Biological agents Chapter 2.3 JF Gehanno, M.D., Ph.D. University of Rouen

Biological hazards Non infectious effects – Toxic effects : Part of the membranes of bacteria (Endotoxins) Toxins produced by moulds (mycotoxins) – Allergy Infectious effects – Bacteria, fungi, viruses … – We will focus on infection …

European Classification of biological agents (based only on the risk of infection) Group Can cause human disease Can be a hazard for workers Can spread to the community Effective prophylaxis or treatment available 1No--- 2Yes UnlikelyYes 3 PossibleYes 4 High riskNo Hazardous agents are those belonging to group 2, 3 and 4 Exemples : Group 2 : Clostridium perfringens, Cytomegalovirus Group 3 : Mycobacterium tuberculosis, Hepatitis B virus, Plasmodium falciparum Group 4 : Lassa virus, Ebola virus

Sources of exposure Patients in hospital settings Bugs (ticks, sarcoptes …) Animals (veterinarians, slaughterhouses)

The way to infection Emission of germs Aerial Contact – ingestion Percutaneous Infection if susceptible Reservoir Host Dispersion infection

Main occupations exposed Healthcare workers (many viruses) – hazards represented by biological agents present in patients Farmers (brucellosis, zoonosis) Outdoor workers (Leptospirosis, lyme disease)

Some biological agents

Hepatitis A Spread in the feces of infected individuals – Risk for travellers in low income countries Risk of spreading to the community by infected food handlers

Hepatitis B A high risk for healthcare workers (HCWs) Blood exposure – Needlestick exposures for HCWs Up to 45% of risk to be infected in case of needlestick exposure with a needle that have been used for an infected patient – Skin contact (rescuers) – Wounds (police officers, fire fighters)

Tuberculosis Occupational risk for – HCWs – People working with migrants from high prevalence countries Transmition by small dropplets released by infected patients – Dropplets too small to settle – Can spread at several meters from the patient

Prevention

Risk assessment Identify the sources of biological agents Identify the possible ways of transmission Identify susceptible workers

Avoid exposure Isolation of patient Reservoir Host Dispersion

Avoid exposure Reservoir Host Dispersion Barriers Gloves Masks Long sleeves for outdoor workers

Which mask for HCWs ? Big dropplets (pertussis, meningococcal infection, influenza …) – Settle at short distance (1m) & straight trajectory – Surgical mask enough Small dropplets (tuberculosis, chickenpox …) – Don’t settle (airborne transmission) – Respirator needed (N95 or FFP2)

Avoid contamination Reservoir Host Dispersion Hand washing Standard precautions Desinfection of surfaces Early removal of ticks

Vaccination Hepatitis B vaccine for HCWs Hepatitis A vaccine for sewage workers Leptospirosis vaccine for foresters Reservoir Host Dispersion

Avoid infection Chemoprophylaxis for HIV in case of needlestick exposure Antibioprophylaxis in case of exposure to Bordetella pertussis Reservoir Host Dispersion infection Preventive treatment

Treat infection Antibiotics in case of erythema migrans skin lesion following tick bite Reservoir Host Dispersion infection Early treatment

Treat infection Reservoir Host Dispersion infection Follow up Screaning

And in any case … INFORMATION OF THE WORKER ABOUT THE RISKS AND THEIR PREVENTION

Don’t forget the WARP Work : could the work of the patient be (part of) the cause or the aggravation of his/her complaint or disease? Skin lesion for a sewage worker Activities : could the complaint / disease of the patient have consequences for his/her activities and participation in work Hepatitis B infection in a surgeon Tuberculosis in an HCW Referral : should I refer my patient to an occupational physician or another specialist Should this pregnant HCW, unprotected against rubella, take specific precautions ? Prevention : Can I do something to prevent the (return of the) complaint or disease? Is this HCW protected against hepatitis B ?

Some useful links Siegel JD, Rhinehart E, Jackson M, Chiarello L, and the Healthcare Infection Control Practices Advisory Committee, 2007 Guideline for Isolation Precautions: Preventing Transmission of Ifnectious Agents in Healthcare Settings, June 2007 – Canadian Centre for Occupational Health and Safety. Biological Hazards. National Institute for Occupational Safety and Health (NIOSH). Health Care Workers. National Institute for Occupational Safety and Health (NIOSH). Diseases & Injuries.