Antivirals May Reduce Symptoms In Monkeypox Patients, Suggests Study In Lancet

The study, published in The Lancet Infectious Diseases journal, reports the patient response to the first off-label use of two different antiviral medications to treat monkeypox.

Certain antiviral medications could potentially reduce symptoms and decrease the amount of time a monkeypox patient is contagious, according to a new retrospective study. | Representative Photo ( Image Source :Getty )

New Delhi: Certain antiviral medications could potentially reduce symptoms and decrease the amount of time a monkeypox patient is contagious, according to a new retrospective study. As many as seven patients diagnosed with monkeypox in the United Kingdom between 2018 and 2021 were analysed as part of the study.  

The cases represent the first instances of in-hospital transmission and household transmission outside of Africa. The study, published in The Lancet Infectious Diseases journal, reports the patient response to the first off-label use of two different antiviral medications to treat monkeypox. The two antiviral medications are brincidofovir and tecovirimat. 

Where Was Monkeypox Virus Detected In The Patients?

While the study found little evidence that brincidofovir was of clinical benefit, it concluded that further research into the potential of tecovirimat would be warranted. Monkeypox virus was detected in blood and throat swabs of the patients, the authors report in the study. Data from the study could help inform global efforts to further understand the clinical features of monkeypox and transmission dynamics, as optimum infection control and treatment strategies for the disease are not established yet.

Study Offers Some Of The First Insights Into Use Of Antivirals For Monkeypox Treatment

According to a Lancet statement, Dr Hugh Adler, the lead author on the paper, said that as public health officials are trying to understand what is causing the May 2022 monkeypox outbreaks in Europe and North America, the study offers some of the first insights into the use of antivirals for the treatment of monkeypox in humans. The outbreaks in Europe and North America have affected several patients who reported neither travel nor an identified link to a previously unknown case. 

Adler added that although the latest monkeypox outbreak has affected more patients than the researchers had previously encountered in the UK, historically, monkeypox has not transmitted very efficiently between people, and overall, the risk to public health is low.

Centres Are Important Manage Outbreaks Of Monkeypox-Like Diseases

In the same statement, Nick Price, senior author on the paper, said the cases reported in the study, in addition to the recent outbreaks, highlight the importance of maintaining a collaborative network of centres on standby to manage sporadic, outbreaks of high consequence pathogens, such as monkeypox. The cases the researchers observed were challenging and resource-intensive to manage, even in the high-income setting of the UK, Price added.

The researcher also said that 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. 

Monkeypox Has Been A Rare Condition In UK Until Now

The authors said that until now, monkeypox has been a rare, imported condition in the UK and the NHS High Consequence Infectious Diseases Network has treated all seven of the UK's confirmed cases until 2021. The researchers added that outbreaks outside of Africa are unusual but in recent days, significant outbreaks have been reported in several European countries, including the UK, and further afield globally. "Clinical trial data is lacking and we are pleased to share some of our collective experience in managing this previously rare and sporadic condition," the researchers said.

Monkeypox: Transmission, Symptoms, And More

Monkeypox virus is a close relative of the smallpox virus, and causes monkeypox, which is a rare disease classified as a High Consequence Infectious Disease (HCID) by the UK Health Security Agency. No licensed treatments for monkeypox are currently available. Also, data on the duration of its contagiousness is limited. The incubation period of monkeypox ranges from five to 21 days. In order to prevent spreading the virus to others, patients usually stay in isolation in a speciality hospital.

Monkeypox is a zoonotic disease, which means it is spread through animal-to-human transmission. An animal bite or eating improperly cooked meat can cause monkeypox if the animal had the disease. The virus can spread via human-to-human transmission in rare cases. In 1970, the first human case of monkeypox was reported in the Democratic Republic of Congo.

The disease rarely occurs outside Central and Western African countries. There has been little research into data into cases of monkeypox in high-income countries.

Monkeypox symptoms include fever, rash, and swollen lymph nodes. Complications associated with monkeypox include inflammation of the lungs, inflammation of the brain, sight-threatening inflammation of the cornea, and secondary bacterial infections. The published mortality rates for monkeypox varu greatly, ranging from one to 10 per cent in the Congo Basin, and less than three per cent in Nigeria. 

Four Out Of Seven Cases Imported From West Africa

According to the study, four out of the seven UK monkeypox cases analysed were imported from West Africa with three further cases occurring due to human-to-human transmission within the case clusters. The study authors described the duration and clinical features of monkeypox in a high-income setting by observing clinical data alongside laboratory results from blood tests and nose-and-throat swabs. The scientists reported patient response to antiviral medications developed to treat smallpox, which have previously demonstrated efficacy against monkeypox in animals. These antiviral medications are brincidofovir and tecovirimat.

Of the seven patients, four were treated for monkeypox in High Consequence Infectious Disease (HCID) units in England between 2018 and 2019. Three of these cases were imported from West Africa, and the fourth case occurred in a healthcare worker 18 days after initial exposure to the monkeypox virus. This was the first example of monkeypox transmission in a hospital setting outside of Africa. 

Initial Three Patients Treated With Brincidofovir

According to the study, the initial three patients were treated with brincidofovir seven days after the initial onset of the rash. The researchers observed alterations in liver blood tests. Also, brincidofovir was not observed to have any convincing clinical benefit in treating monkeypox. 

It is not known whether brincidofovir administration earlier in the course of the disease or at a different dosing schedule would have yielded different clinical outcomes, the authors note in the study. Nevertheless, all four patients made a full recovery.

Three Further Cases Reported In UK In 2021

In 2021, three further cases of monkeypox were reported in the UK in a family travelling from Nigeria. Of these, two cases were the first examples of household transmission outside of Africa. According to the study, one of the cases occurred in a child, who was observed carefully because of the association of a higher likelihood of mortality from monkeypox in children. The child experienced mild illness and fully recovered. 

One Of The Three Patients Treated With Tecovirimat

One of these patients was treated with tecovirimat and experienced a shorter duration of symptoms and upper respiratory tract viral shedding than the other cases in the cluster, according to the researchers. Since the cohort is small, conclusions are unable to be drawn on antiviral effectiveness, the authors note in the study. This calls for further research into antivirals to treat the neglected tropical disease. 

Severe Mild Disease Observed For All Patients

According to the study, all patients experienced mild disease and were treated in a hospital setting for infection control purpose and not due to the severity of the infection, and no patients experienced the commonly recognised severe complications of monkeypox. These complications include pneumonia or sepsis. However, one patient experienced a mild relapse six weeks following hospital discharge, another patient developed a deep tissue abscess that required drainage, and some patients experienced low mood, likely stemming from isolation in High Consequence Infectious Disease facilities.

Dr Catherine Houlihan, one of the co-authors of the paper, said that during previous outbreaks of monkeypox, patients were considered infectious until all lesions crusted over. In the seven UK cases considered in the study, viral shedding was observed for at least three weeks following infection, she said, adding that data on infectivity remains limited, and is an important area of future study.