Chapter 9 - Biological Hazards Flashcards
Biological Hazards
substances that are biological in nature and pose a threat to the health of living organisms
Bacteria, viruses, insects, plans, birds, animals, and humans
Health effects from skin irritation to infections
Anthrax
Bacillius anthracis
Primary occupations at risk- agricultural workers, handling goat hair wool and hides, and veterinarians
Ingestion, inhalation, or cutaneous routes
soil spores
impermeable clothing and equipment, prevention of skin contact, especially open wounds and the use of high-efficiency respiratory protection
Vaccine- only useful if administered well in advance of exposure
Annual boosters recommended
Leptospirosis
Bacterial disease caused by genus Leptospira- if untreated kidney damage, meningitis, liver failure and respiratory distress
Occupations of special interest include farmers, field worker, sugarcane workers, meatpacking house workers, sewer workers, miners, and military personnel
Animal urine contamination
Treated with antibiotics
Plague
Yersina pestis- infected animals
At risk populations- shepherds, farmers, ranchers, hunters, and geologists
Antibiotics are effective, but must be promptly treated
Preventative measure to control rodents and fleas around places where people live, work, and play -
Environmental sanitation, public education, and preventative antibiotic therapy recommended
Tetanus
Clostridium tetani
Found as spores in soil or as parasites in the gastrointestinal tract of animals
enters through break in the skin
Effective vaccine
Occupations at risk: those who work around domestic animals/soil
Tuberculosis
Mycobacterium tuberculosis
Spread through the air, - most infections asymptomatic/latent
Goals - ensure prompt detection, airborne precautions, and treatment of persons who have suspected or confirmed TB disease
Health-care settings- high risk exposure
Tularemia
Disease of animals and humans caused by Francisella tularensis
Human infection through ticks, deer fly bites, skin contact with infected animals, ingestion of contaminated water, or inhalation of contaminated dusts or aerosols
Steps to prevent tularemia include use of insect repellent, wearing gloves when handling sick or dead animals
Primary occupations at risk- forestry workers, butchers, meat plant operators
Cat scratch Fever
Bacterial disease caused by Bartonella henselae
Occupations at risk include animal laboratory workers, veterinarians, and animal housing employees
Hepatitis A
Acute infectious disease of the liver caused by HAV
Caused by fecally contaminated food or water - HAV contaminated cooked food- food prep inadequate
Occupations with greatest exposure - daycare, food prep workers, sewer and sanitation workers
Hepatitis B
HBV- incubation period from the time of exposure to onset of symptoms 6 months-6 weeks
Efficiently transmitted by percutaneous or mucous membrane exposure to infectious blood or body fluids that contain blood
Primary risk factors- unprotected sex, birth with infected mother, drug injection
CDC National strategy - routine screening of all pregnant women, routing infant vaccine, vaccination of children and adolescents, and unvaccinated adults
Occupational exposures - health-care industry and emergency medicine
Orf
Sore mouth disease caused by poxvirus
From scabs of infected animals serve as source of susceptible animals- contaminated bedding, feed, or trucks
People infected from infected animals - occupations of greatest exposures shepherds, stockyard workers, and shearers
Prevention- gloves and good hygiene
Rabies
preventable viral disease of mammals most often transmitted through the bite of a rabid animal- virus in saliva
Early symptoms similar to all viral disease- progression includes nervous/emotional symptoms, hydrophobia, hypersalivation and difficulty swallowing
Common reservoirs are raccoons, skunks, foxes, bats, and coyotes
Vaccination - post-exposure should include passive antibody human rabies immune globulin and vaccine
Psittacosis (Ornithosis)
Zoonotic infectious disease caused by Chlamydophil psittaci contracted from species of birds - most frequently pet birds and poultry
Infection from inhaling dried secretions from infected birds
Risky occupations include: bird owners, pet shop employees, and veterinarians- workers in poultry plants
Prevention - education PPE N9 respirator when handling infectious animals or bedding
Rocky Mountain Spotted Fever
most severe tick-borne rickettsial disease
Occupations at risk - military personnel, foresters, rangers, rangers, farmers, trappers, construction and lumber workers
Primary vectors - American dog tick and rocky mountain wood tick
Prevention- light colored clothing, tuck in socks, apply repellents, body checks
Q fever
Zoonotic disease caused by Coxiella buretii- cattle, sheep, and goats are primary reservoirs
Risky occupations include veterinarians, dairy farmers, ranchers, stockyard workers, slaughterhouse employees, wool handlers, and rendering plant workers
Human infection by inhalation organisms from barnyard dust contaminated with dried placental material, birth fluids, and excreta of infected animals
Prevention: education, clean birthing areas and dispose, restrict infected animals, pasteurized milk, sterilization of contaminated clothing, vaccination, quarantine, facilities for sheep away from urban areas
Aspergillosis
Found in soil, plants, decaying plant matter - spores
Farmers and grain workers are primary occupational expposure
Allergic bronchopulmonary aspergillosis or invasive aspergillosis (damages tissues in the body)
Prevention- avoidance of dust exposure, n95 respirators, EEPA filtration
Candidiasis / Thrush
fungal infection of a Candida species, usually albicans
Occupational risk - dishwashers, bartenders, cooks, bakers, poultry and packinghouse workers
Usually localized as skin or mucosal membranes of oral cavity, pharynx, or esophagus, the gastrointestinal tract, urinary bladder or genitalia
Sexually transmitted
Prevention - frequent hand washing and avoidance of hand to mouth or genitalia when handling contaminated items
Coccidioidomycosis - Valley fever
Fungal disease caused by Coccidioides species in soil of semi-arid areas
Occupational exposures - construction, agriculture, military field training, and archaeological exploration
Histoplasmosis
Fungal - primarily affects the lungs
Disseminated histoplasmosis affects other organs and can be fatal if untreated
Found in soil or material contaminated with bat or bird droppings. Spores become airborne when soil disturbed
Occupations at greatest risk include environmental remediation workers, farmers, poultry workers and veterinarians
Primary containment
protect personnel and the immediate lab environment from exposure to infectious agents
Secondary containment
protection of the envrionment outside of the laboratory
Three basic elements to a containment program
laboratory practice and technique
safety equipment
facility design
Laboratory Practice and Technique
SOP, training,
limited access to lab, work areas decontaminated daily, contaminated materials decontaminated before disposal, no food or drink, frequent handwashing, protective clothing, decontamination station may be required
Safety Equipment
biological safety cabinets, fume hoods, personal protective equipment, and safety centrifuge cups