Monkeypox symptoms, contagious phase can be reduced by anti-viral drugs: Lancet study

Some antiviral medications might have the potential to shorten symptoms of monkeypox and reduce the amount of time a patient is contagious, according to a study of seven patients diagnosed with the rare viral disease in the UK between 2018 and 2021.

The cases analysed in the study, published recently in The Lancet Infectious Diseases journal, represent the first instances of in-hospital transmission and household transmission outside of Africa.

The research also reported the patient response to the first off-label use of two different anti-viral medications — brincidofovir and tecovirimat — to treat the disease. The study found little evidence that brincidofovir was of clinical benefit, but concluded that further research into the potential of tecovirimat would be warranted.

The researchers also reported detection of monkeypox virus in blood and throat swabs. As optimum infection control and treatment strategies for this disease are not yet established, data from the study could help inform global efforts to further understand the clinical features of the disease as well as transmission dynamics, they said.

“As public health officials are trying to understand what is causing the May 2022 monkeypox outbreaks in Europe and North America — which have affected several patients who reported neither travel nor an identified link to a previously known case — our study offers some of the first insights into the use of antivirals for the treatment of monkeypox in humans,” said Hugh Adler from Liverpool University Hospitals NHS Foundation Trust, the UK.

“Although this latest outbreak has affected more patients than we had previously encountered in the UK, historically, monkeypox has not transmitted very efficiently between people, and overall, the risk to public health is low,” Adler, lead author on the paper, said.

With international travel returning to pre-pandemic levels, public health officials and healthcare workers around the world must remain vigilant to the possibility of new cases of monkeypox, said Nick Price from Guy’s & St Thomas’ NHS Foundation Trust, senior author on the paper.

Of the seven UK monkeypox cases analysed in the study, four were imported from West Africa with three further cases occurring due to human-to-human transmission within the case clusters.

Monkeypox, a close relative of the smallpox virus, is a rare disease classified as a High Consequence Infectious Disease (HCID) by the UK Health Security Agency. There are currently no licensed treatments for monkeypox and there is limited data on the duration of its contagiousness, with the incubation period ranging from five to 21 days.

The study authors observed clinical data alongside laboratory results from blood tests and nose-and-throat swabs to describe the duration and clinical features of monkeypox in a high-income setting. Researchers also reported patient response to antiviral medications developed to treat smallpox — brincidofovir and tecovirimat — which have previously demonstrated some efficacy against monkeypox in animals.

Between 2018 and 2019, four patients observed in the study were treated for monkeypox in HCID units in England. Three of these cases were imported from West Africa. The fourth case occurred in a healthcare worker 18 days after initial exposure to the virus and was the first example of monkeypox transmission in a hospital setting outs