Economic Recession and Emergence of an HIV-1 Outbreak among Drug Injectors in Athens Metropolitan Area: A Longitudinal Study

<div><p>Background</p><p>During 2011, a dramatic increase (1600%) of reported HIV-1 infections among injecting drug users (IDUs) was noted in Athens, Greece. We herein assess the potential causal pathways associated with this outbreak.</p><p>Methods</p><p>Our study employed high resolution HIV-1 phylogenetic and phylogeographic analyses. We examined also longitudinal data of ecological variables such as the annual growth of gross domestic product (GDP) of Greece in association with HIV-1 and HCV sentinel prevalence in IDUs, unemployment and homelessness rates and HIV transmission networks in Athens IDUs before and during economic recession (2008–2012).</p><p>Results</p><p>IDU isolates sampled in 2011 and 2012 suggested transmission networks in 94.6% and 92.7% of the cases in striking contrast with the sporadic networking (5%) during 1998–2009. The geographic origin of most HIV-1 isolates was consistent with the recently documented migratory waves in Greece. The decline in GDP was inversely correlated with annual prevalence rates of HIV and HCV and with unemployment and homelessness rates in IDUs (all p<0.001). The slope of anti-HCV prevalence in the sentinel populations of IDUs and in “new” drug injectors was found 120 and 1.9-fold (p = 0.007, p = 0.08 respectively) higher in 2008–2012 (economic recession) compared with 2002–2006. The median (25th, 75th) size of transmission networks were 34 (12, 58) and 2 (2, 2) (p = 0.057) in 2008–2012 and 1998–2007, respectively. The coverage of harm reduction services was low throughout the study period.</p><p>Conclusions</p><p>Scaling-up harm reduction services and addressing social and structural factors related to the current economic crisis should be urgently considered in environments where HIV-1 outbreaks may occur.</p></div

a Sentinel anti-HIV prevalence in IDUs entering drug treatment or accessing low-threshold services during the years 2002–2012 in Athens and areas other than Athens. b Sentinel anti-HCV prevalence in injecting drug users (IDUs) entering drug-related treatment or accessing low-threshold services during 2002–2012 in Athens and areas other than Athens. c Sentinel anti-HCV prevalence in IDUs with injecting history of less than 2 years (“new” IDUs) entering drug-related treatment or accessing low-threshold services during 2002–2012 in Athens and areas other than Athens. d Unemployment and homelessness rate drug injectors during 2002–2011 in Athens. Data were not collected in 2007.

<p>a Sentinel anti-HIV prevalence in IDUs entering drug treatment or accessing low-threshold services during the years 2002–2012 in Athens and areas other than Athens. b Sentinel anti-HCV prevalence in injecting drug users (IDUs) entering drug-related treatment or accessing low-threshold services during 2002–2012 in Athens and areas other than Athens. c Sentinel anti-HCV prevalence in IDUs with injecting history of less than 2 years (“new” IDUs) entering drug-related treatment or accessing low-threshold services during 2002–2012 in Athens and areas other than Athens. d Unemployment and homelessness rate drug injectors during 2002–2011 in Athens. Data were not collected in 2007.</p

Patterns of HIV-1 spread in IDUs.

<p>IDUs: Injecting Drug Users.</p>*<p>Comparisons of each group with the IDUs samples during 1998–2009.</p

Plot of the reporting rate of HIV-1 infection among injecting drug users (IDUs) per 100,000 of population in relation with the annual growth rate of gross domestic product (GDP).

<p>IDU clusters are shown by triangles proportional to the number of sequences. The time to most recent common ancestor (tMRCA) for the different outbreaks is denoted at the top of each triangle. The tMRCA for both subtype B clusters 1 and 2 was estimated before 2002 not shown in figure.</p

Number of reported HIV-1 cases among injecting drug users (IDUs) (blue) and the total population (red) over different years.

<p>Number of reported HIV-1 cases among injecting drug users (IDUs) (blue) and the total population (red) over different years.</p

Molecular clock analyses of HIV-1 sequences from: A. subtype A and CRF35_AD B. subtype B and C. subtype G and CRF14_BG sampled from different geographic areas and Greece.

<p>Molecular clock analyses of HIV-1 sequences from: A. subtype A and CRF35_AD B. subtype B and C. subtype G and CRF14_BG sampled from different geographic areas and Greece.</p

Characteristics of phylogenetic clusters among injecting drug users (IDUs).

<p><b>FSU:</b> Former Soviet Union.</p><p><b>tMRCA:</b> Time to most recent common ancestor.</p><p><b>HPD:</b> Higher Posterior Density.</p><p><b>NA:</b> Not Available.</p

Working hypothesis for the HIV-1 outbreak in Athens Metropolitan Area.

<p>Bold arrows indicate causal pathways suggested in the current study. Thin arrows indicate other possible causal pathways.</p

Study flow chart for each study period.

<p>CDI: <i>Clostridium difficile</i> infection</p

Impact of solid tumor malignancy and Charlson’s Comorbidity Index score more than 6 on the time until development of CDI.

<p>Impact of solid tumor malignancy and Charlson’s Comorbidity Index score more than 6 on the time until development of CDI.</p