April 20, 2023
The global outbreak of mpox, previously known as monkeypox, infected more than 30,000 people and caused 42 deaths in the United States over a nine-month period last year.
The virus, endemic in parts of central and western Africa, had largely been contained since the 1970s. There had been a minor U.S. outbreak in 2003, when pet prairie dogs in the Midwest came in contact with infected African rodents and the virus spread to people, totaling only 47 cases. But there was no human-to-human transmission in that outbreak and mpox was still considered extremely rare outside of Africa.
Last May, the virus re-emerged in Europe and spread rapidly from human transmission, predominantly occurring among gay and bisexual men, as well as transgender and non-binary people, data showed. The primary mode of transmission between people is skin-to-skin contact.
Last year's outbreak reached more than 100 countries and infected nearly 87,000 people globally. About one-third of the reported cases were in the U.S., where vaccine shortages and limited testing capacity slowed efforts to contain the spread of mpox.
The U.S. Centers for Disease Control and Prevention's analysis of the outbreak found that people can spread mpox virus to others several days before their own symptoms appear. Even with vaccines and other therapeutics, preventing mpox infections proved difficult in many parts of the world during the peak of the outbreak. These findings make early detection a critical priority in preventing future outbreaks.
Researchers at Penn State University have developed the first mpox rapid test, which can detect the virus within minutes. Unlike like PCR tests, which require health care providers to swab lesions and submit them for an analysis that can take several days, the rapid tests could be self-administered at home if they become commercially available.
"This is a major breakthrough in terms of how we manage the virus, as it is the first rapid test for mpox," said Dipanjan Pan, who led the research team at Penn State. "While current caseloads are relatively low, as the weather warms and people become more active, cases could spike as they did last summer."
The public health emergency for mpox only ended in January when daily case counts fell into the single digits, down from about 450 last August.
The rapid test developed at Penn State uses a selective molecular sensor made from nanomaterials that can detect trace amounts of genetic materials in biological samples. The technology was recently reported in the journal Advanced Functional Materials.
"We were interested in developing a sensitive detection method for pathogens generally, and also wanted to apply the concept to an emerging pathogen like mpox, because there is a real-world urgency for this rapid nucleic acid test," Pan said. "There will be a significant impact on public health as a result of this technology."
The new rapid test is currently being tested against other pathogens to determine its overall effectiveness in viral detection. Once the test is clinically validated, the research team will seek commercial partners to make it available to the public.
Mpox typically begins with a fever followed by a rash on the face, inside the mouth and on other parts of the body, including the hands, feet, chest, genitals and anus. Swollen lymph nodes also may occur. Symptoms usually last for two to four weeks. The disease is rarely fatal.
During the outbreak, many major U.S. cities, including Philadelphia, were compelled to quickly implement testing and vaccine protocols and get the prevention message out to the public. This was made more difficult by stigmas surrounding the association of mpox with sex among gay and bisexual men, who had to overcome additional hurdles of communication and access to medical care to receive appropriate guidance and clinical attention.
Particularly alarming for public health officials are the parallels of racial disparities between the COVID-19 pandemic and the mpox outbreak. About 60% of the mpox cases reported in Philadelphia to date have been among Black residents. More than 70% of the city's cases have been among people between 20-40 years old. The COVID-19 pandemic also disproportionately affected people of color in Philadelphia.
Late last July, Philadelphia reported a peak of 74 new mpox cases in one week, according to health department data. The total in the city stood at 552 as of early April.
