FIFA mass gatherings (6/1/2026)

Marin County Public Health | Health Advisory

Issued by: Melanie Thompson, DO, MPH

Date: June 1, 2026

Increased Public Health Risks During Mass Gatherings

Audience & Purpose

Intended Audience:

Clinicians, emergency departments, urgent care providers, infection prevention and control personnel, Marin County healthcare facilities

Purpose:

To alert clinicians and healthcare facilities to increased public health risks during the 2026 FIFA World Cup and to provide guidance on surveillance, screening, isolation, and reporting.

Summary

The 2026 FIFA World Cup will occur from June 11 to July 19, 2026, with Bay Area matches hosted at Levi’s Stadium in Santa Clara. The tournament is expected to bring significant international and domestic travel to the region and coincides with local mass gatherings, including Pride Month activities and the Marin County Fair. Together, these events may increase population mixing, healthcare utilization, and presentations related to infectious diseases, sexually transmitted infections, foodborne illness, substance-related morbidity, and injury.

Recent local and regional activity, including mpox cases and increasing STI rates, further underscores the need for timely prevention messaging, early detection, testing, isolation when indicated, and prompt reporting to public health.

Key Information

• FIFA World Cup: June 11 – July 19, 2026; Bay Area venue: Levi’s Stadium, Santa Clara
• Elevated risk: infectious disease (measles, mpox, TB, foodborne illnesses), STIs, heat illness, substance-related emergencies, and traumatic injury
• Recent Marin County context: active mpox cases and rising STI rates increase local relevance
• Risk to Marin County: ELEVATED - significant international travel expected to and from the Bay Area throughout the tournament period

Ebola: Risk to Marin County remains very low. In the context of increased international travel during the 2026 FIFA World Cup, clinicians should ask about recent international travel, transit countries, and relevant exposures when evaluating febrile illness. See Public Health Advisory: Ebola

Background & Context

Situation Overview

The 2026 FIFA World Cup is one of the largest international sporting events in history, with matches across the United States, Canada, and Mexico from June 11 through July 19, 2026. The Bay Area, including Marin County, is a major hub for international travel, and Levi’s Stadium in Santa Clara is among the designated U.S. match venues. Large volumes of international visitors are expected to travel through SFO and the broader region throughout the tournament.

Mass gatherings of this scale are well-documented drivers of infectious disease transmission and healthcare utilization surges. Emergency departments and urgent care settings in Marin County may experience increased visits for a wide range of conditions, including travel-associated infections, STIs, heat-related illness, substance-related morbidity, and traumatic injury. 

Relevance to Marin County

Marin County clinicians should anticipate patients presenting with travel-associated conditions throughout the World Cup period, including visitors to the region and returning local residents. The following conditions warrant heightened clinical awareness:

Potential Health Impacts During the Tournament Period

Heat-Related Illness

• Heat-related illness and dehydration
• Exacerbation of chronic medical conditions related to heat exposure

Sexually Transmitted Infections (STIs)

• HIV, syphilis, gonorrhea, chlamydia
• Mpox associated with close personal or sexual contact

Respiratory and Gastrointestinal Illness

• Influenza-like illness and other respiratory viral infections
• COVID-19
• Measles
• Norovirus and other gastrointestinal outbreaks

Travel-Associated Infectious Diseases

• Tuberculosis (TB)
• Dengue and other arboviral diseases
• Malaria
• Typhoid fever

Substance-Related Morbidity

• Alcohol-related illness and injury
• Opioid and other substance-related overdose
• Intoxication-related emergencies

Traumatic Injury

• Pedestrian and transportation-related injury
• Crowd-related injury
• Violence-related injury

Recommendations

For All Clinicians

• Ask: Routinely assess patients presenting with infectious illness, STI concerns, heat-related illness, intoxication, or injury for recent international and domestic travel, attendance at World Cup matches or related events, exposure to large gatherings, and potential high-risk exposures associated with travel or close personal contact.
• Consider: Travel-associated and non-endemic diseases in the differential, including measles, mpox (including clade I), TB, dengue and other arboviral diseases, malaria, and typhoid fever.
• Document: Record “World Cup” attendance and event details in the medical record when applicable.
• Review: Facility infection prevention and surge response plans in advance of the tournament period.

 For Clinicians — STI Screening

5. Screen broadly: Offer HIV, syphilis, gonorrhea, and chlamydia screening with a low threshold for testing, including asymptomatic patients with new or multiple sexual partners, recent travel or event attendance, or patient request.
6. Implement opt-out screening: Where feasible, incorporate opt-out STI screening into emergency care workflows. Emergency departments serve as a critical sentinel site for identifying undiagnosed STIs during this period.

For Clinicians — Isolation and Infection Control

• Mpox: Consider mpox in any patient with new unexplained rash (especially vesicular or pustular lesions), lymphadenopathy, recent travel, or close personal or sexual contact exposure. Implement contact and droplet precautions immediately for suspected cases. Add airborne precautions if aerosol-generating procedures are performed.
• Measles and TB: Immediately place patients with suspected measles or pulmonary TB in airborne infection isolation (AIIR). Do not delay isolation pending laboratory confirmation.

For Clinicians — Reporting

• Notify immediately: Contact Marin County Public Health for all suspected reportable diseases, disease clusters, or unusual clinical presentations.

Clinical Reference: Travel & Exposure History - Assess in All Relevant Encounters

• International and domestic travel — include transit countries, not only final destinations
• Attendance at World Cup matches, fan zones, or other large gatherings
• Exposure to ill contacts or crowded venues
• Sexual history and potential high-risk exposures

REPORT IMMEDIATELY

Suspected Measles, Mpox, Disease Clusters, or Other Reportable Conditions

Marin County Public Health: 415-473-4163 / After hours: 415-479-5305

For More Information

• CDC — Mass Gatherings: Yellow Book | CDC (cdc.gov)
• CDPH — Mpox Guidance
• CDPH — Measles Healthcare Exposure Investigation Quicksheet
• CDPH — Office of STIs and HCV, Clinical Guidelines and Job Aids
• CDC — Travel-Associated Infections and Diseases

This message was distributed to clinicians, emergency departments, urgent care providers, infection prevention and control personnel, and Marin County healthcare facilities. AI was used to format and edit this message.