Volume 30, Number 5—May 2024
Research
Analysis of Suspected Measles Cases with Discrepant Measles-Specific IgM and rRT-PCR Test Results, Japan
, Minoru Nidaira, Noriyuki Maeshiro, Katsuhiro Komase, Hajime Kamiya, and Hisako Kyan
Table 1
Characteristics of 24 suspected measles cases with discrepant measles-specific IgM and rRT-PCR test results, Japan*
| Characteristics | Value |
|---|---|
| Sex |
|
| M |
13 (54.2) |
| F |
11 (45.8) |
| Age |
|
| 6–11 mo |
12 (50.0) |
| 1 y |
7 (29.2) |
| 4 y |
1 (4.2) |
| >19 y |
4 (16.7) |
| Fever, temperature >37.5°C† |
20 (83.3) |
| Rash |
23 (95.8) |
| No. doses of measles vaccine‡ |
|
| 1 |
20 (83.3) |
| 2 |
0 (0) |
| Unknown§ |
4 (16.7) |
| Median time from vaccination to specimen collection, d (range) |
25 (4–136) |
| Time from illness onset to specimen collection, d |
|
| Median (range) |
3 (0–10) |
| <4 |
14 (58.3) |
| >4 |
10 (41.7) |
| No epidemiologic link to confirmed measles case | 24 (100) |
*Values are no. (%) except as indicated. rRT-PCR, real-time reverse transcription PCR. †The other 4 cases also had reported fever, but details of body temperature were unknown. ‡In Japan, the measles-rubella vaccine is used for routine vaccination and has the following schedule: first dose at 1 year of age, second dose at 5–7 years of age. During the 2018 measles outbreak in Okinawa, Japan, 12 infants 6–11 months of age were vaccinated as part of the outbreak response before routine vaccination. §Four adult cases had no details of vaccination history. Among those cases, 1 patient recalled receiving 2 doses of the measles vaccine but did not have a vaccination record.
1Current affiliation: Center for Emergency Preparedness and Response, National Institute of Infectious Diseases, Tokyo, Japan.