Last data update: Jan 27, 2025. (Total: 48650 publications since 2009)
Records 1-19 (of 19 Records) |
Query Trace: Landry K[original query] |
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An indicator framework for the monitoring and evaluation of event-based surveillance systems
Crawley AW , Mercy K , Shivji S , Lofgren H , Trowbridge D , Manthey C , Tebeje YK , Clara AW , Landry K , Salyer SJ . Lancet Glob Health 2024 Event-based surveillance (EBS) systems have been implemented globally to support early warning surveillance across human, animal, and environmental health in diverse settings, including at the community level, within health facilities, at border points of entry, and through media monitoring of internet-based sources. EBS systems should be evaluated periodically to ensure that they meet the objectives related to the early detection of health threats and to identify areas for improvement in the quality, efficiency, and usefulness of the systems. However, to date, there has been no comprehensive framework to guide the monitoring and evaluation of EBS systems; this absence of standardisation has hindered progress in the field. The Africa Centres for Disease Control and Prevention and US Centers for Disease Control and Prevention have collaborated to develop an EBS monitoring and evaluation indicator framework, adaptable to specific country contexts, that uses measures relating to input, activity, output, outcome, and impact to map the processes and expected results of EBS systems. Through the implementation and continued refinement of these indicators, countries can ensure the early detection of health threats and improve their ability to measure and describe the impacts of EBS systems, thus filling the current evidence gap regarding their effectiveness. |
Lymphocytic choriomeningitis virus in person living with HIV, Connecticut, USA, 2021
Dyal J , Gandhi S , Cossaboom CM , Leach A , Patel K , Golden M , Canterino J , Landry ML , Cannon D , Choi M , Krapiunaya I , Klena JD , Shoemaker T . Emerg Infect Dis 2023 29 (9) 1886-1889 Lymphocytic choriomeningitis virus is an underreported cause of miscarriage and neurologic disease. Surveillance remains challenging because of nonspecific symptomatology, inconsistent case reporting, and difficulties with diagnostic testing. We describe a case of acute lymphocytic choriomeningitis virus disease in a person living with HIV in Connecticut, USA, identified by using quantitative reverse transcription PCR. |
Streamlining malaria prevention recommendations for travellers: current and future approaches
McGuinness SL , Veit O , Angelin M , Antonini P , Boecken G , Boering M , Bühler S , Calleri G , Éperon G , Flaherty G , Gossner C , Askling HH , Holmberg V , Kuenzli E , Landry P , Lefevre E , Libman M , Longley N , Maniewski-Kelner U , Neumayr A , Rapp C , Ridpath AD , Rodriguez N , Rosdahl A , Rosenbusch D , Rossanese A , Rothe C , Schlagenhauf P , Soentjens P , Staehelin C , Visser J , Visser L , Wagner A , Walker A , Wiedermann U , Wroczynska A , Hatz C . J Travel Med 2024 |
Early introductions and community transmission of SARS-CoV-2 variant B.1.1.7 in the United States (preprint)
Alpert T , Brito AF , Lasek-Nesselquist E , Rothman J , Valesano AL , MacKay MJ , Petrone ME , Breban MI , Watkins AE , Vogels CBF , Kalinich CC , Dellicour S , Russell A , Kelly JP , Shudt M , Plitnick J , Schneider E , Fitzsimmons WJ , Khullar G , Metti J , Dudley JT , Nash M , Beaubier N , Wang J , Liu C , Hui P , Muyombwe A , Downing R , Razeq J , Bart SM , Grills A , Morrison SM , Murphy S , Neal C , Laszlo E , Rennert H , Cushing M , Westblade L , Velu P , Craney A , Fauntleroy KA , Peaper DR , Landry ML , Cook PW , Fauver JR , Mason CE , Lauring AS , George KS , MacCannell DR , Grubaugh ND . medRxiv 2021 The emergence and spread of SARS-CoV-2 lineage B.1.1.7, first detected in the United Kingdom, has become a global public health concern because of its increased transmissibility. Over 2500 COVID-19 cases associated with this variant have been detected in the US since December 2020, but the extent of establishment is relatively unknown. Using travel, genomic, and diagnostic data, we highlight the primary ports of entry for B.1.1.7 in the US and locations of possible underreporting of B.1.1.7 cases. Furthermore, we found evidence for many independent B.1.1.7 establishments starting in early December 2020, followed by interstate spread by the end of the month. Finally, we project that B.1.1.7 will be the dominant lineage in many states by mid to late March. Thus, genomic surveillance for B.1.1.7 and other variants urgently needs to be enhanced to better inform the public health response. |
Development of an international glossary for clinical guidelines collaboration
Christensen RE , Yi MD , Kang BY , Ibrahim SA , Anvery N , Dirr M , Adams S , Amer YS , Bisdorff A , Bradfield L , Brown S , Earley A , Fatheree LA , Fayoux P , Getchius T , Ginex P , Graham A , Green CR , Gresele P , Hanson H , Haynes N , Hegedüs L , Hussein H , Jakhmola P , Kantorova L , Krishnasamy R , Krist A , Landry G , Lease ED , Ley L , Marsden G , Meek T , Meremikwu M , Moga C , Mokrane S , Mujoomdar A , Newton S , O'Flynn N , Perkins GD , Smith EJ , Prematunge C , Rychert J , Saraco M , Schünemann HJ , Senerth E , Sinclair A , Shwayder J , Stec C , Tanni S , Taske N , Temple-Smolkin RL , Thomas L , Thomas S , Tonnessen B , Turner AS , Van Dam A , van Doormaal M , Wan YL , Ventura CB , McFarlane E , Morgan RL , Ogunremi T , Alam M . J Clin Epidemiol 2023 158 84-91 OBJECTIVE: Clinical practice guidelines are often created through collaboration among organizations. Use of inconsistent terminology may cause poor communication and delays. This study aimed to develop a glossary of terms related to collaboration in guideline development. STUDY DESIGN AND SETTING: A literature review of collaborative guidelines was performed to develop an initial list of terms related to guideline collaboration. The list of terms was presented to the members of the Guideline International Network Guidelines Collaboration Working Group, who provided presumptive definitions for each term and proposed additional terms to be included. The revised list was subsequently reviewed by an international, multidisciplinary panel of expert stakeholders. Recommendations received during this pre-Delphi review were implemented to augment an initial draft glossary. The glossary was then critically evaluated and refined through two rounds of Delphi surveys and a virtual consensus meeting with all panel members as Delphi participants. RESULTS: Forty-nine experts participated in the pre-Delphi survey and 44 participated in the two-round Delphi process. Consensus was reached for 37 terms and definitions. CONCLUSION: Uptake and utilization of this guideline collaboration glossary by key organizations and stakeholder groups may facilitate collaboration among guideline-producing organizations by improving communication, minimizing conflicts, and increasing guideline development efficiency. |
Outbreak of Acute Respiratory Illness Associated with Human Adenovirus Type 4 at the U.S. Coast Guard Academy, 2019.
Chu VT , Simon E , Lu X , Rockwell P , Abedi GR , Gardner C , Kujawski SA , Schneider E , Gentile M , Ramsey LA , Liu R , Jones S , Janik C , Siniscalchi A , Landry ML , Christopher J , Lindstrom S , Steiner S , Thomas D , Gerber SI , Biggs HM . J Infect Dis 2021 225 (1) 55-64 ![]() ![]() BACKGROUND: Although a human adenovirus (HAdV) vaccine is available for military use, officers-in-training are not routinely vaccinated. We describe an HAdV-associated respiratory outbreak among unvaccinated cadets at the U.S. Coast Guard Academy and its impact on cadet training. METHODS: We defined a case as a cadet with new onset cough or sore throat during August 1-October 4, 2019. We reviewed medical records and distributed a questionnaire to identify cases and to estimate impact on cadet training. We performed real-time PCR testing on patient and environmental samples and whole genome sequencing on a subset of positive patient samples. RESULTS: Among the 1,072 cadets, 378 (35%) cases were identified by medical records (n=230) or additionally by the questionnaire (n=148). Of the 230 cases identified from medical records, 138 (60%) were male and 226 (98%) had no underlying conditions. From questionnaire responses, 113/228 (50%) cases reported duty restrictions. Of cases with respiratory specimens, 36/50 (72%) were HAdV positive; all 14 sequenced specimens were HAdV-4a1. Sixteen (89%) of 18 environmental specimens from the cadet dormitory were HAdV-positive. CONCLUSIONS: The HAdV-4-associated outbreak infected a substantial number of cadets and significantly impacted cadet training. Routine vaccination could prevent HAdV respiratory outbreaks in this population. |
Early introductions and transmission of SARS-CoV-2 variant B.1.1.7 in the United States.
Alpert T , Brito AF , Lasek-Nesselquist E , Rothman J , Valesano AL , MacKay MJ , Petrone ME , Breban MI , Watkins AE , Vogels CBF , Kalinich CC , Dellicour S , Russell A , Kelly JP , Shudt M , Plitnick J , Schneider E , Fitzsimmons WJ , Khullar G , Metti J , Dudley JT , Nash M , Beaubier N , Wang J , Liu C , Hui P , Muyombwe A , Downing R , Razeq J , Bart SM , Grills A , Morrison SM , Murphy S , Neal C , Laszlo E , Rennert H , Cushing M , Westblade L , Velu P , Craney A , Cong L , Peaper DR , Landry ML , Cook PW , Fauver JR , Mason CE , Lauring AS , St George K , MacCannell DR , Grubaugh ND . Cell 2021 184 (10) 2595-2604 e13 ![]() The emergence and spread of SARS-CoV-2 lineage B.1.1.7, first detected in the United Kingdom, has become a global public health concern because of its increased transmissibility. Over 2,500 COVID-19 cases associated with this variant have been detected in the United States (US) since December 2020, but the extent of establishment is relatively unknown. Using travel, genomic, and diagnostic data, we highlight that the primary ports of entry for B.1.1.7 in the US were in New York, California, and Florida. Furthermore, we found evidence for many independent B.1.1.7 establishments starting in early December 2020, followed by interstate spread by the end of the month. Finally, we project that B.1.1.7 will be the dominant lineage in many states by mid- to late March. Thus, genomic surveillance for B.1.1.7 and other variants urgently needs to be enhanced to better inform the public health response. |
COVID-19 intra-action reviews: potential for a sustained response plan.
Greiner AL , Nguyen L , Shamout M , Krishnan S , Stowell D . Lancet Glob Health 2021 9 (5) e594 We echo Landry Ndriko Mayigane and colleagues’ call (December, 2020)1 for countries to plan and conduct intra-action reviews regularly throughout the COVID-19 response. An intra-action review is a country-led process that reviews past response actions to identify crucial gaps and optimise response plans going forward. WHO guidance for conducting a country COVID-19 intra-action review includes more than 300 discussion questions that can be adapted to a country’s context.2 | | However, given that 26 of 33 countries that have already completed an intra-action review are experiencing ongoing SARS-CoV-2 transmission at the time of writing,3 the retrospective intra-action review process does not sufficiently address ongoing and protracted response planning. Within this context, we advocate for the inclusion of a prospective response examination in the intra-action review process—ie, examining how to sustain response measures to ensure resiliency and plan effectively for the future. |
Epidemiology of dengue, chikungunya, and Zika virus disease in the U.S. states and territories, 2017
Adams LE , Martin SW , Lindsey NP , Lehman JA , Rivera A , Kolsin J , Landry K , Staples JE , Sharp TM , Paz-Bailey G , Fischer M . Am J Trop Med Hyg 2019 101 (4) 884-890 Dengue, chikungunya, and Zika viruses, primarily transmitted by Aedes species mosquitoes, have caused large outbreaks in the Americas, leading to travel-associated cases and local mosquito-borne transmission in the United States. We describe the epidemiology of dengue, chikungunya, and noncongenital Zika virus disease cases reported from U.S. states and territories in 2017, including 971 dengue cases, 195 chikungunya cases, and 1,118 Zika virus disease cases. Cases of all three diseases reported from the territories were reported as resulting from local mosquito-borne transmission. Cases reported from the states were primarily among travelers, with only seven locally acquired mosquito-transmitted Zika virus disease cases reported from Texas (n = 5) and Florida (n = 2). In the territories, most dengue cases (n = 508, 98%) were reported from American Samoa, whereas the majority of chikungunya (n = 39, 100%) and Zika virus disease (n = 620, 93%) cases were reported from Puerto Rico. Temporally, the highest number of Zika virus disease cases occurred at the beginning of the year, followed by a sharp decline, mirroring decreasing case numbers across the Americas following large outbreaks in 2015 and 2016. Dengue and chikungunya cases followed a more seasonal pattern, with higher case numbers from July through September. Travelers to the United States and residents of areas with active virus transmission should be informed of both the ongoing risk from dengue, chikungunya, and Zika virus disease and personal protective measures to lower their risk of mosquito bites and to help prevent the spread of these diseases. |
West Nile virus and other domestic nationally notifiable arboviral diseases - United States, 2018
McDonald E , Martin SW , Landry K , Gould CV , Lehman J , Fischer M , Lindsey NP . MMWR Morb Mortal Wkly Rep 2019 68 (31) 673-678 Arthropodborne viruses (arboviruses) are transmitted to humans primarily through the bites of infected mosquitoes and ticks. West Nile virus (WNV) is the leading cause of domestically acquired arboviral disease in the continental United States (1). Other arboviruses, including eastern equine encephalitis, Jamestown Canyon, La Crosse, Powassan, and St. Louis encephalitis viruses, cause sporadic cases of disease and occasional outbreaks. This report summarizes surveillance data reported to CDC for 2018 on nationally notifiable arboviruses. It excludes dengue, chikungunya, and Zika viruses because they are primarily nondomestic viruses typically acquired through travel. In 2018, 48 states and the District of Columbia (DC) reported 2,813 cases of domestic arboviral disease, including 2,647 (94%) WNV disease cases. Of the WNV disease cases, 1,658 (63%) were classified as neuroinvasive disease (e.g., meningitis, encephalitis, and acute flaccid paralysis), for a national incidence of 0.51 cases of WNV neuroinvasive disease per 100,000 population. Because arboviral diseases continue to cause serious illness and have no definitive treatment, maintaining surveillance is important to direct and promote prevention activities. Health care providers should consider arboviral infections in patients with aseptic meningitis or encephalitis, perform appropriate diagnostic testing, and report cases to public health authorities. |
Patients with laboratory evidence of West Nile virus disease without reported fever
Landry K , Rabe IB , Messenger SL , Hacker JK , Salas ML , Scott-Waldron C , Haydel D , Rider E , Simonson S , Brown CM , Smole SC , Neitzel DF , Schiffman EK , Strain AK , Vetter S , Fischer M , Lindsey NP . Epidemiol Infect 2019 147 e219 In 2013, the national surveillance case definition for West Nile virus (WNV) disease was revised to remove fever as a criterion for neuroinvasive disease and require at most subjective fever for non-neuroinvasive disease. The aims of this project were to determine how often afebrile WNV disease occurs and assess differences among patients with and without fever. We included cases with laboratory evidence of WNV disease reported from four states in 2014. We compared demographics, clinical symptoms and laboratory evidence for patients with and without fever and stratified the analysis by neuroinvasive and non-neuroinvasive presentations. Among 956 included patients, 39 (4%) had no fever; this proportion was similar among patients with and without neuroinvasive disease symptoms. For neuroinvasive and non-neuroinvasive patients, there were no differences in age, sex, or laboratory evidence between febrile and afebrile patients, but hospitalisations were more common among patients with fever (P < 0.01). The only significant difference in symptoms was for ataxia, which was more common in neuroinvasive patients without fever (P = 0.04). Only 5% of non-neuroinvasive patients did not meet the WNV case definition due to lack of fever. The evidence presented here supports the changes made to the national case definition in 2013. |
Young adults in endemic areas: An untreated group in need of school-based preventive chemotherapy for schistosomiasis control and elimination
Korir HK , Riner DK , Kavere E , Omondi A , Landry J , Kittur N , Ndombi EM , Ondigo BN , Secor WE , Karanja DMS , Colley DG . Trop Med Infect Dis 2018 3 (3) Parasitologic surveys of young adults in college and university settings are not commonly done, even in areas known to be endemic for schistosomiasis and soil-transmitted helminths. We have done a survey of 291 students and staff at the Kisumu National Polytechnic in Kisumu, Kenya, using the stool microscopy Kato-Katz (KK) method and the urine point-of-care circulating cathodic antigen (POC-CCA) test. Based on three stools/two KK slides each, in the 208 participants for whom three consecutive stools were obtained, Schistosoma mansoni prevalence was 17.8%. When all 291 individuals were analyzed based on the first stool, as done by the national neglected tropical disease (NTD) program, and one urine POC-CCA assay (n = 276), the prevalence was 13.7% by KK and 23.2% by POC-CCA. Based on three stools, 2.5% of 208 participants had heavy S. mansoni infections (>/=400 eggs/gram feces), with heavy S. mansoni infections making up 13.5% of the S. mansoni cases. The prevalence of the soil-transmitted helminths (STH: Ascaris lumbricoides, Trichuris trichiura and hookworm) by three stools was 1.4%, 3.1%, and 4.1%, respectively, and by the first stool was 1.4%, 2.4% and 1.4%, respectively. This prevalence and intensity of infection with S. mansoni in a college setting warrants mass drug administration with praziquantel. This population of young adults is 'in school' and is both approachable and worthy of inclusion in national schistosomiasis control and elimination programs. |
Subacute liver failure due to autochthonous hepatitis E virus infection in an elderly man in the United States
Landry ML , Kamili S , Jain D . Hum Pathol (N Y) 2018 12 68-70 Hepatitis E virus (HEV) infection in immunocompetent individuals is uncommon in the United States. We report a case of elderly man who presented with jaundice, cholestatic hepatitis, and subacute liver failure with fatal outcome. The patient was started on steroids based on ANA positivity. Liver biopsy showed panlobular hepatitis with cholestasis. The histologic differential diagnosis included drug/toxic injury, biliary obstruction, and acute hepatitis C or hepatitis E. Drug/toxic injury was favored initially. However, subsequent serology was positive for anti-HEV IgM and IgG, and HEV RNA genotype 3 was detected in both serum and liver tissue. Awareness of autochthonous hepatitis E and its inclusion in the differential diagnosis is needed for early diagnosis and appropriate management. |
Update: Noncongenital Zika virus disease cases - 50 U.S. states and the District of Columbia, 2016
Hall V , Walker WL , Lindsey NP , Lehman JA , Kolsin J , Landry K , Rabe IB , Hills SL , Fischer M , Staples JE , Gould CV , Martin SW . MMWR Morb Mortal Wkly Rep 2018 67 (9) 265-269 Zika virus is a flavivirus primarily transmitted to humans by Aedes aegypti mosquitoes (1). Zika virus infections also have been documented through intrauterine transmission resulting in congenital infection; intrapartum transmission from a viremic mother to her newborn; sexual transmission; blood transfusion; and laboratory exposure (1-3). Most Zika virus infections are asymptomatic or result in mild clinical illness, characterized by acute onset of fever, maculopapular rash, arthralgia, or nonpurulent conjunctivitis; Guillain-Barre syndrome, meningoencephalitis, and severe thrombocytopenia rarely have been associated with Zika virus infection (1). However, congenital Zika virus infection can result in fetal loss, microcephaly, and other birth defects (1,2). In 2016, a total of 5,168 noncongenital Zika virus disease cases were reported from U.S. states and the District of Columbia. Most cases (4,897, 95%) were in travelers returning from Zika virus-affected areas. A total of 224 (4%) cases were acquired through presumed local mosquitoborne transmission, and 47 (1%) were acquired by other routes. It is important that providers in the United States continue to test symptomatic patients who live in or recently traveled to areas with ongoing Zika virus transmission or had unprotected sex with someone who lives in or traveled to those areas. All pregnant women and their partners should take measures to prevent Zika virus infection during pregnancy. A list of affected areas and specific recommendations on how to prevent Zika virus infection during pregnancy are available at https://www.cdc.gov/pregnancy/zika/protect-yourself.html. |
Adenovirus type 4 respiratory infections among civilian adults, northeastern United States, 2011-2015(1)
Kajon AE , Lamson DM , Bair CR , Lu X , Landry ML , Menegus M , Erdman DD , St George K . Emerg Infect Dis 2018 24 (2) 201-209 Human adenovirus type 4 (HAdV-4) is most commonly isolated in military settings. We conducted detailed molecular characterization on 36 HAdV-4 isolates recovered from civilian adults with acute respiratory disease (ARD) in the northeastern United States during 2011-2015. Specimens came from college students, residents of long-term care facilities or nursing homes, a cancer patient, and young adults without co-morbidities. HAdV-4 genome types 4a1 and 4a2, the variants most frequently detected among US military recruits in basic training before the restoration of vaccination protocols, were isolated in most cases. Two novel a-like variants were recovered from students enrolled at a college in Tompkins County, New York, USA, and a prototype-like variant distinguishable from the vaccine strain was isolated from an 18-year-old woman visiting a physician's office in Ulster County, New York, USA, with symptoms of influenza-like illness. Our data suggest that HAdV-4 might be an underestimated causative agent of ARD among civilian adults. |
Atypical hand-foot-and-mouth disease associated with coxsackievirus A6 infection
Lott JP , Liu K , Landry ML , Nix WA , Oberste MS , Bolognia J , King B . J Am Acad Dermatol 2013 69 (5) 736-41 ![]() BACKGROUND: Hand-foot-and-mouth disease (HFMD) is an acute viral illness commonly caused by coxsackievirus (CV)-A16 and enterovirus 71 infections. Recently, atypical HFMD has been reported in association with CV-A6, an uncommon enterovirus strain. OBJECTIVE: We sought to describe the clinical features of atypical HFMD associated with CV-A6 infection and its diagnostic laboratory evaluation. METHODS: Patients presenting to our institution with history and examination suggestive of atypical HFMD from January 2012 to July 2012 were identified. Morphology and distribution of mucocutaneous lesions were recorded. Enterovirus infection was assessed by reverse transcriptase polymerase chain reaction of biologic specimens. Enterovirus type was determined by viral capsid protein 1 gene sequencing. RESULTS: Two adults and 3 children with atypical HFMD were identified. Four of 5 patients exhibited widespread cutaneous lesions. In 2 patients with a history of atopic dermatitis, accentuation in areas of dermatitis was noted. Associated systemic symptoms prompted 4 of 5 patients to seek emergency care, and both adults were hospitalized for diagnostic evaluation. Infection with CV-A6 was confirmed in all patients. LIMITATIONS: This study is a case series from a single institution. CONCLUSION: Consideration of the expanded range of cutaneous findings in atypical HFMD caused by CV-A6 infection may assist clinicians in diagnosis and management. |
Hepatitis E virus infection in a liver transplant recipient: delayed diagnosis due to variable performance of serologic assays
Yoo N , Bernstein J , Caldwell C , Dong C , Drobeniuc J , Kamili S , Landry ML . Transpl Infect Dis 2013 15 (4) E166-8 ![]() Hepatitis E virus (HEV) infection within the United States has traditionally been associated with travel to hyperendemic regions. Recent reports have shown that autochthonous HEV occurs in developed countries and is caused by HEV genotype 3, which commonly infects swine 1. In Europe, clusters of HEV genotype 3 infections have been reported in immunocompromised hosts, especially solid organ transplant recipients in whom risk factors include eating game meat, pork products, and mussels 1, 2. Chronic HEV infection is common in transplant patients and early ribavirin treatment may be lifesaving 3, 4. Unfortunately, serologic assays for diagnostic testing for HEV infection have variable performance characteristics 5, 6, which can delay accurate diagnosis and thus affect the decision to initiate therapy as illustrated in the case presented below. | Five years after liver transplantation, a 58-year-old man presented with 1 week of dark urine and fatigue, with elevated total and direct bilirubin (3.16 mg/dL, 1.26 mg/dL), elevated transaminase levels (aspartate aminotransferase 260 U/L, alanine aminotransferase [ALT] 532 U/L), and a normal alkaline phosphatase (114 U/L). Liver biopsy was read as moderate acute cellular rejection (ACR). The patient was given intravenous methylprednisolone, his tacrolimus dose was doubled, and he was started on mycophenolate mofetil. Three weeks later, repeat testing revealed ALT of 668 U/L, and a second liver biopsy suggested mild ACR. He was given increased immunosuppression and his transaminase levels slowly decreased, but never returned to normal. |
Human T-cell lymphotropic virus type 3 (HTLV-3)- and HTLV-4-derived antisense transcripts encode proteins with similar Tax-inhibiting functions but distinct subcellular localization.
Larocque E , Halin M , Landry S , Marriott SJ , Switzer WM , Barbeau B . J Virol 2011 85 (23) 12673-85 ![]() The human T-cell lymphotropic virus (HTLV) retrovirus family is composed of the well-known HTLV type 1 (HTLV-1) and HTLV-2 and the most recently discovered HTLV-3 and HTLV-4. Like other retroviruses, HTLV-1 and HTLV-2 gene expression has been thought to be orchestrated through a single transcript. However, recent reports have demonstrated the unique potential of both HTLV-1 and HTLV-2 to produce an antisense transcript. Furthermore, these unexpected and newly identified transcripts lead to the synthesis of viral proteins termed HBZ (HTLV-1 basic leucine zipper) and APH-2 (antisense protein of HTLV-2), respectively. As potential open reading frames are present on the antisense strand of HTLV-3 and HTLV-4, we tested whether in vitro antisense transcription occurred in these viruses and whether these transcripts had a coding potential. Using HTLV-3 and HTLV-4 proviral DNA constructs, antisense transcripts were detected by reverse transcriptase PCR. These transcripts are spliced and polyadenylated and initiate at multiple sites from the 3' long terminal repeat (LTR). The resulting proteins, termed APH-3 and APH-4, are devoid of a typical basic leucine zipper domain but contain basic amino acid-rich regions. Confocal microscopy and Western blotting experiments demonstrated a nucleus-restricted pattern for APH-4, while APH-3 was localized both in the cytoplasm and in the nucleus. Both proteins showed partial colocalization with nucleoli and HBZ-associated structures. Finally, both proteins inhibited Tax1- and Tax3-mediated HTLV-1 and HTLV-3 LTR activation. These results further demonstrate that retroviral antisense transcription is not exclusive to HTLV-1 and HTLV-2 and that APH-3 and APH-4 could impact HTLV-3 and HTLV-4 replication. |
Confidence about vaccines in the United States: understanding parents' perceptions
Kennedy A , Lavail K , Nowak G , Basket M , Landry S . Health Aff (Millwood) 2011 30 (6) 1151-9 The United States has made tremendous progress in using vaccines to prevent serious, often infectious, diseases. But concerns about such issues as vaccines' safety and the increasing complexity of immunization schedules have fostered doubts about the necessity of vaccinations. We investigated parents' confidence in childhood vaccines by reviewing recent survey data. We found that most parents-even those whose children receive all of the recommended vaccines-have questions, concerns, or misperceptions about them. We suggest ways to give parents the information they need and to keep the US national vaccination program a success. |
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