Challenges in understanding and treating the rare monkey pox disease

A new retrospective study of seven patients diagnosed with monkeypox in the UK between 2018 and 2021, suggests that some antiviral medications might have the potential to shorten symptoms and reduce the amount of time a patient is contagious. The cases analysed in the study, published in The Lancet Infectious Diseases journal, represent the first instances of in-hospital transmission and household transmission outside of Africa, as well as reporting the patient response to the first off- label use of two different antiviral 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 authors also report 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.

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. Patients typically stay in isolation in a specialty hospital to prevent spreading the virus to others.

Monkeypox is spread via animal-to-human transmission, typically from an animal bite or eating improperly cooked meat. In rare cases, the virus can spread via human-to-human transmission. The first human case of monkeypox was reported in 1970 in the Democratic Republic of the Congo and rarely occurs outside central and western African countries. To date, there has been little research into cases of monkeypox in high-income countries.

The reported symptoms of monkeypox include fever, rash, and swollen lymph nodes. Complications have also been reported, including inflammation of the lungs, inflammation of the brain, sight- threatening inflammation of the cornea, and secondary bacterial infections. Published mortality rates vary greatly, from between 1-10% in the Congo Basin, and less than 3% in Nigeria. Most deaths from monkeypox occur in children and people living with HIV.

One of the 2021 UK patients was treated with tecovirimat and experienced a shorter duration of symptoms and upper respiratory tract viral shedding than the other cases in this cluster. However, the authors note that conclusions are unable to be drawn on antiviral effectiveness against monkeypox in such a small cohort, calling for further research into antivirals to treat this neglected tropical disease.