Zika virus infection and microcephaly in Vietnam.

We read with great concern of the recent Zika virus outbreak in Singapore as reported by the Singapore Zika Study Group.1The Singapore Zika Study GroupOutbreak of Zika virus infection in Singapore: an epidemiological, entomological, virological and clinical analysis.Lancet Infect Dis. 2017; (published online May 17.)http://dx.doi.org/10.1016/S1473-3099(17)30249-9Google Scholar Although Zika virus infection has been previously associated with congenital malformations and neurological syndromes,2Hazin AN Poretti A Di Cavalcanti Souza Cruz D et al.Computed tomographic findings in microcephaly associated with Zika virus.N Engl J Med. 2016; 374: 2193-2195Crossref PubMed Scopus (190) Google Scholar, 3Cao-Lormeau VM Blake A Mons S et al.Guillain-Barré Syndrome outbreak associated with Zika virus infection in French Polynesia: a case-control study.Lancet. 2016; 387: 1531-1539Summary Full Text Full Text PDF PubMed Scopus (1627) Google Scholar no antenatal or postnatal abnormalities were detected in pregnant women during the Singapore outbreak.1The Singapore Zika Study GroupOutbreak of Zika virus infection in Singapore: an epidemiological, entomological, virological and clinical analysis.Lancet Infect Dis. 2017; (published online May 17.)http://dx.doi.org/10.1016/S1473-3099(17)30249-9Google Scholar The spectrum of disease associated with vertical Zika virus infection in the region remains unclear, and considering the rapidly expanding Zika virus epidemic in Asia, further detailed assessment is urgently needed. As of March 1, 2017, 23 laboratory-confirmed cases of Zika virus infection had been identified in Vietnam. Before reports of exported Zika virus cases in December, 2015, no cases had been reported in Vietnam.4Duong V Dussart P Buchny P Zika virus in Asia.Int J Infect Dis. 2017; 54: 121-128Summary Full Text Full Text PDF PubMed Scopus (61) Google Scholar Following the detection of local cases of Zika virus infection in March, 2016, local authorities intensified Zika virus disease surveillance and control measures. During the outbreak, on June, 2016, a girl was born with microcephaly in Dak Lak Province, in the Central Highlands region of Vietnam, at 37 weeks of gestation (figure). The infant's mother (aged 23 years) had experienced symptoms of fever and rash associated with Zika virus infection during her second trimester. The symptoms resolved uneventfully. When the child was 3–4 months of age, the child, mother, and four intermediate family members (father, grandmother, uncle, and an adopted child) had high concentrations of Zika virus-specific neutralising antibody (the serum titre required to reduce viral plaques by 50% [PRNT50] was 1/160–1/1280; appendix), confirming recent viral exposure. Both the mother and child did not have a recent history of travel. Of the 17 people that the mother or child had come into contact with or who were neighbours, two were seropositive for Zika virus, suggesting a recent local outbreak in the area. Toxoplasmosis, rubella, cytomegalovirus, herpes simplex, dengue, and Japanese encephalitis were ruled out in both the mother and child, following local and WHO guidelines.5Oladapo OT Souza JP De Mucio B de León RG et al.WHO interim guidance on pregnancy management in the context of Zika virus infection.Lancet Glob Health. 2016; 4: e510-e511Summary Full Text Full Text PDF PubMed Scopus (17) Google Scholar Follow-up examinations were done at ages 4 and 9 months. CT images of the child's brain showed multiple isolated foci of calcification of the frontal and parietal lobes, and ventriculomegaly with decreased brain volume at age 4 months (appendix). The CT findings were consistent with those of children with vertical Zika virus infection in the Americas.2Hazin AN Poretti A Di Cavalcanti Souza Cruz D et al.Computed tomographic findings in microcephaly associated with Zika virus.N Engl J Med. 2016; 374: 2193-2195Crossref PubMed Scopus (190) Google Scholar At age 9 months, the infant showed psychomotor developmental delays, with generalised spastic dystonia and cerebral palsy. She also reacted poorly to external stimulation and showed fixed, dilated pupils upon examination, suggesting ocular manifestations. The spectrum of the congenital Zika virus syndrome and epidemiology in Asia remains undefined. We thus advocate further efforts to determine the extent of Zika virus vertical infection in the region to gain a better understanding of the risks of congenital Zika virus syndrome in different parts of the world. We declare no competing interests. We thank the health-care practitioners of the clinics and hospitals in Vietnam who supported the study. We thank Phu Ly Minh Huong and Satoshi Shimada for helpful discussion. We also thank Shashika Lavangi Wijesooriya for technical assistance. This work was supported by grants from the Japan Initiative for Global Research Network on Infectious Diseases (JGRID) and the Research Program on Emerging and Re-emerging Infectious Diseases of the Japan Agency for Medical Research and Development (AMED); e-Asia Joint Research Program (e-Asia JRP) of the Japan Science and Technology Agency (JST); and MSD Life Science Foundation International. The ethics committee of the Institute of Tropical Medicine, Nagasaki University, Japan (08061924–7) and National Institute of Hygiene and Epidemiology, Hanoi, Vietnam (IRB-VN01057/2016) approved the study. Download .pdf (.3 MB) Help with pdf files Supplementary appendix Outbreak of Zika virus infection in Singapore: an epidemiological, entomological, virological, and clinical analysisThe outbreak shows the ease with which Zika virus can be introduced and spread despite good baseline vector control. Disease surveillance, enhanced vector control, and community awareness and engagement helped to quickly curb further spread of the virus. These intensive measures might be useful for other countries facing the same threat. Full-Text PDF Long-term surveillance needed to detect Zika virus outbreaks in endemic regionsWe read Sarah C Hill and colleagues' Article1 about the emergence of the Asian lineage of Zika virus in Angola with great interest. The study suggests that Zika virus had been circulating in Angola for 17–28 months before the major outbreak was reported, raising the challenges of early disease detection and containment. Full-Text PDF