DISEASE X - What it is, and what it is not

Preventing future pandemics means preparing for both known and unknown viral disease threats. That’s why scientists are focusing some of their viral defence research on a hypothetical future ‘Disease X’. With the concept of Disease X at the heart of international efforts to be better prepared, CEPI looks at what people most want to find out about this unknown pathogen.

Using ‘Answer the Public’, we analysed some of the most popular search terms related to Disease X across four countries, Ethiopia, India, the UK, and the United States, which were among the top countries searching ‘Disease X’ over the past 12 months, according to Google Trendsat the time of publishing.

Those questions, and CEPI’s answers, are below.

What is Disease X?

Disease X is the name given by scientists and the World Health Organization to an unknown pathogen that could emerge in future and cause a serious international epidemic or pandemic. In February 2018, Disease X was included in the WHO’s updated Blueprint list of diseases for which investing in research and development should be an international priority. It is also a priority for CEPI’s research and development investments.

Does Disease X really exist? And could Disease X kill you?

Disease X itself is hypothetical: it does not exist. But the concept of Disease X describes a very real and growing threat to human health – and one the world must prepare better to respond to. The most recent Disease X to emerge was the SARS-CoV-2 virus that causes COVID-19. Because we were not properly prepared to defend ourselves against it, COVID-19 swiftly spread and caused a deadly pandemic, killing millions worldwide. Safe and effective vaccines have significantly reduced COVID-19’s mortality and morbidity, saving an estimated 20 million lives in the first year of their roll-out.

Will Disease X happen? And when is Disease X coming? 

No-one can predict where or when the next Disease X will emerge. What is certain, however, is that a future Disease X is out there and will, at some point, spill over from animals into people and begin to spread in a disease outbreak. Recent history shows us that outbreaks of pathogens capable of causing severe disease and death in people are becoming increasingly frequent. In the 21st century alone, there have been outbreaks of SARS-CoV-1, MERS, Zika and many other new and re-emerging viral diseases.

Research published in 2022 found that the chance of a pandemic, with a similar impact to COVID-19, is about 1 in 50 in any year. This means the lifetime probability of anyone reading this experiencing a pandemic similar to COVID-19 is about 38 percent. Unfortunately, environmental change is a major contributor to that increasing risk.

Will Disease X cause the next pandemic?

While it’s likely that the next pandemic threat could emerge as a novel Disease X, there’s also a risk of already known pathogens mutating and/or re-emerging and then spreading into international disease epidemics—such as has happened with Chikungunya virus—or pandemics.

Where will the next Disease X come from?

Novel diseases emerge all the time in all parts of the world, often making the leap from animals such as bats into humans. Scientists believe the next Disease X is highly likely to be caused by a new virus that will emerge from one of around 25 families of viruses that have already shown their capability to cause disease in people.

How can we prepare for Disease X if it doesn’t exist yet?

Just because we can’t precisely predict its features or the time of its arrival, that doesn’t mean we can’t plan for Disease X. By getting to know as much as we can about the 25 or so viral families that are most likely to harbour a novel Disease X, scientists can get a head start in creating new medical defences such as vaccines and treatments that can be swiftly adapted to target a new viral disease.

CEPI’s 100 Days Mission is a plan to make new vaccines against known or novel infectious diseases within three months of their pandemic threat being recognised.

Global outbreak of Mpox disease, 
formerly known as Monkey pox, has been ongoing since 2022. 
South Africa is among the countries currently experiencing the outbreak of Mpox, a viral infection which spreads between people, 
and occasionally from the environment to people, via objects and surfaces that have been touched by a person with Mpox.

The country has recorded a total number of 5 laboratory-confirmed cases and one death. Two of these cases were confirmed in Gauteng and three in KwaZulu-Natal. 
The death that occurred is among the two cases reported in Gauteng. 
The patient passed-on on Monday, 10 June 2024 in Tembisa Hospital. All cases/patients are males aged between 30-39 years without travel history to 
the countries currently experiencing an outbreak, which suggests there is local transmission of this infectious disease in the country.

All five cases were classified severe cases as per WHO definition requiring hospitalisation. 
The cases have co-morbidities and have been identified as key populations, Men who have Sex with Men (MSM). 
Thus, the Department is reaching out to organisations working on HIV programmes and with key populations in addition to other stakeholders 
to implement targeted communication to intensify awareness about the outbreak and local transmission of the disease.

One patient has been discharged, one discharged for home isolation and follow ups being made. 
Two cases are still admitted in hospital. Sequencing analysis of three of the cases revealed mpox clade IIb, 
in keeping with the multi-country mpox outbreak which began in 2022.

The National Institute for Communicable Diseases (NICD) continues with epidemiological and surveillance activities to identify cases for investigation 
to estimate the magnitude of disease through systematic data collection and analysis. A total of 38 contacts were identified in KwaZulu-Natal 
by the outbreak response teams. 
The contacts include household contacts (16), hospital contacts (10), partners/sexual partners (5) and friends (7). 
One of the cases indicated to have had sexual contact 
with multiple partners including both males and females.

At the current moment, there is no registered treatment for Mpox in South Africa. However, 
the World Health Organization recommends the use of Tecovirimat (known as TPOXX) for treatment of severe cases, such as in individuals with a 
CD4 count of less than 350. However, the Department has obtained Tecovirimat via Section 21 SAPHRA approval on compassionate use basis for the five known 
patients with severe disease.

MEDIA BRIEFING STATEMENT BY THE MINISTER OF HEALTH ON THE OUTBREAK OF MPOX DISEASES IN 
SOUTH AFRICA AND EFFORTS TO CURB THE SPREAD WEDNSDAY, 12 JUNE 2024 – PRETORIA

A global outbreak of Mpox disease, formerly known as Monkey pox, has been ongoing since 2022. 
Mpox is a notifiable medical condition which the Health Care Workers are required to report all the suspected and confirmed cases. 
Notifiable Medical Conditions refer to diseases that are of public health importance because they pose significant public health risks 
that can result in disease outbreaks or disease epidemics with high case fatality rates both nationally and internationally. 
The last time South Africa recorded positive cases of Mpox was in 2022 when five cases confirmed in the Western Cape, KwaZulu-Natal, Limpopo and Gauteng, 
with no cases reported in 2023. According to the World Health Organization multi-country outbreak of mpox published on 31 May 2024, 
cumulatively from 01 January 2022 through 30 April 2024, a total of 97 208 laboratory confirmed cases of mpox, including 186 deaths from 117 countries in all six 
WHO regions were reported. A total of 528 new laboratory-confirmed cases were reported in April, which represents a 21.2% decline in the number 
of new cases reported during the preceding month of March, including retrospectively reported for previous months. The most affected WHO regions, 
in order by number of laboratory-confirmed cases, were the Region of the Americas, the African Region, the European Region, the South-East Asia Region, 
and the Western Pacific Region. In the 2 African Region, the DRC reported the most (99.6%) of the confirmed mpox cases in the reporting month. 
The disease is caused by the monkeypox virus (MPXV), an orthopoxvirus that transmits from person to person through close contact, 
and from unknown animal reservoirs in East, Central, and West Africa. This multi-country Mpox outbreak is characterised by sustained human-to-human transmission 
via direct skin-to-skin and sexual contact; people living with HIV are disproportionately affected. 
South Africa is amongst the countries currently experiencing the outbreak of Mpox, 
a viral infection which spreads between people and occasionally from the environment to people via objects and surfaces 
that have been touched by a person with mpox. 
South Africa has recorded a total number of 5 laboratory-confirmed cases and one death. 
Two of these cases were confirmed in Gauteng and three in KwaZulu-Natal. 
The death that occurred is amongst the two cases reported in Gauteng. 
The patient passed-on on Monday, 10 June 2024 in Tembisa Hospital. 
All cases/patients are males aged between 30-39 years without travel history to the countries currently experiencing an outbreak, 
which suggests there is local transmission of this infectious disease in the country. 
All five cases were classified severe cases as per WHO definition requiring hospitalisation. 
The cases have co-morbidities and have been identified as key populations, Men who have Sex with Men (MSM). 
Thus, the Department is reaching out to organisations working on HIV programmes and with key populations in addition to other 
stakeholders to implement targeted communication to intensify awareness about the outbreak and local transmission of the disease. 
3 One patient has been discharged, one discharged for home isolation and follow ups being made. Two cases are still admitted in hospital. 
Sequencing analysis of three of the cases revealed mpox clade IIb, in keeping with the multi-country mpox outbreak which began in 2022.

Breakdown of the cases

Cases

Confirmation Date

Area/Province

Age

Hospitalised

Case 1

8 May 2024

Sedibeng, GP

35

Yes

Case 2

21 May 2024

eThekwini, KZN

39

Yes

Case 3

31 May 2024

eThekwini, KZN

30

Yes

Case 4

03 June 2024

eThekwini, KZN

33

Yes

Case 5

07 June 2024

Tembisa, GP

37

Yes

All National Health Laboratory Service (NHLS) laboratories have been sensitised to the ongoing outbreak and are referring samples for 
testing to the NICD. Private sector laboratories are also testing for mpox while NICD serves as the reference laboratory. 
Since the beginning of 2024, the NICD has received twelve mpox test requests, with three testing positive. 
The other two cases were diagnosed by private laboratories. Guidelines have been updated and shared widely across networks of healthcare workers 
using various platform. EPIDEMIOLOGY AND SURVEILLANCE The National Institute for Communicable Diseases (NICD) continues with epidemiological and 
surveillance activities to identify cases for investigation to estimate the magnitude of disease through systematic data collection and analysis. 
A total of 38 contacts were identified in KwaZulu-Natal by the outbreak response teams. 
The contacts include household contacts (16), hospital contacts (10), partners/sexual partners (5) and friends (7). 
One of the cases indicated to have had sexual contact with multiple partners including both males and females. 
4 Regarding the case notified on the 08 May 2024 in Gauteng, seven (07) contacts have been followed up for 21 days, 
and none showed any signs and symptoms of mpox. Regarding the case notified on the 07 June 2024, the line list of the identified contacts was developed, 
they will be monitored for symptoms for a period of 21 days. Attempts will be made to identify other additional contacts. 
The provinces have been notifying all the cases that meet the case definition of a suspected mpox case in the Notifiable Medical Condition (NMC) System. 
Meanwhile, the Outbreak Response Team comprising of experts from the Department, provinces, NICD, 
WHO and other stakeholders in the health sector have embarked on contact tracing and case finding in the affected provinces. 
TREATMENT At the current moment, there is no registered treatment for Mpox in South Africa. However, 
the World Health Organization recommends the use of Tecovirimat (known as TPOXX) for treatment of severe cases, 
such as in individuals with a CD4 count of less than 350. However, 
the Department has obtained Tecovirimat via Section 21 SAPHRA approval on compassionate use basis for the five known patients with severe disease. 
Three of the five cases had access to Tecovirimat treatment as advocated by the NICD. 
The drug was obtained via Section 21 and the SAPHRA approval process; and donated by the WHO. 
SAPHRA has since approved a request for a small stockpile of Tecovirimat which the WHO will support as a donation. 
Our intention is to obtain a stockpile of Tecovirimat treatment for rapid deployment in case the current situation leads to a wider outbreak. 
The stock will be donated by the World Health Organization. 
5 As far as the vaccine is concerned, options are being considered as to which population groups should be targeted. 
South Africa is trying to source vaccine from WHO member countries who have stockpiles that exceed their needs as well as from GAVI. 
These vaccines will be stored and distributed from our provincial depots. 
Additional intervention is being considered, as National Advisory Group for Immunisation (NAGI) Technical Working Group for Mpox vaccines 
has been appointed and is considering mpox vaccine for both pre and post-exposure administration for high-risk groups, 
including but not limited to sex workers, menwho-have-sex-with-men, healthcare workers and laboratory workers. 
RISK COMMUNICATIONS The Department working together with partner organisations, 
has intensified both targeted and public awareness using various channels of communications to empower 
the citizens with crucial information related to Mpox to make well informed health decisions. 
As part of additional efforts to increase opportunity for engagement, 
a clinical management webinar has been convened and was attended by five-hundred healthcare workers and public health professionals from across the country. 
However, the most important intervention at present remains risk communication and community engagement (RCCE), which is being implemented, 
including addressing the high-risk population without discriminating to avoid stigma. 
We are also reaching out to organisations working with the HIV programmes and key populations such as the MSM to reach their members since they fall 
under the category of people at risk. Although, the World Health Organization has not recommended any travel restrictions, 
it is important for travellers to and from endemic countries to alert health officials on the situation to enable them to provide 
guidance for case 6 detection and management. We can prevent further spread of this infectious disease if those with suspected symptoms 
or who were in contact with known cases/patients present themselves at health care facilities on time for early diagnosis and effective treatment. 
We can disrupt the local transmission by supporting those diagnosed with this disease to take their treatment to prevent infecting others. 
We can prevent avoidable deaths by cooperating with health officials when they conduct contact tracing and case finding. 
One death is too many, especially from a preventable and manageable disease like mpox.

I thank you