Recession and income inequality have fuelled HIV infections in European drug users

Georgios Nikolopoulos, of the University of Athens, presenting at AIDS 2014. Image by Roger Pebody (
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In European countries, increases in rates of reported HIV infections among people who inject drugs in recent years have been associated with the economic downturn and income inequality, Georgios Nikolopoulos of the University of Athens told the 20th International AIDS Conference (AIDS 2014) in Melbourne today.

In most European countries, HIV infection rates in people who inject drugs have been stable or have declined over the past decade. However, Greece and Romania experienced an almost 20-fold increase in new diagnoses between 2010 and 2012. It has been suggested, but not proven, that these outbreaks were caused by the economic crisis that began in 2007, with cuts to harm reduction services possibly being a crucial factor.

There is limited quantitative evidence on the associations between economic problems and HIV infections, especially in a pan-European context. The researchers therefore examined data from 30 different European countries, collecting national statistics from a ten-year period (2003-2012) on:

  • economic indicators (GDP per capita, GDP growth, income inequality, poverty, unemployment, etc.),
  • services and policies (government expenditure on health and social programmes, numbers receiving opioid substitution therapy, availability of needle and syringe programmes, etc.), and
  • drug use (number of people who inject drugs, number using opiods, etc.).


odds ratio (OR)

Comparing one group with another, expresses differences in the odds of something happening. An odds ratio above 1 means something is more likely to happen in the group of interest; an odds ratio below 1 means it is less likely to happen. Similar to ‘relative risk’. 

multivariable analysis

Statistical technique often used to reduce the impact of confounding factors, in order to attempt to identify the real association between a factor of interest and an outcome. 

harm reduction

Harm reduction is a set of practical strategies and ideas aimed at reducing negative consequences associated with drug use (including safer use, managed use and abstinence). It is also a movement for social justice built on a belief in, and respect for, the rights of people who use drugs.

retention in care

A patient’s regular and ongoing engagement with medical care at a health care facility. 


Confounding exists if the true association between one factor (Factor A) and an outcome is obscured because there is a second factor (Factor B) which is associated with both Factor A and the outcome. Confounding is often a problem in observational studies when the characteristics of people in one group differ from the characteristics of people in another group. When confounding factors are known they can be measured and controlled for (see ‘multivariable analysis’), but some confounding factors are likely to be unknown or unmeasured. This can lead to biased results. Confounding is not usually a problem in randomised controlled trials. 

Dr Nikolopoulos and colleagues examined the associations of these factors with periods of time in which specific countries had experienced significant increases in the HIV diagnosis rate among people who inject drugs. As well as the dramatic outbreaks in Greece and Romania, a number of other countries had experienced smaller rises and spikes in infection during the ten-year period.

He used “lagged values” – in other words, considering the possibility that economic problems or a cut in harm reduction services would only have an impact on HIV diagnoses one, two or three years later. The figures below are based on an assumption of a two-year lag between economic effects and health impact, but similar results were produced if a one- or two-year lag were assumed.

Even in the first (univariable) analysis, the only factors significantly associated with increases in HIV infections were economic: the GDP growth rate, poverty and three separate measures of income inequality (S80/S20, Gini-coefficient and the Public Wealth Index).

And in multivariable analysis, after adjusting for confounding factors, only two factors were significantly associated with an increase in diagnoses. Firstly, countries with continued growth in GDP were less likely to have rises in HIV diagnoses (odds ratio 0.65, 95% confidence interval 0.48-0.86). Secondly, countries with a higher Gini-coeffecient (income inequality) were more likely to have more diagnoses (odds ratio 1.49, 95% CI: 1.00-2.22).

Put more simply, countries in economic recession or with greater income inequality were more likely to have jumps in HIV infections in people who inject drugs.

Presenting the data, Georgios Nikolopoulos noted numerous other examples of economic crises, conflicts and other social upheavals having an impact on health. Several studies have found evidence of worse infectious disease outcomes during recession, often as a result of higher rates of infectious contact in poor living circumstances, worse access to therapy, or poor retention in care. When the Soviet Union broke up, the subsequent economic crisis and collapse of existing social structures was associated with massive increases in HIV and TB infections, alongside other health problems. Globally, countries with worse income inequality have higher prevalence of HIV.

He commented that the mechanisms through which economic problems lead to infections remain unclear, but it is unlikely to be entirely due to less provision of harm reduction services – in many settings, very few services were available even before the recession.

He concluded that governments should be aware that they could help avert HIV epidemics in people who inject drugs through economic policies that assure economic growth and a more equal distribution of a country's wealth.


Nikolopoulos G et al. Recession and income inequality are associated with large increases in rates of reported HIV infections among people who inject drugs in Europe. 20th International AIDS Conference, Melbourne, abstract MOAD0104, 2014.

View the abstract on the conference website.