ATHENS — Greece’s efforts to control its debt crisis threaten to hobble the fight against an outbreak of HIV that has become the largest among drug users in the European Union.
The nation’s Organization Against Drugs, or Okana, may close treatment centers after its budget was more than halved to $23.5 million this year from about 40 million euros in 2011, said Meni Malliori, Okana’s president.
That’s jeopardizing progress the group has made in almost tripling the number of centers it operates in Athens to help arrest new infections.
‘‘We have to face this very difficult problem under the worst circumstances,’’ Malliori said in a telephone interview. ‘‘If we don’t get more money, we can’t even maintain what we did during the last year.’’
New infections among drug users have exploded 35-fold in two years, adding pressure on a strained medical system that’s been battling simultaneous outbreaks of malaria and West Nile virus with shrinking resources amid the financial crisis.
A government hiring freeze and spending cuts aimed at curbing the nation’s spiraling debt threaten to stall the response and extend the almost four-year wait for opioid substitutes that ease withdrawal symptoms so addicts can quit and avoid HIV.
The Greek outbreak contributed to the first increase in cases among drug users since at least 2004 in the European Economic Area.
Greece had more cases in that group than any of the region’s other members in 2011, according to a report published in November by the European Centre for Disease Prevention and Control.
Infections among injecting drug users more than doubled to 487 as of the end of October, from 206 in the same period in 2011 and 14 in 2010, according to data on the Hellenic Center for Disease Control and Prevention’s website.
Injecting drug use accounted for almost half of all new infections, overtaking sex between men for the first time as the main means of transmission, the data show.
‘‘It’s going to get worse and worse,’’ said Nikos Dedes, the chairman of Positive Voice, an Athens-based AIDS charity. ‘‘You have to respond to a galloping problem, and at the same time the entities that are responsible to do it are losing money.’’