Ireland diagnosed a record high number of new H.I.V. infections in 2018, new health data suggests, a trend that contrasts with a general decline in infections across Europe, and that some Irish activists attribute to poor sex health education and insufficient access to preventive drugs.
Preliminary figures released last month by the Health Protection Surveillance Center, a state watchdog, suggested that 531 new cases of H.I.V. infection had been diagnosed in Ireland last year, an increase from 492 the previous year. And though intravenous drug use was the main way H.I.V. spread through Ireland in the late 1980s and early 1990s, in recent years sex between gay and bisexual men has become the most common route for transmission, accounting for more than half of new cases.
Dr. Derval Igoe, a specialist in public health at the Irish government’s Health Services Executive, said that although the number of diagnosed H.I.V. infections in Ireland had recently increased after several years of stability, the rise did not necessarily indicate a widening epidemic.
Overall, Ireland’s rate of new diagnoses, at 10.2 per 100,000 people in 2017, was higher than the European average of roughly 6.2 per 100,000. But it was not the highest in the European Union: Latvia reported 18.8 cases per 100,000 people, and Estonia 16.6 cases per 100,000, according to European health officials.
Dr. Igoe said that a high proportion of the new cases involved migrants who had been infected before they came to the country, and people whose infection was detected through a local testing program introduced in 2016 that encourages people to discover their status early.
“It’s really a rare bright note in the treatment of H.I.V. that we can tell people, ‘If you take a test, find out your status early on, you can deal with it so that you don’t get sick, and you won’t make other people sick either,’” she said. “As we say, if the virus is undetectable, it’s untransmittable too.”
In recent years, government campaigns to reduce the harm from drugs, including the introduction of needle exchanges, methadone treatments and health education, have decreased the number of H.I.V. cases transmitted through drug use. In 2017, only 5 percent of the new H.I.V. diagnoses were found to have been transmitted via infected needles, while 53 percent were attributable to sex between men, according to health officials.
At the same time, the proportion of new cases via heterosexual transmission, once a small part of the total, has now risen to 33 percent. Dr. Igoe said many of these new cases involved migrants who were not aware of an infection and had come from countries with a much higher prevalence of heterosexual H.I.V. transmission, such as in sub-Saharan Africa.
Barriers to medicines may have also contributed to the increase. Andrew Leavitt, a spokesman for the Irish chapter of the international H.I.V. activist group Act Up, said the use of medications to prevent infection before and after exposure — so-called PrEP drugs that are particularly effective at reducing transmission among gay and bisexual men — has been hampered in Ireland by the slow introduction of cheaper generic versions of the drugs.
These preventive drugs are now available as prescriptions in Ireland, at costs varying from 50 to 80 euros, or about $56 to $90, for a 30-day supply — prices that are down, Mr. Leavitt said, from several hundred euros a month for the patent brand, Truvada. In several other Western European countries, the drugs are available cheaply or at no charge from public health services.
“The more widely available these drugs are, if they’re used properly, the fewer infections there will be,” Mr. Leavitt said.
He said that while some of the increase in sexual transmission in recent years could, in part, be ascribed to the new popularity of “hookup” apps and to unsafe drug use in conjunction with sex, the activist group is particularly concerned about what it regards as the poor sex education in Irish schools.
“It hasn’t really changed in 20 years,” he said. “There’s a lot of stuff about pregnancy and contraception but not much about sexual health, how to minimize risks, and there’s virtually nothing about H.I.V. in the schools. That has to change, if we’re going to make progress.”
Dr. Igoe, the public health specialist, said the Irish authorities were aware of the potential benefits of more widespread use of PrEP drugs to block H.I.V. infection, and they are conducting a study to determine the costs and benefits of PrEP programs. She said that the government had committed to introducing one such program later this year, though how it would work in detail was still unknown.