![\"Transmission](\"https:\/\/images.newscientist.com\/wp-content\/uploads\/2024\/06\/25170126\/SEI_210355592.jpg\")
<\/div>Transmission electron micrograph of mpox virus particles (teal) within an infected cell<\/p>\n
NIAID<\/p>\n<\/div>\n<\/figcaption><\/figure>\n<\/p>\n
Urgent action is needed to try to contain the spread of a new strain of mpox transmitted mainly by heterosexual sex that has caused more than 1000 cases in the Democratic Republic of the Congo, say health experts dealing with the outbreak. They fear the condition is poised to spread to neighbouring countries and possibly further afield.<\/p>\n
\u201cIt\u2019s undoubtedly the most dangerous so far of all the known strains of mpox considering how it is transmitted, how it is spread and also the symptoms,\u201d says John Claude Udahemuka<\/a> at the University of Rwanda.<\/p>\n The new strain was first identified in the small mining town of Kamituga in South Kivu province in the east of the DRC in September. In recent weeks it has spread to cities in the area. It may already have reached neighbouring countries such as Rwanda, Burundi and Uganda, says Leandre Murhula Masirika at the South Kivu health department.<\/p>\n Yesterday, the city of Goma, which is on the border with Rwanda, confirmed its first cases, says Masirika.<\/p>\n <\/p>\n The experts hope a vaccination campaign targeting sex workers and health<\/a> workers can halt the spread of the new strain. This could use existing stocks of smallpox vaccines, which are known to protect against other mpox strains. However, it isn\u2019t yet known whether any existing vaccine will work against this new strain, says Udahemuka. \u201cWe hope it will.\u201d<\/p>\n So far, no vaccines<\/a> used for mpox have reached the affected region, and when they will arrive is unclear.<\/p>\n For decades, there have been occasional outbreaks of mpox \u2013 formerly known as monkeypox \u2013 in Central Africa caused by clade 1 mpox, which circulates in non-human animals<\/a> and can infect people who handle bushmeat. Clade 1 can spread by close contact with an infected individual or contaminated items, but doesn\u2019t usually spread beyond households.<\/p>\n In September 2023, health workers in Kamituga noticed a number of cases that appeared to be spread via sex, as well as other close contact. It appeared different in other ways as well, causing more serious symptoms that lasted longer than usual, and with many cases among children. \u201cThey are seeing horrendous whole body rashes,\u201d says Trudie Lang<\/a> at the University of Oxford.<\/p>\n The sexual transmission suggested the cases might be due to the clade 2 mpox strain that spread to many countries around the world in 2022. In the West, vaccination was targeted at those most at risk<\/a>, including men who have sex with men.<\/p>\n However, when Udahemuka and his colleagues sequenced the genome of samples from Kamituga in February, they discovered the cases were caused by a mutated strain of clade 1, now known as clade 1B. Unlike clade 2, clade IB is spread primarily by heterosexual sex and non-sexual contact.<\/p>\n \u201cIt\u2019s incredibly worrying,\u201d says Lang. There is high transmission between mothers and other carers and children,\u00a0and also non-sexual person-to-person transmission outside of households, she says.<\/p>\n