In a new risk assessment document, the European Center for Disease Prevention and Control (ECDC) summarizes what we currently know about monkeypox and recommends that European countries focus on identifying and managing the disease as well as contract tracing and timely notification of new virus cases.
From May 15 to 23, in eight European Union (EU) member states (Belgium, France, Germany, Italy, the Netherlands, Portugal, Spain and Sweden), a total of 85 cases of monkeypox were reported; they were acquired by indigenous transmission. Currently diagnosed cases of monkeypox have been primarily recorded in men who have sex with men, suggesting that transmission may occur during sexual intercourse, through infectious material coming into contact with mucous membranes or damaged skin, or via large respiratory droplets during prolonged face-to-face contact. – facial contact.
Andrea Ammon, MD, Director of ECDC, said “Most current cases have presented with mild symptoms of illness, and for the general population the risk of spread is very low. However, the likelihood of ‘further spread of the virus through close contact, for example during sexual activity between people with multiple partners, is greatly increased.
Stella Kyriakides, European Commissioner for Health and Food Safety, added: “I am concerned about the increase in cases of monkeypox in the EU and globally. We are currently monitoring the situation and although at this time the likelihood of it spreading to the general population is low, as the situation is evolving we must all remain vigilant, ensure that contact tracing and a capacity to sufficient diagnostics are in place and ensure the availability of vaccines and antivirals, as well as sufficient personal protective equipment [PPE] for healthcare professionals.”
Monkeypox does not spread easily among people. Person-to-person transmission occurs through close contact with infectious material, from skin lesions of an infected person, through air droplets in the case of prolonged face-to-face contact, and through fomites. Cases diagnosed so far suggest that transmission can occur during sexual intercourse.
The incubation period is 5-21 days and patients are symptomatic for 2-4 weeks.
According to the ECDC, the likelihood of spreading this infection is increased in people who have more than one sexual partner. Although most current cases have mild symptoms, monkeypox can cause severe illness in certain groups (such as young children, pregnant women, and immunocompromised people). However, the likelihood of severe illness cannot yet be accurately estimated.
The overall risk is considered moderate for people with multiple sex partners and low for the general population.
The disease is initially manifested by fever, myalgia, fatigue and headache. Within 3 days of the onset of prodromal symptoms, a centrifugal maculopapular rash appears at the site of primary infection and rapidly spreads to other parts of the body. The palms of the hands and the soles of the feet are involved in cases where the rash has spread, which is a feature of the disease. Usually within 12 days, the lesions progress, simultaneously changing from macules to papules, blisters, pustules and crusts before falling off. Lesions may have a central depression and be extremely itchy.
If the patient scratches them, a bacterial superinfection may set in (for which treatment with oral antihistamines is indicated). Lesions may also be present in the oral or ocular mucosa. Before or at the same time as the rash appears, patients may experience swollen lymph nodes, which is not usually seen with smallpox or chickenpox.
The appearance of the rash is considered the beginning of the infectious period; however, people with prodromal symptoms can also transmit the virus.
Most cases in people have mild or moderate symptoms. Complications observed in endemic countries include encephalitis, secondary bacterial skin infections, dehydration, conjunctivitis, keratitis and pneumonia. The mortality rate ranges from 0% to 11% in endemic areas, with deaths from the disease occurring mainly in young children.
There is not much information available about the disease in immunocompromised people. During the 2017 Nigerian outbreak, patients with co-infection with HIV had more severe disease, with more skin lesions and genital ulcers, than HIV-negative people. No deaths have been reported among HIV-positive patients. The main sequelae of the disease are usually disfiguring scars and permanent corneal damage.
No smallpox vaccine is authorized against monkeypox, but the third generation smallpox vaccine Imvanex (Modified Vaccinia Ankara) has been authorized by the European Medicines Agency (EMA) for the EU market against smallpox and is has been shown to provide protection in primates.
Older generation smallpox vaccines have significant side effects, are no longer licensed, and should no longer be used. It is also important to note the lack of safety data for the use of Imvanex in immunocompromised people.
For this reason, national immunization technical advisory groups have been asked to develop specific guidelines for the immunization of close contacts of patients with monkeypox. The use of a smallpox vaccine for pre-exposure prophylaxis cannot be considered today given the benefit/risk ratio.
Regarding treatment, tecovirimat is the only antiviral drug with an EMA-cleared indication for orthopoxvirus infection.
Brincidofovir is not licensed in the EU but has been cleared by the US Food and Drug Administration. However, availability in the European market is somewhat limited by the number of doses.
According to the ECDC, health authorities should provide information on which groups should have priority access to treatment.
The use of antivirals for post-exposure prophylaxis should be further investigated. Cidofovir is active in vitro for smallpox but has a pronounced nephrotoxicity profile which makes it unsuitable for first-line therapy.
The ECDC document also proposes a provisional case definition for epidemiological reporting. Further guidance will also be provided for the management of monkeypox cases and close contacts. Infected persons must remain isolated until the scabs have fallen off and must above all avoid close contact with at-risk or immunocompromised persons as well as with pets.
Most infected people can stay home with supportive care.
Close contacts of monkeypox cases should monitor their symptoms until 21 days have passed since their most recent exposure to the virus.
Health workers should wear appropriate PPE (gloves, waterproof gowns, FFP2 masks) when screening suspected cases or when working with confirmed cases. Laboratory personnel should also take precautions to avoid workplace exposure.
Close contacts of an infected person should not donate blood, organs, or bone marrow for at least 21 days from the last day of exposure.
Finally, ECDC recommends increasing proactive risk communication to raise awareness and provide updates and guidance to those most at risk, as well as the general public. These messages should emphasize that monkeypox is transmitted through close person-to-person contact, particularly within the family unit, and also potentially through sexual intercourse. However, a balance must be maintained between informing those most at risk and communicating that the virus does not spread easily and that the risk to the general population is low.
Transmission from human to animal
A potential risk of human-to-animal transmission exists in Europe; therefore, close collaboration is needed between human and veterinary health authorities, working together to manage domestic animals exposed to the virus and to prevent disease transmission to wildlife. To date, the European Food Safety Authority is not aware of any case of animal infection (domestic or wild) within the EU.
Many unknowns still surround this epidemic. ECDC continues to closely monitor any developments and will update the risk assessment as new data and information become available.
If human-to-animal transmission occurs and the virus spreads among animal populations, there is a risk that the disease could become endemic in Europe. Therefore, human and veterinary health authorities should work closely together to manage cases of domestic animals exposed to the virus and prevent disease transmission to wildlife.
This article was translated from Univadis Italy .
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