Comparison between Indirect Immunofluorescence Assay and Shell Vial Culture for Detection of Mumps Virus from Clinical Samples

Abstract

We report a prospective comparison of the efficacies of an indirect immunofluorescence assay (IFA) and shell vial culture (SVC) of throat swab and urine samples from patients with mumps. Throat swab samples were used for the IFA; the urine samples and throat swabs were inoculated into vials of Vero cells. We studied 62 patients by using 62 throat swabs and 50 urine samples (50 patients with both samples). Sixty (96.7%) throat samples were positive in the SVC, and 61 (98.3%) were positive in the IFA. For the 50 patients from whom both samples were available, the IFA was positive in 50 (100%) cases, the urine sample was positive in 49 (98%) cases, and the throat swab was positive in 48 (96%) cases (P > 0.05). This comparison of throat swabs and urine samples has shown that the two clinical samples are similar in efficacy.Parotiditis (mumps or infectious parotitis) is a disease, caused by the mumps virus, that affects especially children less than 15 months old who have not been vaccinated or children or young adults living in geographical areas with low vaccination rates (1,3,10,14). Nevertheless, there have been reports of mumps outbreaks in vaccinated populations although it was later found that, in the majority of the cases, the vaccine used was the Rubini strain, which offers slight protection against this disease (7, 13).The diagnosis of mumps is generally clinical (parotid gland inflammation, swelling, and pain) when associated with a community epidemic outbreak. However, it is always advisable to perform a serological study of the patients and to try to isolate the mumps virus in order to establish its antigenic characteristics (2, 10, 14, 15). There is no specific rapid diagnostic technique for the mumps virus. Immunofluorescence assay (IFA) and the reverse transcription-PCR technique appear to be the methods with the greatest clinical efficacy (5, 9-11). Isolation in cell culture, especially by the shell vial method, has been recommended for a rapid and specific diagnosis, but it takes a minimum of 2 to 3 days (6,12,16).Taking advantage of an epidemic outbreak of mumps in our community, we performed a prospective and comparative study of the direct antigen detection technique (IFA) versus shell vial culture from throat swab and urine samples from patients with clinical symptoms of mumps.All throat swabs were placed in a virus transport medium and sent to the laboratory immediately. Sample volumes of 250 l were used for cytospin preparations by centrifugation onto glass slides at 700 rpm for 10 min with a cytocentrifuge (Cytospin 3; Shandon Scientific, Runcorn, England). After being air dried, the slides were fixed with acetone at Ϫ20°C for 10 min and then stained with a mouse monoclonal antibody against mumps virus (clone 75; Argene-Biosoft) by an indirect IFA. The presence of cytoplasmic or membrane type-specific immunofluorescence was considered a positive result.Urine samples were first centrifuged at 1,000 ϫ g for 15 min to remove cells and debris and then inoculated (250 l per sample) into two vials ...

Rapid Diagnostic Method for Detection of Mumps Virus Genome by Loop-Mediated Isothermal Amplification

“…Mumps virus can usually be isolated in 40 to 60% of patients, and virus isolation is time consuming for more than 1 to 2 weeks. Recently, a more sensitive shell vial culture method has been employed (21,22). In a clinical setting, rapid virological diagnosis is required to prevent further extension of the outbreak.…”