Type of test Blood, miscellaneous

Normal findings

Negative for viral antibody

 Test explanation and related physiology Testing for a virus is indicated when a person with specific indicative viral symptoms lives in or has traveled to an area harboring the virus. Testing is also done when a patient has severe symptoms contributing to significant morbidity. Testing can also identify a viral outbreak and its extent. Finally, testing can indicate immunity after exposure to the virus or a vaccination.

Viral testing is performed by identifying antibodies (usually IgM and IgG) to viral particles in the blood or in other body fluids. Virus can be cultured in special media tissue or body flu ids and subsequently identified (see viral culture, previous test). Finally viral RNA or DNA can be identified in body fluids (e.g., nasopharyngeal mucus or blood) heavily contaminated by the live virus. Epstein-Barr, hepatitis, respiratory syncytial, SARS (coronavirus), herpes, parainfluenza, HIV, Dengue fever, coxsackie, choriomeningitis, mumps, West Nile virus (WNV), arbovirus, equine, cytomegalovirus, rubella, and influenza A and B (including H1N1 ) can all be detected by identifying antibodies to some part of the viral particle. Testing is now available to identify antibodies to many viruses in the same sample, indicating all past and present viral infections affecting a particular patient.

Front-line testing measures IgM or IgG antibodies to the virus that may or may not be specific to that particular virus. If the front-line testing is positive, confirmatory tests may be carried out. This testing may be particularly important for public health officials and researchers. Serum and blood (plasma) should be collected early in the illness. Both acute and convalescent serum specimens should be collected for antibody testing. Some viruses (e.g., WNV) can be transmitted through donated blood or blood components. For that reason, WNV testing kits for WNV anti bodies are routinely performed on all donated blood.

Rapid antigen detection tests and rapid molecular assay tests (for viral nucleic acid) are commonly performed for influenza on nasopharyngeal swab specimens. Results can be obtained in 15 minutes.

Interfering factors

• Other viral infections will cause elevations of serologic testing, especially when combined total immunoglobulin (Ig) M and IgG are tested.

Procedure and patient care

Before

* Explain the procedure to the patient.

 • Observe all universal precautions in handling the specimen.

• Observe strict isolation technique. This disease is contagious.

 During

• To obtain a nasopharyngeal wash/aspirate, have the patient sit with the head tilted slightly backward. Instill 1 to 1.5 mL of nonbacteriostatic saline (pH 7.0) into one nostril. Flush a plastic catheter or tubing with 2 to 3 mL of saline. Insert the tubing into the nostril. Aspirate nasopharyngeal secretions. Repeat this procedure for the other nostril. Collect the specimens in sterile vials.

 • To obtain a nasopharyngeal or oropharyngeal swab, use only sterile Dacron or rayon swabs with plastic shafts. Do not use a cotton swab or swabs with wooden sticks because they may contain substances that inactivate some viruses and inhibit polymerase chain reaction testing. Insert the swab into the nostril. Leave the swab in place for a few seconds to absorb secretions. Swab both nostrils. (For oropharyngeal culture, swab the posterior pharynx and tonsillar areas, avoiding the tongue.)

• To collect sputum, educate the patient about the difference between sputum and oral secretions. Have the patient rinse the mouth with water and then expectorate deep-cough sputum directly into a sterile screw-cap sputum collection cup or sterile, dry container.

 • To collect blood, collect whole blood in a serum separator tube. Collect blood in an EDTA (ethylenediaminetetraacetic acid; purple-top) tube for plasma testing.

After

• Provide acute care for respiratory illness.

• If shipping the specimen domestically, use cold packs to keep the sample at 4° C. If shipping internationally, pack in dry ice.

Abnormal findings

 Viral infections (acute and chronic)

اخر الاخبار

اخبار العتبة العباسية المقدسة

قسم الشؤون الفكرية يصدر كتاب (دروس تمهيدية في الفقه – العبادات)

قسم الشؤون الطبية يشرع بتقديم لقاح الانفلونزا للمنتسبين

المجمع العلمي يختتم مسابقة العميد لحفظ القرآن الكريم في بغداد

لجنة البرامج المركزية تختتم فعاليات البرنامج المركزي الأسبوعي لمنتسبي العتبة العباسية المقدسة

المزيد

الآخبار الصحية

عناصر منزلية قد تؤثر على الخصوبة وفرص الحمل

شكل الدماغ قد يتنبأ بخطر الخرف قبل سنوات

طريقة صينية بسيطة للوقاية من السكري

هل تساعد المانغو في الوقاية من السكري؟

المزيد

الآخبار التكنلوجية

رقم غامض ولا إنترنت.. متوجون بنوبل للطب لم يعلموا بفوزهم

"سيري" تحت المجهر.. تحقيق فرنسي جديد ضد شركة "آبل"

أميركيان وياباني يفوزون بجائزة نوبل للطب

تحول غير مسبوق.. إنستغرام تمنح مفاتيحها للمستخدمين

المزيد

مواضيع ذات صلة

white blood cell scan (WBC scan, Inflammatory scan)

white blood cell count and differential count (WBC and differential, Leukocyte count)

vitamin D (25-hydroxy vitamin D2 and D3 ; 1,25-dihydroxyvitamin D [1,25(OH)2 D])

Basal Hormone Measurements of Testis

vitamin B12 (Cyanocobalamin and methylmalonic acid [MMA])

viral cultures

Laboratory Investigations of Pheochromocytoma and Paraganglioma

varicella virus testing (Antibody testing for Varicella zoster virus, Varicella zoster virus [VZV], Herpes virus-3)

uroporphyrinogen-1-synthase

urine culture and sensitivity (C&S)

uric acid, blood, and urine

urea breath test (UBT, Helicobacter pylori breath test)