sharing materials and data. The remaining authors have declared that no competing interests exist.

Figures

Fig 1
Fig 1. MTBC lineages in Tanzania.
A. MTBC lineage classification of 2,039 nationwide clinical strains. B. MTBC lineage frequencies and geographical distribution in Tanzania.
See this image and copyright information in PMC

References

    1. WHO. Global tuberculosis report Geneva: World Health Organization; 2017.
    1. NTLP. Annual report for 2016. Dar es Salaam. 2016;1–48.
    1. Nagu TJ, Aboud S, Mwiru R, Matee M, Fawzi W, Mugusi F. Multi Drug and Other Forms of Drug Resistant Tuberculosis Are Uncommon among Treatment Naïve Tuberculosis Patients in Tanzania. Surolia A, editor. PLoS One. 2015;10(4):e0118601 10.1371/journal.pone.0118601 - DOI - PMC - PubMed
    1. MoHSW. First tuberculosis prevalence survey in the United Republic of Tanzania. 2013;
    1. Rieder HL. Epidemiologic Basis of Tuberculosis Control First edition 1999. 1999.

Publication types