Pandemiology Watch (November 19-25, 2025)
Emerging outbreaks
On November 19, 2025, CBS News reported on a significant surge in whooping cough (pertussis) cases across the United States, noting that several states are seeing higher numbers than in recent years. Infants remain the age group most at risk, as they are more likely to develop severe complications. According to public health officials, vaccination rates have fallen since the COVID-19 pandemic, when many children missed routine appointments, and some parents use nonmedical exemptions based on religious or personal beliefs to skip recommended vaccines.
H5N1
U.S.
The first U.S. human case of H5N5 avian influenza, a Grays Harbor County resident, has died, the Washington State Department of Health confirmed on November 21, 2025. The patient, an older adult with underlying health conditions, had contact with domestic poultry exposed to wild birds.
Following the above the total human H5N1 cases in the United States to 71, with two deaths reported as of November 24, according to the Centers for Disease Control and Prevention. No person-to-person transmission has been reported
MEASLES
U.S.
Utah and South Carolina reported new measles cases, according to CIDRAP on November 24. Utah reported five new cases in Wasatch County bringing its total to more than 90, while South Carolina reported a total of 55 cases.
As of November 19, 2025, Center for Disease Control reports a total of 1,753 confirmed measles cases in the U.S. in 2025. 12 % of cases have required hospitalization (211 cases of 1,753), and three deaths have been reported.
Canada.
As of November 24, 2025, Canada has reported 5,222 measles cases where 71% occurred in children, according to the Public Health Agency of Canada. Ontario accounts for 46% of the cases, followed by Alberta with 38%. 89% were unvaccinated, and 7% required hospitalization. Genotype D8 remains the most frequently detected strain. 2 deaths have been reported.
MPOX
Europe.
On November 21, 2025, The Independent reported on a more severe variant of mpox, known as Clade?1b, spreading across several European countries, including Germany, Belgium, the Netherlands, France, Ireland, Italy, Spain, Greece, Portugal, and Sweden. The cases mainly affect unvaccinated individuals, including some children, who are at highest risk of severe illness and face a mortality rate of up to 10 per cent. Some patients have required hospitalization. The UK separately recorded 19 cases between October 2024 and last month, mostly linked to travel from affected countries. UK health authorities are advising men who are gay, bisexual, or have sex with men to consider vaccination,
Africa.
Sierra Leone: The World Health Organization (WHO) reported 5,442 confirmed mpox cases as of October 26, and no new data have been released in the past week.
Uganda: As of November 2, 2025, Uganda reported 7,007 confirmed mpox cases, according to the World Health Organization. This is an increase of 37 cases since October 26. No new data from WHO have been reported for the past week.
Guinea: As of November 9, 2025, The World Health Organization has reported 1,169 cases in 2025 and one death in Guinea. This is an increase of 34 cases since November 2. No new data from WHO have been reported for the past week.
Rift Valley Fever
Senegal.
As of November 22, the Africa Centres for Disease Control and Prevention (Africa CDC) reported a total of 11,936 suspected Rift Valley Fever cases in Senegal, including 2,783 new cases since the last update on November 17. The number of confirmed cases has risen to 463 (32 new), with 31 deaths (1 new). Of the cases reported, 65% were males, 19% aged 20-25, and 87% occurred in the Saint Louis region.
Mauritania.
As of November 22, Africa CDC reported a total of 227 suspected Rift Valley Fever cases in Mauritania, including 9 new suspected cases since the last update on November 17. The number of confirmed cases is 49 with no new cases. 15 deaths have been reported. Of the cases reported, 77% were male, and 94% were in individuals over 10 years old.
POLIO
As of November 19, 2025, Global Polio Eradication Initiative reported new poliovirus detections. Pakistan detected 47 WPV1-positive environmental samples, Germany reported one WPV1-positive environmental sample, and Papua New Guinea identified two cVDPV2-positive environmental samples.
In Africa, Chad recorded four cVDPV2 cases and three cVDPV2-positive environmental samples, Djibouti reported one cVDPV1-positive environmental sample, and Nigeria confirmed two cVDPV2 cases along with one cVDPV2-positive environmental sample.