Some people newly diagnosed with sexually transmitted diseases may also have monkeypox, said the Centers for Disease Control and Prevention, which warns doctors to monitor and test both, as monkeypox can look very to an STD.
CDC director Rochelle Walensky said some patients with monkeypox also had infections with syphilis, herpes, gonorrhea or chlamydia. The rash that characterizes monkeypox can look like herpes or syphilis, Walensky said.
“It’s important to be aware that cases of smallpox can be similar to some sexually transmitted infections and can be confused with other diagnoses,” Walensky said in a call to reporters Friday. Patients with symptoms should be evaluated for all sexually transmitted infections as well as smallpox, he said.
“Healthcare providers should not rule out monkeypox just because a patient has another diagnosis or another STI,” Walensky told reporters.
According to the CDC, the United States has confirmed 45 cases of smallpox in 15 states and Washington DC as of Thursday. No deaths were reported. The current outbreak is unusual because the virus is spreading outside of West and Central Africa, where the disease has been present for decades. More than 1,300 cases have been reported worldwide in 31 countries, according to the CDC.
Smallpox usually starts with flu-like symptoms, such as fever, headache, muscle aches, chills, exhaustion, and swollen lymph nodes. The disease then progresses to a painful rash that can spread throughout the body. Most patients recover within two to four weeks without specific medical treatment, according to the CDC.
However, some patients during the current outbreak have developed a rash only in the genitals or anus before they experience any flu-like symptoms, Walensky said. In some cases, patients developed a rash with no flu-like symptoms, he said. In many cases, the localized rash has not spread to other parts of the body or only to certain areas, the CDC director said.
People diagnosed with smallpox during the current outbreak have reported close physical contact with other people infected with the virus, Walensky said. The virus can be spread by direct contact with sores, body fluids, or materials such as clothing or sheets.
Walensky said it is unclear whether the virus can spread through semen or vaginal fluid as a sexually transmitted disease. The CDC also does not know if the virus can spread to infected people who have no or mild symptoms.
At least 75 percent of monkeypox patients in the United States have reported exposure to the virus during international travel, according to Dr. Jennifer McQuiston, head of the CDC. Most cases have been reported among men who have sex with men, according to the CDC.
Some patients are unsure of how they caught the monkey’s smallpox, suggesting the virus may be spreading in the United States at a low level, McQuiston said. However, the CDC has not identified any U.S. cities or regions where there is an outbreak, he said.
“There are only those occasional, rare cases that are unsure of how they acquired monkeypox,” McQuiston said. “Most likely, they bought it from someone who has recently traveled, but they’re not sure,” he said.
Montreal, Canada’s third-largest city, has reported an outbreak, McQuiston said. Montreal is just across the border from New York State and New England.
Monkeypox can also spread through the respiratory tract when people have close, sustained face-to-face contact, Walensky said. The virus is not believed to stay in the air or be transmitted through short periods of shared airspace, such as casual conversations at the grocery store, Walensky said. Nor is it believed that the monkey’s smallpox spreads to briefly touch the same element, such as a door knob, he said.
According to Dr. Raj Panjabi, who heads the White House pandemic preparedness office, no transmission of smallpox has been reported by air. The difference is that respiratory drops fall quickly to the ground while aerosol particles are much smaller and can remain in the air for a longer period of time, Panjabi said. Covid-19, for example, spreads through aerosol particles, which is one of the reasons it is so infectious.
According to Punjabi, the federal government has provided 1,400 vaccine courses and 110 antiviral treatments for people who have been exposed to high-risk exposures or monkeypox infections. The United States has also performed 300 tests so far for orthopox, the family of viruses that includes monkeypox. When people test positive for orthopox, they are supposed to have smallpox until the Atlanta CDC confirms the diagnosis.
“We are working to make testing through public health labs more convenient and expand testing beyond public health labs through business partners,” Panjabi told reporters in the call on Friday.
The United States currently has 72,000 doses of the Jynneos vaccine, a smallpox vaccine that is also approved to fight monkeypox, which is immediately available in the strategic national stock, according to Dawn O’Connell, who runs the Health and Human Services office responsible for inventory. Manufacturer Bavarian Nordic is also shipping 300,000 more doses to the United States, O’Connell told reporters.
Jynneos is a two-dose vaccine approved by the Food and Drug Administration to prevent monkeypox in people 18 years of age and older. The United States also has more than 100 million doses of an older-generation smallpox vaccine, ACAM2000, which can also prevent monkeypox infection. Smallpox and smallpox are in the same virus family, although smallpox is much milder.
The CDC generally recommends Jynneos above ACAM2000, because the latter vaccine can have serious side effects. The U.S. currently does not have enough doses of Jynneos in the supply chain to vaccinate everyone in the event of a public health emergency, McQuiston said. As a result, the Jynneos vaccine is being given only to those who will benefit the most, he said. ACAM2000 has a role to play in vaccinating people who are not at risk of vaccine side effects to help maintain an adequate supply of Jynneos for those who need it, he said.