Sexually transmitted diseases are climbing at an alarming pace in Maine and across the country, especially common bacterial infections like chlamydia and gonorrhea, threatening the long-term health of thousands of Mainers and millions of Americans.

Chlamydia cases climbed to 4,551 in 2017, according to the Maine Center for Disease Control and Prevention, compared to 2,586 cases in 2010, a 76 percent increase. The cases have been rising steadily every year. Meanwhile, gonorrhea cases rose sharply in 2017 to 577, after 451 cases in 2016, a 28 percent increase. There were 162 gonorrhea cases in 2010.

Syphilis cases also increased, from 48 in 2016 to 84 in 2017, an 83 percent increase. In one bright spot, HIV-positive cases declined from 47 in 2016 to 32 last year, down 47 percent.

The overall trends are worrisome to Maine public health experts, who are puzzled by the increases. Sexually transmitted diseases are also on the rise across the United States.

“What is going on?” said Evelyn Kieltyka, senior vice president at Maine Family Planning, an Augusta-based nonprofit that has 18 clinics across the state offering STD screening and treatment. The clinics include more populated areas like Bangor, Augusta and Lewiston, as well as more rural locations, such as in Calais, Fort Kent and Rumford.

“We can’t seem to push the needle in the other direction,” Kieltyka said.

The U.S. Centers for Disease Control and Prevention said last September that the number of reported cases of STDs in 2016 – the most recent year available for national statistics – was the highest ever recorded at about 2 million across the nation. Chlamydia was by far the most common disease, with 1.6 million new cases in 2016.

Chlamydia is a bacterial infection that, if untreated, can lead to serious complications. In women, it can damage the fallopian tubes or lead to pelvic inflammatory disease, while men can experience testicular inflammation and potential sterility.

“Increases in STDs are a clear warning of a growing threat,” said Dr. Jonathan Mermin, director of the CDC’s National Center for HIV/AIDS, Viral Hepatitis, STD and TB Prevention, in a statement. “STDs are a persistent enemy, growing in number, and outpacing our ability to respond.”

MANY POTENTIAL REASONS BEHIND THE INCREASE

While most are easily treatable with antibiotics – and even HIV is much more treatable than it was decades ago – if left untreated STDs can have long-term health consequences for patients, including infertility, increased likelihood of certain cancers, pelvic inflammatory disease and increased chances of stillbirths.

Syphilis is more serious, and in the later stages of the disease can cause damage to the organs, mental illness, blindness and nerve problems. Syphilis has come back to become a public health problem after plummeting to extremely low levels in the late 1990s and early 2000s.

There doesn’t appear to be any definitive national research on why STDs are increasing, but some are speculating that anonymous sex from online dating and cutbacks in public health spending may be fueling the rise, and there are some concerns about condom use declining among at-risk populations. For instance, among sexually active high school students, condom use increased from 46 percent in 1991 to 63 percent in 2003, but declined to 57 percent by 2015, according to Child Trends, a Maryland-based think tank. However, according to a U.S. CDC report released in 2017, condom use among people 15-44 stayed the same or increased slightly in 2011-15 when compared to the study’s baseline year, 2002.

Dr. Christina DeMatteo, medical director at the Portland Community Free Clinic on India Street, said online dating is making it difficult for public health workers to track down sexual partners, a standard practice after someone tests positive for an STD.

“That’s much harder to do with anonymous online dating,” DeMatteo said. “There’s no doubt the rates in Maine are very rapidly rising.”

Dr. Noah Nesin, vice president of medical affairs for Penobscot Community Health Center in Bangor, said he also doesn’t know why STDs are increasing, but a weakened Maine CDC and fewer routine Pap smears for young female patients could be factors. Health professionals are recommending fewer Pap smears for young women because overscreening was counterproductive for other gynecological problems, Nesin said. But the primary care system has overall done a substandard job of making sure that women at risk of STDs are getting tested who previously would have been screened annually for STDs when they came in for their gynecological appointments. STDs are often asymptomatic, so screening is key.

Nesin said sexually active baby boomers could also be contributing to the problem, as could the opioid epidemic.

“Unfortunately, people are trading sex for money or drugs,” Nesin said.

SCREENINGS RECOMMENDED FOR AT-RISK POPULATIONS

Kieltyka said that part of the increase, at least in Maine, may have to do with better and more frequent screenings, and keeping better track of the screening data.

At Maine Family Planning, for instance, health professionals recommend routine STD screening for at-risk populations who walk in the door, even if the patients are coming to the clinics for other reasons.

DeMatteo said closing STD clinics in Lewiston and Bangor in recent years did not help Maine’s public health infrastructure, but it’s difficult to point to those clinics closing as a reason for the STD increase. Maine had the 12th-highest per-capita state CDC spending, according to a 2017 study by the Trust for America’s Health. However, CDC spending encompasses many subject areas other than STD education and prevention, including responding to the flu, vaccine programs, public health nurses and other health programs. While the Maine CDC’s spending is relatively high compared to other states, it shoulders more of the public health burden because many other states have county health departments, while Maine does not.

The Portland free clinic serves about 900 patients per year, and its numbers have been flat for a few years, DeMatteo said.

She said patients can make appointments, or show up as a walk-in, from 3-5:30 p.m. on Tuesdays and Thursdays. Screenings include taking blood samples, urine tests and mouth and rectum swabs. In many cases, if STDs are detected, staff can treat the patient on the spot with antibiotics. In many cases, staff can give one dose and it will take care of the STD.

“We offer no-fee, judgment-free screenings,” she said.

Staff members hold an informal meeting before opening the STD free clinic on Feb. 1 at the India Street Public Health Center. (Derek Davis/Portland Press Herald)