Health · Public Health & Disease · 1 hr ago
Mpox clade 1b detected in São Paulo and Rio de Janeiro
Brazil has detected Mpox clade 1b in São Paulo and Rio de Janeiro in 2026.
São Paulo health officials reported 103 cases linked to the variant by November 13, mostly in the metropolitan area.
Rio reported 30 recent cases associated with clade 1 and 11 with clade 2, and one Mpox death this year.
São Paulo and Rio account for more than 76% of Brazil’s 1,055 recorded cases, with 409 in São Paulo and 395 in Rio.
Clade 1b drove an outbreak in parts of Africa in 2024, including more than 78,000 cases and 1,000 deaths in the Democratic Republic of the Congo.
Studies outside Brazil suggest clade 1b may spread more easily and cause more severe illness than clade 2b, which was dominant in Brazil in 2022, but it is not known whether that pattern will hold in Brazil.
Health officials do not yet know if the variant has been found in other Brazilian states, and the article gives no further steps.
São Paulo and Rio de Janeiro recorded the presence of mpox clade 1b in 2026, according to CNN Brasil.
São Paulo had 103 cases identified as clade 1b by Friday, November 13, with most concentrated in the metropolitan region.
In Rio de Janeiro, 30 identified cases were associated with clade 1 and 11 with clade 2 in the most recent period reported.
The two states together accounted for more than 76% of Brazil’s 1,055 recorded mpox cases, according to figures updated November 13.
An infectious disease specialist said clade 1b has shown greater transmissibility and potential to cause more severe illness abroad, but it is not yet known whether those traits will be seen in Brazil.
- Who
- Health authorities in São Paulo and Rio de Janeiro reported the cases. Infectious disease specialist Bruno Tavares discussed the concerns.
- What
- Mpox clade 1b was recorded in São Paulo and Rio de Janeiro in 2026.
- When
- In 2026; figures cited in the article were updated Friday, November 13.
- Where
- São Paulo and Rio de Janeiro, Brazil.
- Why
- Not stated
This story does not have two clearly opposing sides.
Clade 1b was responsible for an mpox outbreak in some African countries, including the Democratic Republic of the Congo.
São Paulo and Rio de Janeiro recorded the presence of clade 1b.
São Paulo’s health department reported 103 clade 1b cases, and national figures showed 1,055 mpox cases in Brazil.
- São Paulo clade 1b cases
- 103 by November 13
- Rio de Janeiro clade 1 cases
- 30 in the most recent period reported
- Rio de Janeiro clade 2 cases
- 11 in the most recent period reported
- Brazil mpox cases
- 1,055 as of November 13
- São Paulo and Rio de Janeiro cases
- 409 and 395, respectively
What people are saying
The difference of this variant from the old one, and whether it is more concerning, is precisely that it has shown itself to be more transmissible and to have a more pathogenic capacity, as we call it, and a greater capacity to transmit and cause more severe disease