Nasopharyngeal and oropharyngeal swabs
Keep specimen at 4C
Collection of COMBINED THROAT AND NASOPHARYNGEAL SWABS. For collection of nasopharyngeal swab specimen: 1. Insert swab into one nostril. 2. Press swab tip on the mucosal surface of the mid-inferior portion of the inferior turbinate, and rub the swab tip several times across the mucosal surface to loosen and collect cellular material. 3. Withdraw the swab; place swab into tube of Viral Transport Medium. For collection of oropharyngeal swab specimen: 1. Ask patient to open mouth widely and phonate an 'ah'. 2. Gently depress the tongue with a tongue blade. 3. Guide a swab over the tongue into the posterior oropharynx. 4. Using a gentle back-and-forth sweeping motion, swab the area behind the uvula and between the tonsillar pillars. 5. Withdraw the swab; place swab into the same tube of Viral Transport Medium that contains the nasoparyngeal swab. Immediately transport to the Clinical Virology Laboratory. Nasal aspirates or washings, tracheal aspirates, and bronchoalveolar lavage specimens may be submitted. Tracheal or transtracheal aspirates or bronchoalveolar lavage specimens are superior for the indication of lower respiratory tract infections.
Swab specimens not received in viral transport medium or received in bacteriological transport medium are discouraged. DO NOT USE CALCIUM ALGINATE OR WOODEN SHAFT SWABS FOR COLLECTION OF SPECIMENS; ONLY USE DACRON OR RAYON TIPPED SWABS ON PLASTIC OR METAL SHAFTS.
Amplification and detection of HHV-6 DNA U65-U66 gene region using TaqMan real-time PCR technology. The test is performed pursuant to an agreement with Roche Molecular Systems, Inc.
If positive, results are reported as human herpesvirus-6 DNA detected.
Negative or no human herpesvirus-6 DNA detected
Clinical Utility: Human herpes virus type-6 (HHV-6) is the cause of roseola infantum, an illness characterized by an erythematous maculopapular rash with high fever in 20% of children. The disease is also called exanthum subitum and Sixth disease. Other illnesses include undifferentiated febrile illness without rash or localized signs, febrile seizures (common with roseola), infectious mononucleosis-like syndromes, hepatitis, and neurologic syndromes (e.g., encephalitis). Transplant recipients may have fever, hepatitis, leukopenia, delayed engraftment, neurologic disease, skin rashes, pneumonia, and bone marrow suppression. The virus may contribute to disease progression with HIV-1 and exacerbate disease with other viruses. The diagnosis of HHV-6 infection is increasingly being made by PCR, and HHV-6 DNA has been detected in specimens from solid-organ and bone marrow transplant recipients; children with roseola, acute febrile illnesses, encephalitis and febrile seizures, and other manifestations of primary infection; and AIDS patients. Quantitative PCR assays should be used in immunocompromised patients to associate infection with disease, predict and monitor disease progression, assess efficacy of antiviral therapy, and to facilitate our understanding of the pathogenesis of HHV-6. In these patients, viremia is considered to be the best predictor of disease, and quantitative measures of HHV-6 DNA in blood is useful for the continued surveillance and management of transplant patients.