Zika Virus Disease and Pregnancy Outcomes in Colombia.

BACKGROUND: In 2015 and 2016, Colombia had a widespread outbreak of Zika virus. Data from two national population-based surveillance systems for symptomatic Zika virus disease (ZVD) and birth defects provided complementary information on the effect of the Zika virus outbreak on pregnancies and infant outcomes. METHODS: We collected national surveillance data regarding cases of pregnant women with ZVD that were reported during the period from June 2015 through July 2016. The presence of Zika virus RNA was identified in a subgroup of these women on real-time reverse-transcriptase-polymerase-chain-reaction (rRT-PCR) assay. Brain or eye defects in infants and fetuses and other adverse pregnancy outcomes were identified among the women who had laboratory-confirmed ZVD and for whom data were available regarding pregnancy outcomes. We compared the nationwide prevalence of brain and eye defects during the outbreak with the prevalence both before and after the outbreak period. RESULTS: Of 18,117 pregnant women with ZVD, the presence of Zika virus was confirmed in 5926 (33%) on rRT-PCR. Of the 5673 pregnancies with laboratory-confirmed ZVD for which outcomes had been reported, 93 infants or fetuses (2%) had brain or eye defects. The incidence of brain or eye defects was higher among pregnancies in which the mother had an onset of ZVD symptoms in the first trimester than in those with an onset during the second or third trimester (3% vs. 1%). A total of 172 of 5673 pregnancies (3%) resulted in pregnancy loss; after the exclusion of pregnancies affected by birth defects, 409 of 5426 (8%) resulted in preterm birth and 333 of 5426 (6%) in low birth weight. The prevalence of brain or eye defects during the outbreak was 13 per 10,000 live births, as compared with a prevalence of 8 per 10,000 live births before the outbreak and 11 per 10,000 live births after the outbreak. CONCLUSIONS: In pregnant women with laboratory-confirmed ZVD, brain or eye defects in infants or fetuses were more common during the Zika virus outbreak than during the periods immediately before and after the outbreak. The frequency of such defects was increased among women with a symptom onset early in pregnancy. (Funded by the Colombian Instituto Nacional de Salud and the Centers for Disease Control and Prevention.).

Etiology of Microcephaly and Central Nervous System Defects during the Zika Epidemic in Colombia.

OBJECTIVE: To estimate the prevalence of microcephaly and central nervous system (CNS) defects during the Zika virus (ZIKV) epidemic in Colombia and proportion attributable to congenital ZIKV infection. STUDY DESIGN: Clinical and laboratory data for cases of microcephaly and/or CNS defects reported to national surveillance between 2015 and 2017 were reviewed and classified by a panel of clinical subject matter experts. Maternal and fetal/infant biologic specimens were tested for congenital infection and chromosomal abnormalities. Infants/fetuses with microcephaly and/or CNS defects (cases) were classified into broad etiologic categories (teratogenic, genetic, multifactorial, and unknown). Cases classified as potentially attributable to congenital ZIKV infection were stratified by strength of evidence for ZIKV etiology (strong, moderate, or limited) using a novel strategy considering birth defects unique or specific to ZIKV or other infections and laboratory evidence. RESULTS: Among 858 reported cases with sufficient information supporting a diagnosis of microcephaly or CNS defects, 503 were classified as potentially attributable to congenital ZIKV infection. Of these, the strength of evidence was considered strong in 124 (24.7%) cases; moderate in 232 (46.1%) cases; and limited in 147 (29.2%). Of the remaining, 355 (41.4%) were attributed to etiologies other than ZIKV infection (syphilis, toxoplasmosis, rubella, cytomegalovirus, herpes 1 and herpes 2 viruses only, n = 32 [3.7%]; genetic, n = 16 [1.9%]; multifactorial, n = 42 [4.9%]; unknown, n = 265 [30.9%]). CONCLUSIONS: Fifty-eight percent of cases of microcephaly and/or CNS defects were potentially attributable to congenital ZIKV infection; however, the strength of evidence varied considerably. This surveillance protocol might serve as a model approach for investigation and etiologic classification of complex congenital conditions.

Evaluation of Serial Testing After Exposure to COVID-19 in Early Care and Education Facilities, Illinois, March-May 2022.

OBJECTIVE: To understand SARS-CoV-2 transmission in early care and education (ECE) settings, we implemented a Test to Stay (TTS) strategy, which allowed children and staff who were close contacts to COVID-19 to remain in person if they agreed to test twice after exposure. We describe SARS-CoV-2 transmission, testing preferences, and the number of in-person days saved among participating ECE facilities. METHODS: From March 21 through May 27, 2022, 32 ECE facilities in Illinois implemented TTS. Unvaccinated children and staff who were not up to date with COVID-19 vaccination could participate if exposed to COVID-19. Participants received 2 tests within 7 days after exposure and were given the option to test at home or at the ECE facility. RESULTS: During the study period, 331 TTS participants were exposed to index cases (defined as people attending the ECE facility with a positive SARS-CoV-2 test result during the infectious period); 14 participants tested positive, resulting in a secondary attack rate of 4.2%. No tertiary cases (defined as a person with a positive SARS-CoV-2 test result within 10 days after exposure to a secondary case) occurred in the ECE facilities. Most participants (366 of 383; 95.6%) chose to test at home. Remaining in-person after an exposure to COVID-19 saved approximately 1915 in-person days among children and staff and approximately 1870 parent workdays. CONCLUSION: SARS-CoV-2 transmission rates were low in ECE facilities during the study period. Serial testing after COVID-19 exposure among children and staff at ECE facilities is a valuable strategy to allow children to remain in person and parents to avoid missing workdays.

Pregnancy, Birth, Infant, and Early Childhood Neurodevelopmental Outcomes among a Cohort of Women with Symptoms of Zika Virus Disease during Pregnancy in Three Surveillance Sites, Project Vigilancia de Embarazadas con Zika (VEZ), Colombia, 2016-2018.

Project Vigilancia de Embarazadas con Zika (VEZ), an intensified surveillance of pregnant women with symptoms of the Zika virus disease (ZVD) in Colombia, aimed to evaluate the relationship between symptoms of ZVD during pregnancy and adverse pregnancy, birth, and infant outcomes and early childhood neurodevelopmental outcomes. During May-November 2016, pregnant women in three Colombian cities who were reported with symptoms of ZVD to the national surveillance system, or with symptoms of ZVD visiting participating clinics, were enrolled in Project VEZ. Data from maternal and pediatric (up to two years of age) medical records were abstracted. Available maternal specimens were tested for the presence of the Zika virus ribonucleic acid and/or anti-Zika virus immunoglobulin antibodies. Of 1213 enrolled pregnant women with symptoms of ZVD, 1180 had a known pregnancy outcome. Results of the Zika virus laboratory testing were available for 569 (48.2%) pregnancies with a known pregnancy outcome though testing timing varied and was often distal to the timing of symptoms; 254 (21.5% of the whole cohort; 44.6% of those with testing results) were confirmed or presumptive positive for the Zika virus infection. Of pregnancies with a known outcome, 50 (4.2%) fetuses/infants had Zika-associated brain or eye defects, which included microcephaly at birth. Early childhood adverse neurodevelopmental outcomes were more common among those with Zika-associated birth defects than among those without and more common among those with laboratory evidence of a Zika virus infection compared with the full cohort. The proportion of fetuses/infants with any Zika-associated brain or eye defect was consistent with the proportion seen in other studies. Enhancements to Colombia's existing national surveillance enabled the assessment of adverse outcomes associated with ZVD in pregnancy.