Clinical value of enzyme immunoassay that detects rubella‐specific immunoglobulin M immediately after disease onset

Abstract

A total of 300 patients with nucleic acid test-confirmed rubella, mostly adults, were investigated to determine the clinical value of a rubella-specific IgM test using an EIA kit. IgM titers increased after rash onset, the median IgM titer being significantly higher 3 days post-onset than on previous days (P < 0.0001). Similarly, the IgMpositive rate at 3 days post-onset (61.5%) was significantly higher than on previous days (P < 0.0001). This IgM test against rubella at 3 days or more post-disease onset provides the clinically relevant information. K E Y W O R D S immunoglobulin M, laboratory diagnosis, nucleic acid test, rubella Abbreviations: EIA, enzyme immunoassay; NAT, nucleic acid test; RU, relative unit; WHO, World Health Organization. 32 |

Conjunctivitis, the key clinical characteristic of adult rubella in Japan during two large outbreaks, 2012–2013 and 2018–2019

“…The possibility of misclassification of false-positive rubella IgM was thought to be low. Moreover, previous reports showed that this rubella-specific IgM test (EIA kit) indicated highly positive results for rubella (reaching 80%) among patients who received this test after 5 days of the onset of symptoms [27]. Therefore, we conducted the multivariate analysis between 33 AR and 72 ANR who were diagnosed after 5 days of onset of symptoms or confirmed by RT-PCR.…”