Pathogen Update: 7-21-2026
Daily Automatic Update
Daily Global Pathogen and Outbreak Briefing - 2026-07-21
Executive summary
- Ebola remains the most consequential global outbreak signal today. WHO reports 2,145 confirmed Bundibugyo Ebola cases across DRC, Uganda, and one case diagnosed in France, with 830 deaths reported overall. DRC continues to worsen, while Uganda has had no new case since 21 June and has begun its 42-day countdown toward declaring the outbreak over.
- Global respiratory-virus activity is generally low, but there are regional exceptions. WHO reports low global SARS-CoV-2, influenza, and RSV activity overall, with elevated pockets in parts of the Americas, Africa, Asia, and the southern hemisphere. Australia is seeing RSV and influenza activity increase in winter surveillance.
- Measles remains a major vaccine-preventable threat. The Americas continue to report multi-country transmission, the United States is near its full-year 2025 case total, and Bangladesh’s large nationwide outbreak remains important because of high pediatric burden and immunity gaps.
- Zoonotic influenza warrants continued watch: recent human avian influenza A(H5N1) in Cambodia, avian influenza A(H5) in Bangladesh, and swine-origin influenza A(H3N2)v in Brazil were all reported without detected onward spread among contacts.
- Other notable developments: a U.S. multistate Cyclospora outbreak linked to recalled iceberg lettuce has more than 1,644 cases in the five-state linked cluster; ECDC reports stable but ongoing mpox clade I transmission in the EU/EEA; WHO considers the cruise-linked Andes hantavirus outbreak contained.
SARS-CoV-2
Status: Low globally; mostly stable, with localized increases.
Notable countries/regions:
- WHO’s latest global respiratory-virus update for week 26 reported SARS-CoV-2 positivity stable and low across most reporting countries, with elevated positivity in countries in Central America and the Caribbean, Tropical South America, Middle Africa, Western Asia, and South-East Asia.
- United States: CDC reported very low and stable national COVID-19 activity as of 17 July, but early signs of increase mainly in the South.
- Australia: the Australian Respiratory Surveillance Report for 29 June-12 July recorded 3,824 COVID-19 notifications in the fortnight, down 10.2% from the prior fortnight, and 51,998 year-to-date notifications, 56.5% below the same period in 2025. NB.1.8.1 was the most common variant under monitoring.
Direction: Stable to mildly increasing in selected regions.
Why it matters now: SARS-CoV-2 is not the dominant respiratory threat globally today, but summer/winter regional increases and variant monitoring remain relevant for healthcare demand and vaccination strategy.
Measles
Status: Worsening in several regions; high-risk where immunity gaps persist.
Notable countries/regions:
- United States: CDC reported 2,260 confirmed measles cases as of 16 July 2026, with 34 outbreaks reported in 2026 and 93% of confirmed cases outbreak-associated. This is already close to the full-year 2025 total of 2,289 confirmed cases.
- Americas: PAHO’s regional situation reporting has continued to document multi-country transmission in 2026, with a May report showing Mexico, Guatemala, the United States, and Canada accounting for most confirmed cases at that point. PAHO’s later 2 July situation report noted 479 new confirmed cases across seven countries/territories during epidemiological weeks 23-24.
- Bangladesh: WHO’s May DON remains a significant signal. Bangladesh reported a nationwide increase across 58 of 64 districts, with 19,161 suspected cases and 2,973 laboratory-confirmed cases from 15 March to 14 April, plus 166 suspected measles-related deaths. Children under 5 accounted for 79% of reported cases.
Direction: Worsening in the United States and still active across the Americas; Bangladesh remains high risk though today’s search did not identify a newer WHO DON.
Why it matters now: Measles is a direct marker of under-immunization. Imported and outbreak-linked cases continue to threaten elimination status and can rapidly strain public-health response capacity.
Pertussis
Status: Elevated post-pandemic baseline, but no major new global escalation found today.
Notable countries/regions:
- United States: CDC says preliminary 2026 data show fewer reported pertussis cases than at the same time in 2025; the last major peak was in November 2024.
- Australia: after record high 2024-2025 activity, Australian CDC reporting earlier in 2026 indicated activity had fallen substantially compared with 2025. Current Australian respiratory surveillance still includes pertussis among monitored respiratory pathogens, but no new national pertussis surge was identified today.
- Global immunization context: WHO/UNICEF’s 15 July coverage update reported 2025 DTP1 coverage of 90% and DTP3 coverage of 85%, with 13.5 million zero-dose children. These gaps sustain pertussis risk, particularly for infants.
Direction: Stable to improving compared with 2024-2025 peaks, with persistent vulnerability.
Why it matters now: The main current concern is infant protection and delayed recovery of routine immunization, not a newly detected international surge.
Ebola
Status: DRC worsening; Uganda improving; international risk management active.
Notable countries/regions:
- Democratic Republic of the Congo: WHO reported 2,124 confirmed cases and 828 deaths in DRC as of 15 July, with 390 recoveries. WHO also reported 664 additional confirmed cases and 376 confirmed deaths in DRC since its prior 3 July DON. ECDC’s week 29 report says five DRC provinces have been affected: Ituri, North Kivu, South Kivu, Tshopo, and Haut-Uele, with Ituri most affected.
- Uganda: 20 confirmed cases and two deaths have been reported; no new case since 21 June. The last Ebola patient was discharged on 16 July and Uganda began the 42-day countdown toward declaring the outbreak over.
- International/cross-border: WHO reports one case in France and two DRC cases later treated in Germany. CDC has continued U.S. entry restrictions and traveler measures for people recently in DRC, Uganda, or South Sudan, with the July 13 order in effect for 30 days.
Direction: Worsening in DRC, improving in Uganda, unclear overall because surveillance scale-up and insecurity complicate interpretation.
Why it matters now: This is a PHEIC involving Bundibugyo virus disease, for which there are no licensed vaccines or specific treatments. Community deaths, affected health workers, insecurity, and population movement raise the risk of under-detection and regional spread.
RSV
Status: Low globally overall, but active in several seasonal or regional pockets.
Notable countries/regions:
- WHO: RSV positivity remained low globally in week 26, but was elevated in a few countries in Central America and the Caribbean, Tropical and Temperate South America, and above 30% in single countries in Eastern Africa and Southern Asia.
- United States: CDC reported RSV activity very low in most areas, with ED visits and hospitalizations low but still highest among infants and children under 4.
- EU/EEA: ECDC reported RSV activity low and inter-seasonal in week 27.
- Australia: RSV is an important winter signal. The 29 June-12 July Australian report recorded 12,475 RSV notifications in the fortnight, up 6.0% from the prior fortnight, and 85,002 year-to-date notifications. RSV admissions contributed to increased sentinel severe acute respiratory infection admissions in the previous severity reporting period.
- South Africa: NICD week 28 surveillance found RSV in 17 of 103 samples tested, with RSV activity currently at low level after an earlier season start in week 11.
Direction: Stable/low globally; increasing in Australia and selected countries.
Why it matters now: RSV is currently a bigger operational issue in some southern hemisphere settings than in the U.S. or EU/EEA, especially for infants and older adults.
Influenza A
Status: Seasonal influenza A remains low globally overall, with important regional increases and zoonotic A events.
Notable countries/regions:
- WHO: global influenza detections remained low in week 26, with influenza A and B detected in fairly similar proportions. Elevated positivity was noted in parts of Temperate South America, Central America and the Caribbean, Southern Asia, Western/Southern Asia, Southern Africa, and South-East Asia. In elevated zones, A(H3N2) predominated in Central America/Caribbean, Temperate South America, Southern Africa, and South-East Asia; A(H1N1)pdm09 predominated in Western and Southern Asia.
- United States: CDC FluView week 27 reported seasonal influenza activity low. Clinical lab positivity was 0.6%; of positive clinical specimens, 67.2% were influenza A.
- Australia: influenza notifications increased 47.1% in the 29 June-12 July fortnight, driven largely by NSW and WA, but activity remained lower than the same time in previous years.
- Zoonotic influenza: ECDC’s week 29 report highlighted a Cambodian infant hospitalized with avian influenza A(H5N1), a Bangladesh child with avian influenza A(H5), and a Brazil child with swine-origin influenza A(H3N2)v. No additional cases were detected among identified contacts in these reported events.
Direction: Low overall but increasing in parts of the southern hemisphere; zoonotic risk remains sporadic but consequential.
Why it matters now: The seasonal signal is not globally severe, but increasing southern hemisphere activity and sporadic human A(H5)/A(H3N2)v infections are important for vaccine-match, exposure-control, and pandemic-risk monitoring.
Influenza B
Status: Low to moderate contribution depending on region; no major standalone influenza B escalation found today.
Notable countries/regions:
- WHO: influenza A and B detections were reported in fairly similar proportions globally in week 26, and influenza B predominated in Western Africa among zones with elevated positivity.
- United States: CDC week 27 clinical lab data showed influenza B accounted for 44 of 134 positive clinical specimens, or 32.8%; cumulative 2025-26 clinical positives were 29.6% influenza B.
- EU/EEA: ECDC reported overall influenza activity low and inter-seasonal.
Direction: Stable/low globally, with localized predominance in Western Africa per WHO.
Why it matters now: Influenza B is not the top global respiratory signal today, but its substantial share of detections means it remains relevant for surveillance and vaccine performance.
Other outbreaks of interest
Avian and swine-origin influenza events
- Cambodia: A nine-month-old child with A(H5N1) was reported on 11 July and remained hospitalized receiving intensive care; contact investigation and antiviral prophylaxis were underway.
- Bangladesh: A child in Sylhet Division had A(H5) detected in June, recovered, and no additional cases were detected among contacts. ECDC notes this was Bangladesh’s third laboratory-confirmed human A(H5) case in 2026.
- Brazil: WHO reported one swine-origin A(H3N2)v infection in a child in Santa Catarina state, with likely swine exposure through a household contact. No additional cases were found among identified contacts.
- Assessment: Sporadic zoonotic infections remain the pattern; no sustained human-to-human transmission reported in these events.
Mpox
- EU/EEA, Western Balkans, Türkiye: ECDC reported 129 mpox clade I cases in June 2026 across nine EU/EEA countries, describing transmission as relatively stable after earlier increases. Twenty-two clade II cases were reported by six countries, continuing a decreasing trend. Transmission remains concentrated in sexual networks, most cases are among unvaccinated people, and summer travel/mass gatherings could support further spread.
- Direction: Stable for clade I in the EU/EEA after prior increases; clade II decreasing.
Cyclosporiasis - United States
- CDC is investigating a multistate Cyclospora outbreak linked to shredded iceberg lettuce in five states. As of the 18 July CDC alert, the linked outbreak had more than 1,644 cases, 94 hospitalizations, and no deaths. Taylor Farms de Mexico recalled all iceberg lettuce sourced from central Mexico on 17 July. CDC separately noted 1,645 confirmed domestically acquired cases nationally since 1 May and awareness of more than 5,100 additional cases requiring confirmation or classification.
- Direction: Worsening/active investigation.
- Why it matters: The national burden is substantially higher than the same point in 2025, the outbreak involves widely distributed produce/food-service supply chains, and diagnostic under-detection is likely.
Hantavirus - cruise-linked Andes virus
- WHO’s 2 July DON reported 13 cases, including three deaths, linked to the M/V Hondius cruise ship. All identified contacts completed follow-up without additional secondary cases. WHO assessed the outbreak as contained and no longer posing a public-health risk.
- Direction: Improving/contained.
- Why it matters: It was a notable international contact-tracing event across multiple countries, but it is now primarily a lessons-learned watch item.
Watch items for the next 24-72 hours
- DRC Ebola: daily case and death growth, new affected health zones or provinces, healthcare worker infections, community deaths, and cross-border signals involving Uganda, South Sudan, Rwanda, or air travel.
- Uganda Ebola: completion of the 42-day countdown without new cases.
- Measles: updated PAHO situation reporting, U.S. weekly CDC update, and any new deaths or healthcare-facility exposures.
- Southern hemisphere respiratory season: Australia, South Africa, and South America for influenza A(H3N2), RSV hospitalization pressure, and SARS-CoV-2 variant shifts.
- Zoonotic influenza: any new human A(H5), A(H5N1), or swine-origin infections and whether contact follow-up remains negative.
- U.S. cyclosporiasis: CDC/FDA traceback updates, additional recalls, and whether the outbreak remains limited to iceberg lettuce or expands to other produce vehicles.
Key sources consulted
WHO Global Respiratory Virus Activity Weekly Update No. 585, 9 July 2026: https://www.who.int/publications/m/item/global-respiratory-virus-activity--weekly-update-n--584
WHO Ebola Disease Outbreak News, 17 July 2026: https://www.who.int/emergencies/disease-outbreak-news/item/2026-DON613
ECDC Communicable Disease Threats Report, week 29, 17 July 2026: https://www.ecdc.europa.eu/en/publications-data/communicable-disease-threats-report-13-17-july-2026-week-29
CDC Respiratory Illnesses Data Channel, 17 July 2026: https://www.cdc.gov/respiratory-viruses/data/index.html
CDC Measles Cases and Outbreaks, 17 July 2026: https://www.cdc.gov/measles/data-research/index.html
CDC Pertussis Surveillance and Trends: https://www.cdc.gov/pertussis/php/surveillance/index.html
WHO/UNICEF immunization coverage release, 15 July 2026: https://www.who.int/news/item/15-07-2026-global-childhood-immunization-coverage-inches-forward-despite-conflict-and-hesitancy---unicef--who
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
South Africa NICD Weekly Respiratory Pathogens Surveillance Report, week 28: https://www.nicd.ac.za/diseases-a-z-index/disease-index-covid-19/surveillance-reports/weekly-respiratory-pathogens-surveillance-report-week/
CDC Cyclosporiasis outbreak alert, 18 July 2026: https://www.cdc.gov/cyclosporiasis/outbreaks/07-26/index.html
CDC HAN: Domestically Acquired Cyclosporiasis Cases in Multiple U.S. States, 14 July 2026: https://www.cdc.gov/han/php/notices/han00531.html
WHO Hantavirus Disease Outbreak News, 2 July 2026: https://www.who.int/emergencies/disease-outbreak-news/item/2026-DON611
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.