The World Health Organization on Saturday declared the monkeypox outbreak a global health emergency, as the number of cases, and countries reporting them, has climbed over the last month.

"We have an outbreak that has spread around the world rapidly, through new modes of transmission, about which we understand too little," WHO Director General Dr. Tedros Adhanom Ghebreyesus said during a press conference.

Tedros said there are now more than 16,000 reported cases from 75 countries, up from 3,040 reported cases from 47 countries a month ago. Five people have died as a result of the current outbreak, Tedros said. About 2,900 cases have been confirmed throughout the United States and Puerto Rico, according to the US Centers for Disease Control and Prevention.

Tedros said, however, that we have the tools to bring the outbreak under control, and he called on countries to carry out a coordinated response. That includes implementing measures for halting transmission and protecting vulnerable groups; increasing the monitoring of the outbreak's progress; speeding up research into vaccines and treatments; and developing recommendations for international travel.

Read more: What We Know About the Monkeypox Vaccine

Monkeypox spreads between people primarily through contact with infectious sores, scabs or bodily fluids, according to the CDC, but it can also spread through prolonged face-to-face contact via respiratory droplets or by touching contaminated clothing or bedding. Anyone can be infected with monkeypox, but so far many of the outbreak cases have involved men who have sex with men.

"Although I'm declaring a public health emergency of international concern," Tedros said, "for the moment, this is an outbreak that's concentrated among men who have sex with men, especially those with multiple sexual partners. That means that this is an outbreak that can be stopped with the right strategies in the right groups."

Tedros cautioned that "stigma and discrimination can be as dangerous as any virus" and he called on countries to adopt measures that "protect the health, human rights and dignity of affected communities."

He also said countries should work closely with those communities to develop services and outreach programs, and he said the WHO intends to partner with civil organizations, including groups with experience working with people who have HIV, to fight discrimination and stigma.

Gay and bisexual communities tend to have particularly "high awareness and rapid health-seeking behavior when it comes to their and their communities' sexual health," Dr. Hans Henri P. Kluge, the WHO's regional director for Europe, said in a statement at the end of May, noting that those who sought early health care services should be applauded.

A monkeypox infection typically begins with flulike symptoms, including fatigue, intense headache, fever and swollen lymph nodes. Within one to three days of a fever developing, according to the CDC, a rash or sores develop and can be located pretty much anywhere on the body, including the hands, genitals, face, chest and inside of the mouth.

Read more: What to Know About Monkeypox

Notably, some people never experience flulike symptoms, the CDC says, and people may experience all or only a few of the typical monkeypox symptoms. For safer sex and social gatherings where people may be in close contact with other peoples' bodies, the CDC has a fact sheet for practices to consider.  

Close contact is a key element in the transmission of monkeypox. That, along with the fact that the virus that causes monkeypox appears to have a slower reproduction rate than the COVID-19 virus, sets it apart from the ongoing COVID-19 pandemic, Dr. Tom Inglesby, director of the Center for Health Security at the Johns Hopkins Bloomberg School of Public Health, said last month at a media briefing.

CNET's Jessica Rendall contributed to this report.

The information contained in this article is for educational and informational purposes only and is not intended as health or medical advice. Always consult a physician or other qualified health provider regarding any questions you may have about a medical condition or health objectives.