GENEVA — More than 6,500 deaths have been reported in the Donbass region, where Ukrainian forces have battled Russian-supported separatist fighters for control since April 2014. The political violence has led to a humanitarian crisis. More than 8,000 patients being treated for H.I.V. or drug dependence have had life-saving medicines cut off, or will soon be without them, unless action is taken right now to allow a humanitarian convoy through.

Health care was an early casualty of the conflict in the Donbass. The Ukrainian government, saying it wished to ensure that national resources did not fall into the hands of armed groups, cut off funding in November to all facilities in the region, including hospitals, and told patients who remained in the conflict zone that they could travel to government-controlled territory to receive medicines. Unsurprisingly, this has proved impractical for many people who are sick, poor or simply frightened. Mechanisms to monitor and respond to disease outbreaks are no longer functional in the territory; immunization coverage is low, and health experts now fear possible outbreaks of polio and for the safety of blood supplies.

People at risk for, or living with, H.I.V. are already suffering. Ukraine has one of the highest rates of H.I.V. infection in Europe; the majority of patients were infected with the virus through contaminated drug injections. Before the conflict, Ukrainian programs helped control H.I.V. infections in the Donbass by providing sterile needles and syringes and methadone, a medicine the World Health Organization recommends to reduce use of and craving for heroin. Ukraine successfully reduced H.I.V. infections, particularly among young people who inject drugs, for whom infection rates decreased more than fivefold between 2007 and 2013.

Unfortunately, the Donbass conflict now jeopardizes that progress. According to the International H.I.V./AIDS Alliance in Ukraine, a nongovernmental organization based in Kiev, more than 1,000 patients in the Donbass have either had their methadone stopped or reduced to substandard doses, forcing men and women to undergo painful withdrawal or return to street drugs. Requests to the Ukrainian government to replenish methadone supplies, accompanied by an offer by Doctors Without Borders to oversee distribution, were met with the response that the medicine — distributed routinely to hundreds of thousands of patients across Western Europe — could be transported, under Ukrainian law, only by armed convoys. In June, a number of patients sent a video appeal to government officials, saying they feared for their lives because their treatment had been interrupted. It is not known how many people have succumbed to overdose or suicides after methadone treatments were ended, though the video reported nine deaths.