WHO Disease Outbreak News

Mpox Recombinant Strain With Clade Ib and IIb Genomic Elements Detected in UK and India

WHO has confirmed two cases of a recombinant mpox virus containing genomic elements of clades Ib and IIb — one in the United Kingdom (December 2025, with travel to Asia Pacific) and one in India (September 2025, with travel to the Arabian Peninsula). The Indian case represents the earliest known detection globally, having preceded the UK event. Full genome sequencing showed 99.9% similarity between the two strains, with 16 recombinant tracts common to both. Contact tracing in both countries is complete; no secondary cases were detected and neither patient experienced severe outcomes. The overall WHO public health risk assessment remains unchanged: moderate risk for men who have sex with men with new and/or multiple partners and sex workers, low for the general population.

Cereulide Toxin in Infant Formula, 144 Cases, 99 Countries

WHO has published a Disease Outbreak News report on multi-country infant formula contamination with cereulide toxin, a heat-stable emetic toxin produced by Bacillus cereus. Contaminated arachidonic acid (ARA) oil used as an ingredient in infant formula has been distributed to 99 countries and territories across six WHO Regions, with recalls initiated on 10 December 2025. Between 1 January and 25 February 2026, 144 suspected and confirmed cases were reported across 10 countries, with Belgium reporting 8 laboratory-confirmed cases. WHO assesses the overall public health risk as Moderate due to infant vulnerability, ongoing uncertainty about full product distribution and root cause, and gaps in case detection.

First Imported Human Case Avian Influenza A(H9N2) Italy Senegal Origin

Italy's National IHR Focal Point notified WHO on 21 March 2026 of a human case of avian influenza A(H9N2) in an adult male who had resided in Senegal for more than six months before traveling to Italy in mid-March. Next-generation sequencing confirmed the H9N2 subtype, with genetic analysis showing close similarity to strains previously identified in poultry in Senegal. This is the first imported human case of avian Influenza A(H9N2) reported in the European Region. No direct animal exposure was identified, and all traced contacts in Italy tested negative. WHO assesses the current risk to the general population as low.