Salmonella Antibodies Test – Detect Typhoid and Systemic Infections

The Salmonella Antibodies Test detects IgG and IgM antibodies against Salmonella typhi and other Salmonella species in the blood. This serological test is used to diagnose typhoid fever and systemic salmonellosis, particularly when stool cultures are negative or delayed. It is especially valuable for travelers returning from endemic regions.

Symptoms That Indicate You May Need This Test

If you have the following symptoms, especially after consuming contaminated food or traveling abroad:

 
• High, sustained fever (103–104°F)
 
• Abdominal pain and bloating
 
• Diarrhea or constipation
 
• Headache, weakness, and fatigue
 
• Loss of appetite
 
• Rose spots (pink, flat spots on the chest or abdomen)
 

These are classic signs of typhoid fever caused by S. typhi.

Natural Production and Role in the Body

When Salmonella bacteria enter the body through contaminated food or water, the immune system responds by producing specific antibodies. IgM appears within 1 week of infection, indicating acute or recent exposure. IgG rises later and may persist for months or years, suggesting past infection or vaccination.

What Happens If Left Untreated?

Untreated typhoid fever can lead to severe complications, including:

 
• Intestinal perforation and peritonitis
 
• Life-threatening sepsis
 
• Encephalopathy or meningitis
 
• Chronic carrier state (asymptomatic shedding in stool)
 
• Death in up to 10–20% of untreated cases
 

Early diagnosis and antibiotic treatment are critical to recovery.

Test Overview

A 2 mL blood sample is drawn from a vein and collected in an SST or red-top tube. The test detects antibody titers in serum. A rising titer between acute and convalescent samples (taken 1–2 weeks apart) confirms active infection. Results are typically available the same day.

Frequently Asked Questions (FAQs)

Can this test give false positives?

Yes—previous infection, vaccination, or cross-reacting infections (like malaria) may cause elevated IgG. IgM is more specific for recent infection.

Is this test better than stool culture?

It's complementary. Blood antibodies are useful when cultures are negative or delayed.

Do I need a repeat test?

Sometimes—doctors may order a second test 1–2 weeks later to confirm rising antibody levels.