The rate in the East – 51.1 new cases diagnosed by 100,000 people – was "disproportionately higher" than in the West, which had a rate of 6.4 new cases per 100,000 people, the report found Central Europe's rate was 3.2 diagnoses per 100,000 people.
Rates were highest in Russia, where 71 new homes were diagnosed for 100,000 people in 2017, followed by Ukraine and Belarus.
As a result, the region is not on track to meet the target 90-90-90 by 2020, as outlined by WHO and the Joint United Nations Program on HIV / AIDS.
The aim is to diagnose 90% of all HIV-positive people, provide antiretroviral therapy for 90% of those diagnosed and achieve viral suppression for 90% of those treated.
The target is part of the Sustainable Development Goal of eliminating HIV in Europe, and worldwide, by 2030.
"We are quite far behind achieving those targets, particularly in Eastern Europe and Central Asia," said Dr. Masoud Dara, coordinator of communicable diseases and HIV team lead at WHO Europe.
"The significance in this report is that we can see a sharp difference between Eastern Europe and the European Union where the number of HIV infections is dropping."
In order to meet the target, new infections would need to decline by 78% by 2020, the report said.
Over the past three decades, more than 2,32 million people have been diagnosed with HIV in Europe. According to WHO, 36.9 million people were living with HIV globally in 2017. Africa, where the estimated number of people living with HIV is 25.7 million, was most affected.
Improving HIV testing
Dara said there were several factors behind the HIV rate in Eastern Europe, with the most important one being lack of prevention.
"The most important thing is to make sure that people … injecting drug users, commercial sex workers and men who have sex with men have good preventative measures in place," Dara said.
"For injecting drug users, they need to have clear needle exchange programs. We do not have many of these in Eastern European countries as opposed to Western Europe," he said, adding that early testing for HIV needs to be in place, as well as treatment.
"Treatment has proven to be a prevention," he explained, and it helps suppress the virus, preventing people from infecting others.
Intravenous drug use and heterosexual contact were the most common ways HIV was transmitted in the Eastern region of Europe, the report said. Sex between men was responsible for transmission in the European Union and European Economic Area.
In a statement, WHO Regional Director for Europe Zsuzsanna Jakab called on governments to "scale up your response now."
The report calls on governments to do this by "tailoring interventions to those most at risk" and to invest in prevention, testing and treatment.
Everyone is at risk
Dr. Anton Pozniak, president of the International AIDS Society, said there needs to be a focus on removing stigma that surrounds HIV diagnosis.
"Policies that reduce social marginalization, stigma and discrimination are needed as are increased funding for prevention and testing," Pozniak said in a statement.
"In the East, particularly in Russia, the shift away from progressive policies towards socially conservative legislation is a barrier to implementing HIV prevention and treatment."
With heterosexual contact and intravenous drug use among the most commonly reported means of transmission in the East, Dara said, it is important for everyone to realize that they could be at risk of infection.
"No one should think, 'I will not ever have HIV,'" he said. "That's very important, and we have to make sure that people are coming for tests at all levels."
Pozniak reiterated that there could be a shift in who is most affected by HIV in Russia.
"People who inject drugs account for the largest proportion of new diagnoses of any key population at 48.8%, but heterosexual sex may soon overtake injecting drug use as the main means of HIV transmission," he said.
"This is a potential shift from mainly affecting key populations to affecting the general population."