A new case of mpox in New Zealand appears to be linked to the Queenstown Winter Pride event in August.
Last Saturday, Te Whatu Ora asked attendees of the event to watch for symptoms, as they may have been in contact with people who have since tested positive for mpox overseas.
A new case was confirmed last night, with a link to the festival ‘likely’.
These are cases of clade II mpox, the more common variant, rather than the more severe clade I.
The SMC asked experts to comment.
Professor Michael Baker, Public Health, University of Otago, comments:
“The identification of an Mpox case in Aotearoa New Zealand (NZ) this week is a further reminder about the ongoing global spread of this infection. Prevention and control of this virus is a challenge for high income countries like NZ, but a health disaster for Africa.
“The World Health Organization (WHO) has now declared two Public Health Emergencies of International Concern (PHEIC) in recognition of the severe threat that Mpox poses in Africa: the first PHEIC was for Clade II Mpox from 2022–23, and the second for the more severe Clade I Mpox declared on 14 August 2024. Much of the rationale for these declarations is to stimulate a stronger focus on providing essential health resources, including testing and vaccines, to support African countries to better prevent and control this disease threat.
“It is important to remember that Mpox has continued to circulate widely since the epidemic in 2022-23. Even though that epidemic peaked in August 2022, this infection continues to spread in many counties with more than 100,000 cases reported to date. NZ has had 54 diagnosed Mpox cases since 2022, with at least 5 cases already this year. All these cases have so far been Clade II, but we are likely to see Clade I cases in the future.
“The good news for high income countries like NZ is that Mpox is a manageable epidemic and elimination is a realistic national goal. This virus is largely transmitted by close physical contact and is not considered an airborne infection like Covid-19 (though droplet spread is likely, and masks are also part of infection control when caring for Mpox cases). Consequently, basic public health and social measures such as case diagnosis, isolation, contact tracing and quarantine of contacts are highly effective at limiting spread of Mpox.
“The other good news is that there are effective vaccines available for Mpox, though supplies are limited. Organisations such as the Burnett Foundation have been effective at alerting men who have sex with men and other higher risk groups about how to protect themselves and their partners from this infection.”
No conflicts of interest.
Associate Professor Mark Thomas, Molecular Medicine and Pathology, University of Auckland, comments:
“Mpox, also known as monkeypox, is present in two closely related forms in Africa, a more severe form (Clade IA and Clade IB) that is spreading widely in central Africa, and a less severe form (Clade II) that spread from West Africa to cause large outbreaks of disease in men who have sex with men (MSM), in many developed countries, in May 2022. These outbreaks, often involving thousands of MSM were brought under control by vaccination of people at the highest risk of infection and self-isolation of those with the disease.
“However the initial success in curtailing the spread of mpox in many developed countries has been followed in recent months by new outbreaks in several countries, including Thailand, Vietnam, South Africa and Australia.
“Mpox has become established as a new sexually transmitted infection in many countries, including NZ, and is likely to continue to cause intermittent outbreaks in those countries where sufficient numbers of high risk MSM remain unvaccinated.
“The disease lasts about two weeks, and may cause significant discomfort at the site of initial infection, but is very rarely fatal.
No conflicts of interest.
Professor Michael Plank, Mathematics and Statistics, University of Canterbury, comments:
“Several different strains of mpox (called clades or subclades) are spreading globally with different characteristics. In 2022, there was a global outbreak of clade II, which spread primarily via sexual transmission among men who have sex with men (MSM).
“Last month, the World Health Organisation declared an international public health emergency, triggered in part by the emergence of a new strain, called clade Ib. This is spreading mainly in central and east African countries and isolated cases have also been reported in Sweden and Thailand.
“Part of the reason for the increase in global transmission of mpox is likely that the smallpox vaccine provided cross-immunity against mpox. However, smallpox vaccination was discontinued after the disease was eradicated in 1980. That means that the number of people without immunity has been creeping up ever since.
“According to Te Whatu Ora, all cases detected in New Zealand so far are clade II. It is important that samples from any new cases are genomically sequenced so that we know if clade Ib does arrive here and can respond appropriately.
“Clade Ib may have different transmission patterns and affect different population groups compared to clade II. There have been some reports that clade Ib has a higher fatality rate. However, this is difficult to pinpoint because the number of undetected cases is unknown, and it is difficult to disentangle the impacts of the different clades and subclades that are spreading concurrently in Africa.
“There are vaccines which are effective against mpox. Men who have sex with men, and others at high risk of getting mpox may be eligible. New Zealand also needs to play its part in getting vaccines to African countries that are struggling to control outbreaks and where vaccines are in short supply.”
No conflicts of interest declared.