Bird Flu Returns, Pertussis Surges, and Cruise Ship Norovirus—What Matters Now

In this episode of Thermometer HQ, I sit down with my friend and colleague Dr. Jon Epstein to make sense of the infection signals that matter right now—from the return of H5N1 in U.S. poultry to rising pertussis in Florida and stubborn norovirus on cruise ships. Our goal, as always, is to separate fact from noise and offer practical guidance for people and professionals.

We start with masks—not as political symbols, but as what they are: situational personal protective equipment. Jon describes choosing to wear a high-quality mask at a packed indoor concert the week before a speaking engagement. That deliberate, episodic use is the right mental model. Most of us already adapt our gear to hazards—work gloves for splinters, boots for job sites. Respiratory hazards deserve the same logic. Creating social permission helps: just as free condoms boosted safer sex in the pre-PrEP era, making good masks readily available at venue entrances normalizes use without mandates and reduces friction for anyone who wants that extra layer of protection.

Turning to H5N1, the current story is primarily an animal health and economic one—millions of poultry culled in the Upper Midwest as wild-bird migration seeds outbreaks in commercial and backyard flocks. That means pressure on eggs and potentially on Thanksgiving turkeys if large farms are affected. For people, the immediate risk remains low. Seasonal human influenza is a different virus; while reassortment is theoretically possible if someone were co-infected with both, today’s actual human exposure to H5N1 is limited. The real watchpoint is mammalian spillover—dairy herds, wildlife—because every mammal infection gives the virus another chance to adapt. Surveillance and rapid culling remain the backbone of control.

Unfortunately, respiratory season won’t be just flu and COVID. Florida, which has loosened school vaccine requirements, is reporting a sharp rise in pertussis (whooping cough)—nearly 1,300 cases through September, with almost two-thirds in children under 10. This is the predictable consequence of lower immunization coverage: vaccine-preventable diseases resurge first where protections are rolled back. Pediatricians and schools should plan now for testing, treatment, and catch-up vaccination campaigns. Parents: check that your child is up to date on DTaP/Tdap; pertussis can be severe for infants and disruptive for families and classrooms.

We also highlight Legionnaires’ disease, prompted by a cluster in an Illinois rehab center with Legionella detected both in a patient room tap and in a cooling tower. That dual finding is a reminder: exposures come from community aerosol sources—like cooling towers—and from building plumbing, especially where water stagnates and is inadequately heated or disinfected. Health-care and residential facilities housing older or immunocompromised people need robust water-management plans, routine maintenance, and rapid environmental testing when cases appear. Clinicians should think Legionella in severe pneumonia, particularly with relevant exposure histories.

Cruise ship norovirus is back in the headlines as well, with a Royal Caribbean voyage among several outbreaks this year. Norovirus is brutal precisely because it is efficient: a tiny infectious dose, environmental persistence, and intense person-to-person spread in close quarters. Cruise lines invest heavily in prevention, but once the virus is on board, it is hard to eradicate before a voyage ends. If you cruise, maximize handwashing with soap and water (alcohol gels are less effective against norovirus), avoid shared utensils at buffets, and don’t “push through” early symptoms—report promptly so isolation and cleaning can start. Clinicians evaluating returning travelers with acute gastroenteritis should keep norovirus and ship exposures in mind.

A less familiar threat—melioidosis—surfaced in Hong Kong with three severe cases in September, including one death. Caused by the environmental bacterium Burkholderia pseudomallei, melioidosis is associated with soil and water exposures in Southeast Asia and can follow storms or flooding that aerosolize contaminated soil. Most people can’t realistically avoid that kind of exposure, which is why clinician awareness is the preventive tool here. If a traveler (or animal) presents with severe pneumonia or sepsis after time in endemic regions, consider melioidosis and treat promptly; delayed therapy raises mortality.

Our focus topic this week is the turbulence inside CDC. The past several months have brought mass layoff notices, abrupt program cuts, and partial reversals—confusing for staff and damaging to morale. What concerns us most is the impact on three core public-health functions: (1) data collection (e.g., national health surveys), (2) analysis and guidance (including MMWR editorial capacity), and (3) communication to policymakers (e.g., the Washington office). Epidemics are defeated with data, guidance, and trust. When those are disrupted, response speed and coherence suffer. Public health works best when science leads and communication is clear and consistent.

Practical takeaways for the week:

• Treat masks like seatbelts: use them situationally when risk spikes—crowded indoor events, boarding/deplaning flights, when you need to stay healthy for work or family. Venues can help by offering free, high-quality masks at entry alongside hand sanitizer.
• Get vaccinated: seasonal flu and updated COVID vaccines protect you and the people you rely on. For families, verify that kids are current on DTaP/Tdap; pertussis thrives on gaps.
• For facilities serving high-risk populations: tighten water-management plans and test promptly when Legionnaires’ is suspected.
• Cruising soon? Prioritize handwashing with soap and water, be mindful at buffets, and report symptoms early.
• Clinicians: ask about travel and storm exposure; keep melioidosis on the differential in severe pneumonia or sepsis with relevant geography.
• Support the public-health workforce. Robust surveillance and transparent communication aren’t luxuries; they are the infrastructure that keeps communities safe and economies stable.

The through-line across these stories is simple: biology doesn’t care about politics. We lower risk when we align norms, tools, and communication with the best available evidence—and we keep those systems strong enough to act quickly when signals change.

👉 Watch the full episode on YouTube: https://youtu.be/FRIBPq3_SRU