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Deciphering the Complex Distribution of Human Immunodeficiency Virus Type 1 Subtypes among Different Cohorts in Northern Tanzania.

Njai, H. F., Ewings, F. M., Lyimo, E., Foulongne, V., Ngerageza, D., Mongi, A., Ssemwanga, D., Andreasen, A., Nyombi, B., Ao, T., Michael, D., Urassa, M., Todd, J., Zaba, B., Changalucha, J., Hayes, R. and Kapiga, S. H. (2013) Deciphering the Complex Distribution of Human Immunodeficiency Virus Type 1 Subtypes among Different Cohorts in Northern Tanzania. PloS one, 8 (12). e81848. ISSN 1932-6203

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Increased understanding of the genetic diversity of HIV-1 is challenging but important in the development of an effective vaccine. We aimed to describe the distribution of HIV-1 subtypes in northern Tanzania among women enrolled in studies preparing for HIV-1 prevention trials (hospitality facility-worker cohorts), and among men and women in an open cohort demographic surveillance system (Kisesa cohort). The polymerase encompassing partial reverse transcriptase was sequenced and phylogenetic analysis performed and subtype determined. Questionnaires documented demographic data. We examined factors associated with subtype using multinomial logistic regression, adjusted for study, age, and sex. Among 140 individuals (125 women and 15 men), subtype A1 predominated (54, 39%), followed by C (46, 33%), D (25, 18%) and unique recombinant forms (URFs) (15, 11%). There was weak evidence to suggest different subtype frequencies by study (for example, 18% URFs in the Kisesa cohort versus 5-9% in the hospitality facility-worker cohorts; adjusted relative-risk ratio (aRR) = 2.35 [95% CI 0.59,9.32]; global p = 0.09). Compared to men, women were less likely to have subtype D versus A (aRR = 0.12 [95% CI 0.02,0.76]; global p = 0.05). There was a trend to suggest lower relative risk of subtype D compared to A with older age (aRR = 0.44 [95% CI 0.23,0.85] per 10 years; global p = 0.05). We observed multiple subtypes, confirming the complex genetic diversity of HIV-1 strains circulating in northern Tanzania, and found some differences between cohorts and by age and sex. This has important implications for vaccine design and development, providing opportunity to determine vaccine efficacy in diverse HIV-1 strains.

Item Type: Article
Keywords: Virus Type 1, HIV-1, Polymerase, phylogenetic, Kisesa, Vaccine, Tanzania
Subjects: HIV > Surveillance
HIV > Prevention
Divisions: National Institute for Medical Research
Depositing User: Mr Joseph Madata
Date Deposited: 23 Jan 2014 07:58
Last Modified: 23 Jan 2014 07:58

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