Mpox is a viral disease that resembles smallpox in humans and whose causative viruses are also related to the smallpox viruses. It is a zoonosis, meaning that the viral disease can be transmitted from animals to humans and vice versa. The disease in humans is similar to smallpox, but fatal courses are rare; mpox is usually cured after a good three weeks.
The symptoms are treated. The drug Tecovirimat has been approved for the treatment of smallpox, mpox and cowpox in the EU since January 2022. The approval is granted under "exceptional circumstances" due to the rarity of the diseases.
Mpox can be prevented by paying attention to hygiene and avoiding contact with infected persons or objects used by them. Frequent anonymous sexual contact increases the risk. "Safer sex" rules are not enough for Mpox, as the virus can be transmitted through skin contact.
Two vaccines against Mpox have been available in Austria since 2022. These are available to risk groups.
Situation in Austria
Since 23 May 2022, 341 cases of Mpox have been reported in Austria (as of 09 February 2024). Of these, eleven Mpox cases were reported in 2023, so far three cases in 2024. The disease is notifiable.
A joint ECDC/WHO Regional Office for Europe report provides an overview of the total number of Mpox cases detected by the ECDC and the WHO Regional Office for Europe.
The World Health Organisation (WHO) calls on healthcare facilities to consider Mpox as a differential diagnosis in the event of corresponding symptoms. If the suspicion of Mpox is confirmed, patients should be isolated and contacts traced. Anyone who has symptoms themselves should be examined by infectious disease specialists, especially men who have sex with men with changing partners should be vigilant.
Mpox virus is one of the orthopox viruses. The disease in humans is similar to smallpox; symptoms include high fever, severe headache, sore throat, cough, malaise, and occasionally diarrhea. In the second stage of the disease, a smallpox-like exanthema (skin rash) may appear. Fatal courses are rare, usually mpox is healed after a good three weeks.
Mpox is usually introduced into Europe by travelers or transmitted by introduced animals in isolated cases. In Europe, human-to-human transmission is more common. This is one reason why the disease is now under increased scrutiny. The EU health authority ECDC classifies the probability of further spread in groups of people with many changing sexual partners as high. Whether or how many cases with a severe course are to be expected cannot be reliably estimated at present. The ECDC estimates the probability of such courses in the majority of the population as low. All EU countries are called upon to identify and isolate cases as quickly as possible and to follow up on close contacts. For this purpose, diagnostic capacities should be created and a functioning system for contact tracing should be established. Health care and laboratory personnel should wear appropriate protective equipment (gloves, FFP2 mask, waterproof overgarments) when mpox is suspected.
WHO encourages health facilities to consider mpox as a differential diagnosis when symptoms are present. If mpox is suspected, patients should be isolated and contacts followed up. Especially men who have sex with men with changing partners should be vigilant.
Fragebogen Mpox für Patient:innen mit Verdacht auf Mpox-Infektion
The vaccine against smallpox (Imvanex ®) approved in the EU was also approved against mpox on 22.7.2022. In Austria, Imvanex and the U.S. vaccine Jynneos with a U.S. Food and Drug Administration (FDA) approval against mpox are available in limited quantities - see "Monkeypox Vaccine Recommendation".
Both Jynneos and Imvanex are vaccines manufactured by Bavarian Nordic, which is a 3rd generation live attenuated vaccine (MVA-BN) based on the modified vaccinia virus Ankara and is licensed in both the EU (Imvanex) and the US (Jynneos) as a mpox vaccine in addition to its use against smallpox. These two vaccines are comparable and have only minor differences in terms of the manufacturing process.
Imvanex Technical and Instructions for Use (see Product information: Technical information pages 2-13, Instructions for Use pages 24-29).
The English-language US technical information is provided for users here.
Should side effects occur during or after use of the vaccine, they can and should be reported to the Austrian Medicines Agency (BASG), as with any other medicinal product.
Mpox is a notifiable animal disease under the Animal Diseases Act.
The mpox virus is endemic to West and Central Africa. Here it circulates mainly in small mammals. Rodents in particular are the reservoir of the pathogen for primates and humans. Primates and humans are actually false hosts.
Mpox has been detected in many rodents in Africa: in rats such as the hamster rats popular as pets, the Gambian giant hamster rat(Cricetomys gambianus), in other Cricetomys species, in red-nosed rats(Oenomys hypoxanthus) and proboscis rats (Petrodromus sp.) as well as in striped grass mice(Lemniscomys sp.), in dormice (dormice, African Lorrain's milk Graphiurus lorraineus), in squirrels (e.g., in African chipmunks Funisciurus sp. and sun squirrels(Heliosciurus sp.), and in shrews. The exact host range is not yet known. Many of these rodent species, which are also readily exported to other continents as zoo or pet animals, can - if infected with the pathogen - transmit it to other animal species but also to humans (e.g., in 2003 in the USA to prairie dogs and humans).
Transmission of infection from pets and zoo animals to humans can occur through direct contact (bites, secretions, respiratory droplets, skin-to-skin contact with smallpox lesions). Contact via the environment, e.g., through virus-containing shed skin crusts during cage cleaning, is also possible. Particularly high concentrations of pathogens are found in typical smallpox lesions. Smallpox viruses can persist in the environment for a very long time in the shed skin crusts. Conversely, people suffering from mpox should avoid any contact with their pets (especially rodents) in order to protect the animals.
To date, no endemic occurrence of mpox in animals - especially rodents - has been detected in either the Americas or Europe. In any case, pets and zoo animals imported from Africa should be examined by a veterinarian for the skin lesions typical of smallpox and kept in quarantine for a short time before being brought together with other animals. Specialized personnel in zoos and pet shops should be aware of the risk of mpox infection upon first contact with these animals imported from Africa and implement protective and hygienic measures accordingly: These include wearing disposable gloves, disposable masks, disposable work coats, hand disinfection, avoiding stirring up dust when cleaning cages, proper disposal of bedding material.
Suspect samples can be sent to AGES:
Institute for Medical Microbiology and Hygiene Vienna
Währingerstraße 25a, 1090 Vienna
Phone: +43 50 555-37111
Institute for Veterinary Investigations Mödling
Robert Koch-Gasse 17, 2340 Mödling
Phone: +43 50 555-38112
Last updated: 09.02.2024