Viral Update: Illness and Volume Trends, and Helpful Resources for Our Community

Our goal is to share information and resources with our larger community as we all work together to care for patients facing viral illnesses.  

Update on Masking and Visitation Policies at Seattle Children’s

Due to rising respiratory virus transmission, Seattle Children’s implemented high-transmission protocols in mid-December, including required masking for workforce members when patient-facing in all clinical areas. Masking remains optional for patients, caregivers, and visitors, though care teams may recommend it. Updated visitation guidelines will also be in effect for inpatient, ambulatory, and ED settings to help protect patients, families, and staff, particularly those at higher risk.

• Inpatient: Up to four designated caregivers per patient; four caregivers/adult visitors allowed at the bedside at one time (up to two overnight). Asymptomatic siblings >10 years may visit; siblings <10 years may not, with limited exceptions for prolonged stays. Infants <12 months do not count toward visitor limits. No non-sibling visitors under 18. Transmission-based precaution rules apply when indicated.
• Ambulatory: Up to four caregivers/siblings total may accompany a patient; limiting caregivers and siblings is encouraged. Infants <12 months do not count toward limits. The ED may apply additional restrictions as needed.

These measures will remain in place until ED respiratory illness activity stays below the alert threshold for at least two consecutive weeks.

Viral Trends and Hospital Volumes

ED Volumes: ED volumes are currently stable, likely due to the school holidays. We anticipate volumes will begin rising the second week of January, with influenza and RSV peaking in late January. ED census is expected to be elevated into March and a longer tail into mid-May as spring respiratory viruses rise.  

Measles: The U.S. confirmed measles case count for 2025 is now 1,986, the highest since 1992. Canada has lost measles elimination status, and the U.S. is expected to follow in January. Multiple outbreaks are ongoing, driven by lower vaccination rates.

Influenza: Influenza activity continues to rise nationally. This season remains dominated by influenza A (H3N2) Subclade K, which is associated with more severe pediatric illness than A (H1N1). At Seattle Children’s, all influenza A detections with subtyping available this week were H3N2, and nearly 90% of subtyped samples were Subclade K. Western states are approaching or exceeding last year’s peak activity, while King County remains below last year’s peak but continues to rise. A test-and-treat strategy is recommended at current activity levels unless there is known exposure or a positive home test.

RSV: RSV positives are elevated and continue to climb. School holidays have less impact on RSV transmission than influenza. We expect continued increases in the coming weeks. Continue to encourage immunization and prophylaxis.

SARS-CoV-2: Local wastewater and ED data show COVID-19 activity remains near baseline levels.

Botulism: An infant botulism outbreak associated with ByHeart infant formula has grown to 51 cases across 19 states, including two cases in Washington. Botulism can present up to 30 days after exposure. The affected formula was recalled on November 11. Suspected cases and testing should be coordinated through Public Health.

Mpox: WHO has downgraded the mpox emergency internationally, but mpox activity persists locally. King County is reporting its highest levels in three years. Mpox testing is available at Seattle Children’s – if you feel your patient may have Mpox and want them tested, please call Mission Control at 206-987-8899.   

Other Respiratory Viruses: Rhino/enterovirus remains the most common non-influenza/RSV positive. This channel represents multiple virus strains and does not include all enteroviruses. Seasonal coronaviruses and hMPV remain low. Parainfluenza activity is declining following its typical fall increase; croup activity is expected to taper.

Mycoplasma: Mycoplasma activity remains low, with a 2% positivity rate last week. Empiric double coverage with a penicillin and macrolide is not indicated.

Pertussis: Pertussis activity continues to increase statewide and nationally, with Washington ranking second in the U.S. for reported cases in 2025. Locally, we continue to see 0 to 2 positives per week. Continue to encourage vaccination.

Norovirus and Rotavirus: Norovirus and rotavirus activity remain at moderate levels and are rising. Testing should be reserved for appropriate clinical scenarios, and routine gastroenteritis PCR testing is not recommended.

Special Pathogens Team Update

Seattle Children’s has a special pathogens team that is continuously monitoring worldwide outbreaks to keep our staff, patients and community providers informed.

The Marburg Virus outbreak in Ethiopia is up to 14 cases and 9 deaths. A fatal case of Crimean-Congo hemorrhagic fever was reported in Namibia on November 22^nd but there have been no updates since.

The Ebola outbreak in the Democratic Republic of the Congo was declared over as of December 1^st and resulted in 64 cases and 45 deaths.

If you are treating a patient with recent (within the last month) travel to areas in Africa affected by hemorrhagic fevers and suspect a related illness, please contact your local public health department immediately.

If you are referring an ill patient that needs urgent evaluation to Seattle Children’s, please call Mission Control at 206-987-8899 before sending the patient.

Measles Resources

• Webinar Recording: Measles Community Response
• Measles One-Pager for Healthcare Providers (AAP)
• Measles - For Healthcare Professionals (CDC)
• Measles Specimen Collection Instructions for RT-PCR (DOH)
• Measles Specimen Collection Instructions for Serology (DOH)
• Immunization Schedules (CDC)
• Safety Information for Measles, Mumps, Rubella (MMR) Vaccines (CDC)
• Recognizing Measles in Your Patients (Pediatric Pandemic Network)
• Vitamin A and Measles Vaccine Talking Point (Pediatric Pandemic Network)
• Measles FAQ for Families & Caregivers (Pediatric Pandemic Network)

How You Can Help

• To help maintain ED volumes, consider reminding families of your clinic’s resources and procedures for urgent and after-hours patient needs to help direct them to the most appropriate site of care.
• Encourage families to review our ED vs. Urgent Care guide to find the most appropriate care setting – we have options for in-person and virtual urgent care, orthopedic urgent care, and psychiatric urgent care.
• Families should be prepared that, if viral testing is deemed clinically appropriate, it will typically be performed using a panel that identifies only influenza, RSV, and COVID-19.
• Before sending your patient to the ED, contact our Mission Control team with as much notice as possible at 206-987-8899. This helps us plan for your patient’s arrival, especially if there are concerns for communicable diseases.

Additional Resources

• View the respiratory virus data dashboard for the latest Seattle/King County trends for COVID, RSV and influenza-related ED visits.
• Read the situational summary on H5 Bird Flu to stay updated on the current Highly Pathogenic Avian Influenza A(H5N1) outbreak.
• View these resources on vaccine guidance for the most current COVID vaccination recommendations.
• Review the latest viral activity on the National Respiratory and Enteric Virus Surveillance System dashboard.