Salmonella – Symptoms and Causes

Overview

Salmonella infection affects the intestinal tract and is caused by bacteria passed through stool. People typically get infected by consuming contaminated food or water.

Symptoms vary among individuals. Many experience diarrhea, fever, and stomach cramps within 8-72 hours of exposure. For healthy individuals, recovery usually occurs within a week without specific treatment.

Common symptoms include:

• Diarrhea
• Fever
• Abdominal cramps

In severe cases, dehydration from diarrhea requires medical attention. Complications can become life-threatening if the infection spreads beyond the intestines.

Signs

Salmonella infection often shows itself through several common symptoms.

People typically experience diarrhea, stomach cramps, and fever after exposure to the bacteria. Many individuals often confuse these symptoms with a typical stomach flu.

The body may also react with nausea and vomiting as it tries to fight the infection. Some people report chills and headaches during their illness. In more severe cases, blood might appear in the stool.

Symptoms usually begin anywhere from 6 hours to 6 days after consuming contaminated food or drink.

Common sources include:

• Raw or undercooked meat and poultry
• Undercooked eggs or egg products
• Unpasteurized milk

Most people recover within a week, though diarrhea can last up to 10 days. Your digestive system might take several months to fully return to normal.

Some rare types of salmonella bacteria can cause typhoid fever, which is more serious and more common in developing countries.

When to see a doctor

Most people recover from salmonella infection without medical help in a few days. However, certain groups need medical attention if symptoms continue or worsen.

Contact your healthcare provider if you or someone you care for experiences:

• Illness lasting more than a few days
• High fever
• Bloody stools
• Signs of dehydration including:
  • Urinating less frequently
  • Dark-colored urine
  • Dry mouth and tongue

It’s especially important to seek medical care for infants, young children, older adults, and people with weakened immune systems who show these symptoms.

How Infection Happens

Salmonella bacteria typically live in the intestines of humans, animals, and birds. Most infections occur when people eat food or drink water that has been contaminated with fecal matter.

Several foods commonly carry these bacteria:

• Raw animal products: Meat, poultry, and seafood can get contaminated during processing. Seafood might contain bacteria if harvested from polluted waters.

• Eggs (raw or undercooked): Some infected hens produce eggs that contain Salmonella before the shell forms. This affects homemade foods like mayonnaise.

• Raw milk products: Unpasteurized dairy items may harbor harmful bacteria. Pasteurization kills these germs.

• Fresh produce: Fruits and vegetables might be washed or irrigated with contaminated water. Cross-contamination can also happen in kitchens when juices from raw meat touch other foods.

Poor Food Handling

Food often becomes contaminated through improper handling.

People who don’t wash their hands well after using the bathroom, changing diapers, or touching contaminated food can spread bacteria to otherwise safe foods.

Contaminated Surfaces

People can get infected by touching contaminated objects and then putting their fingers in their mouths. Bacteria can live on many surfaces and transfer to humans through touch.

Animals and Pets

Animals can carry Salmonella on their bodies or in their waste.

Birds and reptiles pose a particular risk as they may have the bacteria on their:

• Feathers
• Skin
• Fur
• Feces

Some pet foods also contain Salmonella, which can make animals sick and create a path for human infection through handling pets or their supplies.

Risk Factors

Higher Exposure Risks

International travel can put you at greater risk for salmonella infection, especially in countries with poor sanitation systems. The bacteria that cause salmonella, including those responsible for typhoid fever, are more common in these areas.

Animal contact is another concern.

Handling or petting certain animals, particularly birds and reptiles, may expose you to salmonella bacteria. The bacteria can be present in animal enclosures, tanks, cages, and litter boxes.

Digestive System Conditions

Your body naturally protects against salmonella. Strong stomach acid typically kills many Salmonella bacteria. However, certain conditions can weaken these defenses.

• Taking Antacids – These medications reduce stomach acid, allowing more bacteria to survive.
• Inflammatory Bowel Disease – Damage to your intestinal lining makes it easier for salmonella to establish infection.
• Recent Antibiotic Use – Antibiotics can reduce helpful gut bacteria that normally help fight off infections.

Weakened Immunity

Several health conditions and medications can weaken your immune system, making it harder for your body to fight salmonella:

Health conditions that increase risk:

• HIV/AIDS
• Sickle Cell Disease
• Malaria

Medications that may increase risk:

• Organ transplant anti-rejection drugs
• Corticosteroids

Health Complications

Fluid Loss Issues

Salmonella infections commonly cause diarrhea, which can lead to serious fluid loss in the body. Watch for these warning signs:

• Passing less urine or dark-colored urine
• Dry mouth and tongue
• Sunken eyes
• No tears when crying
• Unusual fatigue
• Confusion or irritability

These symptoms need quick medical attention, especially in young children, older adults, and people with weak immune systems.

Blood Infection

When Salmonella enters the bloodstream, it can spread to other body parts and cause serious problems such as:

• Infections in the urinary system
• Inflammation of tissues around the brain and spinal cord
• Infections of heart valves or lining
• Bone or bone marrow infections
• Infections in blood vessel linings (particularly risky for people with vascular grafts)

This spread happens more often in people with weakened immune defenses.

Joint Inflammation

Some people develop joint problems after a Salmonella infection. This condition involves:

• Eye irritation and redness
• Pain during urination
• Painful, swollen joints

This reaction happens when the body’s immune system responds abnormally after fighting the infection.

Preventing Foodborne Illness

Keep Your Hands Clean

Washing your hands is one of the best ways to prevent salmonella.

Scrub with soap and water for at least 20 seconds after using the bathroom, changing diapers, or handling raw meat.

Always wash your hands after touching pets, especially reptiles and birds, or cleaning up animal waste. These simple steps prevent bacteria from spreading to your food or mouth.

Prevent Cross-Contamination

Keeping raw foods separate from ready-to-eat items helps stop bacteria from spreading.

Store raw meat, poultry, and seafood on the bottom shelf of your refrigerator, away from other foods.

Use separate cutting boards for raw meat and produce. A color-coding system works well—red for raw meat, green for vegetables. Never put cooked food on plates that held raw meat without washing them first.

Clean all kitchen surfaces thoroughly with soap and water after food preparation.

Skip Raw Egg Products

Raw eggs may contain salmonella bacteria. Avoid homemade foods with uncooked eggs, such as:

• Cookie dough
• Ice cream
• Mayonnaise
• Hollandaise sauce
• Eggnog

If a recipe calls for raw eggs, look for pasteurized eggs instead. These have been heated to kill harmful bacteria while keeping the egg usable in recipes.

Proper Cooking and Storage

Temperature Guidelines:

Food	Safe Internal Temperature
Chicken & poultry	165°F (74°C)
Ground meat	160°F (71°C)
Whole cuts of beef/pork	145°F (63°C)
Fish	145°F (63°C)

Refrigerate perishable foods within two hours of cooking. If the temperature is above 90°F (32°C), do so within one hour.

Keep your refrigerator below 40°F (4°C) to slow bacterial growth.