CNA Explains: Deadlier and more contagious – how dangerous is the new mpox variant?

SINGAPORE: In just two years, the World Health Organization (WHO) on Aug 14 declared mpox a global public health emergency for the second time.
The highest level of alert, categorised as how COVID-19 was, followed an mpox outbreak from the Democratic Republic of Congo (DRC) that spread to neighbouring countries.
The latest surge of mpox has been of the deadlier strain, clade 1b.
Previously known as “monkeypox” until the term was phased out in November 2022, mpox has now crossed to other nations and detected in Sweden and Pakistan.
Thailand also confirmed Asia’s first known case of clade 1b on Thursday.
CNA takes a look at the newer, deadlier strain, and how likely it is to reach Singapore.
Mpox has two subtypes: Clade 1 and clade 2.
For decades, the deadlier clade 1 has been endemic in the Congo Basin in Central Africa.
Clade 1 mpox is “known for causing more severe disease in young children, pregnant women, and immunocompromised people”, said Jonas Albarnaz, who specialises in pox viruses at the Pirbright Institute in Britain, in a report by Reuters last week.
The less severe clade 2 has become endemic in parts of West Africa.
The new, mutated strain of clade 1 – clade 1b – emerged in September last year and was detected among sex workers in the DRC. 
On Aug 14, the WHO said that more than 100 laboratory-confirmed cases of clade 1b were reported over the past month in four countries neighbouring the DRC. These countries – Burundi, Kenya, Rwanda and Uganda – had not reported mpox cases before.
It added experts believe that the real figure was higher than that as a large proportion of clinically compatible cases had not been tested.
Clade 1b causes death in about 3.6 per cent of cases, with children more at risk, according to the WHO. 
Because of the recent and rapid surge of the new variant, the WHO declared mpox a public health emergency of international concern.
Mpox is mainly spread from human to human through close contact with an infected person. This can include sex, kissing or just merely touching. 
Talking or breathing close to an infected person is another way it can spread, due to the infectious respiratory particles generated.
If an infected person touches items such as clothing, bedding, towels, objects and surfaces, the virus can also linger on it.
Someone may also contract mpox through physical contact with an animal that carries the virus, such as some species of monkeys and rodents. Physical contact with animals can happen through bites, scratches, or eating contaminated meat that has not been cooked properly.
Mpox, whether it is the new or old strain, is not the new COVID-19, WHO regional director for Europe Hans Kludge said on Tuesday, adding that the risk to the general population is low.
It is not a new virus and spreads differently than COVID-19, according to the California Department of Public Health in December 2022.
The mpox virus carries a double strand of DNA, and DNA viruses typically do not mutate that quickly.
Coronaviruses, on the other hand, consist of single-stranded RNA, which has high mutation rates.
Dr Leong Hoe Nam, an infectious disease specialist at Mount Elizabeth Novena Hospital, told CNA that mpox and its new strain “really needs touch” to spread.
“You can not touch (mpox), but you cannot not breathe (COVID-19). Transmission via droplets is very unlikely unless you are immediately next to a mouth or nose,” he said.
To protect against the spread of mpox, one should maintain a high standard of personal hygiene and avoid direct contact with the skin lesions of those infected, said Singapore’s Ministry of Health (MOH) on Thursday.
High-risk activities such as having multiple sex partners or casual sex should also be avoided.
The public is also advised to refrain from contact with wild animals and consuming bush meat.
Health authorities noted that a person who suspects he or she might have mpox should seek medical advice and isolate from others until fully evaluated and tested.
Mpox vaccines are available, the WHO said, such as MVA-BN or LC16, or the ACAM2000 vaccine when the others are not available. 
But only those who are at risk should be considered for the vaccines and the WHO does not recommend mass vaccination.
“WHO currently recommends vaccines for people who have been close contacts of someone who has mpox, or people who belong to a group at high risk of exposure to mpox.”
Symptoms of mpox can vary. These include a rash that may last for two to four weeks, fever, headache, muscle aches and swollen lymph nodes.
For rashes, it can appear in the form of blisters or sores on areas like the face, palms, soles of the feet, or genital areas.
As for mpox treatment, the Centers for Disease Control and Prevention said there are currently no specific approved ones for the virus.
For infected people who have intact immune systems and no skin disease, supportive care and pain control will help them recover without medical treatment.
The WHO also noted that a smallpox treatment, tecovirimat, was approved by the European Medicines Agency in January 2022 to treat mpox under “exceptional circumstances”.
The DRC, the epicentre of clade 1b, has seen more than 17,000 suspected cases and over 500 deaths this year, mainly among children in Congo, said Africa’s top public health body in August. 
Besides DRC, the latest strain has also been detected in Sweden and Pakistan.
Argentine authorities on Tuesday quarantined a cargo ship due to a suspected mpox case onboard.
In Bangkok, a 66-year-old European traveller was confirmed to be infected with clade 1b on Thursday after arriving in Thailand’s capital on Aug 14.
The mpox surge has prompted many countries across Asia to be on high alert, with China announcing on Aug 16 that all overseas arrivals would be screened for symptoms of the virus over the next six months.
Hong Kong, which reported 13 cases this year, said it would continue to monitor the situation closely and “enhance preventative measures” following WHO’s announcement. 
In Japan, its foreign ministry issued a level-one health alert on Aug 15, warning its citizens to be cautious when travelling to or staying in seven African countries.
Singapore on Thursday also announced that temperature and visual screening will be conducted from Friday for certain inbound travellers and crew at air and sea checkpoints as a precautionary measure against mpox.
The WHO noted in its announcement on Aug 14 that it anticipates an immediate funding requirement “of an initial US$15 million to support surveillance, preparedness and response activities”.
The global health authority also released US$1.45 million from the WHO Contingency Fund for Emergencies for an immediate support.
The spread of clade 1b to Singapore is not a case of if, but when, said Mount Elizabeth Novena Hospital’s Dr Leong.
Health Minister Ong Ye Kung also noted on Aug 17 that while the immediate risk of mpox to the country is low, the virus will likely make its way here soon due to Singapore’s global flight connections.
Singapore does not have any direct flights to and from the affected areas in Africa.
As of Thursday, 13 confirmed mpox cases have been detected in Singapore this year, all of which are of the less severe clade 2 infections.
But, even with Singapore’s stepped-up measures in place, Dr Leong noted that it “won’t help” to curb the spread of mpox.
“After travelling a long flight, you just want to go home or to the hotel. If you have a fever, you will take panadol, or drink a glass of cold water to overcome the fever. If you have a rash, you want to see your own doctor and not get quarantined after a long flight.”
He suggested instead that the authorities “make it very obvious that they can seek help – even free medical care if there is a rash that they are worried about for mpox”.
Even with no clade 1 cases in Singapore, the protection of key essential services, especially hospitals, should be strengthened and numbers monitored once a clade 1b case is recorded in the country, said Dr Leong.
Foreign workers should also not be forgotten, he noted, as they live in close proximity with one another in dormitories.
“If the numbers are coming out to be in alarmingly fast rates (because of yet further new mutations – which is extremely unlikely), they may need to create quarantine areas for the public.”