Salmonella & Pests

Simon Berenyi • 10 December 2022

Salmonella and Pest Control

What Is Salmonella?

Salmonella is a species of bacteria of which there are over 3000 known strains. It gets its name from the American vet, Daniel Elmer Salmon (1850-1914).

Is Salmonella Dangerous?

Not all strains or varieties of bacteria are considered dangerous to humans. Unfortunately, some are so significant that death is not uncommon. The most common forms of Salmonella bacteria associated with transmission to humans include – S.typhi , S.paratyphi , S.typhimurium , and S.enteritidis.


Salmonella used as a biological control on rat populations has proved to be useful but not ideal. Rats became resistant, and humans did not. In fact, it was also transmitted to humans, resulting in outbreaks of gastroenteritis. Because of this, The World Health Organisation (WHO) quickly retracted its use.

Is Salmonella Common?

In humans, the disease is common. Each year, millions of people worldwide suffer acute gastroenteritis after becoming infected with Salmonella typhimurium.

How Does Salmonella Attack The Body?

Like all microorganisms, bacteria attack the body in a variety of ways. Some bacteria produce toxins that poison you, while others attack the body.


Salmonella enters our body with contaminated food or water, so it is considered a food-borne pathogen. The word pathogen means – disease-causing from the Greek: pathos “suffering, passion” and genēs “producer of.”


The bacteria attack the body by invading and colonising the lining (mucosa) of the intestine. Bacterial invasion of the lining of your gut causes inflammation (swelling), termed enteritis.

Where Does Salmonella Come From?

Rodents, pets, birds, and insects can all carry salmonella. Most people are unaware that they are carriers of the bacteria (5%) without showing symptoms of the disease. Human to human transmission should not be ruled out for this very reason.

Signs & Symptoms of Salmonella Infection

Symptoms of Salmonella include stomach cramps, dizziness, confusion, and nausea. Signs of infection include vomiting, fever, diarrhoea and severe dehydration, collapse and, in rare cases, death. On average, it takes from 12 to 48 hours for the symptoms to develop (incubation period) after swallowing an infectious dose of salmonella, thought to be around 105 per gram. Symptoms usually last for several days, and most people recover without treatment.


People who become severely ill may need hospital care because dehydration caused by the illness can be life-threatening. One of the most dangerous forms of Salmonella because it has the highest mortality (death) rate is S.choleraesuis. Because Salmonella can multiply between 7C and 45C, fridges must be checked to ensure they are operating at 5C or below. Disinfection of all food preparation surfaces is vital before any food preparation.

Who Gets Salmonella?

Anyone can get salmonella, but young children, the elderly and people who have immune systems that are not working correctly (including people on antibiotics, recovering from illness), have a higher risk of becoming severely ill.

 How Do You Get Infected With Salmonella?

You usually get salmonella by eating or drinking contaminated food and drink. Salmonella bacteria live in the gut or on the surface of many animals, including rodents, birds, and insects. Contamination is also possible when raw and cooked foods become stored together.


It’s impossible to tell from the appearance of foods if bacteria have contaminated it. It will typically look, smell and taste quite ordinary. Bacteria can be spread from person to person because of poor hygiene. Failing to wash your hands properly after going to the toilet or after handling contaminated food.

How Do You Avoid Salmonella Infection?

Hand Hygiene

  1. Wash hands thoroughly with soap and warm water:
  2. Before preparing and eating food
  3. After handling raw foods
  4. Following the use of toilets or waste facilities
  5. After contact with pets or animals and their faeces
  6. Following work in the garden with compost or soil

Also:

  • keep cooked food away from raw food
  • store raw foods below cooked or ready-to-eat foods in the fridge to prevent contamination
  • wash raw fruits and vegetables thoroughly before eating
  • cook food thoroughly, especially meat, so that it is piping hot
  • keep all kitchen surfaces and equipment, including knives, chopping boards and dishcloths, clean
  • do not drink untreated water from lakes, rivers or streams
  • do not keep reptiles or amphibians in households where there is a child under five year of age or someone with a weakened immune system

If someone has salmonella, launder all contaminated clothing, bedding, and towels in the washing machine on the hottest wash cycle possible. Disinfect toilet seats, toilet bowls, flush handles, taps and wash hand basins after use with detergent and hot water, followed by a household disinfectant.

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