No 20b - 2022

Monkeypox outbreak in Europe

In these days, Europe is experiencing a large outbreak of monkeypox. Monkeypox is a condition which, until recently, only rarely caused outbreaks beyond Vest and Central Africa. The condition presents as fever, myalgia, headache and swollen lymph nodes, followed by a rash with blisters, typically after one to three days. The mortality of monkeypox is 1-10%, and the West-African variant believed to be causing the current outbreak is the mildest variant with a mortality of approx. 1%. The condition is caused by transmission of droplets during close physical contact. As per 20 May, international organisations and the media report that a total of 36 confirmed cases and various suspected cases have been detected, mainly among men who have sex with men. 

The current outbreak

The current cases are distributed on Great Britain (9), Spain (7), Portugal (14), Sweden (1), Belgium (2), Italy (1), France (1) and Germany (1). Beyond Europe, cases have been detected in North America (3), and currently Australia has detected a single travel-related case.

On 7 May and once more on 13 May, Great Britain notified the WHO of a total of two laboratory-confirmed cases (PCR test on vesicular swabs and a likely case of monkeypox (West African type).

Two of the three cases were from the same household, where one of the members was a traveller from Nigeria where the disease is endemic. On 15 May, the WHO was notified of an additional four laboratory-confirmed cases in England, all among men who have sex with men (MSM). No epidemiological link was established to travellers from West Africa, but two of the men shared contacts.

Additional studies is underway, including contact tracing. On 18 May another two cases were identified. Based on publicly available information, the additional cases also appear to be men. The clinical presentation of the condition with rash that initially presents in the anogenital area and the fact that the condition has frequently been detected at venereal clinics raises a suspicion that sexual transmission may play a role in the current outbreak.

Based on the rapidly progressing outbreak in Europe, the SSI assesses that cases will likely also occur in Denmark. We therefore encourage that special attention is paid to symptoms among men who have sex with men.

As monkeypox are transmitted through close contact and primarily via direct contact to symptomatic persons, and as asymptomatic infection is not observed, the opportunities for containment are good.

Three recent outbreaks

Monkeypox were detected in humans for the first time ever in 1970 in the Democratic Republic of Congo, in a 9-year-old boy. The condition occurs endemically in West and Central Africa, emanating from a zoonotic reservoir including, among others, squirls, Gambian rats, mice and various species of monkeys. Various countries regularly record monkeypox cases, including the Central African Republic, Cameroun, The Democratic Republic of Congo, Liberia, Nigeria, Congo and Sierra Leone. Following an outbreak in 2017-2019, Nigeria has since reported sporadic cases, including 2022.

From 1 January to 13 September 2020, a total of 4,594 presumed monkeypox cases were recorded, including 171 fatal cases, in the Democratic Republic of Congo.

Monkeypox has previously spread beyond the African continent. In 2018, two cases of monkeypox were diagnosed in Great Britain, both were linked to travellers from Nigeria. One of these led to a secondary case in a healthcare worker due to contaminated bed linen, marking the first ever case of nosocomial transfer outside of the African continent. A third imported case was identified in December of 2019 and fourth in May 2021. This final case triggered another two cases among family members.

Guidelines on the handling of monkeypox in Denmark

Today, the Danish Health Authority and other Danish health authorities have published a guideline describing the handling of monkeypox in Denmark. The guideline will likely be updated as more knowledge of the condition becomes available.

The guideline includes a thorough description of the condition, including notification procedure, case definition and hygiene precautions, contact tracing and treatment. The guideline is available here:

Link go the guideline (in Danish language)

The WHO recommends no travel or trade restrictions based on this outbreak, but the situation is followed closely by the health authorities.

(F.T. Møller, P.H. Andersen, Department of Infectious Disease Epidemiology and Prevention)