Eradication of Wild Poliovirus from the Americas: Wild Poliovirus Surveillance-Laboratory Issues

Pinheiro, F. P.; Kew, Olen M.; Hatch, Milford H.; Silveira, Cristiane M. da; Quadrós, Ciro A. de

doi:10.1093/infdis/175.supplement_1.s43

Cited by 16 publications

(11 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Our studies were also facilitated by the availability of isolates representing well-defined evolutionary pathways obtained over a 10-year period. The 1981 isolates from Venezuela were closely related to the true imported founder virus, and increasingly sensitive poliovirus surveillance in the Americas (16,64) yielded an ample number of well-documented direct descendants of the founder virus. Although comprehensive sequence data sets now exist for poliovirus isolates from other regions of endemicity (7,23), the evolutionary pathways in most areas of endemicity are complex, and isolates closely related to the overall common founder are not generally available (31).…”

Section: Discussionmentioning

confidence: 99%

Calibration of Multiple Poliovirus Molecular Clocks Covering an Extended Evolutionary Range

Jorba

Campagnoli

et al. 2008

J Virol

165

168

View full text Add to dashboard Cite

We have calibrated five different molecular clocks for circulating poliovirus based upon the rates of fixation of total substitutions (K t ), synonymous substitutions (K s ), synonymous transitions (A s ), synonymous transversions (B s ), and nonsynonymous substitutions (K a ) into the P1/capsid region (2,643 nucleotides). Rates were determined over a 10-year period by analysis of sequences of 31 wild poliovirus type 1 isolates representing a well-defined phylogeny derived from a common imported ancestor. Similar rates were obtained by linear regression, the maximum likelihood/single-rate dated-tip method, and Bayesian inference. . Nonsynonymous substitutions at all P1/capsid sites, including the neutralizing antigenic sites, appeared to be constrained by purifying selection. Simulation of the evolution of third-codon positions suggested that saturation of synonymous transitions would be evident at 10 years and complete at ϳ65 years of independent transmission. Saturation of synonymous transversions was predicted to be minimal at 20 years and incomplete at 100 years. The rapid evolution of the K t , K s , and A s clocks can be used to estimate the dates of divergence of closely related viruses, whereas the slower B s and K a clocks may be used to explore deeper evolutionary relationships within and across poliovirus genotypes.Poliovirus is one of the most rapidly evolving viruses known (17,31,38,52,58). Estimates of the rates of total nucleotide substitution into poliovirus capsid regions average ϳ10 Ϫ2 substitutions per site per year (31, 39, 52-54, 89, 90). The rates appear to be similar across the three poliovirus serotypes and for both circulating polioviruses and polioviruses associated with chronic infections. This very rapid rate of genomic evolution has facilitated high-resolution molecular epidemiologic studies, permitting the unambiguous identification of the sources of imported viruses (10, 41) and the resolution of separate lineages during outbreaks (39,43,74,75), during endemic transmission (23,52,90), during prolonged poliovirus replication in immunodeficient patients (9,31,53,89), and from environmental surveillance (23). However, the rapid accumulation of nucleotide substitutions, most of which are synonymous transitions, obscures deeper evolutionary relationships (46,70).Underlying the rapid pace of poliovirus genomic evolution are the high rates of base misincorporation (in the range of 10 Ϫ5 to 10 Ϫ3 per base per replication) by the poliovirus RNAdependent RNA polymerase (2,15,19,81,82,84). These high mutation rates are attributable to the absence of 3Ј35Ј exonuclease proofreading mechanisms for the viral RNA polymerases (19), although other mechanisms may also be involved (17, 18). The strong transition bias of the poliovirus polymerase (2, 46) is reflected in the pattern of fixation nucleotide substitutions into poliovirus genomes.In this report, we have calibrated five different molecular clocks based upon the rates of fixation of total substitutions (K t ), synonymous substitutions (K s ),...

show abstract

Section: Discussionmentioning

confidence: 99%

Calibration of Multiple Poliovirus Molecular Clocks Covering an Extended Evolutionary Range

Jorba

Campagnoli

et al. 2008

J Virol

165

168

View full text Add to dashboard Cite

show abstract

“…(2,4,5) Any chosen set of decisions yields fixed costs, which we estimate using income-group-dependent cost inputs. (5) We characterize the major cost components related to vaccination and field AFP surveillance (i.e., not surveillance costs incurred to run the global polio laboratory network (14,19,20) as countrylevel costs (even if external donors may contribute a proportion of them). We view costs of laboratory surveillance (including environmental surveillance), containment, and the global stockpiles as global programmatic costs.…”

Section: Components Of the Modelmentioning

confidence: 99%

Uncertainty and Sensitivity Analyses of a Decision Analytic Model for Posteradication Polio Risk Management

Tebbens¹,

Pallansch

Kew

et al. 2008

Risk Analysis

View full text Add to dashboard Cite

Decision analytic modeling of polio risk management policies after eradication may help inform decisionmakers about the quantitative tradeoffs implied by various options. Given the significant dynamic complexity and uncertainty involving posteradication decisions, this article aims to clarify the structure of a decision analytic model developed to help characterize the risks, costs, and benefits of various options for polio risk management after eradication of wild polioviruses and analyze the implications of different sources of uncertainty. We provide an influence diagram of the model with a description of each component, explore the impact of different assumptions about model inputs, and present probability distributions of model outputs. The results show that choices made about surveillance, response, and containment for different income groups and immunization policies play a major role in the expected final costs and polio cases. While the overall policy implications of the model remain robust to the variations of assumptions and input uncertainty we considered, the analyses suggest the need for policymakers to carefully consider tradeoffs and for further studies to address the most important knowledge gaps.

show abstract

“…Efforts to eradicate wild polioviruses depend on aggressive global surveillance for AFP cases and detection of circulating polioviruses from fecal samples using the extensive GPLN established in 1988. ( 5 ) Fig. 1 shows the locations of the seven global specialized reference laboratories (SRLs), 15 regional reference laboratories (RRLs), and 123 national laboratories (NLs) that comprise the GPLN.…”

Section: Estimating the Costs Of The Gplnmentioning

confidence: 99%

Global Surveillance and the Value of Information: The Case of the Global Polio Laboratory Network

Gourville

Tebbens²,

Sangrujee³

et al. 2006

Risk Analysis

View full text Add to dashboard Cite

Effective control and eradication of diseases requires reliable information from surveillance activities, including laboratories, which typically incur real financial costs. This article presents data from a survey we conducted to estimate the costs of the Global Polio Laboratory Network (GPLN), which currently supports aggressive global surveillance for acute flaccid paralysis (AFP) to detect circulating polioviruses. The Global Polio Eradication Initiative (GPEI) of the World Health Organization (WHO) provides resources for some of the laboratory network costs, but the total cost of the network remains relatively poorly characterized given the limited documentation of national contributions. We surveyed network laboratories to quantify AFP surveillance support costs and provide data for cost estimates of potential posteradication surveillance policies related to the laboratories. We estimate that the GPLN currently requires millions (US dollars 2002) in total support annually, and that half of the support for national and regional reference laboratories comes from external donors through the WHO or bilateral agreements and half from within nations that host those laboratories. The article also presents the framework for considering the value of information from this global surveillance network and suggests that the expected value of surveillance information from the GPLN currently exceeds its costs. We also provided important insights about how the value of information may change after successful eradication of wild polioviruses.

show abstract

Eradication of Wild Poliovirus from the Americas: Wild Poliovirus Surveillance-Laboratory Issues

Cited by 16 publications

References 4 publications

Calibration of Multiple Poliovirus Molecular Clocks Covering an Extended Evolutionary Range

Calibration of Multiple Poliovirus Molecular Clocks Covering an Extended Evolutionary Range

Uncertainty and Sensitivity Analyses of a Decision Analytic Model for Posteradication Polio Risk Management

Global Surveillance and the Value of Information: The Case of the Global Polio Laboratory Network

Contact Info

Product

Resources

About