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.

Full-length genome characterization and genetic relatedness analysis of hepatitis A virus outbreak strains associated with acute liver failure among children.

Clinical infection by hepatitis A virus (HAV) is generally self-limited but in some cases can progress to liver failure. Here, an HAV outbreak investigation among children with acute liver failure in a highly endemic country is presented. In addition, a sensitive method for HAV whole genome amplification and sequencing suitable for analysis of clinical samples is described. In this setting, two fatal cases attributed to acute liver failure and two asymptomatic cases living in the same household were identified. In a second household, one HAV case was observed with jaundice which resolved spontaneously. Partial molecular characterization showed that both households were infected by HAV subtype IA; however, the infecting strains in the two households were different. The HAV outbreak strains recovered from all cases grouped together within cluster IA1, which contains closely related HAV strains from the United States commonly associated with international travelers. Full-genome HAV sequences obtained from the household with the acute liver failure cases were related (genetic distances ranging from 0.01% to 0.04%), indicating a common-source infection. Interestingly, the strain recovered from the asymptomatic household contact was nearly identical to the strain causing acute liver failure. The whole genome sequence from the case in the second household was distinctly different from the strains associated with acute liver failure. Thus, infection with almost identical HAV strains resulted in drastically different clinical outcomes.

Farmworker Mobility and COVID-19 Vaccination Strategies: Yuma County, Arizona, 2021.

Farmworkers, a group of essential workers, experience a disproportionately high burden of COVID-19 due to their living and working conditions. This project characterized farmworker mobility in and around Yuma County, Arizona, to identify opportunities to improve farmworker access to COVID-19 vaccination. We collected qualitative and geospatial data through a series of in-person and virtual focus group discussions, key informant interviews, and intercept interviews with participatory mapping. Participants included farmworkers, employers, and representatives of local institutions who serve or interact with farmworkers. We identified participants through purposive and referential sampling and grouped people by sociodemographic characteristics for interviews. We used qualitative and geospatial analyses to identify common themes and mobility patterns. The team interviewed 136 people from February 26 to April 2, 2021. Common themes emerged about how farmworkers have little or no access to COVID-19 vaccination unless offered at their workplaces or at locations where they congregate at convenient times. Further, farmworkers described how their demanding work schedules, long commute times, and caretaker commitments make it challenging to access vaccination services. Geospatial analyses identified three geographic areas in Yuma County where farmworkers reported living and working that did not have a COVID-19 vaccine clinic within walking distance. Coordination between local public health authorities and key partners, including employers and trusted representatives from local community-based organizations or the Mexican consulate, to offer vaccination at worksites or other locations where farmworkers congregate can help improve access to COVID-19 vaccines and booster doses for this population.

Epidemiological surveillance of land borders in North and South America: a case study.

This study aims to analyze the different binational/multinational activities, programs, and structures taking place on the borders of Brazil and the U.S. between 2013 and 2015. A descriptive exploratory study of two border epidemiological surveillance (BES) systems has been performed. Two approaches were used to collect data: i) technical visits to the facilities involved with border surveillance and application of a questionnaire survey; ii) application of an online questionnaire survey. It was identified that, for both surveillance systems, more than 55% of the technicians had realized that the BES and its activities have high priority. Eighty percent of North American and 71% of Brazilian border jurisdictions reported an exchange of information between countries. Less than half of the jurisdictions reported that the necessary tools to carry out information exchange were available. Operational attributes of completeness, feedback, reciprocity, and quality of information were identified as weak or of low quality in both systems. Statements, guidelines, and protocols to develop surveillance activities are available at the U.S.-Mexico border area. The continuous systematic development of surveillance systems at these borders will create more effective actions and responses.

Acute viral hepatitis in the United States-Mexico border region: data from the Border Infectious Disease Surveillance (BIDS) Project, 2000-2009.

Little is known about the characteristics of acute viral hepatitis cases in the United States (US)-Mexico border region. We analyzed characteristics of acute viral hepatitis cases collected from the Border Infectious Disease Surveillance Project from January 2000-December 2009. Over the study period, 1,437 acute hepatitis A, 311 acute hepatitis B, and 362 acute hepatitis C cases were reported from 5 Mexico and 2 US sites. Mexican hepatitis A cases most frequently reported close personal contact with a known case, whereas, US cases most often reported cross-border travel. Injection drug use was common among Mexican and US acute hepatitis B and C cases. Cross-border travel during the incubation period was common among acute viral hepatitis cases in both countries. Assiduous adherence to vaccination and prevention guidelines in the US is needed and strategic implementation of hepatitis vaccination and prevention programs south of the border should be considered.

Influenza-like illness surveillance on the California-Mexico border, 2004-2009.

BACKGROUND: Since 2004, the Naval Health Research Center, with San Diego and Imperial counties, has collaborated with the US Centers for Disease Control and Prevention to conduct respiratory disease surveillance in the US-Mexico border region. In 2007, the Secretariat of Health, Mexico and the Institute of Public Health of Baja California joined the collaboration. OBJECTIVES: The identification of circulating respiratory pathogens in respiratory specimens from patients with influenza-like illness (ILI). METHODS: Demographic, symptom information and respiratory swabs were collected from enrollees who met the case definition for ILI. Specimens underwent PCR testing and culture in virology and bacteriology. RESULTS: From 2004 through 2009, 1855 persons were sampled. Overall, 36% of the participants had a pathogen identified. The most frequent pathogen was influenza (25%), with those aged 6-15 years the most frequently affected. In April 2009, a young female participant from Imperial County, California, was among the first documented cases of 2009 H1N1. Additional pathogens included influenza B, adenovirus, parainfluenza virus, respiratory syncytial virus, enterovirus, herpes simplex virus, Streptococcus pneumoniae, and Streptococcus pyogenes. CONCLUSIONS: The US-Mexico border is one of the busiest in the world, with a large number of daily crossings. Due to its traffic, this area is an ideal location for surveillance sites. We identified a pathogen in 36% of the specimens tested, with influenza A the most common pathogen. A number of other viral and bacterial respiratory pathogens were identified. An understanding of the incidence of respiratory pathogens in border populations is useful for development of regional vaccination and disease prevention responses.