What tests are done to diagnose mumps?

The symptoms of many diseases are very similar, so any disease requires relevant examinations before it can be diagnosed. The same is true for mumps. People with mumps have pain and swelling in the parotid glands. Generally speaking, patients need to go to the hospital for peripheral blood tests, serum and urine amylase tests, virus isolation, urine routine tests and electrocardiograms before they can be diagnosed with mumps.

What tests should be done for mumps

1. Peripheral blood count

The white blood cell count is mostly normal or slightly increased, and the lymphocyte count is relatively increased. When there are complications, the white blood cell count may increase, and leukemoid reactions may occasionally occur.

2. Serum and urine amylase determination

90% of patients have mild and moderate elevations in serum amylase, which helps with diagnosis. The degree of increase in amylase is often proportional to the degree of parotid swelling. However, its increase may also be related to lesions of the pancreatic and small intestinal serous enzyme glands.

3. Serological examination

(1) Neutralizing antibody test: A low titer such as 1:2 indicates active infection. In recent years, the gel hemolysis test has been used, which is basically consistent with the neutralization test and is simpler and faster than the detection of neutralizing antibodies, but the method still needs further improvement.

(2) Complement fixation test: It has auxiliary diagnostic value for suspected cases. If the titer of two serum samples (early stage of the disease and 2-3 weeks) increases by more than 4 times, or the titer of one serum reaches 1:64, it has diagnostic significance. If conditions permit, it is advisable to measure S antibody and V antibody at the same time. An increase in S antibody indicates a recent infection, while an increase in V antibody but no increase in S antibody only indicates a past infection.

(3) Hemagglutination inhibition test: The amniotic fluid and allantoic fluid of chicken embryos infected with the virus can cause the chicken's red blood cells to agglutinate. The convalescent serum of mumps patients has a strong inhibitory effect on agglutination, while the inhibitory effect of early serum is weaker. If the titer of two measurements differs by more than 4 times, it is considered positive.

4. Virus Isolation

In early cases, mumps virus can be isolated from saliva, urine, blood, cerebrospinal fluid, and other tissues such as the brain and thyroid. The procedures are rather complicated and there are currently no conditions for its widespread implementation.

5. Urinalysis

When the kidneys are affected, proteinuria, red and white blood cells, etc. may appear in the urine, and even changes in the urine similar to nephritis may occur.

6. Electrocardiogram

When combined with myocarditis, the electrocardiogram shows: arrhythmia, flat T waves, and depressed ST segment.

What diseases should be differentiated from mumps?

1. Suppurative parotitis

It is often unilateral, with obvious local redness, swelling and tenderness. In the late stage, there is a sense of fluctuation. When squeezed, pus flows out of the parotid duct. The total white blood cell count and neutrophil granulocytes in the blood are significantly increased.

2. Neck and preauricular lymphadenitis

The swelling is not centered on the earlobe, but is limited to the neck or preauricular area. It is nuclear-shaped, hard, with clear edges, obvious tenderness, and superficial and movable. Inflammation of tissues related to the lymph nodes in the neck or preauricular area may be found, such as pharyngitis, ear boils, etc., and the total white blood cell count and neutrophil count are increased.

3. Symptomatic parotid gland enlargement

In diabetes, malnutrition, chronic liver disease, or the use of certain drugs such as iodide, phenylbutazone, isoproterenol, etc., the parotid glands may swell symmetrically, without any swelling or pain, and are soft to the touch. Tissue examination mainly shows fatty degeneration.

4. Mumps caused by other viruses

It is known that parainfluenza virus type 1.3, influenza A virus, coxsackie virus type A, herpes simplex virus, lymphochoroidal meningitis virus, and cytomegalovirus can all cause parotid gland swelling and central nervous system symptoms, requiring etiological diagnosis.

5. Parotid gland swelling caused by other reasons

Allergic parotitis and parotid duct obstruction both have a history of recurrent attacks, with sudden onset of swelling and rapid reduction of swelling. Simple parotid gland swelling is mostly seen in adolescent males. It is due to increased functional secretion and compensatory parotid gland swelling without other symptoms.

6. Meningoencephalitis caused by other viruses

Mumps meningoencephalitis may occur before parotid swelling (some people never have parotid swelling), and it is difficult to distinguish it from those caused by other viruses. It can be confirmed with the help of the above-mentioned serological tests, virus isolation and epidemiological surveys.