As drug resistant sexually transmitted infections become a global threat, the judicious use of antibiotics remains at the forefront of care.

Many common sexually transmitted diseases (STDs) are caused by bacteria, and can generally be cleared up with a course of antibiotics.

Most of them, anyway.

According to estimates from the World Health Organization (WHO), every year 131 million people are infected with chlamydia, 78 million with gonorrhea, and 5.6 million with syphilis.

Left untreated, as they sometimes are, the infections remain contagious and can cause reproductive damage and even fetal death.

Drug resistant versions of chlamydia, gonorrhea, syphilis, and other bacteria are now making these common infections more difficult to treat.

Read more: Get the facts on sexually transmitted diseases »

Drug resistant forms of STDs — more medically accurate known as sexually transmitted infections (STIs) — such as gonorrhea have now become a global threat.

In response, WHO officials issued new guidelines regarding how doctors should treat these common infections without increasing the risk of antibiotic resistance.

“The guidelines reflect the recognition that the phenomenon of antibiotic resistance permeates all infections and ensuring that the right medications are prescribed for STIs is crucial,” Amesh A. Adalja, an nfectious disease physician at the University of Pittsburgh Medical Center told Healthline. “Study after study has shown that rising rates of resistance in many STIs were complicating treatment decisions and necessitating updating the guidelines.”

All forms of antibiotic resistant bacteria are responsible for infecting at least 2 million people in the United States each year. Of those infections, 23,000 are fatal, according to the latest assessments from the U.S. Centers for Disease Control and Prevention (CDC).

Emerging research shows the various ways antibiotics can evolve defenses against even the strongest antibiotics, namely through repeated exposure through nonlethal levels of the drugs.

The discovery and development of new antibiotics aren’t keeping pace with the rate bugs are developing resistance, so doctors and infectious disease experts are finding ways to preserve the effectiveness of current antibiotics.

The CDC revised their guidelines for treating STDs last year.

Read more: ‘Nightmare bacteria’ may signal ‘end of the road’ for antibiotics »

Much of WHO’s new guidelines rely on local medical facilities and health professionals to monitor cases of resistance.

In the United States, the CDC and some local and state health departments track these patterns, Adalja said.

“It should be a standard of care for physicians to have local resistance rates of various bacteria readily available, and some institutions and localities have that ability,” he said.

Using that data, WHO produced the following guidelines:

  • Gonorrhea: This common STI — that can
    cause infection in the groin
    and throat — has shown resistance every time a new antibiotic is released. That
    means older and cheaper antibiotics don’t work, so WHO urges countries to update their national gonorrhea treatment guidelines
    in accordance with prevalence of resistance circulating among their population.
    The guidelines do not recommend one class of antibiotics, quinolones, because
    of widespread and high levels of resistance.
  • Syphilis: This STI, if passed from
    mother to child, can often result in the child’s death, WHO states. It’s also
    spread from contact with sores in the groin or mouth. There’s a treatment available that’s effective and cheaper than
    oral antibiotics. WHO recommends a single injection of the antibiotic
    benzathine penicillin into the patient’s buttock or thigh muscle.
  • Chlamydia: The most common of all bacterial STIs. While most infected people don’t have
    symptoms, its trademark is a burning sensation while urinating. The WHO
    guidelines outline nine different treatment strategies
    for children and adults.

WHO’s announcement ended with one parting thought: “When used correctly and consistently, condoms are one of the most effective methods of protection against STIs.”

Read more: Weakening antibiotics could result in 6,300 more infection-related deaths each year »

Part of the driving force of antibiotic resistance is the overprescription of antibiotics, namely in cases where they are not medically needed in humans or animals.

The CDC estimates of all antibiotics prescribed to humans, a third are unnecessary, meaning they’re used for conditions caused by viruses, not bacteria, according to the CDC. This includes the common cold and certain STIs.

For example, one study from St. John Hospital & Medical Center in Detroit found three-fourths of people given antibiotics in the emergency department after showing symptoms for certain STIs actually don’t have those infections. They get antibiotics before lab results are in, resulting in unnecessary and unsafe prescriptions for antibiotics.

“In the U.S., individuals with gonorrhea and chlamydia are often treated empirically before test results are available,” Adalja said.

One such way to reduce these prescriptions, experts say, is increasing the use of cheap, rapid diagnostic testing that can tell if an infection is caused by a bacteria and specifically which one.

“Rapid, highly sensitive, and highly specific diagnostic tests are urgently needed for a variety of infectious diseases,” Adalja said. “Developing diagnostic tests for these STIs that have comparable characteristics to urine pregnancy tests would drastically improve the treatment of STIs.”