After returning from Europe to the United States, on March 1, 2020, a symptomatic teacher received positive test results for severe acute respiratory syndrome coronavirus 2. Of the 21 students exposed to the teacher in the classroom, serologic results suggested past infection for 2. Classroom contact may result in virus transmission.

Response to sudden epidemic infectious disease emergencies can demand intensive and specialized training, as demonstrated in 2014 when Ebola virus disease (EVD) rapidly spread throughout West Africa. The medical community quickly became overwhelmed because of limited staff, supplies, and Ebola treatment units (ETUs). Because a mechanism to rapidly increase trained healthcare workers was needed, the US Centers for Disease Control and Prevention developed and implemented an introductory EVD safety training course to prepare US healthcare workers to work in West Africa ETUs. The goal was to teach principles and practices of safely providing patient care and was delivered through lectures, small-group breakout sessions, and practical exercises. During September 2014-March 2015, a total of 570 participants were trained during 16 course sessions. This course quickly increased the number of clinicians who could provide care in West Africa ETUs, showing the feasibility of rapidly developing and implementing training in response to a public health emergency.

The International Health Regulations (IHR), an international law under the auspices of the World Health Organization (WHO), mandates that countries notify other countries of "travelers under public health observation." Between November 10, 2014, and July 12, 2015, the US Centers for Disease Control and Prevention (CDC) made 2,374 notifications to the National IHR Focal Points in 114 foreign countries of travelers who were monitored by US health departments because they had been to an Ebola-affected country in West Africa. Given that countries have preidentified focal points as points of contacts for sharing of public health information, notifications could be made by CDC to a trusted public health recipient in another country within 24 hours of receipt of the traveler's information from a US health department. The majority of US health departments used this process, offered by CDC, to notify other countries of travelers intending to leave the United States while being monitored in their jurisdiction.

Congenital Zika virus infection can cause microcephaly and severe brain abnormalities. Congenital Zika syndrome comprises a spectrum of clinical features; however, as is the case with most newly recognized teratogens, the earliest documented clinical presentation is expected to be the most severe. Initial descriptions of the effects of in utero Zika virus infection centered prominently on the finding of congenital microcephaly. To assess the possibility of clinical presentations that do not include congenital microcephaly, a retrospective assessment of 13 infants from the Brazilian states of Pernambuco and Ceara with normal head size at birth and laboratory evidence of congenital Zika virus infection was conducted. All infants had brain abnormalities on neuroimaging consistent with congenital Zika syndrome, including decreased brain volume, ventriculomegaly, subcortical calcifications, and cortical malformations. The earliest evaluation occurred on the second day of life. Among all infants, head growth was documented to have decelerated as early as 5 months of age, and 11 infants had microcephaly. These findings provide evidence that among infants with prenatal exposure to Zika virus, the absence of microcephaly at birth does not exclude congenital Zika virus infection or the presence of Zika-related brain and other abnormalities. These findings support the recommendation for comprehensive medical and developmental follow-up of infants exposed to Zika virus prenatally. Early neuroimaging might identify brain abnormalities related to congenital Zika infection even among infants with a normal head circumference.

BACKGROUND: In 2012, Oregon observed its highest numbers of reported pertussis cases since 1953. The greatest morbidity occurred among infants <6 months of age, with higher rates among Hispanics than non-Hispanics. To explain this disparity, we analyzed pertussis surveillance data. METHODS: An analysis was conducted among infants <6 months of age in the Portland metropolitan area during 2010-2012. Characteristics examined were ethnicity (Hispanic or non-Hispanic), household size (>4 or ≤4 persons), pertussis vaccination status (up-to-date or not up-to-date for age), child care center attendance (yes or no), infant birth weight (<2,500 or ≥2,500 g), and maternal age (<20 or ≥20 years). RESULTS: Eighty-two infants <6 months of age with pertussis were identified. Twenty-eight case-infants (34%) were Hispanic, and 54 (66%) were non-Hispanic. By ethnicity, infants with pertussis were similar in illness confirmation method, sex, age, hospitalization status, vaccination status, child care center attendance, infant birth weight, and maternal age. Hispanic infants were more likely than non-Hispanic infants to live in households with >4 persons. Univariate analysis showed Hispanic infants had ~2.3 times the risk for pertussis, compared with non-Hispanic infants, and infants living in households >4 persons had ~2.4 times the risk for illness, compared with those in households with ≤4 persons; stratified risk ratios did not differ between Hispanic (2.4 [confidence interval {CI}: 1.0-5.7]) and non-Hispanic infants (2.0 [CI: 1.2-3.5]). CONCLUSIONS: A household size of >4 persons is a potential risk factor for pertussis; the magnitude of this risk is similar for Hispanic and non-Hispanic infants.

On October 27, 2014, CDC released guidance for monitoring and movement of persons with potential Ebola virus disease (Ebola) exposure in the United States. For persons with possible exposure to Ebola, this guidance recommended risk categorization, daily monitoring during the 21-day incubation period, and, for persons in selected risk categories, movement restrictions. The purpose of the guidance was to delineate methods for early identification of symptoms among persons at potential risk for Ebola so that they could be isolated, tested, and if necessary, treated to improve their chance of survival and reduce transmission. Within 7 days, all 50 states and two local jurisdictions (New York City [NYC] and the District of Columbia [DC]) had implemented the guidelines. During November 3, 2014-March 8, 2015, a total of 10,344 persons were monitored for up to 21 days with >99% complete monitoring. This public health response demonstrated the ability of state, territorial, and local health agencies to rapidly implement systems to effectively monitor thousands of persons over a sustained period.

Through the early 20th century, the human uterus was thought to protect the developing fetus from maternal infections and environmental exposures. However, in the 1940s the first case reports of maternal rubella infection being linked to birth defects appeared in the literature, and, in the early 1960s, it was understood that maternal use of thalidomide caused an epidemic of limb deficiencies. These sentinel events led to the realization that maternal infections and other environmental factors could cause birth defects. This realization, in turn, led to the establishment of birth defects surveillance systems in the United States and other countries. | Public health surveillance is defined as the ongoing, systematic collection, analysis, interpretation, and dissemination of data regarding a health-related event for use in public health action to reduce morbidity and mortality and to improve health in the population (Thacker and Berkelman, 1992; CDC, 2001). Birth defects surveillance data have been used for public health action, program planning and evaluation, and formulating research hypotheses. Some examples of the types of public health action for which birth defects surveillance data have been used include the following: | Guiding action for issues of public health importance or concern. Birth defects surveillance data have been useful in evaluating community concerns about specific environmental exposures (e.g., water fluoridation, airport noise, air pollution) and birth defects (Erickson et al., 1976; Edmonds et al., 1979; Strickland et al., 2009), as well as for addressing concerns about clusters of birth defects possibly associated with less well-defined environmental factors (Calvert et al., 2007; Kucik et al., 2008). | Quantifying the burden of disease. Birth defects surveillance data have been useful in documenting the prevalence of major birth defects in the population (Correa et al., 2007; Rynn et al., 2008), the birth prevalence for specific defects such as Down syndrome, neural tube defects, and heart defects (Siffel et al., 2004; Canfield et al., 2006; Reller et al., 2008), as well as the prevalence of spina bifida and Down syndrome among children and adolescents (Shin et al., 2008; Shin et al., 2009). | Identifying populations at risk and/or health disparities. Birth defects surveillance data have been useful in identifying a higher prevalence of neural tube defects among Hispanics as compared to non-Hispanic whites in the United States (Kirby et al., 2000; Canfield et al., 2006). Similarly, linkages of birth defects surveillance data with vital status data have been useful in identifying race/ethnic disparities in survival for several defects (Dott et al., 2003; Rasmussen et al., 2006; Yang et al., 2006). Such studies have stimulated more research into possible determinants of such disparities in prevalence and survival. | Monitoring trends in the prevalence of birth defects. Birth defects surveillance data have been important in documenting decreasing trends in the prevalence of congenital rubella in relation to declining prevalence of maternal rubella infections (Cochi et al., 1989), trends in prevalence of selected birth defects before and after folic acid fortification (Canfield et al., 2005; Botto et al., 2006), and trends in the prevalence of gastroschisis (Williams et al., 2005; Loane et al., 2007), hypospadias (Carmichael et al., 2003; Dolk et al., 2004; Nassar et al., 2007), and congenital heart defects (Botto et al., 2001). | Evaluating outcomes among children with birth defects. Birth defects surveillance data have been useful in population-based evaluations of whether children with birth defects have an increased prevalence of developmental disorders (Decoufle et al., 2001; Yazdy et al., 2008) and the survival experience of children with birth defects (Nembhard et al., 2001; Wong and Paulozzi, 2001; Cleves et al., 2003; Rasmussen et al., 2006; Copeland and Kirby, 2007; Fixler et al., 2010). | Guiding the planning, implementation, and evaluation of programs to prevent birth defects and adverse exposures. Birth defects surveillance data on the prevalence of neural tube defects and in the variation of such prevalence by race/ethnic groups in the population have been instrumental in the development, implementation, and evaluation of policies for folic acid fortification for the prevention of neural tube defects (Canfield et al., 2005; Botto et al., 2006; Bower, 2006). | Serving as case registries for epidemiologic research. Several birth defects surveillance systems have served as cases registries for epidemiologic studies, including studies of possible associations of birth defects with paternal Vietnam Veteran status (Erickson et al., 1984), maternal vitamin supplement use (Mulinare et al., 1988), diabetes (Correa et al., 2008), obesity (Watkins et al., 2003; Waller et al., 2007; Gilboa et al., 2010), smoking (Honein et al., 2007; Malik et al., 2008), assisted reproductive technologies (Bower and Hansen, 2005; Reefhuis et al., 2009), and certain medications (Reefhuis et al., 2006; Caton et al., 2009; Alwan et al., 2010).