CIRCULATION OF MULTIPLE GENOTYPES OF TORQUE TENO VIRUS (TTV) IN SUBJECTS WITH AND WITHOUT HIV VIRUS INFECTION

Dennis Mwala¹, Dufton Mwaengo^{1, 2}, OnyambuF³, Kirima JM⁴, Omu Anzala^{2, 5}

¹University of Nairobi Institute of Tropical and Infectious Diseases (UNITID), Nairobi, Kenya

²Department of Medical Microbiology, University of Nairobi, Nairobi, Kenya

³University of Nairobi, Molecular Infectious Diseases and Research Laboratory

⁴Meru Teaching and Referral Hospital (MTRH)

⁵KAVI-Institute of Clinical Research

Background

DNA viruses can belong to any of the three major Baltimore classes identifiable as group I (dsDNA viruses), group II (ssDNA viruses) or group VII (dsDNA with RT) based on whether they possess a single stranded DNA or a double stranded DNA with or without a reverse transcriptase. Torque teno virus (TTV) is a member of group II DNA viruses that contains a circular negative sense genome. This virus was previously classified as a circoviridae member but currently has been reclassified as a member of the family Anelloviridae. This thin necklace shaped virus,as seen on electron micrographs, is also described in earlier literature as the transfusion transmitted virus still bearing the abbreviations TTV.A review of studies done in Africa provides scanty information on the distribution of this virus. The only data currently available is on studies done in Gambia, DRC, Nigeria, Egypt, South Africa, Sudan, Ivory Coast, Uganda and Tanzania mostly these studies explored the prevalence of the virus from the general population but have not documented the genotypic characteristics of this virus whenever encountered.

Methodology

This study aimed to use both serological and molecular tools to investigate and document on the prevalence and the genotypic characteristics of the TTV strains circulating in Kenya in both high risk groups and low risk groups.

Results

So far a total of 144 samples have been collected (70 cases and 74 controls). The samples have been stored in -70^oC freezers at the UNITID facility. We started by only screening for human TTV in this series of assays mainly by PCR. A total of 53 samples are positive for TTV out of the 144 screened. That is 32 cases and 21 controls. This accounts for preliminary estimation of 36.8% prevalence. The initial sequencing has been done on 5 representative samples of TTV and the preliminary results indicated that a single individual can be infected by multiple genotypes of the virus. Only 4 genotypes have been observed (genotypes 1, 3, 4 and 5).

Conclusion

Multiple strains of the TTV virus are circulating in healthy subjects and HIV infected subjects in Kenya and genotypes 1, 3, 4 and 5 are the most likely frequent isolates to be encountered.