The Journal of Infectious Diseases The GPLN as a Platform for the Viral Vaccine-Preventable and Emerging Diseases Laboratory Networks • JID 2017:216 (Suppl 1) • S299 The Journal of Infectious Diseases ® 2017;216(S1):S299–307 Te Global Polio Laboratory Network as a Platform for the Viral Vaccine-Preventable and Emerging Diseases Laboratory Networks Ousmane M. Diop, 1 Olen M. Kew, 2 Esther M. de Gourville, 4 and Mark A. Pallansch 3 1 World Health Organization, Geneva, Switzerland; 2 Task Force for Global Health, Decatur, and 3 Centers for Diseases Control and Prevention, Atlanta, Georgia; and 4 Pan American Health Organization, Nassau, Bahamas Te Global Polio Laboratory Network (GPLN) began building in the late 1980s on a 3-tiered structure of 146 laboratories with difer- ent and complementary technical and support capacities (poliovirus isolation, molecular strain characterization including sequencing, quality assurance, and research). Te purpose of this network is to provide timely and accurate laboratory results to the Global Polio Eradication Initiative. Deeply integrated with feld case-based surveillance, it ultimately provides molecular epidemiological data from polioviruses used to inform programmatic and immunization activities. Tis network of global coverage requires substantial investments in laboratory infrastructure, equipment, supplies, reagents, quality assurance, stafng and training, ofen in resource-limited settings. Te GPLN has not only developed country capacities, but it also serves as a model to other global laboratory networks for vaccine-preventable diseases that will endure afer the polio eradication goal is achieved. Leveraging lessons learned during past 27 years, the authors discuss options for transitioning GPLN assets to support control of other viral vaccine-preventable, emerging, and reemerging diseases. Keywords. Poliomyelitis; Eradication; Laboratory; Networking; Legacy. Following the launch of the Global Polio Eradication Initiative (GPEI) in 1988 [1], the World Health Organization (WHO) adopted a model to achieve global coverage of laboratory services to support surveillance for acute faccid paralysis, based on the experience with eradication eforts in the Region of the Americas. Selected laboratories were enrolled into a collaborating network, the Global Polio Laboratory Network (GPLN) coordinated by WHO. Network membership depended on nomination by host government, on-site evaluation by WHO of physical infrastruc- ture, availability of suitably qualifed personnel, and ability to accurately implement recommended procedures for poliovirus detection and characterization. Although not every country has a GPLN laboratory, each is linked to designated laboratories where specimens could be referred for rapid testing. Afer the initial decade of growth linked to introduction of regional eradication goals and corresponding surveillance programs, GPLN mem- bership has been mostly constant; currently, 146 laboratories are enrolled and originally categorized into 3 groups (Figure 1) with defned responsibilities: (1) subnational and national laboratories (n = 123), (2) regional reference laboratories (n = 17), and (3) global specialized laboratories (n = 6). Laboratory diagnosis of poliovirus consists of 3 consecu- tive main procedures: viral isolation for detection of the virus; intratypic diferentiation to distinguish vaccine strains from wild poliovirus (WPV) strains; and, fnally, sequencing for molecular epidemiology. Tese procedures were aligned with the 3 tiers within the GPLN. During recent years, the capac- ities of these laboratories have evolved tremendously, and GPLN’s laboratories have developed new capacities at all lev- els. It is noteworthy that >90 national/intercountry polio lab- oratories currently have intratypic diferentiation capacity, and many regional and some national laboratories have sequencing capacities; 27 laboratories participated in the 2016 profciency testing as part of establishing this recognized capacity. In addi- tion, these expanded capabilities will be an important factor in fulflling requirements of the WHO Global Action Plan to minimize the poliovirus facility–associated risk of introducing eradicated viruses into the population. As part of the process defned by this plan and with the aim of containing poliovirus in a few facilities, some specialized and regional laboratories will be designated as polio-essential facilities for containment of polioviruses. Since the beginning of the program, a core activity of the GPLN has been to test stool specimens from patients with acute faccid paralysis (AFP) for the presence of polioviruses. More recently, sewage specimens are also tested in several countries as a supplement to AFP surveillance. It is noteworthy that strengthening environmental surveillance is driven by the need to improve detection of poliovirus circulation in countries and areas where surveillance and immunization indicators are SUPPLEMENT ARTICLE © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. This is an Open Access article distributed under the terms of the Creative Commons Attribution 3.0 IGO (CC BY 3.0 IGO) License (https://creativecommons.org/licenses/by/3.0/igo/) which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. DOI: 10.1093/infdis/jix092 Correspondence: O. M. Diop, PhD, Polio Eradication, Director General’s Offce, World Health Organization, Avenue Appia, CH-1211, Geneva 27, Switzerland (diopo@who.int).