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Clinical Infection & Immunity

Case Report

Volume 5, Number 2, June 2020, pages 39-40

A Case of Subclinical Rubella Infection During Pregnancy

Rubella can cause a miscarriage or serious birth defects in a developing baby if a woman is infected while she is pregnant [1]. Most people who get rubella usually have a mild illness, with symptoms that can include a low-grade fever, sore throat, and a rash that starts on the face and spreads to the rest of the body. However, we report here a case of subclinical infection of rubella during the first trimester of the pregnancy. In the current case, rubella infection could not be confirmed because of her continued weak positive of rubella immunoglobulin M (IgM) antibody.

A 21-year-old woman, gravida 1, para 0, refereed to our hospital due to high-risk consultation for fetal growth restriction at 30 weeks of gestation. She has no history of rubella infection or vaccination. At 12 weeks of gestation, however, the serum hemagglutination inhibition (HI) antibody against rubella virus was × 256. Thus, the titer of rubella IgM antibody was checked at 15, 20 and 30 weeks of gestation, and the titers were 1.09, 0.98 and 0.96 (normal: < 0.80, slightly positive: 0.80 - 1.20), respectively. Because her pregnancy had progressed uneventfully during the first trimester, we diagnosed her with a history of subclinical infection of rubella during pre-pregnancy with persistent specific IgM antibody. At 34 weeks of gestation, she received cesarean section and gave birth to a male baby of 1,300 g. No major malformations were found in the small-for-gestational-age baby; however, pancytopenia and cataract due to viral infection were recognized. The specific IgM antibody against rubella virus was high (8.01) and the polymerase chain reaction (PCR) using urine revealed deoxyribonucleic acid of rubella virus. The definitive diagnosis of congenital rubella infection was made in the baby.

In Japan, all women can be screened for rubella infection at the first perinatal visit with the Japanese public expenses burden. Based on the guidelines for obstetrical practice in Japan [2], one of the diagnostic measures is titer of HI antibody ≥ × 256 during early pregnancy. The diagnostic measures include both repeated measures of the HI titer in paired sera samples and measures of the specific IgM antibody. In the current case, unfortunately, repeated measures of the HI titer in paired sera samples were not performed, while the presence of persistent specific IgM antibody was suspected in the mother. Usually, the titer of IgM antibody against rubella virus peaks in adults approximately 1 week after the onset of skin rash of rubella infection, and declines in 2 - 3 months. However, the changes in IgM have seemed to be various among individuals such as the presence of IgM persistence [3, 4]. Therefore, it has been thought to be important to distinguish IgM reactivity caused by primary infection from that caused by IgM persistence or cross-reactivity with other antigens, especially in pregnant women.

Japan is one of the few countries with no eradication of rubella infection [5]. It may be difficult to diagnose all cases of rubella infection in adults with clinical symptoms and/or antibody testing. Therefore, eliminating rubella infection with vaccine is one of urgent issues in Japan.

Acknowledgments

The authors would like to thank the Department of Obstetrics and Gynecology of Japanese Red Cross Katsushika Maternity Hospital for helping with the diagnosis and management of the baby and for the support in preparing this case report.

Financial Disclosure

The author has no support or funding to report.

Conflict of Interest

The authors declare that no conflict of interest.

Informed Consent

Written informed consent for publication of the clinical details was obtained from the parent.

Author Contributions

TS as the chief doctor, collected the data, wrote, and reviewed the manuscript. SS designed the report, wrote and reviewed the manuscript, and approved the final draft.

Data Availability

The authors declare that data supporting the findings of this study are available within the article.

1. Centers for Disease Control and Prevention: Rubella (German Measles, Three-Day Measles). 2017. https://www.cdc.gov/rubella/index.html (March 25, 2020).
2. Minakami H, Maeda T, Fujii T, Hamada H, Iitsuka Y, Itakura A, Itoh H, et al. Guidelines for obstetrical practice in Japan: Japan Society of Obstetrics and Gynecology (JSOG) and Japan Association of Obstetricians and Gynecologists (JAOG) 2014 edition. J Obstet Gynaecol Res. 2014;40(6):1469-1499.
   doi pubmed
3. Thomas HI, Morgan-Capner P. The avidity of specific IgM detected in primary rubella and reinfection. Epidemiol Infect. 1990;104(3):489-497.
   doi pubmed
4. Thomas HI, Morgan-Capner P, Roberts A, Hesketh L. Persistent rubella-specific IgM reactivity in the absence of recent primary rubella and rubella reinfection. J Med Virol. 1992;36(3):188-192.
   doi pubmed
5. Ueda K. Epidemiology of rubella and congenital rubella syndrome in Japan before 1989. Vaccine. 2016;34(16):1971-1974.
   doi pubmed

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