Are we creating the melting pot or it does really exist ? EUNID 27-28 May 2005 Rome Airborne precaution – Airborne infection isolation – Aerosol precaution – Respiratory precautions – Cough etiquette etc. Are we creating the melting pot or it does really exist ? Emanuele Nicastri National Institute for Infectious Diseases Rome Italy

Roy NEJM04

Droplet size Droplet size is a subject under discussion. Droplets traditionally have been defined as >5 µm and droplet nuclei, which are associated with airborne transmission, <5 µm in size. Few suggest that tiny droplet (<25 µm) quickly evaporate leaving particulate organisms - droplet nuclei (< 5 µm). The behavior of droplets and droplet nuclei affect recommendations for preventing transmission.

Distance of protection The defintition of droplet transmission is of current interest and under discussion. Historically, the area of defined risk has been a distance of <3 feet around the patient and is based on epidemiologic and simulated studies of selected infections. However, experimental studies with smallpox and investigations of the SARS outbreak suggest that droplets from patients with these two infections rarely could reach persons 6 feet or more away from their source.

Distance of protection/2 Less than 3 feet around the patient is best viewed as an example of “a short distance from a patient” and not used as a criterion for deciding when a mask should be donned to protect from exposure. It may be prudent to don a mask when within 6 to 10 feet of the patient. More information is needed.

Tell me your size and I will say who are you Droplet Pertussis, adenovirus, rhinovirus, mycoplasma SARS-CoV, Streptococcus, Meningococcus Airborne Tuberculosis, Varicela-zoster virus, rubeola virus VHF, monkey pox, small pox? But …….. Time are changing

Musher NEJM03

Agent and mode of spread Musher NEJM03

Tell me your size and I will say who are you …. and influenza ? Obligated AI: tuberculosis Airborne Preferential AI: varicella-zoster virus, rubeola virus Opportunistic AI: SARS CoV

SARS at Amoy Garden DHC Hong-Kong

An initial point-source outbreak with subsequent person-to-person spread is suspected, the dissemination was mediated by a direct and contact spread Blumenfeld JCI 1959

An airplane with 5 crew members and 49 passengers was detained in Homer, Alaska, for 4.5 h, including 2–3 h when the ventilation system was turned off. Moser AmJ Epidemio 1979

72% of the crew and passengers developed flu-like illness, and 91% had a lab-confirmed influenza. Moser AmJ Epidemio 1979

No increased risk infection among persons completing last leg of trip with index case The epidemic curve was consistent with a single point-source outbreak. Airborne transmission is a possible explanation but…. droplet transmission cannot be excluded: most of the crew members and passengers passed within 1 m of the coughing index patient Moser AmJ Epidemio 1979

And the respiratory protection?

NIOHS vs EU Standard NIOHS 42 CFR 84 Particles: diameter 0.3 µ Flow: 85 L/min N 100 (99.7% efficient) N 99 (99% efficient) N 95 (95% efficient) EN 149:2001 Particles: diameter 0.1 µ Flow: 95 L/min FFP3 (98% efficient) FFP2 (92% efficient) FFP1 (78% efficient)

Clinicians need to be aware of their patients’ occupational exposures to airborne toxins. Clinicians should be familiar with the common forms of respiratory protection as well as benefits and limitations ofuse. Clinicians should know that no respirator is fully protective. Clinicians should know that respirators are a relatively inefficient form of protection.

And the respiratory protection?-2 Respiratory protection (i.e. NIOSH-N-95 or higher) is required to prevent exposure to TB. Although there is limited information on the efficacy of respirators or masks in preventing transmission, particulate respirators have been shown to have greater filtration efficiency and better facial fit qualities than surgical masks (Martyny NEJM 2002). The incremental benefit of respirators for preventing transmission of airborne infectious agents has not been assessed.

And the respiratory protection?-3 Some studies have shown control of tuberculosis transmission in hospitals that used surgical masks rather than respirators .. (Maloney AIM 1995; McGowan CID 1995; Jarvis AJIC 1995), but respirators now are required by OSHA for protection of healthcare personnel from TB (CDC guideline for TB 1994).

And the respiratory protection? - 3 Respiratory protection is recommended for other diseases that could be transmitted through the airborne route, including SARS, smallpox, and VHF. Although AII and PPE for mouth and nose protection are recommended for protection from measles and chickenpox, there are no data upon which to base a recommendation for surgical masks or respirators for protection against these two infections

What PPE for what Disease The European perspective

Smallpox CDC: AII & contact EUNID countries Precaution: contact100% droplet 100% AII100% ALL100% >FFP2 100%; FFP3 77.8%; FFP1 0% Hepa-Mask 50%; PARP 42.9% Face shield or any eye protection 92.5% Shoe or hair covering 100%

VHF CDC: AII & contact EUNID countries Precaution: contact100% droplet 100% AII100% ALL100% >FFP2 100%; FFP3 92.5%; FFP1 0%; 2 gloves 71% Hepa-Mask 44%; PARP 66%; Tyvek suite 66.9% Face shield or any eye protection 100% Shoe or hair covering 100%

SARS or Avian flu CDC: AII, droplet, contact for both EUNID countries Precaution: contact100% droplet 100% AII90% ALL90% >FFP2 100%; FFP3 77.8%; FFP1 0% Hepa-Mask 43%; PARP 33%; Tyvek suite 40% Face shield or any eye protection 100% Shoe or hair covering 66.7%

Pulmonary plague CDC: droplet EUNID countries Precaution: contact100% droplet 100% AII55% ALL55% >FFP2 67%; FFP3 50%; FFP1 17%; surg mask 67% Hepa-Mask 28.6%; PARP 42.9%; Face shield or any eye protection 62.5% Shoe or hair covering 50%

Pulmonary anthrax CDC: standard precuation EUNID countries Precaution: contact50% droplet 50% AII 33.3% ALL 20% >FFP2 37%; FFP3 37%; FFP1 17%; surg mask 50% Hepa-Mask 12.5%; PARP 16.6%; Face shield or any eye protection 40% Shoe or hair covering 44.4%%

Pulmonary tuberculosis … and MDR? Pulmonary tuberculosis CDC: AII only EUNID countries Precaution contact 50% droplet 60% AII 78% ALL 20% >FFP2 88.9%; FFP3 75%; FFP1 16.7% Hepa-Mask 27.3%; PARP K 18.2% Face shield or any eye protection 33.3% Shoe or hair covering 33.3%

Critical issues Infection control: suspicion versus overt disease Environmental protection and personal protection: the combination problem The balance between protection and the ability to perform patient care: Is there such a thing as over protection? PPE- proper education and training Expanded EU:different infectious disease prevalence Critical issues

"The important thing is not to stop questioning." Albert Einstein