Pandemiology Watch (February 25-March 3, 2026).
Influenza infections
According to the European Centre for Disease Prevention and Control weekly Communicable Disease Threats Report, published 27 February 2026, health authorities in Spain have confirmed a human infection with variant H1N1 swine influenza (H1N1v) in Catalonia. The case involved an asymptomatic individual, and close contacts tested negative. There is no evidence of onward transmission.
H5N1
According to a University of California, Davis news release published February 25, 2026, seven weaned northern elephant seals at Año Nuevo State Park in California have tested positive for highly pathogenic avian influenza (HPAI) H5N1, marking the first confirmed cases of this virus in marine mammals in the state. The detections were confirmed by the U.S. Department of Agriculture’s National Veterinary Services Laboratory. Researchers reported respiratory and neurological signs in the seals and have temporarily closed public access to the park while continuing ongoing surveillance.
As of March 3, 2026, the Centers for Disease Control and Prevention reports has not reported any cases of person-to-person transmission of H5N1 in the United States. The total remains at 71 confirmed human cases and two deaths.
MEASLES
US.
According to CIDRAP on February 27, 2026, measles cases continue to rise in several US states. Florida has reported 114 cases, including 83 in Collier County linked to an outbreak at Ave Maria University. South Carolina remains the hardest hit state with 986 cases since October, most in Spartanburg County. Additional cases have also been reported in Texas (17 cases), Ohio (6 cases), Utah (319 cases in 2025-2026), and Arizona (55 cases).
On March 2, 2026, the Pan American Health Organization announced that the measles elimination status of the United States and Mexico will be reviewed in November 2026 during the meeting of the Regional Verification Commission. The review follows ongoing measles outbreaks and will assess whether both countries still meet the criteria for measles elimination.
As of February 27, 2026, the United States has reported 1136 measles cases, according to the Center for Disease Control. In 2026, the age group 5-19 accounts for 57% of the cases (653), and children under 5 years account for 24% of the cases (278). Of the cases reported in 2026, 92% were unvaccinated or had an unknown vaccination status and 5% of the cases have been hospitalized (58). A total of 3,417 measles cases and three deaths have been reported to date.
Canada.
As of March 2, 2026, Canada has reported 339 measles cases in 2026, according to the Public Health Agency of Canada. In 2026, 54% of the cases occurred in children (184). Manitoba accounts for 67% of the cases (228), and Alberta accounts for 21% of the cases (72) reported so far in 2026. 86% of the cases reported in 2026 were unvaccinated (291), and five required hospitalization. A total of 5,764 measles cases and two deaths have been reported to date.
MPOX
From February 25-March 3, 2026, there have been no significant updates on mpox outbreaks worldwide.
Nipah Virus Disease
From February 25-March 3, 2026, there have been no significant updates on Nipah virus outbreaks worldwide.