NAME: Salmonella paratyphi
SYNONYM OR CROSS REFERENCE: Enteric fever, Paratyphoid fever, S. paratyphi type A, B and C; S. choleraesuis serotype paratyphi; S. enterica serotype paratyphoid A, B and C
CHARACTERISTICS: Family Enterobacteriaceae; Gram negative rod; motile, aerobic and facultatively anaerobic; serological identification of somatic and flagellar antigens
PATHOGENICITY: Bacterial enteric fever with abrupt onset, continued fever, malaise, headache, anorexia, enlargement of spleen, bradycardia, rose spots on trunk occur on approximately 25% of Caucasians, constipation is more common than diarrhea in adults; complications include perforation/hemorrhage/ulceration of the intestines, less frequently psychosis, hepatitis, cholecystitis, pneumonitis, and pericarditis; clinically similar to typhoid fever but milder with lower case fatality rate; Common enterocolitis may result without enteric fever; characterized by headache, abdominal pain, nausea, vomiting, diarrhea, dehydration may result; mild and asymptomatic infections occur
EPIDEMIOLOGY: Sporadically or in limited outbreaks; infrequently identified in North America; probably more frequent than reported; serotype B is most common, A less frequent, and C extremely rare
HOST RANGE: Humans
INFECTIOUS DOSE: usually>1,000 organisms - ingestion; may be reduced by buffered gastric acidity
MODE OF TRANSMISSION: Direct or indirect contact with feces or rarely urine of patient or carrier; contaminated food, especially milk, milk products, shellfish, may be contaminated by hands of a carrier; flies may be a possible vector; a few outbreaks related to water supplies have been documented
INCUBATION PERIOD: One to 3 weeks for enteric fever; 1-10 days for gastroenteritis; varies with dose ingested
COMMUNICABILITY: Communicable as long as agent persists in excreta throughout illness and for periods up to several weeks or months following; commonly 1-2 weeks after recovery; some are chronic carriers, may persist for years
RESERVOIR: Humans; patients with acute disease and chronic carriers
ZOONOSIS: None
VECTORS: Possibly flies (mechanical only)
DRUG SUSCEPTIBILITY: Susceptible to chloramphenicol, ampicillin, TMP-SMX, fluoroquinolones; Multi-drug resistant (MDR) strains are increasing, drug susceptibility is required
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 I hour)
SURVIVAL OUTSIDE HOST: Butter - 55 days; raw milk - 11 days; bed bugs - 21 days; melon juice - 48 hours; flies - 10 days; some salmonella strains can survive in the environment for years
SURVEILLANCE: Monitor for symptoms; bacteriological examination of blood, feces; examine contaminated food for cases of enterocolitis; serology is not effective
FIRST AID/TREATMENT: Antibiotic therapy following drug susceptibility testing for cases of enteric fever; hydration therapy
IMMUNIZATION: Standard vaccines not proven to be effective - none
PROPHYLAXIS: Antibiotic prophylaxis
LABORATORY-ACQUIRED INFECTIONS: Typhoid is second most commonly reported laboratory infection (256 cases with 20 deaths); salmonellosis is also commonly reported (48 cases)
SOURCES/SPECIMENS: Feces, urine, bile, blood
PRIMARY HAZARDS: Ingestion, parenteral inoculation; importance of aerosol exposure not known
SPECIAL HAZARDS: None
CONTAINMENT REQUIREMENTS: Biosafety level 2 practices, containment equipment and facilities for all activities utilizing known or potentially infectious clinical materials and cultures
PROTECTIVE CLOTHING: Laboratory coat; gloves when contact with infected materials is unavoidable
OTHER PRECAUTIONS: Good personal hygiene and frequent handwashing
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
STORAGE: In sealed containers that are appropriately labelled
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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