Completion of National Laboratory Inventories for Wild Poliovirus Containment --- Region of the Americas, March 2010

Completion of National Laboratory Inventories for Wild Poliovirus Containment --- Region of the Americas, March 2010
Weekly
August 13, 2010 / 59(31);985-988


In May 1988, the World Health Assembly resolved to eradicate wild poliovirus (WPV) transmission globally. By 2006, transmission of indigenous WPV was eliminated in all but four countries (Afghanistan, India, Nigeria, and Pakistan). In May 1999, the World Health Assembly urged member states to begin the process leading to laboratory containment of WPV (1). Containment of infectious and potentially infectious WPV materials after eradication is essential to minimize the risk for reintroducing WPV into poliomyelitis-free communities. The staged containment approach begins with a national survey of all biomedical facilities, which alerts facilities to the need for containment, encourages reduction of WPV materials, and develops a national inventory of facilities holding such materials (Phase I). In May 2008, the World Health Assembly reiterated the need for progress in containment and urged polio-free states to complete Phase I (2, 3). This report describes completion of Phase I by the countries and territories in the World Health Organization (WHO) Region of the Americas during 2001--2010. Of 67,362 biomedical facilities, all 15,541 (23.1%) that were classified as high-risk or medium-risk facilities were surveyed. Of the remaining 51,821 (76.9%) facilities, all classified as low-risk, 44,077 (85.1%) were surveyed; sampling ranged from 12.8% to 100% among countries. After voluntary destruction of some materials during Phase I, a total of 215 facilities in nine countries of the Region of the Americas reported retaining WPV materials as of March 2010. The survey provides a facility registry for use in subsequent steps that will lead to global poliovirus containment.

An elimination initiative began in the Americas in 1985, and the last case of WPV infection was confirmed in 1991; the western hemisphere was certified polio-free in 1994. In 2004, the director of the Pan American Health Organization (PAHO) established the American Regional Commission for the Certification of Poliovirus Laboratory Containment and Verification of Polio-free Status (RCC) to oversee Phase I activities. Forty-three countries and territories in the Region of the Americas conducted Phase I activities during 2001--2010. PAHO advised member states regarding creation of national plans of action, provided technical assistance on implementing national surveys, and monitored progress. National task forces comprised of working groups from various ministries and/or sectors were formed to implement the national plans of action. National certification committees comprised of experts in areas related to polio eradication, epidemiology, virology, pediatrics, and public health were formed to review progress and ensure completeness and accuracy. Seven regional and subregional meetings were held to facilitate exchange between countries on strategies and progress and to assure Phase I quality and consistency. The United States (4) and Canada, the Region of the Americas countries with the largest research laboratory infrastructures, began Phase I containment activities in 2002 because of the expected complexity of the task.

National databases of biomedical institutions and laboratories were commonly compiled through multisector efforts coordinated by the Ministry of Health (MOH), the national certification committee, or joint working groups. Methods used to establish the national database varied by country, but primarily consisted of consolidating and verifying lists from national laboratory registries, accrediting bodies, professional organizations and associations, and institutional and national biosafety networks. Institutions and laboratories included in the national databases were MOH facilities, hospitals, research laboratories, military facilities, environmental and other government agencies, and private industrial companies and clinical diagnostic laboratories. Databases were verified and supplemented by telephone book and Internet searches and by literature reviews. Countries differed in methods for enumerating institutions and laboratories. For example, countries with complex laboratory infrastructures, such as Canada and the United States, counted large universities, government agencies, and vaccine producers as single units to be held accountable for the multiple laboratories under their jurisdictions. Conversely, other countries, with fewer large multilaboratory institutions, counted individual laboratories.

Countries and territories classified each institution and laboratory according to the risk for possessing infectious or potentially infectious WPV materials. High-risk facilities included virology, university, research, and public health laboratories. Medium-risk facilities included environmental, major hospital, industrial, and clinical laboratories with advanced microbiological capabilities. Low-risk facilities included basic public or private clinical or other biomedical laboratories with limited or no capacity for long-term storage of biological specimens. National surveys were guided by WHO standards (3). All high-risk and medium-risk institutions and laboratories were surveyed for the presence of WPV materials. A proportion of low-risk facilities (85.1% overall, ranging from 12.8% to 100% by country) was surveyed to confirm accuracy of classification. All countries exceeded the RCC-recommended 10% sampling minimum for low-risk facilities.

The most common survey methods were electronic forms and letters sent to institutions and laboratories from the MOH or the president of the national certification committee. Follow-up telephone calls and visits were made to recipients who failed to respond. In Argentina, Brazil, Chile, Colombia, Mexico, Peru, and Caribbean countries, national task force members visited high-risk laboratories as well as institutions that had reported possessing infectious or potentially infectious WPV materials. The El Salvador national task force sent letters and survey instruments to laboratories using private couriers who were also responsible for securing and delivering responses. Task forces in Bolivia, Costa Rica, Ecuador, Guatemala, Nicaragua, and Panama conducted personal visits to all laboratories included in the national database and verified response accuracy. Argentina, Brazil, Cuba, and Mexico created subnational teams whose responsibility entailed verifying the completeness of the laboratory list, the accuracy and consistency of the responses, the completion of the survey, and visits to high-risk laboratories. Completeness of the surveys in all countries was assessed by a systematic quality-assurance procedure provided by WHO.

Of 67,362 biomedical facilities, a total of 59,618 (88.5%) were surveyed. All 4,313 (7.2%) laboratories classified as high-risk and all 11,228 (18.8%) classified as medium-risk were surveyed, as well as 44,077 (85.1%) of 51,821 laboratories classified as low-risk (73.9%) (Table). Of all facilities surveyed, 2,629 (4.4%) were virology, university, research, or public health facilities; 10,372 (17.4%) were hospital-based facilities (both medium-risk and low-risk); 41,438 (69.5%) were clinical diagnostic facilities (both medium-risk and low-risk); and 5,179 (8.7%) were environmental, industrial, or other types of facilities.

The number of high-risk or medium-risk facilities holding WPV materials before the survey was not determined. No low-risk facilities were found to be holding WPV materials. After the survey, the number of facilities retaining infectious or potentially infectious WPV materials totaled 215 in nine Region of Americas countries: the United States (180), Canada (eight), Brazil (six), Costa Rica (six), Argentina (five), Mexico (four), Guatemala (three), Chile (two), and Trinidad and Tobago (one). On March 5, RCC reviewed the quality and completeness of the final regional report and declared Phase I of laboratory containment in the Region of Americas complete.

Reported by
Pan American Health Organization, Washington, D.C. World Health Organization (WHO) Regional Office for the Americas, Polio Eradication Dept, WHO, Geneva, Switzerland. Task Force for Global Health, Decatur, Georgia. Global Immunization Div, Div of Viral Diseases, National Center for Immunization and Respiratory Diseases, CDC.

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Completion of National Laboratory Inventories for Wild Poliovirus Containment --- Region of the Americas, March 2010