MATERIAL SAFETY DATA SHEET - INFECTIOUS SUBSTANCES

SECTION I - INFECTIOUS AGENT

NAME: Shigella spp.

SYNONYM OR CROSS REFERENCE: Group A - S. dysenteriae, Group B - S. flexneri, Group C - S. boydii, Group D - S. sonnei; Shigellosis, Bacillary dysentery

CHARACTERISTIC: Family Enterobacteriaceae; Gram negative rod, non-encapsulated, non-sporogenous, non-motile; serological identification of somatic antigens; four serogroups historically treated as species; S. disenteriae may produce enterotoxin (Shiga toxin)

SECTION II - HEALTH HAZARD

PATHOGENICITY: Acute disease of large and small intestine; diarrhea, fever, nausea, and sometimes toxemia, vomiting, cramps and tenesmus; stools contain blood, mucus and pus; alterations in consciousness may occur; mild and asymptomatic infections occur; severity of illness depends on host, dose and serotype - S. dysenteriae infections have up to 20% case fatality rate in hospitalized patients, while S. sonnei infections have negligible fatality rate; S.flexneri precipitate reactive arthritis (Reiter's syndrome) in some patients

EPIDEMIOLOGY: Worldwide; 2/3 of cases and most deaths are children under 10 years; common during weaning period; 10-40% secondary attack rates in households; outbreaks under conditions of crowding and poor sanitation; endemic in tropical and temperate climates

HOST RANGE: Humans, primates (outbreaks have occurred in colonies)

INFECTIOUS DOSE: 10-200 organisms by ingestion

MODE OF TRANSMISSION: By direct or indirect fecal-oral transmission from a patient or carrier; poor hygiene practices spread infection to others by direct physical contact or indirectly by contaminating food; water, milk, cockroach, and fly-borne transmission may occur as the result of direct fecal contamination; sexual transmission in homosexual men

INCUBATION PERIOD: One to 7 days, usually 1-3 days

COMMUNICABILITY: Communicable during acute infection and until agent is no longer present in feces, usually within 4 weeks after illness; asymptomatic carriers may transmit infection; the carrier state may persist for months or longer (although rarely)

SECTION III - DISSEMINATION

RESERVOIR: Humans are the only significant reservoir; outbreaks have occurred in primate colonies

ZOONOSIS: None

VECTORS: Flies (mechanical only)

SECTION IV - VIABILITY

DRUG SUSCEPTIBILITY: Sensitive to one or more of TMP-SMX, ampicillin, chloramphenicol, ciprofloxacin, ofloxacin; multidrug resistant (MDR) strains are common

SUSCEPTIBILITY TO DISINFECTANTS: Susceptible to many disinfectants - 1% sodium hypochlorite, 70% ethanol, 2% glutaraldehyde, iodines, phenolics, formaldehyde

PHYSICAL INACTIVATION: Sensitive to moist heat (121° C for at least 15 min) and dry heat (160-170° C for at least 1 hour)

SURVIVAL OUTSIDE HOST: Feces up to 11 days; flies - up to 12 days; water - 2 to 3 days; shirts of patients - 8 days

SECTION V - MEDICAL

SURVEILLANCE: Monitor for symptoms; confirm by stool culture

FIRST AID/TREATMENT: Fluid and electrolyte replacement; conduct antibiotic susceptibility tests and administer antibiotic therapy if illness is severe (avoid drugs which slow intestinal motility)

IMMUNIZATION: None

PROPHYLAXIS: Administration of antibiotics for prophylaxis generally not recommended

SECTION VI - LABORATORY HAZARDS

LABORATORY-ACQUIRED INFECTIONS: at least 81 reported cases of shigellosis acquired from a laboratory before 1991

SOURCES/SPECIMENS: Feces; rarely, blood of infected humans and animals

PRIMARY HAZARDS: Ingestion or parenteral inoculation; importance of aerosols exposure not known

SPECIAL HAZARDS: Experimentally infected guinea pigs, other rodents and non-human primates are a proven source of infection

SECTION VII - RECOMMENDED PRECAUTIONS

CONTAINMENT REQUIREMENTS: Biosafety level 2 practices, containment equipment, and facilities for all activities utilizing known or potentially infectious clinical materials or cultures; animal biosafety level 2 facilities and practices for activities with experimentally or naturally infected animals

PROTECTIVE CLOTHING: Laboratory coat; gloves when contact with infected materials is unavoidable

OTHER PRECAUTIONS: Good personal hygiene and frequent handwashing

SECTION VIII - HANDLING INFORMATION

SPILLS: Allow aerosols to settle; wearing protective clothing, gently cover spill with paper towels and apply 1% sodium hypochlorite, starting at perimeter and working towards the centre; allow sufficient contact time (30 min) before clean up

DISPOSAL: Decontaminate before disposal; steam sterilization, chemical disinfection, incineration

STORAGE: In sealed containers that are appropriately labelled

SECTION IX - MISCELLANEOUS INFORMATION

Date prepared: March, 2001

Prepared by: Office of Laboratory Security, PHAC

Although the information, opinions and recommendations contained in this Material Safety Data Sheet are compiled from sources believed to be reliable, we accept no responsibility for the accuracy, sufficiency, or reliability or for any loss or injury resulting from the use of the information. Newly discovered hazards are frequent and this information may not be completely up to date.

Copyright ©
Health Canada, 2001

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