Asian countries from China to Pakistan have beefed up surveillance for a mutated monkeypox (mpox) virus that is spreading outside central Africa, where it prompted the World Health Organization (WHO) to declare a global health emergency this month.
A case in Sweden last week highlights the international threat from the so-called 1B strain that is reported to have killed more than 500 people, mostly children, in the Democratic Republic of Congo.
Across Asia, travelers arriving from affected countries are being asked to self-report symptoms, while hospitals heighten surveillance for the disease.
Unlike the mpox-causing virus that spread globally in 2022, the newer strain is more dangerous, with a case fatality rate over 3 per cent. It is also possible that infected individuals may transmit the virus several days before developing symptoms, making it harder to contain by identifying and isolating cases.
China is asking incoming travelers from countries and regions affected, those who have been in contact with mpox patients, and individuals experiencing symptoms to report to customs officials upon entry, where they may be required to undergo testing, according to a statement.
Health authorities in India ordered heightened vigilance at international airports and ports for passengers displaying mpox symptoms, and designated hospitals and labs to handle potential cases, Economic Times reported. Indonesia and Malaysia have also adopted similar measures.
With mpox again in the spotlight, health officials are reporting cases likely caused by the milder 2b strain. Pakistan confirmed a 2b infection on Aug. 13. The Philippines health department said it detected the nation’s first mpox case since December in a 33-year-old male who hadn’t recently traveled. The strain responsible isn’t yet known.
The mutated clade Ib strain is the subject of intense research as disease detectives rush to understand how it spreads and to gauge its propensity to cause serious illness and death. Experts say that it appears so far to spread predominantly through close physical contact, such as carrying an infected child. That’s unlike the SARS-CoV-2 virus, which mostly spreads through the air from an infected person’s breath, making it harder to control.
At the start of the Covid-19 pandemic in early 2020, many governments implemented fever-screening and other surveillance measures to identify incoming passengers infected with the coronavirus. Studies, however, showed the procedures weren’t effective at stopping the introduction of the virus, since a large proportion of carriers have no or minimal symptoms while they are contagious.
A 2022 study from the UK found that more than half of mpox infections were spread by infected individuals who had not yet developed symptoms. Emerging evidence suggests that people incubating the disease may transit mpox virus for up to four days prior to symptom onset.