Molecular Surveillance of HIV-1 in Madrid, Spain: a Phylogeographic Analysis

Abstract

The molecular epidemiology of HIV-1 is constantly changing, mainly as a result of human migratory flows and the high adaptive ability of the virus. In recent years, Spain has become one of Europe's main destinations for immigrants and one of the western European countries with the highest rates of HIV-positive patients. Using a phylogeographic approach, we have analyzed the relationship between HIV-1 variants detected in immigrant and native populations of the urban area of Madrid. Our project was based on two coincidental facts. First, resistance tests were extended to naïve and newly diagnosed patients, and second, the Spanish government legislated the provision of legal status to many immigrants. This allowed us to obtain a large data set (n ‫؍‬ 2,792) from 11 Madrid hospitals of viral pol sequences from the two populations, and with this unique material, we explored the impact of immigration in the epidemiological trends of HIV-1 variants circulating in the largest Spanish city. The prevalence of infections by non-B HIV-1 variants in the studied cohort was 9%, rising to 25% among native Spanish patients. Multiple transmission events involving different lineages and subsubtypes were observed in all the subtypes and recombinant forms studied. Our results also revealed strong social clustering among the most recent immigrant groups, such as Russians and Romanians, but not in those groups who have lived in Madrid for many years. Additionally, we document for the first time the presence of CRF47_BF and CRF38_BF in Europe, and a new BG recombinant form found in Spaniards and Africans is tentatively proposed. These results suggest that the HIV-1 epidemic will evolve toward a more complex epidemiological landscape.

Characteristics of Patients Recently Infected with HIV-1 Non-B Subtypes in France: a Nested Study within the Mandatory Notification System for New HIV Diagnoses

“…Subtype B predominates in the Americas, Europe, Japan, and Australia, whereas non-B subtypes predominate in Africa and in most Asian countries. Many studies have reported an increasing prevalence of non-B subtypes in Europe since the beginning of the epidemic (2)(3)(4)(5)(6)(7)(8)(9)(10). Whereas there is a common notion that HIV-1 infections with non-B subtypes are mainly associated with migrant populations from the developing world, there is increasing evidence that the epidemiology of non-B viruses in Europe results from both migration and domestic transmissions (11)(12)(13).…”

“…Whereas there is a common notion that HIV-1 infections with non-B subtypes are mainly associated with migrant populations from the developing world, there is increasing evidence that the epidemiology of non-B viruses in Europe results from both migration and domestic transmissions (11)(12)(13). Most of the studies have described the increasing prevalence of non-B variants in Europe among newly diagnosed HIV-1 infections or patients referred for antiretroviral resistance testing (4,(6)(7)(8)(9). However, the duration of infection for each new diagnosis was frequently unknown in these studies.…”

Dynamics and molecular evolution of HIV-1 strains in Sicily among antiretroviral naïve patients

“…The present work confirms CRF02_AG as the prevalent circulating recombinant form in our region, as well as in several European countries (González-Alba et al, 2011;von Wyl et al, 2011;Yebra et al, 2012), in contrast to that observed in the northern part of Italy where subtype F1 is the most prevalent non-B clade (Lai et al, 2010), mirroring the extensive influx of immigrants from Romania, an European country with a massive prevalence of subtype F1 HIV-1 infections .…”

Estudios de epidemiología molecular en población inmigrante en España

“…Los trabajos analizados diferían sustancialmente en el tamaño de las muestras estudiadas, desde un mínimo de 8 individuos 18 hasta un máximo de 2.792 9 . Ambos estudios se realizaron sobre el mismo organismo, el VIH, y tuvieron como objetivo básico el genotipado y el origen de las variantes del virus encontradas.…”

“…No obstante, dependiendo del patógeno y de los objetivos iniciales del estudio molecular, todavía se encuentran trabajos basados en estas aproximaciones. La facilidad para la obtención de secuencias génicas, incluso genómicas, ha permitido que la epidemiología molecular basada en el conocimiento de estas secuencias sea la metodología más extendida, bien de forma directa, especialmente para el estudio de virus [7][8][9][10] , o bien tras su codificación en variantes discretas, como en los sistemas de tipado multilocus (MLST) adoptados en muchas bacterias.…”