The Hepatitis E Virus IgM (HEV IgM) test is a blood test that looks for IgM antibodies your immune system makes when you are infected with the Hepatitis E virus (HEV). IgM antibodies are typically produced early in an infection, so this test is mainly used to help identify a recent or active hepatitis E (acute hepatitis) infection.

Hepatitis E is a type of viral infection that can inflame the liver and affect liver health. In many parts of the world, HEV spreads as a waterborne disease, often through contaminated drinking water. In other settings, it can also be linked to food exposures (such as undercooked pork or game meat), depending on the region.

What the results may mean:

Positive HEV IgM usually means you have a current or very recent Hepatitis E infection. Your clinician may interpret this alongside your symptoms, liver enzyme tests (like ALT/AST), and sometimes additional HEV testing (such as HEV RNA PCR or HEV IgG) to confirm the diagnosis and assess timing.

Negative HEV IgM usually means there is no evidence of a recent Hepatitis E infection. However, early testing (before antibodies rise) or testing later after IgM has declined can sometimes lead to a negative result despite infection. If suspicion remains high—based on infection symptoms, exposure history, or abnormal liver tests—your clinician may repeat testing or order other tests.

Indeterminate/Equivocal means the result is not clearly positive or negative. This may happen early in infection or due to testing limitations, and repeat testing is often recommended.

The HEV IgM diagnostic test is most often ordered when a person has signs of acute hepatitis or unexplained liver inflammation, especially when there is a possible exposure risk.

Your clinician may order HEV IgM if you have symptoms such as:

Jaundice (yellowing of skin/eyes), dark urine, pale stools, itching, fatigue, nausea/vomiting, loss of appetite, right upper abdominal pain, fever, or generally feeling unwell—particularly when bloodwork shows elevated liver enzymes (ALT/AST) or bilirubin.

It is also commonly done when there are risk factors for Hepatitis E, including:

Recent travel to areas where hepatitis E is more common, especially where safe water access is limited; drinking untreated water or exposure to contaminated water (including during floods or outbreaks); close contact in settings with poor sanitation; or suspected foodborne exposure (region-dependent).

The test is especially important in higher-risk situations because hepatitis E can be more severe in some people, such as:

Pregnancy (particularly in the third trimester), immunocompromised individuals (for example, organ transplant recipients or people on immune-suppressing medications), and people with underlying chronic liver disease. In these cases, prompt diagnosis can guide monitoring, supportive care, and infection control measures relevant to public health.

• Acute Hepatitis E infection
• Acute viral hepatitis (evaluation of hepatitis symptoms alongside hepatitis A, B, and C testing)
• Drug-induced liver injury vs. viral hepatitis (as part of the differential diagnosis)
• Acute liver inflammation (hepatitis) with elevated ALT/AST and bilirubin
• Severe hepatitis in pregnancy (hepatitis E-associated risk)
• Hepatitis in immunocompromised patients (including transplant recipients)
• Outbreak-associated hepatitis related to contaminated water (public health investigations)

• Identifying the cause of acute hepatitis symptoms (jaundice, fatigue, nausea, abdominal pain)
• Protecting liver health by confirming a viral cause of elevated liver enzymes and guiding appropriate monitoring
• Reducing transmission risk through timely diagnosis and exposure counseling (waterborne/foodborne prevention)
• Supporting pregnancy health by rapidly evaluating hepatitis symptoms in pregnant patients
• Care planning for immunocompromised individuals with suspected viral hepatitis
• Public health outbreak control by helping confirm hepatitis E during suspected water contamination events