WASHINGTON, United States (CMC) – Following the detection of a Clade I variant case for the first time in the region, the Pan American Health Organization (PAHO) says countries of the Americas, including the Caribbean, need to maintain mpox surveillance.

PAHO said the Clade I case was reported by the United States Centers for Disease Control and Prevention (CDC) on November 16. Clade I has historically caused more severe illness and death than Clade II.

In an epidemiological alert, issued by the health organization on Tuesday, PAHO urged countries to remain vigilant and “to continue with their surveillance efforts, with a special emphasis on high-risk groups.”

“The individual had a history of recent travel to East Africa and was treated shortly after arrival in the United States,” PAHO said. “Health authorities are working to identify and follow-up with potential contacts.”

To date, no further cases of Clade I have been detected in the region, PAHO said. It said that, between January 2022 and October 31, 2024, 115,101 confirmed cases of mpox, including 255 deaths, were reported in 123 World Health Organization (WHO) member-states.

PAHO noted that, on August 14, 2024, WHO Director-General Dr Tedros Adhanom Ghebreyesus determined that an upsurge of mpox due to clade Ib in the Democratic Republic of Congo (DRC) and a growing number of countries in Africa constitutes a public health emergency of international concern (PHEIC).

In the Americas, PAHO said the highest number of mpox cases was recorded during 2022, peaking in August 2022. This was followed by a progressive decrease in cases that has continued throughout 2023 and 2024 and all cases in the Americas, except for the recent imported case of Clade Ib, were due to Clade II, PAHO said.

Symptoms include fever, intense headache, muscle aches, back pain, low energy, swollen lymph nodes, and a skin rash, or mucosal lesions, PAHO said. It said the rash tends to be concentrated on the face, palms of the hands, and soles of the feet, but can also be found on the mouth, anogenital region and eyes.

In the alert, PAHO also reminded all member states to continue surveillance efforts to characterize the situation and respond rapidly in the event of an introduction of Clade I mpox virus.

“Efforts should focus on early detection and diagnosis, isolation and contact tracing,” PAHO urged. “While vaccination can help prevent infection for people at risk, ‘mass vaccination against mpox in the population is neither required nor recommended.’”