Update: Interim Guidance for Preconception Counseling and Prevention of Sexual Transmission of Zika Virus for Men with Possible Zika Virus Exposure - United States, August 2018.

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.

Conveyance Contact Investigation for Imported Middle East Respiratory Syndrome Cases, United States, May 2014.

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.

A Tale of Many Cities: A Contemporary Historical Study of the Implementation of School Closures during the 2009 pA(H1N1) Influenza Pandemic.

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.

Public health response to commercial airline travel of a person with Ebola virus infection - United States, 2014.

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.

Public health emergency preparedness: lessons learned about monitoring of interventions from the National Association of County and City Health Official's survey of nonpharmaceutical interventions for pandemic H1N1.

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.

Assessment of public health events through International Health Regulations, United States, 2007-2011.

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-Barré 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.

United States Notifications of Travelers from Ebola-Affected Countries.

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.

Travel and Border Health Measures to Prevent the International Spread of Ebola.

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).

Guideline for collection, analysis and presentation of safety data in clinical trials of vaccines in pregnant women.

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.

Fever after immunization: current concepts and improved future scientific understanding.

Fever is a common clinical complaint in adults and children with a variety of infectious illnesses, as well as a frequently reported adverse event following immunization. Although the level of measured temperature indicative of a "fever" was first defined in 1868, it remains unclear what role fever has as a physiologic reaction to invading substances, how best to measure body temperature and compare measurements from different body sites, and, consequently, how to interpret fever data derived from vaccine safety trials or immunization safety surveillance. However, even with many aspects of the societal, medical, economic, and epidemiologic meanings of fever as an adverse event following immunization (AEFI) still elusive, it is a generally benign--albeit common--clinical sign. By standardizing the definition and means of assessment of fever in vaccine safety studies, thereby permitting comparability of data, we hope to arrive at an improved understanding of its importance as an AEFI.

Developments in the screening for Chlamydia trachomatis: a review.

Many studies have evaluated selective screening criteria for women in various settings. Most have concluded and all guidelines recommend that all women aged < 25 be screened yearly for C. trachomatis infection. Behavioral criteria, such as the number of sex partners, new or more than one sex partners, and previous infection, also can serve as criteria for screening women aged > 25. Because re-infection rates are high and occur within a few months, complications may be reduced further if partners are treated and women rescreened 4 to 6 months after initial infection. Revised recommendations for C. trachomatis screening programs have stated that more frequent screening may be considered among women < 20 and those with recent infection. Screening in nontraditional settings and careful evaluation of local prevalence and risk factor information should be encouraged. Private providers and emergency room providers should discuss screening recommendations and adopt a C. trachomatis screening policy for the population they serve. The HEDIS measure should serve to encourage at least annual screening of 15- to 25-year-old sexually active females through providers linked to managed care organizations. In general, high yields (ie, percentage of tests that are positive) in nontraditional settings and enhanced feasibility and acceptability of urine-based tests may encourage further innovative approaches to reach and screen populations at risk. Several issues remain to be addressed to increase the effectiveness of screening efforts. If more sensitive amplification tests are used widely, more infected persons will be identified and treated, and transmission patterns may change, particularly if partner treatment also occurs. Current screening criteria should continue to be re-evaluated. An important issue that affects testing methods includes the possible need for confirmation testing when using NAATs if the prevalence of C. trachomatis is less than 2%. If the sensitivity of an NAAT is 85% and specificity is 99%, in a hypothetical population of 10,000 with a prevalence of 2%, the positive predictive value is 170/268 (63%). A second important issue affecting testing methods and feasibility of using NAATs for screening large numbers of individuals is the pooling of urine specimens, which has been evaluated in several studies and found to be very effective for reducing costs. A research issue for pooling is the determination of the most cost-effective prevalence levels for pooling. An additional research question is in which populations should a NAAT be used for detection of C. trachomatis and N. gonorrhoeae. There are no recommendations for the routine screening of men because of the paucity of data showing that this strategy can reduce sequelae. The CDC is conducting a multisite study to examine the feasibility, acceptability, and usefulness of screening of asymptomatic men. There are a few studies have determining cost-effective prevalence threshold levels, particularly with NAATs. A recently developed decision analysis model by CDC designed to maximize the effectiveness of screening strategies for C. trachomatis infections may be useful for decision makers. It is intended to serve as an easy and flexible tool to determine cost effectiveness at a local level and takes into account positivity rates and test performance characteristics (SOCRATES). It is unclear if recurrent infection is caused by true re-infection by the same or a different partner or recurrence of initial infection. Recurrence may be caused by persistence of C. trachomatis or antibiotic resistance. This distinction is of scientific interest because the appropriate intervention differs (eg, identification of risk factors for the former and microbiologic investigations for the latter). Effective partner management and retesting are critical to reducing sequelae of C. trachomatis infection. Screening for C. trachomatis infection remains an essential component of C. trachomatis control. It is cost effective, most infections are asymptomatic, and symptom-based health care seeking and testing identify few of those infected. The likelihood that opportunities for screening are missed is high particularly in non-STD clinic settings. Local studies using NAATs to determine C. trachomatis prevalence and risk factors are helpful to health care providers so they can make evidence-based decisions on who to screen. The use of nontraditional, non-clinic-based test settings should be explored further. We have focused on summarizing the medical evidence regarding recommendations for screening for C. trachomatis. High-risk populations for C. trachomatis infection may overlap with populations for other STDs, and comprehensive STD prevention programs that involve a range of STD service providers are needed to successfully reduce the STD-related health burden in the population.

Selecting nonpharmaceutical strategies to minimize influenza spread: the 2009 influenza A (H1N1) pandemic and beyond.

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.

Public response to the 2009 influenza A H1N1 pandemic: a polling study in five countries.

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.

Internet-based reporting to the vaccine adverse event reporting system: a more timely and complete way for providers to support vaccine safety.

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.

Applicability, reliability, sensitivity, and specificity of six Brighton Collaboration standardized case definitions for adverse events following immunization.

We evaluated the applicability, reliability, sensitivity, and specificity of six standardized case definitions for adverse events following immunization (AEFI) (for fever, generalized convulsive seizure, hypotonic-hyporesponsive episode, intussusception, nodule, and persistent crying) developed by the Brighton Collaboration using the U.S. Vaccine Adverse Event Reporting System (VAERS). The evaluation included: (a) the development of codified search strings using standardized coding terminology, and (b) for sensitivity and specificity analyses, the development of a "gold standard" for case determination by clinical expert reviews, and its comparison against the application of the definitions to VAERS reports by nonclinicians. Application of the case definitions in an automated approach proved to be valid, feasible, and unlikely to miss confirmed cases of the reported clinical event. The definitions had variable but generally high sensitivity and specificity compared to clinician review, which in itself yielded inconsistent case determination. The study demonstrated the need for the developed standardized definitions for AEFI and their usefulness in passive surveillance.

Live attenuated measles and mumps viral strain-containing vaccines and hearing loss: Vaccine Adverse Event Reporting System (VAERS), United States, 1990--2003.

Hearing loss (HL) is a known complication of wild measles and mumps viral infections. As vaccines against measles and mumps contain live attenuated viral strains, it is biologically plausible that in some individuals HL could develop as a complication of vaccination against measles and/or mumps. Our objectives for this study were: to find and describe all cases of HL reported in the scientific literature and to the US Vaccine Adverse Events Reporting System (VAERS) for the period 1990--2003; and to determine reporting rate of HL after live attenuated measles and/or mumps viral strain-containing vaccines (MMCV) administration. We searched published reports for cases of HL identified after vaccination with MMCV. We also searched for reports of HL after MMCV administration submitted to VAERS from 1990 through 2003 and determined the dose-adjusted reporting rate of HL. Our main outcome measure was reported cases of HL after immunization with MMCV which were classified as idiopathic. We found 11 published case reports of HL following MMCV. The review of the VAERS reports identified 44 cases of likely idiopathic sensorineural HL after MMCV administration. The onset of HL in the majority of VAERS and published cases was consistent with the incubation periods of wild measles and mumps viruses. Based on the annual usage of measles-mumps-rubella (MMR) vaccine, we estimated the reporting rate of HL to be 1 case per 6-8 million doses. Thus, HL following MMCV has been reported in the literature and to the VAERS. Further studies are needed to better understand if there is a causal relationship between MMCV and HL.

A local reaction at or near injection site: case definition and guidelines for collection, analysis, and presentation of immunization safety data.

The need for developing a case definition and guidelines for a local reaction at or near the injection site, methods for the development of the case definition and guidelines as an adverse event following immunization as well as the rationale for selected decisions about the case definition for a local reaction at or near the injection site are explained in the Preamble section. The case definition is structured in 2 levels of diagnostic certainty: level 1 includes any description of morphological or physiological change at or near the injection site that is described or identified by a healthcare provider. Level 2 is any description of morphological or physiological change at or near injection site that is described by any other person. In Guidelines section, the working group recommends to enable meaningful and standardized data collection, analysis, and presentation of information about a local reaction at or near the injection site. However, implementation of all guidelines might not be possible in all settings. The availability of information may vary depending upon resources, geographic region, and whether the source of information is a prospectively designed clinical trial, a post-marketing surveillance or epidemiologic study, or an individual report of a local reaction at injection site.

Vaccine safety perceptions and experience with adverse events following immunization in Kazakhstan and Uzbekistan: a summary of key informant interviews and focus groups.

Few studies have examined vaccine safety attitudes in developing countries and countries in economic transition. The objectives of this study were to identify concerns about immunizations and strategies to address these concerns in Kazakhstan and Uzbekistan, two Central Asian countries in economic transition. Qualitative text analysis was conducted on 16 focus groups and 24 key informant interviews to identify discussion themes related to the study objectives. Specific areas of concern included: adverse events following immunizations, vaccine quality, healthcare worker competence, and lack of vaccine information available to parents. Focus group participants also suggested relevant topics and sources for informational materials.