Environmental
Reservoir
Salmonella has several animal reservoirs, including human. Person to person transmission is very possible and more or less likely depending on habitat conditions.
Common animal reservoirs include: human, chicken, turkey, ducks, pigs, cows, horses, cats, dogs, guinea pigs, and hamsters. There are many others.
Shedding
Carriers of salmonella my excrete up to 10^10 Salmonella / g of feces (Thomson 1954,1955)
Occurrence
Surface Water
Salmonella is present in surface waters receiving waste from animal populations. This includes most streams, rivers and lakes in the non-built environment. And those within the built environment will be subject to human waste.
| Organism | Location | Concentration | Method of Analysis | Reference |
|---|---|---|---|---|
| Salmonella | Streams through agricultural land (England, UK) | 71% of sites investigated were positive for Salmonella | Smith, Jones, and Watson 1978 | |
| Salmonella | Streams (Texas, USA) | Low flow: 5,800 / 100 ml Storm flow: 2,500 / 100 ml |
Davis 1979 | |
| Salmonella | Swabs suspended in streams (New York, USA) | 39% of 322 swabs were positive for salmonella | Dondero et al 1977 | |
| Salmonella | Unpolluted mountain streams (Georgia, USA) | 44% of samples contained salmonella | Cherry et al. 1972 | |
| Salmonella | Urban stormwater (Cincinnati, OH) | 4,500 bacteria / 100 ml | Geldreich et al. 1968 | |
| Salmonella | Urban stream water and stormwater (Baltamore, Maryland, USA) | 6 - 140 / 100 ml | Olivieri, Kawata, Kruse 1978 | |
| Salmonella | St. Lawrence River (Canada) | 24% of samples containing less than 9 fecal coliforms / 100 ml | Dutka and Bell 1973 | |
| Salmonella | Various streams throughout USA | 54% of samples containing 1 - 1,000 fecal coliforms / 100 ml 96% of samples containing more than 1,000 fecal coliforms / 100 ml |
Geldreich and Bordner 1971 | |
| Salmonella | River water & sediment | 0.6% of water samples, yet 4.6% of bottom sediments from the same river (Georgia, USA) | Hendricks 1971 | |
| Salmonella | River water & sediment | 8% positive in water samples 46% positive in sediment samples |
Van Donsel & Geldreich 1971 | |
| Salmonella | Seawater (Chesapeake Bay, USA) | 1:100 to 1:1000 (salmonella:fecal coliforms ratio) | Colwell and Kaper 1978 | |
| Salmonella | Baltimore Harbor (Maryland, USA) | Up to 240 salomonellae / 100 ml (April - November); None isolated during winter months | Colwell and Kaper 1978 | |
| Salmonella | Canals bordering Galveston Bay (Texas, USA) (Receive waste discharge) | 47% of samples were positive (0-150 / 100 ml) | Goyal, Gerba and Melnick (1977) |
Drinking Water
| Organism | Location | Concentration | Method of Analysis | Reference |
|---|---|---|---|---|
| Salmonella | Tap water (Aurangabad, India) | 9% of samples were positive | Raman and others 1979 | |
| Salmonella | Tap and reservoir water (Riverside, CA, USA) During outbreak of salmonellosis | 7% of samples were positive | Boring, Martin and Elliot 1971 | |
| Salmonella | Deep wells (unchlorinated) | 1.7 S. typhimurium / 100 ml | Boring, Martin and Elliot 1971 | |
| Salmonella | Water and sediments from river used as drinking water(Jakarta, Indonesia) | 48% of water samples and 63% of sediment samples collected were collected | Gracey et al. 1979 |
Sewage
Concentrations of Salmonella in sewage vary wildly from report to report.
| Organism | Location | Concentration | Method of Analysis | Reference |
|---|---|---|---|---|
| Salmonella | Sewage (India) | 7-250 / 100 ml | Phirke 1974 | |
| Salmonella | Sewage (South Africa) | 2-41 / 100 ml | Grabow and Nupen 1972 | |
| Salmonella | Sewage (Baltimore, MA, USA) | 500 / 100 ml | Olivieri, Kawata and Kruse 1978 | |
| Salmonella | Sewage (Houston, TX, USA) | 8000 / 100 ml | Davis 1979 | |
| Salmonella | Sewage (Finland) | 2.3 / 100 ml | Hirn 1980 | |
| Salmonella | Sewage (England) | 7240 / 100 ml | Jones 1977 | |
| Salmonella | Sewage (Holland) | 670 / 100 ml | Kampelmacher and Van Noorle Jansen 1970 | |
| Salmonella | Sewage (Hull, England) | 150-400 / 100 ml | McCoy 1977 | |
| Salmonella | Sewage, peak flow (Guildford, England) | 20 - >1800 / 100 ml (median: 130) | Yaziz and Lloyd 1979 | |
| Salmonella | Sewage, peak flow (Woking, England) | 11 - >1600 / 100 ml (median: 170) | Yaziz and Lloyd 1979 | |
| Salmonella | Sewage from a refugee camp (Bangladesh) | Geometric Mean: 7.1 & 7.7 / 100 ml (Note: Authors report difficulty in isolating salmonella from turbid samples) | Daniel and Lloyd 1980 |
Persistence
There are considerable variations in persistence between serotypes of salmonella (Enkiri and Alford 1971) Comparative studies have shown S. typhimurium to be hardier than S. typhi and S. paratyphi B (McFeters and others 1974).
General survival times range from 1 - 100 days with typical t90 values of 20-200 hours (Feachem, 1983). Survival is prolonged significantly in lower temperatures and moderately in darkness. Growth in the environment has been shown at 30°C (Hendricks, 1972).
| Organism | Location | Concentration | Temperature | Reference |
|---|---|---|---|---|
| Salmonella | Membrane chambers suspended in well water | t90 (Over 2 days): 19 - 80 hours | 9-13°C | McFeters et al. 1974 |
| Salmonella | Storm Water | t90 (over 14 days): 240 hours | 10°C | Geldreich et al. 1968 |
| Salmonella | Storm Water | t90 (over 14 days): 160 hours | 20°C | Geldreich et al. 1968 |
| Salmonella | Membrane chambers suspended in Lake Ontario and Hamilton Bay | t90 (Over 3 days): 19-180 hours | 17-19°C | Dutka and Kwan 1980 |
| Salmonella | "Clean water" | Complete inactivation @ 2 weeks (t90: <56 hours) | Tannock and Smith 1971 | |
| Salmonella | Unsterilized water w/ 5% sheep feces | Complete inactivation @ 12-16 weeks (t90: 340-450 hours) | Tannock and Smith 1971 | |
| Salmonella | Autoclaved river water | Positive growth | 30°C | Hendricks 1972 |
| Salmonella | Autoclaved river water | No growth | 20°C & 5°C | Hendricks 1971 |
| Salmonella | Sterilized seawater (Salinities of 0.5%, 2%, and 3.5%) | Maximum survival of 7 days (t90 = 23hrs) @ 0.5% salinity Minimum survival was 5 days (t90 = 17hrs) @ 3.5% salinity |
4°C | Jamieson, Madri and Claus 1976 |
| Salmonella | Sterilized seawater | 1.5 log reduction (t90 = 6hrs) | 14.5°C | Vasconcelos and Swartz 1976 |
| Salmonella | Feces from typhoid patients (Chicago, USA) | Survival for 3 - 52 days | "Room Temperature" | Jordan 1926 |
| Salmonella | Sheep feces (New Zealand) | 6 - 18 weeks (t90 = 150 - 450 hrs) | Outdoors (Survival was longer in shaded regions) | Tannock and Smith 1972 |
| Salmonella | Wet poultry excreta (80% water) | >1 month (t90 = 184 hrs) (Growth occurred before decline, up to 1.4 log above initial concentration) | 9-12°C | Berkowitz, Kraft and Finstein 1974 |
| Salmonella | Wet poultry excreta (80% water) | >1 month (t90 = 112 hrs) (Growth occurred before decline, up to 1.4 log above initial concentration) | 18-20°C | Berkowitz, Kraft and Finstein 1974 |
| Salmonella | Wet poultry excreta (80% water) | >1 month (t90 = 40 hrs) (Growth occurred before decline, up to 1.4 log above initial concentration) | 30°C | Berkowitz, Kraft and Finstein 1974 |
Sewage
| Organism | Location | Concentration | Temperature | Reference |
|---|---|---|---|---|
| Salmonella | Sewage (Sludge & Slurries) | t90: 77-108 hours | 7-20°C | Green and Beard 1938 |
| Salmonella | Sewage (Jerusalem, Israel) | Survival for 22 days (t90: 60 hours) | Bergner-Rabinowitz 1956 |