Evaluation of a commercial rubella IgM assay for use on oral fluid samples for diagnosis and surveillance of congenital rubella syndrome and postnatal rubella

• Published in: Journal of clinical virology 2006-12, Vol.37 (4), p.265-268
• Main Authors: Vijaylakshmi, P., Muthukkaruppan, V.R., Rajasundari, A., Korukluoglu, G., Nigatu, W., L.A.Warrener, Samuel, D., Brown, D.W.G.
• Format: Article
• Language: English
• Subjects: Antibodies, Viral - blood; Biological and medical sciences; Biological Assay - economics; Female; Fundamental and applied biological sciences. Psychology; Human viral diseases; Humans; IgM; Immunoglobulin M - analysis; Infectious diseases; Medical sciences; Microbiology; Miscellaneous; Oral fluid; Pregnancy; Pregnancy Complications, Infectious - prevention & control; Pregnancy Complications, Infectious - virology; Reagent Kits, Diagnostic; Rubella; Rubella - congenital; Rubella - diagnosis; Rubella - epidemiology; Rubella - immunology; Saliva - virology; Sensitivity and Specificity; Viral diseases; Viral diseases with cutaneous or mucosal lesions and viral diseases of the eye; Virology
• ISSN: 1386-6532; 1873-5967
• DOI: 10.1016/j.jcv.2006.09.005

Clinical diagnosis (surveillance) of rubella is unreliable and laboratory confirmation is essential. Detection of virus specific IgM in serum is the most commonly used method. However, the use of serum necessitates the drawing of blood, either through venipuncture or finger/heel prick, which can be difficult in young babies. Oral fluid samples have proved useful as an alternative, less invasive sample for virus specific IgM detection however until recently no commercial rubella IgM tests were available, restricting the usefulness of this approach. To evaluate the performance of the Microimmune Rubella IgM capture EIA using oral fluid samples from outbreaks as well as in cases of suspected congenital rubella syndrome (CRS). Paired serum and oral fluids were collected from cases during a rubella outbreak in three provinces in Turkey. Matched serum and oral fluid samples were collected from children with suspected CRS in an active surveillance programme at the Aravind Eye Hospital in South India. Serum samples were collected as part of the measles surveillance programme in Ethiopia. On serum samples the sensitivity and specificity of the Microimmune Rubella IgM capture EIA compared to Behring Enzygnost rubella IgM test was 96.9% (62/64; 95% CI 94.2–100%) and 100% (53/53; 95% CI 93.2–100%). On oral fluids compared to matched Behring results on serum the sensitivity was 95.5% (42/44; 95% CI 84.5–99.4%). The sensitivity and specificity of Microimmune Rubella IgM capture EIA on oral fluids from suspected CRS cases compared to serum results using Behring Enzygnost IgM assay was 100% (95% CI 84.5–100%) and 100% (95% CI 95.8–100.0%) respectively. Microimmune Rubella IgM capture EIA has adequate performance for diagnosis and surveillance of rubella in outbreak using either serum or oral fluid specimens.