The mpox virus, a new and potentially deadlier strain, is spreading internationally. Four countries outside of Africa – Sweden, Thailand, Philippines, and Pakistan – have confirmed cases, in addition to fourteen countries within Africa. The World Health Organization has declared the virus a “public health emergency of international concern”. The outbreak is triggered by Clade 1, believed to be a more serious variant that spreads through skin-to-skin contact. This strain was first traced to the Democratic Republic of the Congo (DRC) and a new Clade 1b variant has emerged in African countries.
The Clade 2 variant of mpox, which causes milder infections, spread mainly through sexual contact and resulted in a multicountry outbreak in 2022. Cases of this strain have been reported in more than 100 countries. The fatality rate for Clade 2 is 0.2 percent while it is 3.9 percent for Clade 1. Despite the official declaration by the WHO that the Clade 2 outbreak was over in May 2023, cases are still being recorded. The current focus is on Clade 1 and Clade 1b strains spreading in Africa, with the DRC experiencing the biggest outbreak ever recorded.
In Africa, the Clade 1 variant of mpox has been detected in several countries including Burundi, Cameroon, Central African Republic, DRC, Ghana, Liberia, Nigeria, Rwanda, South Africa, Uganda, Kenya, and Mozambique. The DRC is facing the largest outbreak, with thousands infected and the government declaring an epidemic. Most of the reported cases in Africa are from the DRC, with children under 15 accounting for 60 percent of cases. The new Clade 1b strain has also been detected in neighbouring countries Kenya, Rwanda, and Uganda this year.
Outside of Africa, cases of mpox have been reported in Asia in the Philippines, Thailand, and Pakistan. In Thailand, a case of the new Clade 1b strain was confirmed in a European male who had recently traveled from an African country experiencing a large outbreak. The Philippines reported a case of the milder Clade 2 variant and Pakistan reported a case infected with Clade 2. The patient in the Philippines had no travel history, indicating possible local transmission.
In Europe, only Sweden has reported an mpox case, caused by the more serious Clade 1 variant. The European Centre for Disease Prevention and Control has warned that more cases are likely due to frequent air travel between Europe and Africa. However, sustained transmission may be low if cases are quickly diagnosed and proper measures are in place. In the Americas, no new cases of Clade 1 mpox have been reported, but the region should remain alert, as cases of Clade 2 have been previously reported. Oceania and the Middle East have not reported any cases of the Clade 1 virus so far.
