The presence of HIV-1 non-B subtypes in Germany has been increasing in recent years and is commonly attributed to migration from non-European countries. We combined molecular epidemiology and geospatial data to explore dynamics of HIV-1 non-B subtypes in Germany, before and after the European migrant crisis 2015.
Sociodemographic, geographic and HIV-1 pol sequence data were obtained from individuals who accessed care at seven University Hospitals (Bonn, Cologne, Freiburg, Frankfurt, Hamburg, Hannover, Munich) in Germany, between 2001 and 2018. Phylogenetic and genetic network analyses were performed to infer putative transmission links (genetic distance ≤1.5%). Individuals‘ origins were grouped into six regions: Western Europe and other high resource countries; Eastern Europe; North Africa and the Middle East; sub-Saharan Africa; Latin America and the Caribbean; and Asia.
We included data from 3,110 HIV-1 infected individuals. The overall proportion of the non-B subtypes increased from 27% (673/2,490) before January 2015 to 31.5% (195/620) after 2015 (subtype G 7.4%; 184/2,490 before 2015 vs. 9.5%; 59/620 after). This was particularly driven by the year 2017, where non-B subtypes made up 39.4% of new HIV diagnoses. The proportion of non-B infected individuals, originating from Eastern Europe [8.9% (254/673) to 13.3% (60/195), p= 0.027], and the North Africa and Middle East region [1.34% (9/673) to 5.6% (11/195), p< 0.001] increased significantly after 2015. However, there were only three new non-B diagnoses after 2015 among individuals from the top 5 countries of origin of the 2015 immigrants (i.e. Syria, Kosovo, Afghanistan, Albania, Iraq). Of the 868 non-B HIV infected individuals, 119 (13.7%) were genetically linked, forming 42 transmission clusters (size 2-19 sequences) with heterosexual risk (36.1%; 43/119) and injection drug use (20.1%; 24/119) being predominant. There was an increase in genetically linked men who have sex with men (MSM) with two male only clusters before 2015 and the emergence of six more male only clusters (including 9/18 males, of whom 8/9 originating from Eastern Europe) after 2015 (Figure 1A&B).
The proportion of HIV-1 non-B diagnoses increased after 2015, particularly driven by individuals originating from Eastern Europe, North Africa, and Middle East. However, the number of new diagnoses among migrants originating from the top 5 countries of the European migrant crisis was minimal.