Department of Virology, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan; Department of Tropical Viral Vaccine Development, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan; Center for Vaccines and Therapeutic Antibodies for Emerging Infectious Diseases, Shimane University, Izumo, Japan.
Department of Virology, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan; Department of Biomedical Sciences and Technology, Technical University of Kenya, Nairobi, Kenya.
J Infect Public Health. 2024 Jun;17(6):1050-1056. doi: 10.1016/j.jiph.2024.04.012. Epub 2024 Apr 21.
Chikungunya virus (CHIKV) is an alphavirus (genus Alphavirus, family Togaviridae) that is primarily transmitted to humans by Aedes mosquitoes, and can be transmitted from mother to child. Little is known about CHIKV transmission in Vietnam, where dengue is endemic and Aedes mosquitoes are abundant. This study aimed to determine the prevalence and characteristics of vertical CHIKV infection in a birth cohort, and seroprevalence of anti-CHIKV antibodies with or without confirmation by neutralization tests among women bearing children in Vietnam.
We collected umbilical cord blood plasma samples from each newly delivered baby in Nha Trang, Central Vietnam, between July 2017 and September 2018. Samples were subjected to molecular assay (quantitative real-time RT-PCR) and serological tests (anti-CHIKV IgM capture and IgG indirect enzyme-linked immunosorbent assay, and neutralization tests).
Of the 2012 tested cord blood samples from newly delivered babies, the CHIKV viral genome was detected in 6 (0.3%) samples by RT-PCR, whereas, 15 samples (0.7%) were anti-CHIKV-IgM positive. Overall, 18 (0.9%, 95% CI: 0.6-1.5) samples, including three positives for both CHIKV IgM and viral genome on RT-PCR, were regarded as vertical transmission of CHIKV infection. Of the 2012 cord blood samples, 10 (0.5%, 95% CI: 0.2-0.9) were positive for both anti-CHIKV IgM and IgG. Twenty-nine (1.4%, 95% CI: 1.0-2.1) were seropositive for anti-CHIKV IgG while 26 (1.3%, 95% CI: 0.8-1.9) of them were also positive for neutralizing antibodies, and regarded as seropositive with neutralization against CHIKV infection.
This is the first report of a possible CHIKV maternal-neonatal infection in a birth cohort in Vietnam. The findings indicate that follow-up and a differential diagnosis of CHIKV infection in pregnant women are needed to clarify the potential for CHIKV vertical transmission and its impact in the newborn.
基孔肯雅病毒（CHIKV）是一种甲病毒（属甲病毒属，黄病毒科），主要通过埃及伊蚊传播给人类，也可以由母亲传染给孩子。在登革热流行且埃及伊蚊丰富的越南，人们对 CHIKV 的传播知之甚少。本研究旨在确定一个出生队列中垂直 CHIKV 感染的流行率和特征，以及在越南生育子女的妇女中抗 CHIKV 抗体的血清流行率，无论是否通过中和试验进行确认。
我们于 2017 年 7 月至 2018 年 9 月期间在越南芽庄收集了每个新生儿的脐带血血浆样本。样本进行了分子检测（定量实时 RT-PCR）和血清学检测（抗 CHIKV IgM 捕获和 IgG 间接酶联免疫吸附试验，以及中和试验）。
在 2012 份新分娩婴儿的脐带血样本中，通过 RT-PCR 检测到 6 份（0.3%）样本中存在 CHIKV 病毒基因组，而 15 份（0.7%）样本抗 CHIKV-IgM 阳性。总的来说，18 份（0.9%，95%CI：0.6-1.5）样本，包括 RT-PCR 上 CHIKV IgM 和病毒基因组均阳性的 3 份样本，被认为是 CHIKV 感染的垂直传播。在 2012 份脐带血样本中，10 份（0.5%，95%CI：0.2-0.9）样本同时抗 CHIKV IgM 和 IgG 阳性。29 份（1.4%，95%CI：1.0-2.1）样本抗 CHIKV IgG 血清阳性，而其中 26 份（1.3%，95%CI：0.8-1.9）的样本中和抗体也为阳性，被认为是抗 CHIKV 感染的血清阳性。
这是越南首次报道可能存在 CHIKV 母婴感染的出生队列。这些发现表明，需要对孕妇进行 CHIKV 感染的随访和鉴别诊断，以明确 CHIKV 垂直传播的可能性及其对新生儿的影响。
