This study, through a phylogenetic analysis, is aimed to identify potential epidemiological networks and sequence interrelationships between acute/early and chronic infections in both drug-naïve and drug-experienced individuals within a local, well-defined setting and to investigate the population dynamics of transmitted resistance and the potential contribution of untreated patients to the spread of antiretroviral resistance. A total of 884 HIV-1 B subtype pol gene sequences from 306 drug-naïve (40 recently and 266 chronically infected) and 578 drug-treated HIV-1 infected patients were collected through routine drug-resistance testing between 2000 and 2008 in a single center (Division of Infectious Disease, Bergamo, Northern Italy). Bayesian phylogenetic tree was reconstructed and transmission clusters were recognized using a posterior probability as statistical support of each cluster. Differences among clustered and non-clustered drug-resistance mutations were assessed by Fisher's exact test. In our cohort we identified five clusters including ≥6 sequences with the root posterior probability of 100%. Dated phylogenies reconstructed through Bayesian Markov chain Monte Carlo model was possible for only two main clade (≥10 sequences) originated between 1990 and 2002. Among the 306 drug-naïve individuals, 12% carried a viral strain with at least 1 major mutation associated with transmitted drug resistance and 36% of these strains were involved in significant clusters. We report for the first time that many (34%) of HIV-1 subtype B transmission clusters identified in Italy were only composed by drug-naïve individuals and that the 14% of transmitted drug resistance was linked to transmission clusters composed only of newly diagnosed individuals. The phylogenetic analysis was performed on a large cohort of drug-naïve recently/chronically infected individuals where drug-experienced patients represent almost all infected individuals in a restricted geographical area. Our findings highlight the role of newly diagnosed individuals, not yet exposed to antiretroviral drugs, in the transmission of drug-resistant HIV-1 strains, providing new insights for the planning and management of treatment programs in developing countries.
Epidemiological network analysis in HIV-1 B infected patients diagnosed in Italy between 2000 and 2008 / A. Callegaro, V. Svicher, C. Alteri, A. Lo Presti, D. Valenti, A. Goglio, M. Salemi, E. Cella, C. Perno, M. Ciccozzi, F. Maggiolo. - In: INFECTION GENETICS AND EVOLUTION. - ISSN 1567-1348. - 11:3(2011), pp. 624-632.
|Titolo:||Epidemiological network analysis in HIV-1 B infected patients diagnosed in Italy between 2000 and 2008|
|Parole Chiave:||Epidemiological network; HIV-1 subtype B epidemic; Phylogenetic analysis; Time-scaled phylogenies; Transmitted drug-resistance (TDR)|
|Settore Scientifico Disciplinare:||Settore MED/07 - Microbiologia e Microbiologia Clinica|
|Data di pubblicazione:||2011|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1016/j.meegid.2011.01.019|
|Appare nelle tipologie:||01 - Articolo su periodico|