Flies are A Major Cause of Salmonella

Salmonella can infect any animal with a backbone. It is usually passed by animals coming in contact with fecal matter. But it can be caused by airborne infected dust.or by flies. In Livestock most salmonella outbreaks come in the summer, the same season when flies are out in force. This lead some to believe that flies are the major source of the disease.

The flies have salmonella  on the outside of their body as well as in their gut.Chickens can be around  infected  flies without getting sick. They get sick from eating the flies. Cows and pigs can be infected when they are bitten by the flies.

Once an infection is started in a herd the animals can spread it to each other. Because the animals don’t show symptoms for the first few days the farmer may not be aware of the problem, So the disease can be spread through the herd by coming in contact with manure or by drinking out of the same trough.

Salmonella outbreaks commonly last several months. Protracted problems can be the result of persistence of salmonella in the environment It can survives for 4 to 5 years in water, soil, dust, moist areas out of direct sunlight. One species of Salmonella, S. dublin,  can survive in dry feces for over a year, however  freezing at –4 F kills 85% of Salmonella  in 2 days. . On some dairies, particularly those with large numbers of cattle, the disease may become endemic.

Under appropriate moisture, temperature and pH conditions, The organism can reproduce in

about every 30 minutes.

The most recent studies show that approximately 5% of apparently healthy dairy cows

may be giving off salmonella in their feces and that approximately 20% of all sick cows

on the cull list give off Salmonella. This makes the on-farm location of these cattle as

well as cattle with obvious diarrhea very important because clinically affected animals

give off  more than 1014 organisms per day (infectious dose 109 to 1011 organisms).

If Salmonella infected food is cooked properly it is safe to eat. Most people know to cook Chicken or pork to 170 F. The problem arises with beef which is cooked to 140 F Even though E coli and other pathogens are killed  at 140 F salmonella is not. To get rid of the salmonella everyone would have to have their steak well done.