Last data update: Dec 09, 2024. (Total: 48320 publications since 2009)
Records 1-9 (of 9 Records) |
Query Trace: Williams AJ[original query] |
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Effects of COVID-19 on vaccine-preventable disease surveillance systems in the World Health Organization African Region, 2020
Bigouette JP , Callaghan AW , Donadel M , Porter AM , Rosencrans L , Lickness JS , Blough S , Li X , Perry RT , Williams AJ , Scobie HM , Dahl BA , McFarland J , Murrill CS . Emerg Infect Dis 2022 28 (13) S203-s207 Global emergence of the COVID-19 pandemic in 2020 curtailed vaccine-preventable disease (VPD) surveillance activities, but little is known about which surveillance components were most affected. In May 2021, we surveyed 214 STOP (originally Stop Transmission of Polio) Program consultants to determine how VPD surveillance activities were affected by the COVID-19 pandemic throughout 2020, primarily in low- and middle-income countries, where program consultants are deployed. Our report highlights the responses from 154 (96%) of the 160 consultants deployed to the World Health Organization African Region, which comprises 75% (160/214) of all STOP Program consultants deployed globally in early 2021. Most survey respondents observed that VPD surveillance activities were somewhat or severely affected by the COVID-19 pandemic in 2020. Reprioritization of surveillance staff and changes in health-seeking behaviors were factors commonly perceived to decrease VPD surveillance activities. Our findings suggest the need for strategies to restore VPD surveillance to prepandemic levels. |
CoMPARA: Collaborative Modeling Project for Androgen Receptor Activity.
Mansouri K , Kleinstreuer N , Abdelaziz AM , Alberga D , Alves VM , Andersson PL , Andrade CH , Bai F , Balabin I , Ballabio D , Benfenati E , Bhhatarai B , Boyer S , Chen J , Consonni V , Farag S , Fourches D , Garcia-Sosa AT , Gramatica P , Grisoni F , Grulke CM , Hong H , Horvath D , Hu X , Huang R , Jeliazkova N , Li J , Li X , Liu H , Manganelli S , Mangiatordi GF , Maran U , Marcou G , Martin T , Muratov E , Nguyen DT , Nicolotti O , Nikolov NG , Norinder U , Papa E , Petitjean M , Piir G , Pogodin P , Poroikov V , Qiao X , Richard AM , Roncaglioni A , Ruiz P , Rupakheti C , Sakkiah S , Sangion A , Schramm KW , Selvaraj C , Shah I , Sild S , Sun L , Taboureau O , Tang Y , Tetko IV , Todeschini R , Tong W , Trisciuzzi D , Tropsha A , Van Den Driessche G , Varnek A , Wang Z , Wedebye EB , Williams AJ , Xie H , Zakharov AV , Zheng Z , Judson RS . Environ Health Perspect 2020 128 (2) 27002 BACKGROUND: Endocrine disrupting chemicals (EDCs) are xenobiotics that mimic the interaction of natural hormones and alter synthesis, transport, or metabolic pathways. The prospect of EDCs causing adverse health effects in humans and wildlife has led to the development of scientific and regulatory approaches for evaluating bioactivity. This need is being addressed using high-throughput screening (HTS) in vitro approaches and computational modeling. OBJECTIVES: In support of the Endocrine Disruptor Screening Program, the U.S. Environmental Protection Agency (EPA) led two worldwide consortiums to virtually screen chemicals for their potential estrogenic and androgenic activities. Here, we describe the Collaborative Modeling Project for Androgen Receptor Activity (CoMPARA) efforts, which follows the steps of the Collaborative Estrogen Receptor Activity Prediction Project (CERAPP). METHODS: The CoMPARA list of screened chemicals built on CERAPP's list of 32,464 chemicals to include additional chemicals of interest, as well as simulated ToxCast metabolites, totaling 55,450 chemical structures. Computational toxicology scientists from 25 international groups contributed 91 predictive models for binding, agonist, and antagonist activity predictions. Models were underpinned by a common training set of 1,746 chemicals compiled from a combined data set of 11 ToxCast/Tox21 HTS in vitro assays. RESULTS: The resulting models were evaluated using curated literature data extracted from different sources. To overcome the limitations of single-model approaches, CoMPARA predictions were combined into consensus models that provided averaged predictive accuracy of approximately 80% for the evaluation set. DISCUSSION: The strengths and limitations of the consensus predictions were discussed with example chemicals; then, the models were implemented into the free and open-source OPERA application to enable screening of new chemicals with a defined applicability domain and accuracy assessment. This implementation was used to screen the entire EPA DSSTox database of approximately 875,000 chemicals, and their predicted AR activities have been made available on the EPA CompTox Chemicals dashboard and National Toxicology Program's Integrated Chemical Environment. https://doi.org/10.1289/EHP5580. |
The Stop Transmission of Polio Data Management (STOP DM) assignment and its role in polio eradication and immunization data improvement in Africa
Benke A , Williams AJ , MacNeil A . Pan Afr Med J 2017 27 20 The availability and use of high quality immunization and surveillance data are crucial for monitoring all components of the Global Polio Eradication Program (GPEI). The Stop Transmission of Polio (STOP) program was initiated in 1999 to train and mobilize human resources to provide technical support to polio endemic and at-risk countries and in 2002 the STOP data management (STOP DM) deployment was created to provide capacity development in the area of data management for immunization and surveillance data for these countries. Since 2002, Africa has received the majority of support from the STOP DM program, with almost 80% of assignments being placed in African countries. The STOP DM program has played a valuable role in improving the quality and use of data for the GPEI and has increasingly supported other immunization program data needs. In this report we provide an overview of the history, current status, and future of the STOP DM program, with a specific focus on the African continent. |
Lessons learned and legacy of the Stop Transmission of Polio Program
Kerr Y , Mailhot M , Williams AJ , Swezy V , Quick L , Tangermann RH , Ward K , Benke A , Callaghan A , Clark K , Emery B , Nix J , Aydlotte E , Newman C , Nkowane B . J Infect Dis 2017 216 S316-S323 In 1988, the by the World Health Assembly established the Global Polio Eradication Initiative, which consisted of a partnership among the World Health Organization (WHO), Rotary International, the Centers for Disease Control and Prevention (CDC), and the United Nations Children's Fund. By 2016, the annual incidence of polio had decreased by >99.9%, compared with 1988, and at the time of writing, only 3 countries in which wild poliovirus circulation has never been interrupted remain: Afghanistan, Nigeria, and Pakistan. A key strategy for polio eradication has been the development of a skilled and deployable workforce to implement eradication activities across the globe. In 1999, the Stop Transmission of Polio (STOP) program was developed and initiated by the CDC, in collaboration with the WHO, to train and mobilize additional human resources to provide technical assistance to polio-endemic countries. STOP has also informed the development of other public health workforce capacity to support polio eradication efforts, including national STOP programs. In addition, the program has diversified to address measles and rubella elimination, data management and quality, and strengthening routine immunization programs. This article describes the STOP program and how it has contributed to polio eradication by building global public health workforce capacity. |
Detection of antibodies directed to the N-terminal region of GAD is dependent on assay format and contributes to differences in the specificity of GAD autoantibody assays for type 1 diabetes
Williams AJ , Lampasona V , Schlosser M , Mueller PW , Pittman DL , Winter WE , Akolkar B , Wyatt R , Brigatti C , Krause S , Achenbach P . Diabetes 2015 64 (9) 3239-46 Autoantibodies to glutamate decarboxylase (GADA) are sensitive markers of islet autoimmunity and type 1 diabetes. They form the basis of robust prediction models and are widely used for recruitment of subjects at high risk of type 1 diabetes to prevention trials. However GADA are also found in many individuals at low risk of diabetes progression. To identify the sources of diabetes irrelevant GADA reactivity therefore, we analyzed data from the 2009 and 2010 Diabetes Autoantibody Standardization Program GADA workshop and found that binding of healthy control sera varied according to assay type. Characterization of control sera found positive by radiobinding assay, but negative by ELISA showed that many of these sera reacted to epitopes in the N-terminal region of the molecule. This finding prompted development of an N-terminally truncated GAD65 radiolabel, 35S-GAD65(96-585), which improved the performance of most GADA radiobinding assays (RBAs) participating in an Islet Autoantibody Standardization Program GADA substudy. These detailed workshop comparisons have identified a source of disease-irrelevant signals in GADA RBAs and suggest that N-terminally truncated GAD labels will enable more specific measurement of GADA in type 1 diabetes. |
Effect of time at temperature on wild poliovirus titers in stool specimens
Walker AT , Williams AJ , Gary HE Jr , Pallansch MA , Wassilak SG , Oberste MS . Virology 2015 482 28-31 BACKGROUND: The effect of transport temperature on the viability of poliovirus in stool specimens from paralyzed cases has not been tested. Quality assurance of programmatic indicators will be necessary in the final phase of polio eradication. OBJECTIVE: To estimate the effect of time at elevated temperatures on wild poliovirus titers in stool specimens. METHODS: We exposed aliquots of pooled wild poliovirus type 1 specimens to elevated temperatures (27 degrees C, 31 degrees C, and 35 degrees C) for varying time periods up to 14 days. We determined the virus titer of these aliquots and created decay curves at each temperature to estimate the relationship between time at temperature and virus titer. RESULTS: We found significantly different slopes of decay at each temperature. The negative slopes increased as the temperature increased. CONCLUSIONS: While poliovirus in stool remains relatively stable at moderately elevated temperature, transport at higher temperatures could impact sample integrity and virus isolation results. |
Identification of vaccine-derived polioviruses using dual-stage real-time RT-PCR.
Kilpatrick DR , Ching K , Iber J , Chen Q , Yang SJ , De L , Williams AJ , Mandelbaum M , Sun H , Oberste MS , Kew OM . J Virol Methods 2013 197 25-8 Vaccine-derived polioviruses (VDPVs) are associated with polio outbreaks and prolonged infections in individuals with primary immunodeficiencies. VDPV-specific PCR assays for each of the three Sabin oral poliovirus vaccine (OPV) strains were developed, targeting sequences within the VP1 capsid region that are selected for during replication of OPV in the human intestine. Over 2,400 Sabin-related isolates and identified 755 VDPVs were screened. Sensitivity of all assays was 100%, while specificity was 100% for serotypes 1 and 3, and 76% for serotype 2. The assays permit rapid, sensitive identification of OPV-related viruses and flag programmatically important isolates for further characterization by genomic sequencing. |
Multiple independent emergences of type 2 vaccine-derived polioviruses during a large outbreak in northern Nigeria
Burns CC , Shaw J , Jorba J , Bukbuk D , Adu F , Gumede N , Pate MA , Abanida EA , Gasasira A , Iber J , Chen Q , Vincent A , Chenoweth P , Henderson E , Wannemuehler K , Naeem A , Umami RN , Nishimura Y , Shimizu H , Baba M , Adeniji A , Williams AJ , Kilpatrick DR , Oberste MS , Wassilak SG , Tomori O , Pallansch MA , Kew O . J Virol 2013 87 (9) 4907-22 Since 2005, a large poliomyelitis outbreak associated with type 2 circulating vaccine-derived poliovirus (cVDPV2) has occurred in northern Nigeria, where immunization coverage with trivalent oral poliovirus vaccine (tOPV) has been low. Phylogenetic analysis of P1/capsid region sequences of isolates from each of the 403 cases reported in 2005 to 2011 resolved the outbreak into 23 independent type 2 vaccine-derived poliovirus (VDPV2) emergences, at least 7 of which established circulating lineage groups. Virus from one emergence (lineage group 2005-8; 361 isolates) was estimated to have circulated for over 6 years. The population of the major cVDPV2 lineage group expanded rapidly in early 2009, fell sharply after two tOPV rounds in mid-2009, and gradually expanded again through 2011. The two major determinants of attenuation of the Sabin 2 oral poliovirus vaccine strain (A481 in the 5'-untranslated region [5'-UTR] and VP1-Ile143) had been replaced in all VDPV2 isolates; most A481 5'-UTR replacements occurred by recombination with other enteroviruses. cVDPV2 isolates representing different lineage groups had biological properties indistinguishable from those of wild polioviruses, including efficient growth in neuron-derived HEK293 cells, the capacity to cause paralytic disease in both humans and PVR-Tg21 transgenic mice, loss of the temperature-sensitive phenotype, and the capacity for sustained person-to-person transmission. We estimate from the poliomyelitis case count and the paralytic case-to-infection ratio for type 2 wild poliovirus infections that approximately 700,000 cVDPV2 infections have occurred during the outbreak. The detection of multiple concurrent cVDPV2 outbreaks in northern Nigeria highlights the risks of cVDPV emergence accompanying tOPV use at low rates of coverage in developing countries. |
Outbreak of type 2 vaccine-derived poliovirus in Nigeria: emergence and widespread circulation in an underimmunized population
Wassilak S , Pate MA , Wannemuehler K , Jenks J , Burns C , Chenoweth P , Abanida EA , Adu F , Baba M , Gasasira A , Iber J , Mkanda P , Williams AJ , Shaw J , Pallansch M , Kew O . J Infect Dis 2011 203 (7) 898-909 Wild poliovirus has remained endemic in northern Nigeria because of low coverage achieved in the routine immunization program and in supplementary immunization activities (SIAs). An outbreak of infection involving 315 cases of type 2 circulating vaccine-derived poliovirus (cVDPV2; >1% divergent from Sabin 2) occurred during July 2005-June 2010, a period when 23 of 34 SIAs used monovalent or bivalent oral poliovirus vaccine (OPV) lacking Sabin 2. In addition, 21 "pre-VDPV2" (0.5%-1.0% divergent) cases occurred during this period. Both cVDPV and pre-VDPV cases were clinically indistinguishable from cases due to wild poliovirus. The monthly incidence of cases increased sharply in early 2009, as more children aged without trivalent OPV SIAs. Cumulative state incidence of pre-VDPV2/cVDPV2 was correlated with low childhood immunization against poliovirus type 2 assessed by various means. Strengthened routine immunization programs in countries with suboptimal coverage and balanced use of OPV formulations in SIAs are necessary to minimize risks of VDPV emergence and circulation. |
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