SALMONELLA TYPHI IGM (TYPHI DOT) - SERUM

Salmonella Typhi IgM (Typhidot) – Serum

The Salmonella Typhi IgM (Typhidot) Test is a rapid serological blood test that detects IgM antibodies against Salmonella enterica serovar Typhi, the bacterium responsible for typhoid fever (enteric fever).

Typhoid fever is a bacterial infection transmitted primarily through contaminated food and water. It remains a significant public health concern in many developing countries and can lead to severe complications if left untreated.

Common symptoms include:

• Persistent high fever
• Headache
• Weakness and fatigue
• Loss of appetite
• Abdominal pain
• Constipation or diarrhoea
• Nausea and vomiting
• Rose-colored skin rash (in some patients)

The Typhidot IgM test detects the body's early immune response to Salmonella Typhi. IgM antibodies generally appear during the early phase of infection, making this test useful as a supportive investigation when typhoid fever is clinically suspected.

However, IgM antibodies alone cannot definitively diagnose typhoid fever. According to the CDC, blood culture remains the gold standard for confirming acute typhoid fever, especially when obtained before antibiotic therapy is started. Serological tests should always be interpreted together with clinical findings and culture results. (cdc.gov)

Test Purpose

The Salmonella Typhi IgM (Typhidot) Test helps to:

• Detect early IgM antibodies against Salmonella Typhi.
• Support evaluation of suspected acute typhoid fever.
• Assist when blood culture is unavailable or pending.
• Complement clinical diagnosis.
• Help differentiate early from previous exposure when interpreted with IgG testing.

Benefits

• Rapid antibody detection.
• Useful during the early immune response.
• Requires only a simple blood sample.
• Helpful as an adjunct to blood culture.
• Can support evaluation of prolonged fever.
• Suitable for outpatient and inpatient settings.

Why Doctors Recommend This Test

Doctors may recommend this test for patients with:

• Persistent fever lasting several days.
• Clinical features suggestive of enteric fever.
• History of consuming contaminated food or water.
• Recent travel to typhoid-endemic regions.
• Suspected bacterial fever requiring laboratory evaluation.

The test is often ordered together with:

• Blood culture
• Complete Blood Count (CBC)
• Stool culture
• Urine culture
• Liver Function Tests
• C-Reactive Protein (CRP)
• Salmonella Typhi IgG (Typhidot)

Preparation Before the Test

No fasting is generally required.

Inform your healthcare provider about:

• Current antibiotic treatment
• Previous typhoid infection
• Recent typhoid vaccination
• Duration of fever
• Recent travel history
• Previous culture reports

A blood sample is collected from a vein for serum analysis.

Normal Reporting Time

Typically: 15–30 Minutes after sample processing

Actual report delivery depends on laboratory workflow.

Who Should Take This Test?

This test may be recommended for:

• Patients with suspected acute typhoid fever.
• Individuals with prolonged unexplained fever.
• Patients with abdominal symptoms and fever.
• Travelers returning from endemic regions.
• Individuals exposed to contaminated food or water.
• Patients awaiting blood culture results.
• Individuals undergoing evaluation for enteric fever.
• Patients with suspected bacterial bloodstream infection.
• Individuals referred by an infectious disease specialist.
• Anyone advised by their healthcare provider.