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BACKGROUND: The genetic relatedness of hepatitis A virus (HAV) isolates was determined to identify possible infection sources for case patients in the Sentinel Counties Study of Acute Viral Hepatitis. METHODS: A 315-nucleotide segment of the VP1-P2 region of the HAV genome was amplified and sequenced from serum of case patients and analyzed together with risk-factor data. RESULTS: Of 508 HAV-RNA-positive case patients, 449 (88.4%) were interviewed, and 255 (50.1%) reported >/=1 risk factor. Some 123 unique nucleotide sequence patterns (UNSPs) were identified--77 (62.6%) from only 1 case patient and the rest in 2-99 persons. Among international travelers, a single person was more often infected with a single type of UNSP (17/54 [31.5%]), compared with other case patients (48/393 [12.2%]; P<.001). UNSPs from travelers to Mexico (33/37 [89.2%]) clustered with those from Hispanic children (47/49 [95.9%]). Of 119 men who had sex with men, 96 (80.7%) had the same or similar UNSPs, which were also found in 37 men and 10 women with no identified infection source. CONCLUSION: HAV is often transmitted within networks of persons with similar risk factors, which may be the infection source for others in the community. Copyright © 2005 Infectious Diseases Society of America [ABSTRACT FROM AUTHOR]

There would appear to be little argument that the large outbreaks of E. coli O157:H7 which have occurred since the early 1980s represent a distinct, new phenomenon. The number of reported cases have increased dramatically, starting from zero in 1981; however, it is also clear that this increase in reported cases is in part an artifact of improved surveillance and reporting. Available data suggest that E. coli O157:H7 infections were present prior to 1982, although numbers appear to have been small. At a molecular level, the organism shows evidence of clonal origin, but there is not the striking clonality, with virtually identical pulsed-field gel electrophoresis and ribotyping patterns, which has been seen in situations such as the emergence of Vibrio cholerae O139 Bengal in the Indian subcontinent in 1992 or the introduction of V. cholerae O1 into naïve populations in South America in 1991 (127-129). Findings are more consistent with the image of an organism which arose from a common ancestor, but which has had time to become distributed geographically and to show some evidence of genetic divergence. While this is an "emerging" infection, at least in terms of its distribution and public recognition, it is unlikely that it will be possible to identify the "first" O157:H7 case or to track the clonal spread of the organism through cattle or human populations. [ABSTRACT FROM AUTHOR]

OBJECTIVES: Because of the herd-immunity phenomenon, the benefits of immunization against hepatitis A extend beyond those received by those who are vaccinated. This analysis estimates the impact of herd immunity on the cost-effectiveness of routine hepatitis A immunization among US children. PATIENTS AND METHODS: In an economic model, the costs and benefits of hepatitis A immunization were estimated for immunizing all US children at age 1 year over a 10-year period starting in 2005. The future burden of disease from hepatitis A was also estimated with this model, and the fraction that would be prevented by herd immunity was modeled by using a previously published analysis of the relationship between hepatitis A vaccination coverage and declines in hepatitis A incidence. RESULTS: Without accounting for herd-immunity effects, the costs of routine immunization would average 32,000 dollars per quality-adjusted life-year gained for the first 10 cohorts immunized starting with the 2005 birth cohort. Herd-immunity effects would be expected to produce substantial additional benefits, lowering the cost of the immunization program to 1000 dollars per quality-adjusted life-year gained for the first 10 cohorts. Herd-immunity benefits would be greatest for the first few cohorts, more than doubling the benefits of immunization, and would decline over time. In a univariate sensitivity analysis, estimates were most sensitive to vaccination costs but remained below 20,000 dollars per quality-adjusted life-year under all of the assumptions. CONCLUSIONS: Herd-immunity effects more than double the savings from hepatitis A immunization during the first 10 years of the program. After accounting for these effects, immunization is close to cost-neutral on a cost-per-quality-adjusted-life-year basis. [ABSTRACT FROM AUTHOR]

On December 14, 2020, the United Kingdom reported a SARS-CoV-2 variant of concern (VOC), lineage B.1.1.7, also referred to as VOC 202012/01 or 20I/501Y.V1.* The B.1.1.7 variant is estimated to have emerged in September 2020 and has quickly become the dominant circulating SARS-CoV-2 variant in England (1). B.1.1.7 has been detected in over 30 countries, including the United States. As of January 13, 2021, approximately 76 cases of B.1.1.7 have been detected in 12 U.S. states. † Multiple lines of evidence indicate that B.1.1.7 is more efficiently transmitted than are other SARS-CoV-2 variants (1-3). The modeled trajectory of this variant in the U.S. exhibits rapid growth in early 2021, becoming the predominant variant in March. Increased SARS-CoV-2 transmission might threaten strained health care resources, require extended and more rigorous implementation of public health strategies (4), and increase the percentage of population immunity required for pandemic control. Taking measures to reduce transmission now can lessen the potential impact of B.1.1.7 and allow critical time to increase vaccination coverage. Collectively, enhanced genomic surveillance combined with continued compliance with effective public health measures, including vaccination, physical distancing, use of masks, hand hygiene, and isolation and quarantine, will be essential to limiting the spread of SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19). Strategic testing of persons without symptoms but at higher risk of infection, such as those exposed to SARS-CoV-2 or who have frequent unavoidable contact with the public, provides another opportunity to limit ongoing spread., Competing Interests: All authors have completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. No potential conflicts of interest were disclosed.

After its emergence in Wuhan, China, in late November or early December 2019, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus rapidly spread globally. Genome sequencing of SARS-CoV-2 allows the reconstruction of its transmission history, although this is contingent on sampling. We analyzed 453 SARS-CoV-2 genomes collected between 20 February and 15 March 2020 from infected patients in Washington state in the United States. We find that most SARS-CoV-2 infections sampled during this time derive from a single introduction in late January or early February 2020, which subsequently spread locally before active community surveillance was implemented., (Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

Muin Khoury and co-authors discuss anticipated contributions of genomics and other forms of large-scale data in public health., Competing Interests: The authors have declared that no competing interests exist.

Rapid advances in DNA sequencing technology ("next-generation sequencing") have inspired optimism about the potential of human genomics for "precision medicine." Meanwhile, pathogen genomics is already delivering "precision public health" through more effective investigations of outbreaks of foodborne illnesses, better-targeted tuberculosis control, and more timely and granular influenza surveillance to inform the selection of vaccine strains. In this article, we describe how public health agencies have been adopting pathogen genomics to improve their effectiveness in almost all domains of infectious disease. This momentum is likely to continue, given the ongoing development in sequencing and sequencing-related technologies., (Copyright © 2019 Massachusetts Medical Society.)

A variety of neuromodulation approaches have been described for the management of pelvic neuropathies, including interstitial cystitis, pudendal neuralgia and persistent genital arousal disorder. The benefits of a combined sacral and pudendal nerve neuromodulator has yet to be explored for these patients. In this report, we describe the case of a 35-year-old woman with a complex pelvic neuropathy resulting in urinary, sexual and gastro-intestinal dysfunction. She presented with an established diagnosis of interstitial cystitis; however, she also fulfilled diagnostic criteria for pudendal neuralgia and persistent genital arousal disorder. The patient underwent implantation of a combined sacral and pudendal nerve neuoromodulation device at the time of surgical decompression of the pudendal nerves. An impressive clinical response followed. This case demonstrates a unique clinical presentation and highlights the value of a combined surgical and neuromodulatory approach in the management of patients with complex pelvic neuropathies., (2016 BMJ Publishing Group Ltd.)

Background: Human metapneumovirus (HMPV) infection causes respiratory illness, including bronchiolitis and pneumonia. However, national HMPV seasonality, as it compares with respiratory syncytial virus (RSV) and influenza seasonality patterns, has not been well described., Methods: Hospital and clinical laboratories reported weekly aggregates of specimens tested and positive detections for HMPV, RSV, and influenza to the National Respiratory and Enteric Virus Surveillance System from 2008 to 2014. A season was defined as consecutive weeks with ≥3% positivity for HMPV and ≥10% positivity for RSV and influenza during a surveillance year (June through July). For each virus, the season, onset, offset, duration, peak, and 6-season medians were calculated., Results: Among consistently reporting laboratories, 33 583 (3.6%) specimens were positive for HMPV, 281 581 (15.3%) for RSV, and 401 342 (18.2%) for influenza. Annually, 6 distinct HMPV seasons occurred from 2008 to 2014, with onsets ranging from November to February and offsets from April to July. Based on the 6-season medians, RSV, influenza, and HMPV onsets occurred sequentially and season durations were similar at 21 to 22 weeks. HMPV demonstrated a unique biennial pattern of early and late seasonal onsets. RSV seasons (onset, offset, peak) were most consistent and occurred before HMPV seasons. There were no consistent patterns between HMPV and influenza circulations., Conclusions: HMPV circulation begins in winter and lasts until spring and demonstrates distinct seasons each year, with the onset beginning after that of RSV. HMPV, RSV, and influenza can circulate simultaneously during the respiratory season., (Copyright © 2016 by the American Academy of Pediatrics.)

In 1988, the World Health Assembly resolved to eradicate polio worldwide. Since then, four of the six World Health Organization (WHO) regions have been certified as polio-free: the Americas in 1994, the Western Pacific Region in 2000, the European Region in 2002, and the South-East Asia Region in 2014. Currently, nearly 80% of the world's population lives in areas certified as polio-free. Certification may be considered when ≥3 years have passed since the last isolation of wild poliovirus (WPV) in the presence of sensitive, certification-standard surveillance. Although regional eradication has been validated in the European Region and the Western Pacific Region, outbreaks resulting from WPV type 1 (WPV1) imported from known endemic areas were detected and controlled in these regions in 2010 and 2011, respectively. The last reported case associated with WPV type 2 (WPV2) was in India in 1999, marking global interruption of WPV2 transmission. The completion of polio eradication was declared a programmatic emergency for public health in 2012, and the international spread of WPV1 was declared a public health emergency of international concern in May 2014. The efforts needed to interrupt all indigenous WPV1 transmission are now being focused on the remaining endemic countries: Nigeria, Afghanistan, and Pakistan. WPV type 3 (WPV3) has not been detected in circulation since November 11, 2012. This report summarizes the evidence of possible global interruption of transmission of WPV3, based on surveillance for acute flaccid paralysis (AFP) and environmental surveillance.

Despite substantial progress, global polio eradication has remained elusive. Indigenous wild poliovirus (WPV) transmission in 4 endemic countries (Afghanistan, India, Nigeria, and Pakistan) persisted into 2010 and outbreaks from imported WPV continued. By 2013, most outbreaks in the interim were promptly controlled. The number of polio-affected districts globally has declined by 74% (from 481 in 2009 to 126 in 2013), including a 79% decrease in the number of affected districts in endemic countries (from 304 to 63). India is now polio-free. The challenges to success in the remaining polio-endemic countries include (1) threats to the security of vaccinators in each country and a ban on polio vaccination in areas of Afghanistan and Pakistan; (2) a risk of decreased government commitment; and (3) remaining surveillance gaps. Coordinated efforts under the International Health Regulations and efforts to mitigate the challenges provide a clear opportunity to soon secure global eradication., (Published by Oxford University Press on behalf of the Infectious Diseases Society of America 2014. This work is written by (a) US Government employee(s) and is in the public domain in the US.)

Importance: To verify the elimination of endemic measles, rubella, and congenital rubella syndrome (CRS) from the Western hemisphere, the Pan American Health Organization requested each member country to compile a national elimination report. The United States documented the elimination of endemic measles in 2000 and of endemic rubella and CRS in 2004. In December 2011, the Centers for Disease Control and Prevention convened an external expert panel to review the evidence and determine whether elimination of endemic measles, rubella, and CRS had been sustained., Objective: To review the evidence for sustained elimination of endemic measles, rubella, and CRS from the United States through 2011., Design, Setting, and Participants: Review of data for measles from 2001 to 2011 and for rubella and CRS from 2004 to 2011 covering the US resident population and international visitors, including disease epidemiology, importation status of cases, molecular epidemiology, adequacy of surveillance, and population immunity as estimated by national vaccination coverage and serologic surveys., Main Outcomes and Measures: Annual numbers of measles, rubella, and CRS cases, by importation status, outbreak size, and distribution; proportions of US population seropositive for measles and rubella; and measles-mumps-rubella vaccination coverage levels., Results: Since 2001, US reported measles incidence has remained below 1 case per 1,000,000 population. Since 2004, rubella incidence has been below 1 case per 10,000,000 population, and CRS incidence has been below 1 case per 5,000,000 births. Eighty-eight percent of measles cases and 54% of rubella cases were internationally imported or epidemiologically or virologically linked to importation. The few cases not linked to importation were insufficient to represent endemic transmission. Molecular epidemiology indicated no endemic genotypes. The US surveillance system is adequate to detect endemic measles or rubella. Seroprevalence and vaccination coverage data indicate high levels of population immunity to measles and rubella., Conclusions and Relevance: The external expert panel concluded that the elimination of endemic measles, rubella, and CRS from the United States was sustained through 2011. However, international importation continues, and health care providers should suspect measles or rubella in patients with febrile rash illness, especially when associated with international travel or international visitors, and should report suspected cases to the local health department.

[This corrects the article DOI: 10.1371/journal.pone.0027717.].

Background and Objective: During 2009-2010, a northeastern US religious community experienced a large mumps outbreak despite high 2-dose measles-mumps-rubella (MMR) vaccine coverage. A third dose of MMR vaccine was offered to students in an affected community in an effort to control the outbreak., Methods: Eligible sixth- to 12th-grade students in 3 schools were offered a third dose of MMR vaccine. Baseline and follow-up surveys and physician case reports were used to monitor mumps attack rates (ARs). We calculated ARs for defined 3-week periods before and after the intervention., Results: Of 2265 eligible students, 2178 (96.2%) provided documentation of having received 2 previous doses of MMR vaccine, and a high proportion (1755 or 80.6%) chose to receive an additional vaccine dose. The overall AR for all sixth- to 12th-grade students declined from 4.93% in the prevaccination period to 0.13% after vaccination (P < .001). Villagewide, overall AR declined by 75.6% after the intervention. A decline occurred in all age groups but was significantly greater (96.0%) among 11- to 17-year-olds, the age group targeted for vaccination, than among all other age groups. The proportions of adverse events reported were lower than or within the range of those in previous reports of first- and second-dose MMR vaccine studies., Conclusions: This is the first study to assess the impact of a third MMR vaccine dose for mumps outbreak control. The decline in incidence shortly after the intervention suggests that a third dose of MMR vaccine may help control mumps outbreaks among populations with preexisting high 2-dose vaccine coverage.

Background: The Republic of Congo has had no cases of wild poliovirus type 1 (WPV1) since 2000. In October 2010, a neurologist noted an abnormal number of cases of acute flaccid paralysis (AFP) among adults, which were later confirmed to be caused by WPV1., Methods: Those presenting with AFP underwent clinical history, physical examination, and clinical specimen collection to determine if they had polio. AFP cases were classified as laboratory-confirmed, clinical, or nonpolio AFP. Epidemiologic features of the outbreak were analyzed., Results: From 19 September 2010 to 22 January 2011, 445 cases of WPV1 were reported in the Republic of Congo; 390 cases were from Pointe Noire. Overall, 331 cases were among adults; 378 cases were clinically confirmed, and 64 cases were laboratory confirmed. The case-fatality ratio (CFR) was 43%. Epidemiologic characteristics differed among polio cases reported in Pointe Noire and cases reported in the rest of the Republic of Congo, including age distribution and CFR. The outbreak stopped after multiple vaccination rounds with oral poliovirus vaccine, which targeted the entire population., Conclusions: This outbreak underscores the need to maintain high vaccination coverage to prevent outbreaks, the need to maintain timely high-quality surveillance to rapidly identify and respond to any potential cases before an outbreak escalates, and the need to perform ongoing risk assessments of immunity gaps in polio-free countries.

Background: Salmonella enterica serovar Typhi causes an estimated 22 million cases of typhoid fever and 216 000 deaths annually worldwide. We investigated an outbreak of unexplained febrile illnesses with neurologic findings, determined to be typhoid fever, along the Malawi-Mozambique border., Methods: The investigation included active surveillance, interviews, examinations of ill and convalescent persons, medical chart reviews, and laboratory testing. Classification as a suspected case required fever and ≥1 other finding (eg, headache or abdominal pain); a probable case required fever and a positive rapid immunoglobulin M antibody test for typhoid (TUBEX TF); a confirmed case required isolation of Salmonella Typhi from blood or stool. Isolates underwent antimicrobial susceptibility testing and subtyping by pulsed-field gel electrophoresis (PFGE)., Results: We identified 303 cases from 18 villages with onset during March-November 2009; 214 were suspected, 43 were probable, and 46 were confirmed cases. Forty patients presented with focal neurologic abnormalities, including a constellation of upper motor neuron signs (n = 19), ataxia (n = 22), and parkinsonism (n = 8). Eleven patients died. All 42 isolates tested were resistant to ampicillin, chloramphenicol, and trimethoprim-sulfamethoxazole; 4 were also resistant to nalidixic acid. Thirty-five of 42 isolates were indistinguishable by PFGE., Conclusions: The unusual neurologic manifestations posed a diagnostic challenge that was resolved through rapid typhoid antibody testing in the field and subsequent blood culture confirmation in the Malawi national reference laboratory. Extending laboratory diagnostic capacity, including blood culture, to populations at risk for typhoid fever in Africa will improve outbreak detection, response, and clinical treatment.

Human enterovirus 68 (EV68) infections are rarely reported. We describe a respiratory outbreak associated with EV68 among 18 children admitted to a remote Indian Health Service facility during August 11, 2010 through September 14, 2010. Clinical illness was characterized by pneumonia and wheezing. EV68 should be considered as an etiology in outbreaks of lower respiratory tract illness.

The long-term duration of recombinant hepatitis B vaccine-induced immunity among persons vaccinated starting at birth is still not well understood. Waning of vaccine-induced immunity could leave young adults at risk of hepatitis B virus infection due to behavioral or occupational exposures. We followed a cohort of children immunized starting at birth with a 3-dose regimen of recombinant hepatitis B vaccine (5 mcg, 2.5 mcg, 2.5 mcg). They were challenged with a booster dose of the hepatitis B vaccine 10 and 15 years after vaccination to assess anamnestic response as a measure of persistence of protection. Among 108 participants who had lost protective antibody levels against hepatitis B, the majority (>70%) had an anamnestic response to the booster dose; response rates did not decline significantly between 10 and 15 years follow-up periods. A high antibody concentration following primary vaccination was independently associated with an anamnestic response later on in life. Nonetheless, ~20-30% of participants were unable to mount an immune response after boosting. Hepatitis B revaccination might be required for persons vaccinated starting at birth if opportunities for hepatitis B virus exposure exist. Future vaccine recommendations should be based on studies ascertaining protection against clinically significant disease., (Published by Elsevier Ltd.)

Objectives: The United States eliminated indigenous wild polioviruses (WPVs) in 1979 and switched to inactivated poliovirus vaccine in 2000, which quickly ended all indigenous live poliovirus transmission. Continued WPV circulation and use of oral poliovirus vaccine globally allow for the possibility of reintroduction of these viruses. We evaluated the risk of a U.S. polio outbreak and explored potential vaccine needs for outbreak response., Methods: We synthesized information available on vaccine coverage, exemptor populations, and population immunity. We used an infection transmission model to explore the potential dynamics of a U.S. polio outbreak and potential vaccine needs for outbreak response, and assessed the impacts of heterogeneity in population immunity for two different subpopulations with potentially low coverage., Results: Although the risk of poliovirus introduction remains real, widespread transmission of polioviruses appears unlikely in the U.S., given high routine coverage. However, clusters of un- or underimmunized children might create pockets of susceptibility that could potentially lead to one or more paralytic polio cases. We found that the shift toward combination vaccine utilization, with limited age indications for use, and other current trends (e.g., decreasing proportion of the population with immunity induced by live polioviruses and aging of vaccine exemptor populations) might increase the vulnerability to poliovirus reintroduction at the same time that the ability to respond may decrease., Conclusions: The U.S. poliovirus vaccine stockpile remains an important resource that may potentially be needed in the future to respond to an outbreak if a live poliovirus gets imported into a subpopulation with low vaccination coverage.

Background: The bacterium Salmonella enterica serovar Typhi causes typhoid fever, which is typically associated with fever and abdominal pain. An outbreak of typhoid fever in Malawi-Mozambique in 2009 was notable for a high proportion of neurologic illness., Objective: Describe neurologic features complicating typhoid fever during an outbreak in Malawi-Mozambique, Methods: Persons meeting a clinical case definition were identified through surveillance, with laboratory confirmation of typhoid by antibody testing or blood/stool culture. We gathered demographic and clinical information, examined patients, and evaluated a subset of patients 11 months after onset. A sample of persons with and without neurologic signs was tested for vitamin B6 and B12 levels and urinary thiocyanate., Results: Between March - November 2009, 303 cases of typhoid fever were identified. Forty (13%) persons had objective neurologic findings, including 14 confirmed by culture/serology; 27 (68%) were hospitalized, and 5 (13%) died. Seventeen (43%) had a constellation of upper motor neuron findings, including hyperreflexia, spasticity, or sustained ankle clonus. Other neurologic features included ataxia (22, 55%), parkinsonism (8, 20%), and tremors (4, 10%). Brain MRI of 3 (ages 5, 7, and 18 years) demonstrated cerebral atrophy but no other abnormalities. Of 13 patients re-evaluated 11 months later, 11 recovered completely, and 2 had persistent hyperreflexia and ataxia. Vitamin B6 levels were markedly low in typhoid fever patients both with and without neurologic signs., Conclusions: Neurologic signs may complicate typhoid fever, and the diagnosis should be considered in persons with acute febrile neurologic illness in endemic areas.

Background: Malaria is a major health concern for displaced persons occupying refugee camps in sub-Saharan Africa, yet there is little information on the incidence of infection and nature of transmission in these settings. Kakuma Refugee Camp, located in a dry area of north-western Kenya, has hosted ca. 60,000 to 90,000 refugees since 1992, primarily from Sudan and Somalia. The purpose of this study was to investigate malaria prevalence and attack rate and sources of Anopheles vectors in Kakuma refugee camp, in 2005-2006, after a malaria epidemic was observed by staff at camp clinics., Methods: Malaria prevalence and attack rate was estimated from cases of fever presenting to camp clinics and the hospital in August 2005, using rapid diagnostic tests and microscopy of blood smears. Larval habitats of vectors were sampled and mapped. Houses were sampled for adult vectors using the pyrethrum knockdown spray method, and mapped. Vectors were identified to species level and their infection with Plasmodium falciparum determined., Results: Prevalence of febrile illness with P. falciparum was highest among the 5 to 17 year olds (62.4%) while malaria attack rate was highest among the two to 4 year olds (5.2/1,000/day). Infected individuals were spatially concentrated in three of the 11 residential zones of the camp. The indoor densities of Anopheles arabiensis, the sole malaria vector, were similar during the wet and dry seasons, but were distributed in an aggregated fashion and predominantly in the same zones where malaria attack rates were high. Larval habitats and larval populations were also concentrated in these zones. Larval habitats were man-made pits of water associated with tap-stands installed as the water delivery system to residents with year round availability in the camp. Three percent of A. arabiensis adult females were infected with P. falciparum sporozoites in the rainy season., Conclusions: Malaria in Kakuma refugee camp was due mainly to infection with P. falciparum and showed a hyperendemic age-prevalence profile, in an area with otherwise low risk of malaria given prevailing climate. Transmission was sustained by A. arabiensis, whose populations were facilitated by installation of man-made water distribution and catchment systems.

Background: On 12 February 2008, an infected Swiss traveler visited hospital A in Tucson, Arizona, and initiated a predominantly health care-associated measles outbreak involving 14 cases. We investigated risk factors that might have contributed to health care-associated transmission and assessed outbreak-associated hospital costs., Methods: Epidemiologic data were obtained by case interviews and review of medical records. Health care personnel (HCP) immunization records were reviewed to identify non-measles-immune HCP. Outbreak-associated costs were estimated from 2 hospitals., Results: Of 14 patients with confirmed cases, 7 (50%) were aged ≥ 18 years, 4 (29%) were hospitalized, 7 (50%) acquired measles in health care settings, and all (100%) were unvaccinated or had unknown vaccination status. Of the 11 patients (79%) who had accessed health care services while infectious, 1 (9%) was masked and isolated promptly after rash onset. HCP measles immunity data from 2 hospitals confirmed that 1776 (25%) of 7195 HCP lacked evidence of measles immunity. Among these HCPs, 139 (9%) of 1583 tested seronegative for measles immunoglobulin G, including 1 person who acquired measles. The 2 hospitals spent US$799,136 responding to and containing 7 cases in these facilities., Conclusions: Suspecting measles as a diagnosis, instituting immediate airborne isolation, and ensuring rapidly retrievable measles immunity records for HCPs are paramount in preventing health care-associated spread and in minimizing hospital outbreak-response costs.

During the 2009 influenza pandemic, weekly mortality data were analyzed to estimate excess mortality above a seasonally adjusted baseline modeled from prior years' data. Between the 1962-1963 and 2008-2009 seasons, among persons ≥ 25 years old, excess mortality had been substantially higher during influenza A(H3N2)-dominant years than during A(H1N1)-dominant years. Among persons ≥ 15 years of age, excess mortality was higher in the 1968-1969 influenza pandemic season than during any other season. During the 2009-2010 pandemic, among all age groups <65 years old, excess mortality increased earlier than during any of the previous 47 seasons, eventually exceeding mortality in any prior non-pandemic season. In the ≥ 65-year-old age group, excess mortality remained relatively low, at rates typical of seasonal influenza A(H1N1) seasons. The model provided a timely assessment of severity during the 2009-2010 influenza pandemic, showing that, compared with prior seasons, mortality was relatively high among persons <65 years old and relatively low among those ≥ 65 years old.

Background: Without intervention, up to 25% of individuals chronically infected with hepatitis B virus (HBV) die of late complications, including cirrhosis and liver cancer. The United States, which in 1991 implemented a strategy to eliminate HBV transmission through universal immunization, is a country of low prevalence. Approximately 3,000-5,000 U.S.-acquired cases of chronic hepatitis B have occurred annually since 2001. Many more chronically infected persons migrate to the United States yearly from countries of higher prevalence. Although early identification of chronic HBV infection can reduce the likelihood of transmission and late complications, immigrants are not routinely screened for HBV infection during or after immigration., Methods: To estimate the number of imported cases of chronic hepatitis B, we multiplied country-specific prevalence estimates by the yearly number of immigrants from each country during 1974-2008., Results: During 1974-2008, 27.9 million immigrants entered the U.S. Sixty-three percent were born in countries of intermediate or high chronic hepatitis B prevalence (range 2%-31%). On average, an estimated 53,800 chronic hepatitis B cases were imported to the U.S. yearly from 2004 through 2008. The Philippines, China, and Vietnam contributed the most imported cases (13.4%, 12.5%, and 11.0%, respectively). Imported cases increased from an estimated low of 105,750 during the period 1974-1977 to a high of 268,800 in 2004-2008., Conclusions: Imported chronic hepatitis B cases account for approximately 95% of new U.S. cases. Earlier case identification and management of infected immigrants would strengthen the U.S. strategy to eliminate HBV transmission, and could delay disease progression and prevent some deaths among new Americans.

Nonpharmaceutical interventions (NPIs), such as home isolation, social distancing, and infection control measures, are recommended by public health agencies as strategies to mitigate transmission during influenza pandemics. However, NPI implementation has rarely been studied in large populations. During an outbreak of 2009 Pandemic Influenza A (H1N1) virus infection at a large public university in April 2009, an online survey was conducted among students, faculty, and staff to assess knowledge of and adherence to university-recommended NPI. Although 3924 (65%) of 6049 student respondents and 1057 (74%) of 1401 faculty respondents reported increased use of self-protective NPI, such as hand washing, only 27 (6.4%) of 423 students and 5 (8.6%) of 58 faculty with acute respiratory infection (ARI) reported staying home while ill. Nearly one-half (46%) of student respondents, including 44.7% of those with ARI, attended social events. Results indicate a need for efforts to increase compliance with home isolation and social distancing measures.

We identified 27 cases of hepatitis A among international adoptees (5 persons), their direct or indirect contacts (20 persons), and unvaccinated travelers to the adoptees' countries (2 persons). Most cases occurred among nontraveling contacts of adoptees, suggesting the need to extend prevention guidelines to include hepatitis A vaccination for at-risk nontravelers.

Objective: To examine hepatitis C virus (HCV) seroprevalence among injection drug users in 4 US cities from 1994 through 2004., Methods: Demographic characteristics, behaviors, and prevalence of HCV antibody among 5088 injection drug users aged 18-40 years from Baltimore, Maryland; Chicago, Illinois; Los Angeles, California; and New York, New York, enrolled in 3 related studies--Collaborative Injection Drug User Study (CIDUS) I (1994-1996), CIDUS II (1997-1999), and CIDUS III/Drug User Intervention Trial (2002-2004)--were compared using the chi(2) and Mantel-Haenszel tests of significance. Trends over time were assessed by logistic regression., Results: Prevalence of HCV infection was 65%, 35%, and 35% in CIDUS I, CIDUS II, and CIDUS III, respectively. The adjusted prevalence odds ratio (OR) of being HCV antibody positive increased with the number of years of injection drug use (OR, 1.93 [95% confidence interval {CI}, 1.68-2.21] for each year of injecting within the first 2 years; OR, 1.09 [95% CI, 1.07-1.11] for each year of injecting beyond the first 2 years). Significant decreases were observed in the prevalence of HCV antibody between CIDUS I and CIDUS III in Baltimore (OR, 0.30; 95% CI, 0.20-0.43) and Los Angeles (OR, 0.17; 95% CI, 0.09-0.31) and among people of races other than black in Chicago (OR, 0.12; 95% CI, 0.08-0.17). No decrease in prevalence was seen in New York (OR, 1.04; 95% CI, 0.69-1.58) or among blacks in Chicago (OR, 0.55; 95% CI, 0.16-1.90)., Conclusion: Although regional differences exist, our data suggest that the incidence of HCV infection among injection drug users in the United States decreased from 1994 through 2004.

Objective: To prevent perinatal transmission of hepatitis B virus (HBV), WHO recommends that the first dose of hepatitis B (HepB) vaccine be given within 24 hours after birth. This presents a challenge in remote areas with limited cold-chain infrastructure and where many children are born at home., Methods: Rural townships in three counties in China's Hunan Province were randomized into three groups with different strategies for delivery of the first dose of HepB vaccine. In group 1, vaccine was stored within the cold chain and administered in township hospitals. In group 2, vaccine was stored out of the cold chain in villages and administered by village-based health workers to infants at home. Group 3 used the same strategy as group 2, but vaccine was packaged in a prefilled injection device. Training of immunization providers and public communication conveying the importance of the birth dose was performed for all groups., Findings: Among children born at home, timely administration (within 24 hours after birth) of the first dose of HepB vaccine increased in all groups after the study: group 1, from 2.4% to 25.2%; group 2, from 2.6% to 51.8%; and group 3, from 0.6% to 66.7%; P < 0.001 in each case. No significant difference in antibody response to vaccine was observed between the groups., Conclusion: Timely administration of the first dose of HepB vaccine was improved by communication and training activities, and by out-of-cold-chain storage of vaccine and administration at the village level, especially among children born at home.

Background: Injection drug use (IDU) is important in the epidemiology of blood-borne pathogens. Herein, trends in IDU from 1979 to 2002 are analyzed., Methods: The National Household Survey on Drug Abuse is an ongoing survey of drug use among the US population 12 years and older. Participants were chosen using a multistage sampling design and interviewed by written questionnaire (1979-1998) or audio computer-assisted self-interviewing (1999-2002). Herein, we examine the prevalence of a history of IDU at any time in the past (IDU-ever) or within the past year., Results: In the 2000-2002 surveys, 1.5% (95% confidence interval [CI], 1.4%-1.6%) reported IDU-ever (weighted estimate, 3.4 million persons). Prevalence was highest in persons aged 35 to 49 years (3.1%; 95% CI, 2.8%-3.4%), was higher in men (2.0%; 95% CI, 1.8%-2.2%) than women (1.0%; 95% CI, 0.9%-1.1%), and was higher in whites (1.7%; 95% CI, 1.5%-1.8%) than blacks (0.8%; 95% CI, 0.7%-1.1%) or Hispanics (1.1%; 95% CI, 0.8%-1.4%). Prevalence decreased with increasing annual income and educational level. Of all participants, 0.19% (95% CI, 0.16%-0.23%) reported IDU within the past year (weighted estimate, 440 000 persons). Ten years earlier (1990-1992), 1.6% (95% CI, 1.5%-1.8%) reported IDU-ever; prevalence did not differ by race. From 1979 through 2002, the mean age of participants with IDU within the past year increased from 21 to 36 years; the age of participants with IDU-ever increased from 26 to 42 years. From 2000 to 2002, 59.4% of all persons with IDU-ever were aged 35 to 49 years., Conclusions: The mean age of injection drug users has increased substantially. Persons born between the late 1940s and early 1960s have the highest prevalence of IDU-ever. Self-reported IDU rates are now lower among young blacks than young whites.

Background/aims: End-stage liver disease accounts for one in forty deaths worldwide. Chronic infections with hepatitis B virus (HBV) and hepatitis C virus (HCV) are well-recognized risk factors for cirrhosis and liver cancer, but estimates of their contributions to worldwide disease burden have been lacking., Methods: The prevalence of serologic markers of HBV and HCV infections among patients diagnosed with cirrhosis or hepatocellular carcinoma (HCC) was obtained from representative samples of published reports. Attributable fractions of cirrhosis and HCC due to these infections were estimated for 11 WHO-based regions., Results: Globally, 57% of cirrhosis was attributable to either HBV (30%) or HCV (27%) and 78% of HCC was attributable to HBV (53%) or HCV (25%). Regionally, these infections usually accounted for >50% of HCC and cirrhosis. Applied to 2002 worldwide mortality estimates, these fractions represent 929,000 deaths due to chronic HBV and HCV infections, including 446,000 cirrhosis deaths (HBV: n=235,000; HCV: n=211,000) and 483,000 liver cancer deaths (HBV: n=328,000; HCV: n=155,000)., Conclusions: HBV and HCV infections account for the majority of cirrhosis and primary liver cancer throughout most of the world, highlighting the need for programs to prevent new infections and provide medical management and treatment for those already infected.

Hepatitis E virus (HEV) is an enterically transmitted RNA virus that causes both epidemic and sporadic cases of acute hepatitis. Despite sero-surveys showing antibody to HEV in up to 36% of the US population, acute hepatitis E has been reported among individuals with no history of international travel only three times in the United States. We report a case of apparently locally-acquired hepatitis E that occurred in El Paso, Texas that was 98% similar to a previously isolated HEV found in swine in the United States. Like the three previous cases, a thorough investigation found no conclusive sources of infection. Active case surveillance found no additional cases.

Background: Defining the primary characteristics of persons infected with hepatitis C virus (HCV) enables physicians to more easily identify persons who are most likely to benefit from testing for the disease., Objective: To describe the HCV-infected population in the United States., Design: Nationally representative household survey., Setting: U.S. civilian, noninstitutionalized population., Participants: 15,079 participants in the National Health and Nutrition Examination Survey between 1999 and 2002., Measurements: All participants provided medical histories, and those who were 20 to 59 years of age provided histories of drug use and sexual practices. Participants were tested for antibodies to HCV (anti-HCV) and HCV RNA, and their serum alanine aminotransferase (ALT) levels were measured., Results: The prevalence of anti-HCV in the United States was 1.6% (95% CI, 1.3% to 1.9%), equating to an estimated 4.1 million (CI, 3.4 million to 4.9 million) anti-HCV-positive persons nationwide; 1.3% or 3.2 million (CI, 2.7 million to 3.9 million) persons had chronic HCV infection. Peak prevalence of anti-HCV (4.3%) was observed among persons 40 to 49 years of age. A total of 48.4% of anti-HCV-positive persons between 20 and 59 years of age reported a history of injection drug use, the strongest risk factor for HCV infection. Of all persons reporting such a history, 83.3% had not used injection drugs for at least 1 year before the survey. Other significant risk factors included 20 or more lifetime sex partners and blood transfusion before 1992. Abnormal serum ALT levels were found in 58.7% of HCV RNA-positive persons. Three characteristics (abnormal serum ALT level, any history of injection drug use, and history of blood transfusion before 1992) identified 85.1% of HCV RNA-positive participants between 20 and 59 years of age., Limitations: Incarcerated and homeless persons were not included in the survey., Conclusions: Many Americans are infected with HCV. Most were born between 1945 and 1964 and can be identified with current screening criteria. History of injection drug use is the strongest risk factor for infection.

Little is known about the prevalence of hepatitis C virus (HCV) in Pacific islands. In this study, serum specimens collected in 1985 and 2002 among the general populations of Samoa and American Samoa were tested for antibody to HCV by a third-generation enzyme immunoassay and a recombinant immunoblot assay. Of the 3,466 specimens tested, 8 (0.2%; 95% confidence interval = 0.07-0.4%) were positive for antibody to HCV. Prevalence did not vary by location or demographic characteristic. Thus, HCV is present in the Samoas but at a low prevalence.

The within-outbreak diversity of hepatitis E virus (HEV) was studied during the outbreak of hepatitis E that occurred in Sudan in 2004. Specimens were collected from internally displaced persons living in a Sudanese refugee camp and two camps implanted in Chad. A comparison of the sequences in the ORF2 region of 23 Sudanese isolates and five HEV samples from the two Chadian camps displayed a high similarity (>99.7%) to strains belonging to Genotype 1. But four isolates collected in one of the Chadian camps were close to Genotype 2. Circulation of divergent strains argues for possible multiple sources of infection., (Copyright (c) 2005 Wiley-Liss, inc.)

Background: Molecular epidemiologic investigations can link geographically separate foodborne hepatitis A outbreaks but have not been used while field investigations are in progress. In 2003, outbreaks of foodborne hepatitis A were reported in multiple states., Methods: Case-control studies were conducted in 3 states. Hepatitis A virus was sequenced from serologic specimens from individuals associated with outbreaks and from individuals concurrently ill with hepatitis A in non-outbreak settings in the United States and Mexico., Results: Case-control studies in Tennessee (TN), North Carolina (NC), and Georgia (GA) found green onions to be associated with illness among restaurant patrons (TN: odds ratio [OR], 65.5 [95% confidence interval {CI}, 8.9-482.5; NC: OR, 2.4 [95% CI, 0.3-21.9]; GA: OR, 20.9 [95% CI, 3.9-110.3]). Viral sequences from TN case patients differed by 2 nt, compared with those from case patients in NC and GA. A third sequence, differing from the TN and GA/NC sequences by 1 nt, was identified among case patients in a subsequent outbreak in Pennsylvania. Each outbreak sequence was identical to > or =1 sequence isolated from northern Mexican resident(s) with hepatitis A. The sources of green onions served in restaurants in TN and GA were 3 farms in northern Mexico., Conclusions: Ongoing viral strain surveillance facilitated the rapid implementation of control measures. Incorporation of molecular epidemiologic methods into routine hepatitis A surveillance would improve the detection of hepatitis A outbreaks and increase our understanding of hepatitis A epidemiology in the United States.

Context: During a mass smallpox immunization campaign, vaccine may be exposed to ambient temperatures for extended periods of time., Objective: To determine the viability of undiluted and 5x diluted DryVax smallpox vaccine after cycling vaccine in and out of refrigeration for 2 weeks, as might occur during an immunization campaign., Design: Two vials of Dryvax vaccine were reconstituted as per manufacturer's instructions (1x) and two vials were reconstituted using 5x the recommended diluent (5x). Every 12h over 2 weeks, vials were cycled between refrigeration and room temperature (1x-RT, 5x-RT) or ice bath (1x-cold, 5x-cold). Each vial was sampled in triplicate at time of reconstitution and thereafter at 24 or 48 h intervals., Main Outcome Measures: Viability measured by viral plaque forming units per ml (pfu/ml)., Results: All four vaccine vials showed a decline in virus titer over the 2-week period but remained well above 10(7)pfu/ml. Compared with titers on the day of reconstitution (day 0), titers at the end of the study (day 14) had declined by 0.4--0.6l og in all vials (Table 1). Linear regression analysis suggested that decay in viral titer occurred more rapidly in vials exposed to room temperature compared with vials kept on ice and in vaccine diluted 1x compared with vaccine diluted 5x., Conclusions: After 2 weeks, viability was greater than 10(7)pfu/ml, the titer suggested by Frey et al. as necessary to ensure successful vaccination in more than 97% of vaccinees. When removed from refrigeration, keeping the vaccine on ice lowers the decline in titer.

Objectives: The objectives of this study were to estimate national seroprevalence of herpes simplex virus type 1 (HSV-1), describe trends in seroprevalence, and examine correlates of infection., Goal: The goal of this study was to measure the burden of HSV-1 infection in the U.S. population., Study: We tested serum samples for HSV-1 antibody and analyzed questionnaire data collected for the second and third National Health and Nutrition Surveys (NHANES II, 1976-80; NHANES III, 1988-94). Seroprevalence estimates were weighted to represent the total U.S. population., Results: At the time of NHANES III, two thirds (68%) of the U.S. population 12 years and older had HSV-1 antibody. Prevalence increased with age and varied by race/ethnicity; the majority of persons in all race/ethnic groups were HSV-1-seropositive by age 30. Overall, the national seroprevalence of HSV-1 decreased nonsignificantly by 2% in the years between NHANES II and III; decreases in HSV-1 seroprevalence in some population subgroups were balanced by increases in other groups., Conclusions: There was no overall change in the seroprevalence of HSV-1 in the U.S. population between NHANES II and III.

Hepatitis A rates have declined to historically low rates in the United States. To assess the degree to which this decline was attributable to immunization, we correlated changes in the incidence of hepatitis A with increases in immunization coverage in a Poisson regression model. In a model allowing for herd immunity, an estimated 97,800 hepatitis A cases were averted due to immunization between 1995-2001, including 39% of potential cases in 2001. Assuming no herd immunity; 32,300 cases of hepatitis A would have been prevented. Sensitivity analysis showed that the number of averted cases in this period could range from 45,500 to 172,900. Among children 2-18 years old, vaccination coverage averaged 10% in 2001 and is estimated to have prevented 51% of cases in this age group. These results suggest that much of the recent reduction of hepatitis A rates is attributable to immunization and that immunization has been associated with a strong herd immunity effect.

As part of the 2000 Global Burden of Disease study, we quantified the death and disability from injection-associated infections with hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency virus (HIV). We modelled the fraction of incident infections attributable to health care injections in the year 2000 on the basis of the annual number of injections, the proportion of injections administered with reused equipment, the probability of transmission following percutaneous exposure, the prevalence of active infection, the prevalence of immunity and the total incidence. Infections in 2000 were converted into disability-adjusted life years (DALYs) in 2000-2030 using natural history parameters, background mortality, duration of disease, disability weights, age weights and a 3% discount rate. Four Global Burden of Disease regions where reuse of injection equipment in the absence of sterilization was negligible were excluded from the analysis. In the remaining 10 regions, in 2000, persons received an average of 3.4 injections per year, 39.3% of which were given with reused equipment. In 2000, contaminated injections caused an estimated 21 million HBV infections, two million HCV infections and 260,000 HIV infections, accounting for 32%, 40% and 5%, respectively, of new infections for a burden of 9,177,679 DALYs between 2000 and 2030. Injection overuse and unsafe practices account for a substantial burden of death and disability worldwide. There is a need for policies and plans for the safe and appropriate use of injections in countries where practices are poor.

Background: Blood exposures in the workplace may put first responders, a group which includes firefighters, emergency medical technicians, and paramedics, at increased risk for hepatitis C virus (HCV) infection. To determine the prevalence of antibody to HCV (anti-HCV) and risk factors for infection among first responders, we analyzed data from prevalence surveys conducted among first responders in Atlanta, Ga, in 1991; Connecticut in 1992; and Philadelphia, Pa, in 1999., Methods: Serum or blood samples from participants of the 3 surveys were tested for anti-HCV. Prevalence of anti-HCV was compared with that in the general US population and among participants by occupational (Atlanta) and nonoccupational (Atlanta and Philadelphia) risk factors for infection., Results: Prevalence of anti-HCV among the 2946 participants of the 3 surveys ranged from 1.3% to 3.6% and was no different than among appropriate referent groups in the general US population. First responders in Atlanta reported high rates of skin exposures to blood (174 per 100 person-years) but few mucosal or needle-stick exposures (1 and 0 per 100 person-years, respectively) during the 6 months prior to the survey. Hepatitis C virus infection was not associated with a history of skin exposures to blood (prevalence ratio [PR], 1.1; 95% confidence interval [CI], 0.3-4.2), and HCV prevalence did not increase with longer duration (>10 years) of employment (PR, 1.1; 95% CI, 0.3-4.3). Nonoccupational risk factors associated with HCV infection included history of a sexually transmitted disease (PR, 7.4; 95% CI, 1.6-35.3) among Atlanta participants and histories of illegal drug use (PR, 4.4; 95% CI, 2.6-7.2) and blood transfusion before 1992 (PR, 1.9; 95% CI, 1.1-3.3) among Philadelphia participants., Conclusions: First responders are exposed to blood in the workplace, and standard precautions should be rigorously implemented. Although risk for HCV infection related to percutaneous or mucosal exposures could not be accurately assessed, the low prevalence of HCV infection indicates that routine HCV testing of first responders as an occupational group is not warranted. Testing should routinely be offered to those requiring postexposure management and those with a history of nonoccupational risk factors indicating an increased risk for infection.

Objective: To describe injection practices worldwide in terms of frequency and safety., Design: Literature review. The global burden of disease project of the World Health Organization defined 14 regions on the basis of geography and mortality patterns. Data sources included published studies and unpublished WHO reports. Studies were reviewed by using a standardised decision making algorithm to generate region specific estimates., Setting: Healthcare facilities, both formal and informal., Data Sources: General population and users of healthcare facilities., Main Outcome Measure: Annual number of injections per person and proportion of injections administered with syringes or needles, or both, reused in the absence of sterilisation., Results: The analysis excluded four regions (predominantly affluent, developed nations) where reuse of injection equipment in the absence of sterilisation was assumed to be negligible. In the 10 other regions, the annual ratio of injections per person ranged from 1.7 to 11.3. Of these, the proportion administered with equipment reused in the absence of sterilisation ranged from 1.2% to 75.0%. Reuse was highest in the South East Asia region "D" (seven countries, mostly located in South Asia), the eastern Mediterranean region "D" (nine countries, mostly located in the Middle East crescent), and the western Pacific region "B" (22 countries). No information regarding injection safety was available for Latin America., Conclusions: Overuse of injections and unsafe practices are still common in developing and transitional countries. An urgent need exists to use injections safely and appropriately, to prevent healthcare associated infections with HIV and other bloodborne pathogens.

On November 20, 2001, inhalational anthrax was confirmed in an elderly woman from rural Connecticut. To determine her exposure source, we conducted an extensive epidemiologic, environmental, and laboratory investigation. Molecular subtyping showed that her isolate was indistinguishable from isolates associated with intentionally contaminated letters. No samples from her home or community yielded Bacillus anthracis, and she received no first-class letters from facilities known to have processed intentionally contaminated letters. Environmental sampling in the regional Connecticut postal facility yielded B. anthracis spores from 4 (31%) of 13 sorting machines. One extensively contaminated machine primarily processes bulk mail. A second machine that does final sorting of bulk mail for her zip code yielded B. anthracis on the column of bins for her carrier route. The evidence suggests she was exposed through a cross-contaminated bulk mail letter. Such cross-contamination of letters and postal facilities has implications for managing the response to future B. anthracis-contaminated mailings.