MPOX (Monkeypox)

MPXV is a double-stranded DNA virus belonging to the family Poxviridae, genus Orthopoxvirus (same genus as Variola virus that causes smallpox). There are two genetically distinct groups of the MPXV virus: group I (formerly Central African clade, Congo Basin) and group II (formerly West African clade).

In endemic countries, it is predominantly a zoonosis, through direct contact with infected animals that occurs during activities such as hunting, trapping, and fur processing.

Regardless of the viral group, the virus that causes mpox can spread by person-to-person transmission through close physical contact, such as sexual intercourse, as well as family contact. Close contacts are defined as:

• direct skin-to-skin contact with infected skin lesions;
• mouth-to-mouth or mouth-to-skin contact (kissing), face-to-face (including talking or breathing

in a close manner);

• contact with saliva and upper respiratory tract secretions in a close

and prolonged;

• oral, anal or vaginal sex, or contact with the genitals (penis, testicles, labia and vagina)

or with the anus.

The infection can also be transmitted by contaminated underwear, clothing or surfaces.

The virus can also be transmitted from mother to fetus during pregnancy, during or after delivery through skin-to-skin contact from mother to baby.

Since late 2023, a large outbreak of mpox has affected the Democratic Republic of Congo (DRC), with recent expansion to other African countries-Burundi (61 confirmed, 165 suspected), Central African Republic (35 confirmed, 223 suspected), Republic of Congo (19 confirmed and 150 suspected), Rwanda (4 confirmed cases), Uganda (2 confirmed cases), and other countries such as Cameroon, Côte d'Ivoire, Ghana, Liberia, Kenya, Nigeria, and South Africa. In 2024, a total of 17,541 cases of mpox were reported on the African continent (14,719 suspected and 2,822 confirmed), including 517 deaths.

European spread: As of August 18, 2024, one imported case of MPXV was reported in the EU/EEA in Sweden

Italian spread: From May 20, 2022 (date of the first reported case of mpox in Italy) to August 8, 2024, a total of 1,056 confirmed cases of mpox were reported, most of which occurred in the summer of 2022. From January 1 to August 8, 2024, 65 confirmed cases were reported from 12 regions. All cases refer to infections that occurred in 2023 and early this year; no new cases are referable to August.

Symptoms of mpox usually appear 6-14 days (up to 21 days) after infection. The clinical manifestation of the disease includes general symptoms, such as fever, headache, backache, and muscle pain, and a characteristic rash (papules, vesicles, and pustules) (in 95% of cases), often with concomitant mucosal (oral cavity) lesions. The rash may spread rapidly throughout the body within three days of the onset of symptoms. Lymphadenopathy (enlarged lymph nodes) and proctitis (anorectal involvement) may be present . Most people experience mild to moderate symptoms that usually last two to four weeks followed by complete recovery. Severe pictures of the disease are not excluded, however, and may manifest with visceral localization, bacterial overinfection, and other complications. Children, pregnant women, and people with compromised immune systems, particularly people with untreated HIV, are at risk of developing complications and death.

Testing by PCR/Real time PCR should be conducted following clinical and epidemiological evaluation to confirm a possible diagnostic suspicion because of the higher sensitivity and specificity.

In contrast, serologic testing can support diagnostics but is not a sufficient element to make a diagnosis of infection and still requires evaluation conducted by performing molecular testing using sample taken from skin lesions (skin fragments, exudate swabs).

No treatment is generally necessary in paucisymptomatic or asymptomatic subjects.

Instead, in subjects with worsening clinical conditions, antivirals are administered, which generally act by interfering with an Orthopoxvirus surface protein, thereby preventing replication and slowing the spread of the virus.

As of January 2022, Tecomirivat has been approved by the European Commission for the treatment of Orthopoxvirus infections (smallpox, monkeypox, cowpox), in adults and children with a body weight of at least 13 kg.

Other antiviral drugs are under investigation, including cidofovir and brincidofovir. However, no data are available on the efficacy of cidofovir in treating human cases of monkeypox.

Vaccination against smallpox, a disease caused by a related virus (thus not specific to monkeypox), provides some protection against monkeypox. The vaccine currently usable in Italy is IMVANEX made available only to public facilities.

Several studies have also shown that subjects previously immunized for smallpox (pre-1981) can achieve >85% coverage for monkeypox and consequently have less severe symptomatic manifestations.

Prevention of spread is appropriately contained with timely contact tracing management. This allows for the implementation of infection preventive measures such as isolation of patients deemed potentially infectious pending diagnostic evaluations to confirm/deny the diagnosis.

Close contact with infected persons or contaminated materials should be avoided. Gloves and other personal protective clothing and equipment should be worn when caring for the sick, whether in a health care facility or at home.

Sterilization of clothes, clothing, bedding and utensils contaminated by individuals who test positive is also essential.

World Health Organization (WHO)

CDC Centers for Disease Center

EUROPEAN MEDICINES AGENCY

Ministry of Health CIRCULAR No. 24775