Mpox update – August 2024

The World Health Organization’s (WHO) public health emergency of international concern (PHEIC) announcement following extensive outbreaks of clade Ib mpox in African countries, and the risk implications at a global level. 
Information about the subtypes of monkeypox virus (MPXV) clades I and II. 
The Institute for Environmental Science and Research’s (ESR) updated mpox risk assessment for Aotearoa New Zealand. 
Aotearoa’s preparedness to respond to an mpox outbreak. 
Updated mpox information for travellers
 

1. WHO’s mpox declaration and risk assessment 

On 14 August 2024, WHO declared mpox a global public health emergency of international concern (PHEIC), its highest form of alert, following an outbreak of clade Ib mpox  in the Democratic Republic of Congo (DRC) spreading to neighbouring countries including Burundi, Rwanda, Uganda, Central African Republic, and Kenya.  

You can see the news release here: https://www.who.int/news/item/14-08-2024-who-director-general-declares-mpox-outbreak-a-public-health-emergency-of-international-concern 

WHO’s risk assessment as of 13 August 2024, is that the public health risk of clade Ib mpox: 

for the Eastern DRC and neighbouring countries is assessed as high 
for areas of the DRC where mpox is endemic, the risk is high 
for Nigeria and countries of West, Central and East Afrida where mpox is endemic, the risk is moderate 
for other countries in Africa and globally, the risk is moderate. 

Health New Zealand | Te Whatu Ora (Health NZ) and the Ministry of Health (MoH) are closely monitoring the situation and are considering the implications for Aotearoa. 

2. Clades of monkeypox virus (MPXV)  

There are two genetically and clinically distinct clades or subtypes of MPXV, I (Ia and Ib) and II, and they are endemic to central and west Africa respectively. Clade I has previously been observed to be more transmissible and to cause a higher proportion of severe infections than clade II mpox. The ongoing global mpox outbreak that began in 2022 is caused by MPXV clade II, and sporadic cases continue to be reported worldwide, including Aotearoa.  

Clade I mpox is of heightened concern for multiple reasons, and it appears to be behaving differently with changes to the populations affected. In the current epidemic in the DRC, most cases are in people under age 15 years of age, with approximately equal numbers of men and women affected. Clade I can be both sexually and non-sexually transmitted. By comparison,  clade II mpox primarily affects gay, bisexual, and other men who have sex with men (MSM).  

A response to mpox caused by clade I in Aotearoa would need to be broader than a focus on this cohort and MSM networks.  

The WHO Director-General has extended the Standing Recommendations for a further 12 months (https://www.who.int/publications/m/item/extension-of-the-standing-recommendations-for-mpox-issued-by-the-DG-of-the-WHO-in-accordance-with-the-IHR-2005-21082024) and released Temporary Recommendations for mpox, and Health NZ is working with MoH to consider how these can be applied and implemented in Aotearoa’s setting. 

3. ESR mpox risk assessment 

ESR has updated their mpox risk assessment for Aotearoa and determines: 

The overall public health risk of clade I (Ia and Ib) mpox in Aotearoa is low. 
The overall public health risk of clade II mpox in Aotearoa is low-moderate. 

4. Aotearoa’s outbreak preparedness 

Aotearoa is prepared to respond to an mpox outbreak.  

Testing  

Health NZ and the MoH are planning to strengthen testing and referral pathways to facilitate timely identification and diagnosis of clade I mpox cases, considering the increased public health risk it presents. We are also reviewing the evidence of effectiveness of vaccines and anti-viral medications for the treatment of clade I mpox. 

Several diagnostic laboratories in Aotearoa and ESR’s reference laboratory can test for mpox. In addition, ESR and the Canterbury Health Lab (CHL) have a clade-specific polymerase chain reaction (PCR) test which can distinguish between clade I and clade II. If a clade I case is identified, ESR has the capacity to sequence the virus to determine lineage. 

Local laboratories that can test for mpox have provided reassurance that their test can detect the most recent clade Ib subtype as a positive result. However, current testing settings are such that these laboratories cannot distinguish between clade I and clade II without further testing. 

WHO strongly advise countries need diagnostic capacities capable of detecting both MPXV clades. The Public Health Agency (PHA) is evaluating the current state of readiness of the diagnostic laboratory network, for the purposes of clinical diagnosis and epidemiological surveillance. 

Vaccination 

Preventative treatment by way of a vaccine is already available under Section 29, and work is continuing with MedSafe to seek provisional approval for the vaccine.

We will provide you with an update when we have further information.  

Clinical guidance for management of mpox cases and contacts 

The Communicable Disease Control Manual includes a chapter on mpox to provide guidance on the public health management of cases and contacts. This guidance relates specifically to clade II mpox.  

It is unknown whether the epidemiological trends of clade 1 mpox observed in affected African countries will be seen in other countries due to differences in the prevalence of comorbidities, sociocultural factors, access to healthcare and the level of reporting, among other factors. To date, there has been one reported case of clade 1 mpox outside of Africa (in Sweden) who had been traveling in Africa. 

We are closely monitoring emerging data to get an understanding of whether changes to national clinical guidance and public health advice to support the management of clade I mpox will be required. 

We will communicate any updates with you as required. 

Surveillance 

Global Surveillance continues and NPHS intelligence continues to monitor the domestic situation.  

5. Updated mpox information for travellers

Mpox information on the Ministry of Foreign Affairs and Trade’s Safe Travel website has been updated. This includes prevention advice for people travelling to mpox-affected countries.

Mpox (Monkeypox) outbreak | SafeTravel