Pathogen Update: 7-26-2026
Daily Automatic Update
Daily Global Pathogen and Outbreak Briefing - 2026-07-26
Executive summary
- Highest-concern development: Bundibugyo Ebola transmission remains intense in eastern Democratic Republic of the Congo (DRC), with ECDC citing 2,905 confirmed cases and 1,269 deaths reported by DRC as of 22 July, plus 722 patients hospitalized in isolation. Uganda is in its 42-day enhanced surveillance countdown after discharging its last patient, but the DRC outbreak is still worsening.
- Measles remains a major vaccine-preventable disease signal. The United States has reported 2,318 confirmed cases in 2026 as of 23 July, exceeding the full-year 2025 total and involving 35 new outbreaks. Global cross-border risk remains high because outbreaks are active in all WHO regions.
- Respiratory viruses remain generally low globally, but with pockets of activity. WHO’s week 28 global update says SARS-CoV-2 activity is low overall, influenza remains below 10% positivity globally with influenza B predominant among detections, and RSV is low globally but elevated in selected countries in the Americas, eastern Africa, and southern Asia.
- Other notable event: the U.S. Cyclospora outbreak linked to iceberg lettuce has expanded to 1,947 laboratory-confirmed illnesses across 9 states, with 98 hospitalizations and no deaths; recalled Taylor Farms de Mexico iceberg lettuce had broad foodservice and retail distribution.
Pathogen-by-pathogen briefing
SARS-CoV-2
- Status summary: Global SARS-CoV-2 activity remains low overall, but not absent. WHO reported stable, low positivity in most reporting countries in week 28, with elevated positivity above 10% in countries in Central America and the Caribbean and single countries in tropical South America, western Asia, and South-East Asia.
- Notable countries/regions: Central America and the Caribbean; tropical South America; western Asia; South-East Asia; United States; Australia.
- Severity: Low globally; Moderate watch in parts of the United States because early summer growth signals are accumulating.
- Trend: Stable globally; worsening/early increase in parts of the United States.
- Why it matters now: CDC estimates, as of 22 July, that COVID-19 infections are growing or likely growing in 37 U.S. states, while CDC’s respiratory illness summary still describes national activity as low and stable with early increases in the West and South. WHO’s variant dashboard for 24 May-21 June shows NB.1.8.1 rising to 50% of submitted global sequences; WHO states available evidence does not indicate additional public-health risk from NB.1.8.1, XFG, or BA.3.2 relative to other circulating variants.
Measles
- Status summary: Measles remains one of the most important global vaccine-preventable threats today. The U.S. has now exceeded its full-year 2025 case total, and international import/export risk remains material because outbreaks are occurring in every WHO region.
- Notable countries/regions: United States; Canada; United Kingdom; Israel; EU/EEA; global travel corridors.
- Severity: High.
- Trend: Worsening in the United States; variable globally but still high-risk because of sustained outbreaks and immunity gaps.
- Why it matters now: CDC reports 2,318 confirmed U.S. measles cases as of 23 July 2026, with 93% outbreak-associated and 35 new outbreaks reported in 2026. CDC’s global measles page notes that outbreaks are happening in every region of the world. Recent CDC Emerging Infectious Diseases reporting on Israel’s 2025-2026 outbreak highlights the public-health importance of genomic surveillance and rapid response in preventing sustained transmission.
Pertussis
- Status summary: No major new global escalation found today, but pertussis continues to circulate after the post-pandemic resurgence.
- Notable countries/regions: United States; Australia; EU/EEA; Americas Region.
- Severity: Moderate for infants and under-immunized communities; Low-to-Moderate for general population situational awareness today.
- Trend: Improving compared with 2025 in the United States and Australia, but ongoing circulation persists.
- Why it matters now: CDC says preliminary U.S. pertussis reports in 2026 are lower than at the same point in 2025, after a November 2024 peak. Australia similarly reported in February that early-2026 pertussis activity was about 80% lower than the same period in 2025. Risk remains concentrated in infants too young to be fully vaccinated and in communities with delayed boosters.
Ebola disease, Bundibugyo virus
- Status summary: The DRC outbreak remains the highest-severity item in today’s briefing. Transmission is sustained and still expanding in affected eastern provinces.
- Notable countries/regions: DRC, especially Ituri, North Kivu, Haut-Uele, South Kivu, and Tshopo; Uganda; imported/medically evacuated cases treated in Germany and France.
- Severity: High.
- Trend: Worsening in DRC; improving in Uganda if no further cases emerge.
- Why it matters now: ECDC’s 24 July update cites 2,905 confirmed DRC cases and 1,269 deaths reported up to 22 July, including 97 new confirmed cases and 62 deaths since the previous day. Ituri remains the epicenter, with 2,595 cases and 1,077 deaths, and 47 of 140 health zones affected across five provinces. Uganda reported 20 confirmed cases and 2 deaths as of 17 July, with no new cases since 21 June and its final patient discharged on 16 July, starting the 42-day countdown toward declaring the outbreak over.
Diphtheria
- Status summary: Diphtheria remains a notable vaccine-preventable disease concern, with current public-health focus on Australia, the Americas, and parts of Africa.
- Notable countries/regions: Australia, especially Northern Territory and Western Australia; Americas Region; African Region including Nigeria, Niger, Mali, Mauritania, Guinea, Chad, Algeria, and South Africa.
- Severity: Moderate.
- Trend: Mixed. Australia shows plateauing/slowing after increases; the Americas and parts of Africa remain concerning because of under-immunization and recurrent outbreaks.
- Why it matters now: Australia’s 6 July epidemiological update reported 426 confirmed 2026 cases as of 6 July, with 55% in the Northern Territory and 41.3% in Western Australia; the past fortnight had 30 notifications versus 67 in the previous fortnight. PAHO reported 163 confirmed cases and 5 deaths in the Americas during epidemiological weeks 1-21 of 2026, more than double the comparable period cited in its alert. WHO’s July diphtheria factsheet underscores that recent outbreaks reflect gaps in multi-dose and booster coverage.
RSV
- Status summary: RSV is low globally but elevated in selected regions and seasonally active in parts of the Southern Hemisphere.
- Notable countries/regions: Central America and the Caribbean; tropical and temperate South America; eastern Africa; southern Asia; Australia.
- Severity: Moderate for infants, older adults, pregnant people, and high-risk groups; Low globally today.
- Trend: Stable/low globally; increasing in some localized areas.
- Why it matters now: WHO’s week 28 update says RSV positivity remains low globally, but is elevated above 10% in a few countries in Central America and the Caribbean and tropical/temperate South America, and above 30% in single countries in eastern Africa and southern Asia. Australia reported RSV cases increased 6.0% in the 29 June-12 July fortnight, with 85,002 RSV notifications year-to-date and increased sentinel hospital admissions driven partly by RSV.
Influenza A
- Status summary: Influenza activity remains low globally, but some tropical and Southern Hemisphere areas have elevated positivity and mixed subtype patterns.
- Notable countries/regions: Central America and the Caribbean; Middle Africa; southern Asia; western and South-East Asia; temperate South America; southern Africa; eastern Asia; Australia.
- Severity: Low globally; Moderate in localized seasonal settings and for high-risk groups.
- Trend: Mostly stable/low globally; increasing in Australia and selected tropical/Southern Hemisphere countries.
- Why it matters now: WHO reports global influenza positivity below 10% in week 28. In zones with elevated positivity, A(H3N2) predominated in Central America/Caribbean and Middle Africa; A(H1N1)pdm09 predominated in southern Asia; A(H1N1)pdm09 and A(H3N2) were codominant in western and South-East Asia. Australia reported a 47.1% fortnightly increase in influenza notifications, driven by New South Wales and Western Australia, though activity remains lower than the same period in previous years.
Influenza B
- Status summary: Influenza B is proportionally important among current global influenza detections despite overall low global activity.
- Notable countries/regions: Tropical South America; western Africa; temperate South America; southern Africa; eastern Asia; Australia.
- Severity: Low globally; Moderate in localized seasonal settings and vulnerable groups.
- Trend: Stable/low globally; localized elevation.
- Why it matters now: WHO reports influenza B viruses were predominant among global influenza detections in week 28. Influenza B was predominant in tropical South America and western Africa, and influenza A and B were codominant in temperate South America, southern Africa, and eastern Asia. This matters for vaccine-match monitoring and clinical testing, because influenza B can still drive morbidity even when overall influenza positivity is below seasonal peaks.
Other outbreaks of interest
Cyclospora, United States
- Status summary: Large multistate foodborne outbreak linked to iceberg lettuce.
- Notable countries/regions: United States; cases with Taco Bell exposure in Illinois, Indiana, Kansas, Kentucky, Michigan, Ohio, Oklahoma, Pennsylvania, and West Virginia; recalled product distribution across many additional states.
- Severity: Moderate.
- Trend: Worsening/expanding by case count and states affected, though recall and product removal are active controls.
- Why it matters now: CDC reports 1,947 laboratory-confirmed illnesses, 98 hospitalizations, and no deaths as of the July 24 update, with illness onsets through 20 July. FDA says recalled Taylor Fresh Foods iceberg lettuce products were distributed to foodservice and retail channels across numerous states, and advises consumers, restaurants, and retailers to discard recalled products.
Avian influenza A(H5N1)
- Status summary: Ongoing animal panzootic with sporadic human infections; no current evidence of sustained human-to-human spread in the sources reviewed today.
- Notable countries/regions: United States dairy and poultry settings; global wild bird and poultry systems.
- Severity: Moderate watch item.
- Trend: Ongoing/unclear.
- Why it matters now: CDC continues to describe A(H5) as widespread in wild birds globally, causing poultry outbreaks and U.S. dairy cow infections, with sporadic human cases in exposed workers; CDC states current public-health risk remains low. WHO’s 7 July H5N1 update continues monthly reporting of confirmed human cases under IHR obligations.
Mpox
- Status summary: Continues as a multi-country outbreak with clade I and clade II circulation, but no sharper escalation found in today’s scan than the Ebola, measles, and Cyclospora signals.
- Notable countries/regions: Africa, including countries with clade I transmission; countries outside Africa reporting travel-linked and non-travel-linked clade I cases.
- Severity: Moderate watch item.
- Trend: Ongoing/unclear.
- Why it matters now: WHO’s 26 June external situation report provides the latest global situation through 31 May and Africa data through 14 June. ECDC notes that clade I and II MPXV are circulating in multiple countries globally, including clade I cases outside Africa with and without travel history to countries with ongoing transmission.
Watchlist
- SARS-CoV-2: Watch U.S. West/South increases, CDC Rt estimates, wastewater signals, and whether NB.1.8.1 growth changes severity or healthcare pressure.
- Measles: Watch U.S. outbreak-associated transmission, Canada/UK/Israel and EU/EEA signals, cross-border importations, and MMR coverage response.
- Ebola Bundibugyo: Watch DRC daily case growth, contact follow-up completeness, spread outside Ituri/North Kivu, Uganda’s 42-day countdown, and any additional international medical evacuations or exportations.
- Diphtheria: Watch Australian Northern Territory/Western Australia trends, PAHO follow-up updates, and African Region outbreak persistence.
- RSV/influenza: Watch Southern Hemisphere winter activity, especially Australia, temperate South America, southern Africa, and countries where RSV and influenza are simultaneously elevated.
- Cyclospora: Watch whether U.S. case counts continue rising because of reporting delays and whether traceback identifies broader distribution beyond known recall channels.
- Avian influenza A(H5N1): Watch for human cases outside known exposure groups, mammal outbreaks, and any evidence of adaptation or sustained human transmission.
References
- WHO, Global Respiratory Virus Activity: Weekly Update No. 587, week 28 ending 12 July 2026: https://www.who.int/publications/m/item/global-respiratory-virus-activity--weekly-update-n--587
- WHO COVID-19 dashboard, variant circulation 24 May-21 June 2026: https://data.who.int/dashboards/covid19/summary
- CDC Respiratory Illnesses Data Channel, updated 24 July 2026: https://www.cdc.gov/respiratory-viruses/data/index.html
- CDC Current Epidemic Trends, COVID-19 Rt estimates, 22 July 2026: https://www.cdc.gov/cfa-modeling-and-forecasting/rt-estimates/index.html
- CDC Measles Cases and Outbreaks, updated 24 July 2026: https://www.cdc.gov/measles/data-research/index.html
- CDC Global Measles Outbreaks: https://www.cdc.gov/global-measles-vaccination/data-research/global-measles-outbreaks/index.html
- CDC Emerging Infectious Diseases, Israel measles outbreak genomic/epidemiologic report, published 24 July 2026: https://wwwnc.cdc.gov/eid/article/32/9/26-0625_article
- CDC Pertussis Surveillance and Trends, updated 10 July 2026: https://www.cdc.gov/pertussis/php/surveillance/index.html
- ECDC Ebola disease outbreak in DRC and Uganda, updated 24 July 2026: https://www.ecdc.europa.eu/en/ebola-outbreak-democratic-republic-congo-and-uganda
- WHO Disease Outbreak News, Ebola disease caused by Bundibugyo virus, DRC and Uganda, 17 July 2026: https://www.who.int/emergencies/disease-outbreak-news/item/2026-DON613
- Australian Centre for Disease Control, Diphtheria in Australia epidemiological update, 6 July 2026: https://www.cdc.gov.au/sites/default/files/2026-07/20260707-diphtheria_epi_summary_-_web.pdf
- PAHO, Diphtheria cases rise in the Americas, 15 June 2026: https://www.paho.org/en/news/15-6-2026-paho-urges-countries-strengthen-vaccination-efforts-diphtheria-cases-rise-americas
- WHO Diphtheria factsheet, updated 15 July 2026: https://www.who.int/news-room/fact-sheets/detail/diphtheria
- Australian Respiratory Surveillance Report, 29 June-12 July 2026: https://www.cdc.gov.au/resources/publications/australian-respiratory-surveillance-report-29-june-2026-12-july-2026
- CDC Cyclospora outbreak investigation update, July 2026: https://www.cdc.gov/cyclosporiasis/outbreaks/07-26/investigation.html
- FDA Cyclospora outbreak investigation, iceberg lettuce, July 2026: https://www.fda.gov/food/outbreaks-foodborne-illness/investigation-9-state-outbreak-cyclospora-illnesses-iceberg-lettuce-july-2026
- CDC A(H5) Bird Flu Current Situation: https://www.cdc.gov/bird-flu/situation-summary/index.html
- WHO cumulative confirmed human A(H5N1) cases, 7 July 2026: https://www.who.int/publications/m/item/cumulative-number-of-confirmed-human-cases-for-avian-influenza-a%28h5n1%29-reported-to-who--2003-2026--7-july-2026
- WHO mpox external situation report No. 67, 26 June 2026: https://www.who.int/publications/m/item/multi-country-outbreak-of-mpox--external-situation-report--67---26-june-2026
Next items to monitor
- DRC Ebola daily reporting for whether new cases remain concentrated in Ituri/North Kivu or continue spreading across health zones.
- CDC’s next measles update for new outbreaks and whether U.S. case growth accelerates before the autumn school term.
- U.S. COVID wastewater/Rt updates for confirmation of a summer increase.
- FDA/CDC Cyclospora updates for additional states, hospitalizations, or revised traceback findings.
- Southern Hemisphere respiratory-virus reports for RSV/influenza pressure on hospitals through winter.
Keep up your kindness and hopefully help someone with Long Covid or prevent it by encouraging masking, boosting, and clean air!
Take care,
Joe
I should be wearing a mask for my emoji on X, but I was in the middle of a lake when I took this.