Biological Hazards in Workplace PDF

Biological hazards in workplace Public health and community medicine Department Introduction Biological hazards, also known as biohazards, refer to biological substances that pose a threat to the health of living organism, especially that of humans. These hazards can...

Biological hazards in workplace Public health and community medicine Department Introduction Biological hazards, also known as biohazards, refer to biological substances that pose a threat to the health of living organism, especially that of humans. These hazards can be encountered anywhere in the environment, including home, school or work. The biohazard symbol was developed in 1966 by Charles Baldwin, an environmental-health engineer.  Types of Biological Hazards Micro-organisms: This category includes bacteria, viruses, parasites, and fungi, which can cause a range of infections, allergies, and toxic reactions. Prions: These are infectious proteins that can cause neurodegenerative diseases, and are included as a type of biological hazard. DNA materials: DNA materials are considered biological hazards, and may include genetically modified organisms. Bodily fluids: These include blood and other human fluids that can transmit pathogens such as HIV and hepatitis. Allergens and toxins: Biological agents may produce allergens and toxins that can cause allergic reactions and other health problems. Biological vectors: Living organisms, such as mosquitos, ticks, flies, fleas and lice, that transmit infectious agents are also considered biological hazards.  How Do Biological Hazards Enter the Body? Biological hazards can enter the body in many ways. Inhalation through breathing. Absorption direct contact through breaks in the skin, even chapped skin, or through mucous membranes/contact with eyes, nose, mouth. Ingestion through swallowing. Injection through a puncture.  Activities with possible exposure to biological hazards Food production, Activities where there is contact with animals and/or products of animal origin, Healthcare, including isolation and postmortem units, Clinical, veterinary and diagnostic laboratories, Refuse disposal plants, Sewage purification installations. Occupations and diseases The risk is greatest among health care and laboratory workers who are threatened by human pathogens. Agricultural workers who are at risk from dust-borne biological allergens and toxins and by parasitic worms in warm climates. Biohazards are also important risk factors for many other professions, including sewage and compost workers. Occupations and diseases Occupation Contact source disease Goat and sheep hair, wool , butchers, Dust (spores) on imported wool, anthrax veterinarians, agriculture workers goat hair Slaughterhouse employee, live stock Blood, urine, vaginal discharge, brucellosis producers ,veterinarians, hunters milk, secretions and tissues from cattle, swine, sheep Construction workers , gardeners, Soil, skin puncture by unclean sharp tetanus farmers object veterinarians, agriculture worker, Animal bite rabies Laboratory workers , hunters Biological agents are classified into risk groups, according to their level of risk of infection Group 1 unlikely to cause human disease; can cause human disease and might be a hazard to workers; it is unlikely to spread to Group 2 the community; there is usually effective prophylaxis or treatment available; can cause severe human disease and present a serious hazard to workers; it may Group 3 present a risk of spreading to the community, but there is usually effective prophylaxis or treatment available; causes severe human disease and is a serious hazard to workers; it may present a high Group 4 risk of spreading to the community; there is usually no effective prophylaxis or treatment available.  Biological Agents: Risk of Infection Risk Description Examples group 1 Biological agent unlikely to cause human disease Bacteria in yoghurt Yeast in beer 2 Biological agent that can cause human disease and might be a hazard to Most bacteria workers; it is unlikely to spread to the community; there is usually effective Nearly all moulds prophylaxis or treatment available Most viruses 3 Biological agent that can cause severe human disease and present a serious Hepatitis B hazard to workers; it may present a risk of spreading to the community, but Hepatitis C there is usually effective prophylaxis or treatment available Human immunodeficiency virus Tuberculosis 4 Biological agent that causes severe human disease and is a serious hazard to Lassa virus workers; it may present a high risk of spreading to the community; there is Severe acute respiratory usually no effective prophylaxis or treatment available syndrome? Impact to Workers Outbreaks Pandemic Deaths Workers can become ill/injured Contaminated Environments can cause illness/injury Burden on health care Quarantines Biological Hazards Common sources in the Workplace Sharing equipment, clothing, supplies Hand contact from contaminated surfaces Blood and body fluids Food and waste handling Human handling bites Plant and food allergies/poison Animal handling and/or bites Risk prevention If possible, a harmful biological agent, is to be replaced with a biological agent which, under its conditions of use, is not dangerous or is less dangerous to workers' health. Exposure must be prevented. Prevention measures and requirements are different with respect to the classification of the biological hazard (e.g. Construction of the workplace, registrations of exposures, notification, training programs, collective protection, …) Risk reduction The risk of exposure must be reduced to protect the health and safety of the workers, in particular by the following measures : as low as possible number of workers exposed; work processes and engineering control measures to avoid or minimize the release of biological agents; collective protection measures and/or, in addition, individual protection measures; hygiene measures to prevent or reduce the accidental transfer or release of a biological agent; use of the biohazard sign; plans to deal with accidents; means for safe collection, storage and disposal of waste; arrangements for the safe handling and transport. Hygiene & individual protection No eating or drinking in working areas where there is a risk of contamination by biological agents; Use of appropriate protective clothing or other special clothing; Appropriate and adequate washing and toilet facilities, which may include eye washes and/or skin antiseptics; Hygiene & individual protection Protective equipment properly stored in a well-defined place, checked and cleaned, and replaced if needed; Working clothes and protective equipment, must be removed on leaving the work-area and kept separately from other clothing. Working clothing and protective equipment must be decontaminated and cleaned or, if necessary, destroyed.  3 million healthcare workers exposed to blood borne Blood pathogens each year borne > 90% of infections occur in developing countries Infection 95% of HIV seroconversions in HCWs caused by needle stick injuries among The risk of transmission of blood borne pathogen from Healthcare an infected patient to a HCW by a needle stick injury: Workers 30% for hepatitis B 3% for hepatitis C 0.3% for HIV  Prevention of Blood borne Infection among Healthcare Workers  Risk Reduction Eliminate the hazard ▪ Reduce the number of injections by providing oral medication ▪ Assign a central hospital for treating highly infectious patients  Risk Reduction Remove or isolate the hazard ▪ Use safety needles ▪ Single-use needles designed to retract or cover the sharp end immediately after use ▪ Transport blood specimens in leak- and puncture-resistant boxes ▪ Use puncture-resistant waste boxes for discarding sharp items and needles Risk Reduction Organisational measures ▪Limit number of staff members caring for a patient with certain illnesses: Tuberculosis or MRSA ▪Train staff regularly in safe work practices ▪Establish an occupational safety committee ▪Consider every patient to be potentially infected with hepatitis B or C or HIV ▪Strict adherence to Standard Precautions/Routine Practices ▪Audit compliance with prevention measures periodically  Risk Reduction ▪ Evaluate use of personal protective equipment Gloves Discard and change between patients Use only once or disinfect 2-3 times maximum Gowns Use if spills/splashes are possible Change between patients Single-use gowns preferred If used several times put on and remove it without touching the outer potentially contaminated side e.g., during a shift time  Risk Reduction ▪ Evaluate use of personal protective equipment Eye goggles or face shields Use if spills/splashes to the face possible Disinfect regularly and if visibly soiled Masks and respirators N95/FFP respirators with a tight face seal used if a risk of exposure to airborne pathogens When not available, use surgical masks ▪ Develop written standard operating procedures ▪ For medium and high-risk activities ▪ Include staff protection and vaccination recommendations Risk Reduction Provide a medical examination for all HCWs Examination records and other health information should be kept confidential and stored in a secure place Repeat the examination periodically All injuries documented in the respective staff member’s medical record Provide vaccinations for all non-immune HCWs ▪ Hepatitis B ▪ Influenza ▪ Measles/Rubella/Varicella/Pertussis ▪ Poliovirus ▪ Tetanus, Diphtheria (as a routine adult vaccination) Causes of Needle-stick Injury in Low Resource Countries Recapping of needles Unsafe handling of sharps waste Overuse of injections Lack of supplies disposable syringes, safer needle devices, sharps-disposal containers Failure to place needles in sharps containers immediately after injection Passing instruments from hand to hand(e.g., in the OR) Lack of awareness of the problem Lack of training for staff Post exposure prophylaxis  Hepatitis B Prevention: PEP Post-exposure prophylaxis PEP varies with immune status of HCW An unvaccinated HCW Receive both hepatitis B immune globulin (HBIG) and HBV vaccination Previously vaccinated and known antibody No treatment responder HCW Previously vaccinated, known non-responder Both HBIG and HBV vaccination (a second HCW vaccine series) or 2 doses of HBIG one month apart HCWs whose antibody response is unknown Test the HCW for antibody and administer HBIG + HBV vaccination if results are inadequate (