Read part one here.
How Aspergillosis Spreads in Hospitals
About half of documented aspergillosis outbreaks have been traced to construction work within or near the hospitals.
Ceiling demolition, flooring removal, soil excavation, landscaping, new wall construction, minor ductwork, electrical work above ceilings — all are known to unleash and disperse loads of Aspergillus spores.
However, numerous outbreaks, including the one that struck Seattle Children’s Hospital, don’t stem from construction. Many have been linked instead to improper operation or poor maintenance of air ventilation systems. In one case, four German newborns in the NICU became infected, and three died, likely due to the airborne contamination of incubators from a ventilation system.
Even ventilation cleaning and maintenance, vacuuming, and dry mopping can propel Aspergillus spores into the air, where they can travel great distances via convection currents and wind.
The origins of aspergillosis outbreaks are notoriously difficult to trace.
Bacterial and viral outbreaks tend to surface quickly and cluster in wards and can often be linked to a single contaminated telephone, sink, or patient; by contrast, the source of an aspergillosis outbreak may be elusive. A study of 81 aspergillosis cases at a French hospital found that the fungus struck patients in seven separate wards on different floors of the hospital, “suggesting a diffuse environmental source of contamination.”
Antifungal Resistance: ‘A Global Health Problem”
Most patients with invasive aspergillosis are treated with triazoles, a class of antifungals that have greatly improved survival. Still, mortality rates are 40% to 90% in high-risk groups, which has experts alarmed by the emergence of triazole-resistant strains.
Triazole-resistant A. fumigatus infections, particularly common in Europe, are associated with increased treatment failure and mortality.
“Azole resistance in A. fumigatus is evolving to a global health problem,” Belgian and Dutch authors caution.
The antifungal chemicals used in soil to keep pests and diseases at bay are structurally similar to the triazole antifungals used to treat aspergillosis.
For example, a 63-year-old Dutch patient died from an Aspergillus strain resistant to itraconazole, a drug that is a “virtual copy of the azole pesticides used to dust crops the world over” and accounts for more than one-third of all fungicide sales.”
Studies “strongly suggest that agricultural azoles are responsible for medical treatment failure in azole-naïve patients in clinical settings,” report microbiologists at Switzerland’s University of Lausanne.
Triazole resistance hovers around 5% to 6% in Europe, and resistant strains have been identified in Japan, Kuwait, Taiwan, Australia, and China, among other countries.
Killing Aspergillus, Saving Patients
Just as the bacterial superbug crisis demands the development of new antibiotics, the emergence of super fungi means science will need to develop new antifungals.
But neither will happen any time soon.
For now, hospitals must escalate aspergillosis prevention efforts by protecting vulnerable patients during renovation and killing Aspergillus spores wafting about the hospital.
On the construction front, hospitals must improve dust-control and debris-removal protocols — for example, by creating separate entrances for construction workers, requiring they wear and remove protective clothing on-site, and sealing all windows, doors, air intakes, and exhaust vents in proximity to at-risk patients.
And yet, as the British National Health Service has noted, “Such measures do not seem to be completely effective.”
During renovation at Japanese hospital, for instance, three haematology patients developed aspergillosis, and two died, “even though significant preventive measures had been taken.”
Such cases make air dis-infection all the more critical.
In most countries, no standards exist for airborne mould concentrations, but experts agree that when it comes to Aspergillus, zero is ideal.
Due to advances in air dis-infection technology, notably Novaerus’ ultra-low energy plasma technology, this goal can essentially be achieved. Multiple trials show Novaerus units are “extremely effective at removing viable mould spores from the air.”
In one trial, for example, a sealed, stainless-steel aerosol chamber was used to replicate a contaminated room. Within 30 minutes, levels of A. niger spores had dropped 99.9% and were undetectable at 60 minutes.
Novaerus technology, commonly deployed in European hospitals, can safely operate around vulnerable patients 24/7. The portable air dis-infection units continually eradicate Aspergillus spores, along with infectious viral and bacterial pathogens such as MRSA, Clostridium difficile, influenza, norovirus, tuberculosis, measles, and more.
Invasive aspergillosis is not only dangerous for patients but also expensive for hospitals, costing an extra $15,000 per infected patient, on average. Once discharged, infected patients are 40% more likely to be readmitted within 30 days, incurring even more costs.
When patients are infected with triazole-resistant strains, expenses escalate while survival odds plummet.
With Novaerus technology installed in key areas — such as operating rooms, the ICU, the NICU, and common areas — hospitals can safeguard patients from Aspergillus and other airborne pathogens knowns to cause devastating outbreaks.