Montezuma and La Plata counties rank in the top 20 among Colorado counties for chlamydia and gonorrhea.

Montezuma County had the second highest rate of chlamydia and the third highest rate for gonorrhea in the state during 2016, according to Colorado Department of Public Health and Environment data.

“There is a real concern and a real issue,” said Dr. Dan Shodell, deputy director of the state health department’s Disease Control and Environmental Epidemiology Division.

The U.S. hit a record high for sexually transmitted diseases in 2016 with more than 2 million cases of chlamydia, gonorrhea and syphilis. Chlamydia accounted for the majority of those cases, according to the Centers for Disease Control and Prevention.

If gone untreated, chlamydia and gonorrhea can have serious long-term consequences such as infertility and an increased risk of acquiring HIV, Shodell said.

The number of chlamydia cases statewide has trended upward since 2013, and the state health department doesn’t fully understand why, Shodell said. Gonorrhea cases also have been on the rise since 2011.

It’s possible residents are not getting screened for the diseases because they are not experiencing symptoms and they end up passing them on to partners, he said.

“Unfortunately, we’re building this reservoir of infection, which can attribute to accelerated transmission rates,” he said.

As more people acquire the disease, the faster it spreads, he said.

In 2016, there were 25,569 cases of chlamydia in Colorado, making it the most common STD in the state.

Montezuma County reported 189 cases of chlamydia in 2016, up from 155 cases in 2015.

The rate of chlamydia in Montezuma County was 702 cases per 100,000, which is significantly higher than the state rate of about 461 cases per 100,000.

In La Plata County, there were 202 cases of chlamydia in 2016, down slightly from 239 cases in 2015. La Plata County ranked 18th among all Colorado counties for the disease, with a rate of 362 cases per 100,000.

Using rates per 100,000 allows the data to be compared over time as the population changes, Shodell said. It also allows different-sized counties to be compared. State researchers examined all of the state’s 64 counties for their prevalence of STDs.

While Shodell said people may be forgoing screening, San Juan Basin Public Health spokeswoman Claire Ninde said it’s possible more people are being tested, which would also increase the number of reported cases.

Gonorrhea also is on the rise, but there are far fewer cases across the region. In 2016, there were 60 cases in Montezuma County and 26 in La Plata County, according to the state health department.

Colorado counties bordering La Plata and Montezuma counties do not rank highly for either disease, and that may be associated with low populations. The state health department has noticed hot spots at population centers.

Both infections are treatable, and patients can avoid lasting effects if the diseases are identified early, Shodell said.

The CDC recommends that all sexually active women younger than 25 be screened annually for chlamydia. Those with a new sex partner, multiple sex partners or a sex partner with an STD should also be screened.

mshinn@durangoherald.com