Evaluating Differences in Whole Blood, Serum, and Urine Screening Tests for Zika Virus, Puerto Rico, USA, 2016.

We evaluated nucleic acid amplification testing (NAAT) for Zika virus on whole-blood specimens compared with NAAT on serum and urine specimens among asymptomatic pregnant women during the 2015-2016 Puerto Rico Zika outbreak. Using NAAT, more infections were detected in serum and urine than in whole blood specimens.

Pregnancy Outcomes After Maternal Zika Virus Infection During Pregnancy - U.S. Territories, January 1, 2016-April 25, 2017.

Pregnant women living in or traveling to areas with local mosquito-borne Zika virus transmission are at risk for Zika virus infection, which can lead to severe fetal and infant brain abnormalities and microcephaly (1). In February 2016, CDC recommended 1) routine testing for Zika virus infection of asymptomatic pregnant women living in areas with ongoing local Zika virus transmission at the first prenatal care visit, 2) retesting during the second trimester for women who initially test negative, and 3) testing of pregnant women with signs or symptoms consistent with Zika virus disease (e.g., fever, rash, arthralgia, or conjunctivitis) at any time during pregnancy (2). To collect information about pregnant women with laboratory evidence of recent possible Zika virus infection* and outcomes in their fetuses and infants, CDC established pregnancy and infant registries (3). During January 1, 2016-April 25, 2017, U.S. territories† with local transmission of Zika virus reported 2,549 completed pregnancies§ (live births and pregnancy losses at any gestational age) with laboratory evidence of recent possible Zika virus infection; 5% of fetuses or infants resulting from these pregnancies had birth defects potentially associated with Zika virus infection¶ (4,5). Among completed pregnancies with positive nucleic acid tests confirming Zika infection identified in the first, second, and third trimesters, the percentage of fetuses or infants with possible Zika-associated birth defects was 8%, 5%, and 4%, respectively. Among liveborn infants, 59% had Zika laboratory testing results reported to the pregnancy and infant registries. Identification and follow-up of infants born to women with laboratory evidence of recent possible Zika virus infection during pregnancy permits timely and appropriate clinical intervention services (6).

Epidemiology of Zika.

PURPOSE OF REVIEW: Zika virus (ZIKV) is the latest 'emerging virus' that has affected the Americas. First identified in the mid-20th century in Uganda, it was described as a vector arthropod-borne virus (arbovirus) and subsequently found capable of producing illness in humans. The illness was not different from other flavivirus infections and caused a relatively mild disease characterized by low-grade fever, nonspecific exanthem, nonpurulent conjunctivitis, and mild to moderate arthralgia. It was capable of producing infections described as sporadic isolated cases; in 2007, it was confirmed as the pathogen causing the first known ZIKV epidemic subsequently associated with congenital neonatal microcephaly in many countries in the Americas. RECENT FINDINGS: It rapidly spread to other countries in the Americas and, as of September 2016, it has been detected in 46 countries and territories. Different from other flavivirus infections, ZIKV has proven to be related to more serious complications. These include Guillain-Barré syndrome and neonatal congenital malformations, which includes microcephaly and neurologic damage to the developing fetus, particularly if the maternal infection occurs early in pregnancy. These two complications are a cause of great concern. SUMMARY: It is pivotal to conduct epidemiological laboratory-based surveillance and studies on the virus' inherent characteristics to understand the pathophysiology of this infection and develop adequate strategies to mitigate this new threat.

Prospective cohort study with active surveillance for fever in four dengue endemic countries in Latin America.

To prepare for a Phase III dengue vaccine efficacy trial, 20 investigational sites were selected for this observational study to identify dengue infections in a closed cohort (N = 3,000 children 9-16 years of age). Of 255 acute febrile episodes experienced by 235 children, 50 (21.3%) were considered serologically probable dengue, and 18 (7.7%) were considered virologically confirmed (i.e., dengue NS1 antigen positive) dengue cases. Considering the disease-free and at-risk period from study start to onset of symptoms, the overall incidence density of acute febrile episodes was 17.7 per 100 person-years of follow-up, ranging from 15.3 in Colombia to 22.0 in Puerto Rico. This study showed that all sites were capable of capturing and following up acute febrile episodes within a specific timeframe among the established cohort and to detect dengue cases.