Zika virus infection can occur as a result of mosquitoborne or sexual transmission of the virus. Infection during pregnancy is a cause of fetal brain abnormalities and other serious birth defects (1,2). CDC has updated the interim guidance for men with possible Zika virus exposure who 1) are planning to conceive with their partner, or 2) want to prevent sexual transmission of Zika virus at any time (3). CDC now recommends that men with possible Zika virus exposure who are planning to conceive with their partner wait for at least 3 months after symptom onset (if symptomatic) or their last possible Zika virus exposure (if asymptomatic) before engaging in unprotected sex. CDC now also recommends that for couples who are not trying to conceive, men can consider using condoms or abstaining from sex for at least 3 months after symptom onset (if symptomatic) or their last possible Zika virus exposure (if asymptomatic) to minimize their risk for sexual transmission of Zika virus. All other guidance for Zika virus remains unchanged. The definition of possible Zika virus exposure remains unchanged and includes travel to or residence in an area with risk for Zika virus transmission (https://wwwnc.cdc.gov/travel/page/world-map-areas-with-zika) or sex without a condom with a partner who traveled to or lives in an area with risk for Zika virus transmission. CDC will continue to update recommendations as new information becomes available.

On January 16, 2018, CDC was notified by the Florida Department of Health of potential rabies virus exposure in two persons believed to be residents of Switzerland. Rabies virus infections cause a fatal encephalitis, and persons exposed to the virus are advised to receive postexposure prophylaxis (PEP) as soon as possible (1). On January 10, 2018, a married couple found a bat in a Naples, Florida, shopping mall parking lot and took it to a local veterinary clinic. The woman, estimated to be aged 50–60 years, stated that they were Swiss tourists. No other identifying information was obtained. On January 15, 2018, the bat tested positive for rabies by the direct fluorescent antibody test at the Florida Department of Health public health laboratory. After repeated efforts to identify the couple were unsuccessful, CDC was able to locate the couple by using the national focal point network maintained by World Health Organization (WHO) International Health Regulations (IHR) (2); the two were promptly administered PEP.

In 2014, the Centers for Disease Control and Prevention conducted conveyance contact investigations for 2 Middle East respiratory syndrome cases imported into the United States, comprising all passengers and crew on 4 international and domestic flights and 1 bus. Of 655 contacts, 78% were interviewed; 33% had serologic testing. No secondary cases were identified.

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.

Vaccination during pregnancy is increasingly being used as an effective approach for protecting both young infants and their mothers from serious infections. Drawing conclusions from published studies in this area can be difficult because of the inability to compare vaccine trial results across different studies and settings due to the heterogeneity in the definitions of terms used to assess the safety of vaccines in pregnancy and the data collected in such studies. The guidelines proposed in this document have been developed to harmonize safety data collection in all phases of clinical trials of vaccines in pregnant women and apply to data from the mother, fetus and infant. Guidelines on the prioritization of the data to be collected is also provided to allow applicability in various geographic, cultural and resource settings, including high, middle and low-income countries.

During the 2014-2016 Ebola virus disease (Ebola) epidemic in West Africa, CDC implemented travel and border health measures to prevent international spread of the disease, educate and protect travelers and communities, and minimize disruption of international travel and trade. CDC staff provided in-country technical assistance for exit screening in countries in West Africa with Ebola outbreaks, implemented an enhanced entry risk assessment and management program for travelers at U.S. ports of entry, and disseminated information and guidance for specific groups of travelers and relevant organizations. New and existing partnerships were crucial to the success of this response, including partnerships with international organizations, such as the World Health Organization, the International Organization for Migration, and nongovernment organizations, as well as domestic partnerships with the U.S. Department of Homeland Security and state and local health departments. Although difficult to assess, travel and border health measures might have helped control the epidemic's spread in West Africa by deterring or preventing travel by symptomatic or exposed persons and by educating travelers about protecting themselves. Enhanced entry risk assessment at U.S. airports facilitated management of travelers after arrival, including the recommended active monitoring. These measures also reassured airlines, shipping companies, port partners, and travelers that travel was safe and might have helped maintain continued flow of passenger traffic and resources needed for the response to the affected region. Travel and border health measures implemented in the countries with Ebola outbreaks laid the foundation for future reconstruction efforts related to borders and travel, including development of regional surveillance systems, cross-border coordination, and implementation of core capacities at designated official points of entry in accordance with the International Health Regulations (2005). New mechanisms developed during this response to target risk assessment and management of travelers arriving in the United States may enhance future public health responses. The activities summarized in this report would not have been possible without collaboration with many U.S. and international partners (http://www.cdc.gov/vhf/ebola/outbreaks/2014-west-africa/partners.html).

Applying qualitative historical methods, we examined the consideration and implementation of school closures as a nonpharmaceutical intervention (NPI) in thirty US cities during the spring 2009 wave of the pA(H1N1) influenza pandemic. We gathered and performed close textual readings of official federal, state, and municipal government documents; media coverage; and academic publications. Lastly, we conducted oral history interviews with public health and education officials in our selected cities. We found that several local health departments pursued school closure plans independent of CDC guidance, that uncertainty of action and the rapidly evolving understanding of pA(H1N1) contributed to tension and pushback from the public, that the media and public perception played a significant role in the response to school closure decisions, and that there were some notable instances of interdepartmental communication breakdown. We conclude that health departments should continue to develop and fine-tune their action plans while also working to develop better communication methods with the public, and work more closely with education officials to better understand the complexities involved in closing schools. Lastly, state and local governments should work to resolve lingering issues of legal authority for school closures in times of public health crises.

Before the current Ebola epidemic in West Africa, there were few documented cases of symptomatic Ebola patients traveling by commercial airline, and no evidence of transmission to passengers or crew members during airline travel. In July 2014 two persons with confirmed Ebola virus infection who were infected early in the Nigeria outbreak traveled by commercial airline while symptomatic, involving a total of four flights (two international flights and two Nigeria domestic flights). It is not clear what symptoms either of these two passengers experienced during flight; however, one collapsed in the airport shortly after landing, and the other was documented to have fever, vomiting, and diarrhea on the day the flight arrived. Neither infected passenger transmitted Ebola to other passengers or crew on these flights. In October 2014, another airline passenger, a U.S. health care worker who had traveled domestically on two commercial flights, was confirmed to have Ebola virus infection. Given that the time of onset of symptoms was uncertain, an Ebola airline contact investigation in the United States was conducted. In total, follow-up was conducted for 268 contacts in nine states, including all 247 passengers from both flights, 12 flight crew members, eight cleaning crew members, and one federal airport worker (81 of these contacts were documented in a report published previously). All contacts were accounted for by state and local jurisdictions and followed until completion of their 21-day incubation periods. No secondary cases of Ebola were identified in this investigation, confirming that transmission of Ebola during commercial air travel did not occur.

OBJECTIVES: We assessed local health departments' (LHDs') ability to provide data on nonpharmaceutical interventions (NPIs) for the mitigation of 2009 H1N1 influenza during the pandemic response. DESIGN: Local health departments voluntarily participated weekly in a National Association of County and City Health Officials Web-based survey designed to provide situational awareness to federal partners about NPI recommendations and implementation during the response and to provide insight into the epidemiologic context in which recommendations were made. SETTING: Local health departments during the fall 2009 H1N1 pandemic response. PARTICIPANTS: Local health departments that voluntarily participated in the National Association of County and City Health Officials Sentinel Surveillance Network. MAIN OUTCOME MEASURES: Local health departments were asked to report data on recommendations for and the implementation of NPIs from 7 community sectors. Data were also collected on influenza outbreaks; closures, whether recommended by the local health department or not; absenteeism of students in grades K-12; the type(s) of influenza viruses circulating in the jurisdiction; and the health care system capacity. RESULTS: One hundred thirty-nine LHDs participated. Most LHDs issued NPI recommendations to their community over the 10-week survey period with 70% to 97% of LHDs recommending hand hygiene and cough etiquette and 51% to 78% voluntary isolation of ill patients. However, 21% to 48% of LHDs lacked information of closure, absenteeism, or outbreaks in schools, and 28% to 50% lacked information on outpatient clinic capacity. CONCLUSIONS: Many LHDs were unable to monitor implementation of NPI (recommended by LHD or not) within their community during the 2009 H1N1 influenza pandemic. This gap makes it difficult to adjust recommendations or messaging during a public health emergency response. Public health preparedness could be improved by strengthening NPI monitoring capacity.

BACKGROUND: Many important strategies to reduce the spread of pandemic influenza need public participation. To assess public receptivity to such strategies, we compared adoption of preventive behaviours in response to the 2009 H1N1 influenza pandemic among the public in five countries and examined whether certain non-pharmaceutical behaviours (such as handwashing) were deterrents to vaccination. We also assessed public support for related public health recommendations. METHODS: We used data from simultaneous telephone polls (mobile telephone and landline) in Argentina, Japan, Mexico, the UK, and the USA. In each country, interviews were done in a nationally representative sample of adults, who were selected by the use of random digit dial techniques. The questionnaire asked people whether or not they had adopted each of various preventive behaviours (non-pharmaceutical-such as personal protective and social distancing behaviour-or vaccinations) to protect themselves or their family from H1N1 at any point during the pandemic. Two-tailed t tests were used for statistical analysis. FINDINGS: 900 people were surveyed in each country except the USA where 911 people were contacted. There were wide differences in the adoption of preventive behaviours between countries, although certain personal protective behaviours (eg, handwashing) were more commonly adopted than social distancing behaviours (eg, avoiding places where many people gather) across countries (53-89%vs 11-69%). These non-pharmaceutical behaviours did not reduce the likelihood of getting vaccinated in any country. There was also support across all countries for government recommendations related to school closure, avoiding places where many people gather, and wearing masks in public. INTERPRETATION: There is a need for country-specific approaches in pandemic policy planning that use both non-pharmaceutical approaches and vaccination. FUNDING: US Centers for Disease Control and Prevention and the National Public Health Information Coalition.

Shortly after the influenza A (H1N1) 2009 pandemic began, the U.S. government provided guidance to state and local authorities to assist decision-making for the use of nonpharmaceutical strategies to minimize influenza spread. This guidance included recommendations for flexible decision-making based on outbreak severity, and it allowed for uncertainty and course correction as the pandemic progressed. These recommendations build on a foundation of local, collaborative planning and posit a series of questions regarding epidemiology, the impact on the health-care system, and locally determined feasibility and acceptability of nonpharmaceutical strategies. This article describes recommendations and key questions for decision makers.

Under the current International Health Regulations, 194 states parties are obligated to report potential public health emergencies of international concern to the World Health Organization (WHO) within 72 hours of becoming aware of an event. During July 2007-December 2011, WHO assessed and posted on a secure web portal 222 events from 105 states parties, including 24 events from the United States. Twelve US events involved human influenza caused by a new virus subtype, including the first report of influenza A(H1N1)pdm09 virus, which constitutes the only public health emergency of international concern determined by the WHO director-general to date. Additional US events involved 5 Salmonella spp. outbreaks, botulism, Escherichia coli O157:H7 infections, Guillain-Barre syndrome, contaminated heparin, Lassa fever, an oil spill, and typhoid fever. Rapid information exchange among WHO and member states facilitated by the International Health Regulations leads to better situation awareness of emerging threats and enables a more coordinated and transparent global response.

Viscerotropic disease (VTD) is defined as acute multiple organ system dysfunction that occurs following vaccination. The severity of VTD ranges from relatively mild multisystem disease to severe multiple organ system failure and death. The term VTD was first used shortly after the initial published reports in 2001 of febrile multiple organ system failure following yellow fever (YF) vaccination [1–7]. To date, VTD has been reported only in association with YF vaccine and has been thus referred to as YF vaccine-associated viscerotropic disease (YEL-AVD). | YF vaccine is manufactured from the live attenuated 17D virus substrain. It is considered relatively safe and effective in preventing YF disease, which results from YF virus transmission through the bite of an infected mosquito [8]. YF virus circulates in sub-Saharan Africa and tropical South America, where it causes endemic and intermittently epidemic disease. Most YF disease in these areas is attributable to jungle (sylvatic) or savanna (intermediate) transmission cycles, which occur predominantly in sparsely populated forested areas and rural villages, respectively [8]. To protect vulnerable populations, endemic countries target YF vaccination efforts towards their residents, who reside in both rural and urban settings with varying resources.

This supplement of MMWR celebrates the 50th anniversary of CDC's first publication of MMWR on January 13, 1961 (Figure 1). MMWR was not new in 1961, but it was new to CDC, an agency that itself had been founded only 15 years earlier, in 1946 (1). The longer history of MMWR traces back to July 13, 1878, when the first predecessor of MMWR, called simply The Bulletin of the Public Health, was inaugurated. The Bulletin was established in accordance with the first National Quarantine Act, passed by Congress 2 months earlier. The Act ordered the Surgeon General of the U.S. Marine-Hospital Service to begin publishing abstracted disease reports collected from U.S. consuls in foreign lands to alert U.S. quarantine officials about what diseases could be expected among passengers arriving on steamships (2,3). In the 83 years from 1878 to 1961, MMWR went through several incarnations. By 1952, the publication had its current name and was being published by the National Office of Vital Statistics, an agency within the U.S. Department of Health, Education and Welfare. In 1960, CDC's renowned chief of epidemiology, Alexander D. Langmuir, decided that MMWR should be transferred to CDC (then known as the Communicable Disease Center). After much discussion, and as Langmuir later said in an interview, "all sorts of pulling out teeth by the roots without anesthesia and all kinds of internal frictions," in 1960, MMWR was transferred to CDC (4). | | In 2009, as the 50th anniversary of MMWR loomed, the MMWR Editor (F.E.S.) began discussions with leaders at CDC and the MMWR Editorial Board about how best to commemorate this date. Members of the Board, editors, and friends of MMWR offered many good ideas. In the end, the most persuasive idea was to celebrate the 50th anniversary simply by doing what MMWR has done best for 5 decades at CDC: publish articles of high value to its readers. The title of the supplement is "Public Health Then and Now: Celebrating 50 Years of MMWR at CDC." The supplement's guest editors (F.E.S., K.S.K., L.M.L., S.B.T.) selected a cadre of expert authors who have long experience in their respective fields of public health---enough to enable them to look back over the past 50 years and trace the most important influences and developments. The guest editors asked the authors to answer three key questions. What was the state of the art in 1961? How did it develop through 50 years into its present form? What does the future hold? Thus, with few exceptions, the 16 articles that make up this supplement are not meant to be about MMWR but instead are meant to trace the development of key areas of public health through the 50-year era of MMWR at CDC. | | The authors took up the challenge admirably. The result is a diverse set of articles that portray public health in 1961 and forward in time to the present and beyond. The articles range from detailed historical review, to analyses of MMWR content, to the more whimsical. They are not meant to be exhaustive, nor can they treat their topics as thoroughly as would a longer text, but they do depict the main events, developments, and innovations that led public health to where it stands today.

BACKGROUND: On March 22, 2002, Internet-based reports (IBRs) were added to the Vaccine Adverse Event Reporting System (VAERS) to allow rapid, expedited reporting of adverse events (AEs) in anticipation of wider use of counter-bioterrorism vaccines such as those against smallpox and anthrax. OBJECTIVES: To evaluate the impact of IBRs on the timeliness and completeness of vaccine AE reporting. METHODS: To evaluate timeliness and completeness, we compared the proportions of IBRs with non-Internet-based reports (NIBRs). Report interval was analyzed for timeliness and age at vaccination, birth date, and onset date for report completeness. To evaluate the impact of the smallpox vaccination program, we compared smallpox vaccine reports separately. Because influenza vaccine is the most widely used vaccine in adults each year, we compared influenza vaccine reports separately. RESULTS: During the study period, VAERS received 54 364 NIBRs (85.8%) and 9008 IBRs (14.2%). Sixteen percent (1455) of IBRs followed smallpox vaccination. Overall, for all vaccines and for smallpox vaccine alone, IBRs had a greater proportion of completeness and a shorter report interval. The proportion of most frequently reported AEs did not differ between IBRs and NIBRs. A higher proportion of adults (18-64 years old) who received influenza vaccine chose to complete an IBR (62% vs 48%). CONCLUSIONS: The improved timeliness and completeness of IBRs allow VAERS to more rapidly detect new or rare vaccine AEs. This important advantage is critical in times of increased public concern about vaccine safety. Clinical vaccine providers should be aware of VAERS and use IBRs whenever feasible to report vaccine AEs.

Diarrhea, also spelled diarrhoea, is a common medical condition that is characterized by increased frequency of bowel movements and increased liquidity of stool [1], [2]. Although acute diarrhea is typically self-limiting, it can be severe and can lead to profound dehydration, which can lead to abnormally low blood volume, low blood pressure, and damage to the kidneys, heart, liver, brain and other organs. Acute diarrhea remains a major cause of infant mortality around the world. Over 2 million deaths are attributed to acute diarrhea each year world-wide, most of them in the developing world. [3], [4], [5]. Children and the elderly are particularly prone to dehydration secondary to diarrhea. | Diarrhea has been defined over time by various scientific groups and health organizations in different ways, such as: “the passage of loose unformed stools” [6] or “three looser-than normal stools in a 24-h period” [7], [8] with emphasis on the consistency of stools rather than the number [9]. In epidemiological studies, diarrhea is usually defined as the passage of three or more loose or watery stools in a 24-h period, a loose stool being one that takes the shape of a stool container [8], [9], [10], [11], [12], [13], [14], [15], [16].

Among the various events reported as adverse outcomes following immunizations, neurologic adverse events following immunization (AEFI) are among the most severe and the most difficult to assess. The multifaceted presentation of neurologic illness, the relative lack of familiarity of many clinicians with the approach to and diagnosis of neurologic disease, and the relative scarcity of trained neurologists in many parts of the world make neurologic AEFI some of the most challenging issues in clinical vaccinology. Further, the severity of central and peripheral nervous system events in individual patients often heightens the concern when such illnesses are associated with antecedent immunizations. The lack of a common definition of GBS and FS hinders comparability and uniform reporting of these adverse events. | Sections 2 Clinical case definitions: Guillain–Barré syndrome (GBS), 3 Guidelines for data collection, analysis, and presentation of GBS and FS as adverse events following immunization of this paper provide the case definitions and guidelines for data collection, analysis, and presentation that the Brighton Collaboration GBS Working Group (hereafter referred to as the Working Group) has developed for the standardized collection and assessment of information about GBS and FS. Widespread use of these definitions with their guidelines will improve data comparability and allow for a better understanding of these neurological events that are applicable in study settings with different availability of resources, in health care settings that differ by availability of and access to health care, and in different geographic regions.