Active & Recent Outbreaks

WHO declared a second PHEIC for mpox in August 2024 following the emergence and spread of Clade Ib, a new sublineage showing efficient sexual human-to-human transmission, from DRC into Burundi, Rwanda, Uganda, and Kenya. Clade Ib causes more severe disease than the Clade IIb that drove the 2022 global outbreak.

Since March 2024, H5N1 highly pathogenic avian influenza has spread through US dairy cattle herds across multiple states. As of early 2025, dozens of human cases have been confirmed in farm workers, primarily presenting with conjunctivitis and mild respiratory illness. No confirmed human-to-human transmission. WHO risk to general public remains low but situation is monitored closely.

2024 saw record dengue transmission globally, with the Americas reporting over 9 million cases — more than double any previous annual record. Brazil, Colombia, Argentina, Peru, and many Caribbean nations all reported epidemic transmission. Expanding Aedes aegypti range due to climate change and La Niña weather patterns contributed. PAHO issued repeated alerts.

WHO declared a global cholera alert in 2023 with cases in over 40 countries — the highest in decades. Yemen, Syria, DRC, and Sudan account for the majority of cases, driven by conflict, displacement, damaged water infrastructure, and weakened health systems. The crisis has been exacerbated by reduced OCV (oral cholera vaccine) supply.

COVID-19 remains globally endemic with seasonal waves. JN.1 and KP.2 subvariants dominated in 2024. WHO ended the PHEIC designation in May 2023, transitioning to long-term management. Surveillance continues through genomic sequencing networks. Annual vaccine updates targeting circulating variants are recommended, particularly for vulnerable populations.

Kerala, India has experienced recurrent Nipah virus outbreaks in 2018, 2021, and 2023. The 2023 outbreak (6 cases, 2 deaths) prompted Kerala state to activate emergency response protocols. Pteropus fruit bats remain the likely source. No approved vaccine exists. Each outbreak demonstrates both the continued spillover risk and Kerala's improved containment capacity.

DRC continues to experience sporadic Ebola outbreaks, particularly Zaire ebolavirus. Ring vaccination with Ervebo has been deployed in each outbreak since 2018. REGN-EB3 (Inmazeb) and ansuvimab (Ebanga) are approved treatments. Additionally, Sudan ebolavirus (against which Ervebo does not protect) caused outbreaks in Uganda (2022) and Equatorial Guinea (2023).

Brazil reported record chikungunya transmission in 2023 (over 300,000 cases). Locally-acquired chikungunya cases have been reported in southern France and Italy as Aedes albopictus spreads. IXCHIQ, the first FDA-approved chikungunya vaccine, was licensed in November 2023 for adults at risk — a significant development for travellers and residents of endemic areas.