EH&S: Biosafety Manual - Infectious Agents

A laboratory-acquired infection is defined as one that results from work with infectious agents, whether it occurs in laboratory personnel or in another person who happened to be exposed.

Research or teaching activities involving infectious agents can only be conducted with prior approval by the IBC. Researchers and students must follow requirements as specified in the CDC/NIH publication Biosafety in Microbiological and Biomedical Laboratories (4th Ed., 1999) as the minimum containment required for this work. Containment requirements may be subject to modification by the IBC.

Microorganisms can enter the body through the mouth, the respiratory tract, broken or intact skin and the conjunctivae. In laboratory-acquired infections, the route may not be the same as when the disease is acquired naturally.

Infectious materials and cultures of microorganisms accumulate in large amounts in clinical and microbiological laboratories. Documented and deliberate effort must be made by PIs and laboratory staff to ensure that nobody is exposed to biohazards.

1. Principal Bacterial Infections

Brucellosis
Cholera
Diphtheria
Glanders and Melioidosis
Leptospirosis
Plague
Rat Bite fever
Salmonellosis
Shigellosis
Syphilis, Gonorrhea and Chancre
Tuberculosis
Tularemia
Typhoid fever

Other Bacterial Infections

Anthrax
Bordetella pertussis
Campylobacter
Clostridia
Erysipelothrix
Escherichia coli
Hemophilus
Leprosy
Listeria
Neisseria meningitis
Mycobacteriosis
Mycoplasma
Pasteurella (other than plague)
Relapsing fever
Serratia
Staphylococcus aureus
Streptococci
Vibrios (other than cholera)

2. Viral Infections

Adenoviruses
Bhanja fever
Catu fever
Chikunguya fever
Colorado tick fever
Congo-Crimean fever
Coxsackie B
Dengue fever
Eastern equine encephalitis
Germiston fever
Hantaan (Hanta, Korean hemorrhagic) fever
Hepatitis
Influenza
Japanese encephalitis
Junin
Kunjin fever
Kyasanur Forest disease
Lassa fever
Louping Ill
Lymphocytic choriomeningitis
Marburg disease
Mucambo fever
Mumps
Newcastle disease
Omsk hemorrhagic fever
Oropouche fever
Orungo disease
Piry fever
Pitchinde virus
Poliovirus
Pseudorabies (also known as Aujeszky's disease of cattle)
Rabies
Rift Valley fever
Russian spring summer encephalitis
Simian B virus
Venezuelan equine encephalitis
Vesicular Stomatitis
Wesselbron virus
West Nile
Western equine encephalitis
Yaba and Tanavirus
Yellow fever

3. Chlamydial and Rickettsial Infections

Psittacosis
Q fever
Rocky Mountain spotted fever
Scrub typhus
Trachoma
Typhus (epidemic and murine)

4. Fungal Infections

Blastomycosis
Coccidioidomycosis
Cryptococcosis
Dermatomycoses
Histoplasmosis
Sporotrichosis

5. Parasitic Infections

Babesiosis
Cryptosporidiosis
Fascioliasis
Giardiasis
Isosporiosis
Malaria
Toxoplasmosis
Trypanosomiasis

D. MODES OF INFECTION

There are many regulations in place to prevent laboratory-acquired infections. However, the responsibility for compliance with the regulations still lies primarily with the PI and, secondarily, with the laboratory staff.

In addition, it is crucial for the PI and laboratory staff to remember that organisms that are ordinarily innocuous can be infective in immunocompromised persons. Therefore, additional and more stringent measures must be established by the PI in an effort to prevent the occurrence of laboratory-acquired infections in such individuals.

Modes of infection can be divided into two categories:

1. Infections preceded by overt personal accidents, which include:

a. Inoculation (resulting from pricking, jabbing or cutting the skin with contaminated instruments such as hypodermic needles, scalpels and glassware; and from animal bites or scratches or through contact with breaks in the skin unrelated to laboratory injury.

b. Ingestion (resulting from mouth-pipetting, eating, drinking, smoking, applying cosmetics, lip balm and from splashes)

c. Splashing into the face and eyes.

d. Spillage and direct contact.

2. Infections not preceded by personal accidents:

These are thought to account for up to 82 percent of all laboratory-acquired infections.

Aerosols are defined as a cloud of very small liquid droplets produced whenever energy is applied to a liquid, and such liquid is allowed to escape into the environment. It has been shown that if the liquid contains infectious agents, these would be distributed in the aerosol and would remain viable for some time. The larger droplets (greater than 0.1 mm in diameter) will settle quickly and contaminate the surfaces upon which they come to rest. The smaller droplets do not settle, but rather evaporate very rapidly. Those with a diameter of 0.1 mm evaporate in about 1.7 seconds and those with a diameter of 0.05 mm evaporate in about 0.4 seconds.

The infectious agents in the droplets remain in a dried state as "droplet nuclei" or fomites. The smaller the number of organisms and amount of dried material the longer they will remain airborne. They move around buildings by air currents generated by ventilation and people traffic.

It has been shown that many laboratory techniques using both simple and complex mechanical equipment, as well as laboratory accidents, produce aerosols. These include: use of microbiology loops, pipettes, syringes and needles, opening tubes and bottles, use of centrifuges and blenders, homogenizers, harvesting of eggs and other virological procedures, lyophilization and breakage of cultures.


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	Environmental Health and Safety SDSU Biosafety Manual San Diego State University BIOHAZARD CONTROL PROGRAM Part VI: INFECTIOUS AGENTS A. LABORATORY-ACQUIRED INFECTIONS B. WORK WITH INFECTIOUS AGENTS C. TYPES OF INFECTIONS D. MODES OF INFECTION A. LABORATORY-ACQUIRED INFECTIONS A laboratory-acquired infection is defined as one that results from work with infectious agents, whether it occurs in laboratory personnel or in another person who happened to be exposed. B. WORK WITH INFECTIOUS AGENTS Research or teaching activities involving infectious agents can only be conducted with prior approval by the IBC. Researchers and students must follow requirements as specified in the CDC/NIH publication Biosafety in Microbiological and Biomedical Laboratories (4th Ed., 1999) as the minimum containment required for this work. Containment requirements may be subject to modification by the IBC. Microorganisms can enter the body through the mouth, the respiratory tract, broken or intact skin and the conjunctivae. In laboratory-acquired infections, the route may not be the same as when the disease is acquired naturally. Infectious materials and cultures of microorganisms accumulate in large amounts in clinical and microbiological laboratories. Documented and deliberate effort must be made by PIs and laboratory staff to ensure that nobody is exposed to biohazards. C. TYPES OF INFECTIONS 1. Principal Bacterial Infections Brucellosis Cholera Diphtheria Glanders and Melioidosis Leptospirosis Plague Rat Bite fever Salmonellosis Shigellosis Syphilis, Gonorrhea and Chancre Tuberculosis Tularemia Typhoid fever Other Bacterial Infections Anthrax Bordetella pertussis Campylobacter Clostridia Erysipelothrix Escherichia coli Hemophilus Leprosy Listeria Neisseria meningitis Mycobacteriosis Mycoplasma Pasteurella (other than plague) Relapsing fever Serratia Staphylococcus aureus Streptococci Vibrios (other than cholera) 2. Viral Infections Adenoviruses Bhanja fever Catu fever Chikunguya fever Colorado tick fever Congo-Crimean fever Coxsackie B Dengue fever Eastern equine encephalitis Germiston fever Hantaan (Hanta, Korean hemorrhagic) fever Hepatitis Influenza Japanese encephalitis Junin Kunjin fever Kyasanur Forest disease Lassa fever Louping Ill Lymphocytic choriomeningitis Marburg disease Mucambo fever Mumps Newcastle disease Omsk hemorrhagic fever Oropouche fever Orungo disease Piry fever Pitchinde virus Poliovirus Pseudorabies (also known as Aujeszky's disease of cattle) Rabies Rift Valley fever Russian spring summer encephalitis Simian B virus Venezuelan equine encephalitis Vesicular Stomatitis Wesselbron virus West Nile Western equine encephalitis Yaba and Tanavirus Yellow fever 3. Chlamydial and Rickettsial Infections Psittacosis Q fever Rocky Mountain spotted fever Scrub typhus Trachoma Typhus (epidemic and murine) 4. Fungal Infections Blastomycosis Coccidioidomycosis Cryptococcosis Dermatomycoses Histoplasmosis Sporotrichosis 5. Parasitic Infections Babesiosis Cryptosporidiosis Fascioliasis Giardiasis Isosporiosis Malaria Toxoplasmosis Trypanosomiasis D. MODES OF INFECTION There are many regulations in place to prevent laboratory-acquired infections. However, the responsibility for compliance with the regulations still lies primarily with the PI and, secondarily, with the laboratory staff. In addition, it is crucial for the PI and laboratory staff to remember that organisms that are ordinarily innocuous can be infective in immunocompromised persons. Therefore, additional and more stringent measures must be established by the PI in an effort to prevent the occurrence of laboratory-acquired infections in such individuals. Modes of infection can be divided into two categories: 1. Infections preceded by overt personal accidents, which include: a. Inoculation (resulting from pricking, jabbing or cutting the skin with contaminated instruments such as hypodermic needles, scalpels and glassware; and from animal bites or scratches or through contact with breaks in the skin unrelated to laboratory injury. b. Ingestion (resulting from mouth-pipetting, eating, drinking, smoking, applying cosmetics, lip balm and from splashes) c. Splashing into the face and eyes. d. Spillage and direct contact. 2. Infections not preceded by personal accidents: These are thought to account for up to 82 percent of all laboratory-acquired infections. Aerosols are defined as a cloud of very small liquid droplets produced whenever energy is applied to a liquid, and such liquid is allowed to escape into the environment. It has been shown that if the liquid contains infectious agents, these would be distributed in the aerosol and would remain viable for some time. The larger droplets (greater than 0.1 mm in diameter) will settle quickly and contaminate the surfaces upon which they come to rest. The smaller droplets do not settle, but rather evaporate very rapidly. Those with a diameter of 0.1 mm evaporate in about 1.7 seconds and those with a diameter of 0.05 mm evaporate in about 0.4 seconds. The infectious agents in the droplets remain in a dried state as "droplet nuclei" or fomites. The smaller the number of organisms and amount of dried material the longer they will remain airborne. They move around buildings by air currents generated by ventilation and people traffic. It has been shown that many laboratory techniques using both simple and complex mechanical equipment, as well as laboratory accidents, produce aerosols. These include: use of microbiology loops, pipettes, syringes and needles, opening tubes and bottles, use of centrifuges and blenders, homogenizers, harvesting of eggs and other virological procedures, lyophilization and breakage of cultures.
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Environmental Health and Safety

SDSU Biosafety Manual

Part VI: INFECTIOUS AGENTS

Part VI:
INFECTIOUS AGENTS