London – Researchers who have monitored many outbreaks of smallpox in Africa say they are puzzled by the spread of the disease in Europe and North America.
Cases of smallpox-related disease have previously only been seen among people with connections to central and western Africa. But in the past week, the United Kingdom, Spain, Portugal, Italy, the United States, Sweden and Canada all reported infections, mostly in young men who had not previously traveled to Africa.
France, Germany, Belgium and Australia confirmed their first cases on Friday.
‘I’m shocked by this. Every day I wake up and there are more countries that are infected, says Oyewale Tomori, a virologist who previously led the Nigerian Academy of Science and who sits on several of the World Health Organization’s advisory boards.
“This is not the kind of spread we’ve seen in West Africa, so something new could happen in the West,” he said.
So far no one was killed in the outbreak. Smallpox usually causes fever, chills, rash and damage to the face, hands or genitals. The WHO estimates that the disease is fatal to up to 1 in 10 people, but smallpox vaccine is protective and some antiviral drugs are being developed.
British health authorities are investigating whether the disease is sexually transmitted. Health authorities have asked doctors and nurses to be aware of potential cases, but said the risk to the general population is low. The European Center for Disease Control and Prevention recommended that all suspected cases be isolated and that high-risk contacts be offered smallpox vaccine.
Nigeria reports about 3,000 cases of appox per year, the WHO said. Outbreaks appear to be exacerbated in rural areas, with people in close contact with infected rats and squirrels, Tomori said. He said many cases are likely to be missing.
Dr. Ifedayo Adetifa, head of the country’s Center for Disease Control, said that none of the Nigerian contacts for the British patients had developed symptoms and that investigations were ongoing.
WHO’s European Head, Dr. Hans Kluge, described the outbreak as “atypical”, and said that the onset of the disease in so many countries across the continent indicated that “transmission has been going on for some time.” He said that most of the European cases are mild.
On Friday, the UK Health Security Agency reported 11 new cases of smallpox, saying that “a significant proportion” of recent infections in the UK and Europe have been in young men who have not traveled to Africa who have had sex with men. Authorities in Spain and Portugal said their cases were the same.
Experts have emphasized that they do not know if the disease is spread through sex or other close contact related to sex.
Nigeria has not seen sexual transmission, Tomori said, but he noted that viruses that were initially not known to transmit via sex, such as Ebola, later turned out to do so after major epidemics showed different transmission patterns.
The same can be true for monkey pox, Tomori said.
In Germany, Health Minister Karl Lauterbach said the government was convinced the outbreak could be curtailed. He said the virus was sequenced to see if there were any genetic changes that may have made it more contagious.
Rolf Gustafson, professor of infectious diseases, told SVT that it was “very difficult” to imagine that the situation could worsen.
“We will certainly find further cases in Sweden, but I do not think there will be an epidemic in any way,” said Gustafson. “There is no indication of that at present.”
Researchers said that although it is possible that the outbreak’s first patient contracted the disease while in Africa, what is happening now is exceptional.
“We have never seen anything like it happen in Europe,” said Christian Happi, director of the African Center of Excellence for Genomics of Infectious Diseases. “We have not seen anything that says that the infection patterns of monkey pox have changed in Africa. So if something else happens in Europe, Europe must investigate it.
Happi also pointed out that the abolition of smallpox vaccination campaigns after the disease was eradicated in 1980 may inadvertently help smallpox to spread. Smallpox vaccine also protects against monkey pox, but mass immunization was stopped decades ago.
“Apart from people in West and Central Africa who may have some immunity to monkey pox from previous exposure, it means that having no smallpox vaccination means that no one has any form of immunity to monkey pox,” Happi said.
Shabir Mahdi, professor of vaccinology at the University of the Witwatersrand in Johannesburg, said a detailed study of the outbreak in Europe, including determining who the first patients were, was now critical.
“We really need to understand how this started and why the virus is now gaining ground,” he said. “In Africa, there have been very controlled and rare outbreaks of monkey pox. If that is about to change, we really need to understand why.
Source: sn.dk