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Cervical cancer is the leading cause of cancer deaths among women in Latin America and the Caribbean, and disproportionately affects poorer women. Mortality rates in the region are seven times greater than in North America. In light of the significant public health burden, the Pan American Health Organization has drafted a Regional Strategy for Cervical Cancer Prevention and Control. The Strategy calls for increased action to strengthen programmes through an integrated package of services: health information and education; screening and pre-cancer treatment; invasive cervical cancer treatment and palliative care; and evidence-based policy decisions on whether and how to introduce human papillomavirus (HPV) vaccines. It calls for a seven-point plan of action: conduct a situation analysis; intensify information, education and counselling; scale up screening and link to pre-cancer treatment; strengthen information systems and cancer registries; improve access to and quality of cancer treatment and palliative care; generate evidence to facilitate decision-making regarding HPV vaccine introduction; and advocate for equitable access and affordable HPV vaccines. This proposed strategy, approved by the PAHO Directing Council on 1 October 2008, has the possibility of stimulating and accelerating the introduction of new screening technology and HPV vaccines into programmes throughout Latin America and the Caribbean. [ABSTRACT FROM AUTHOR]

OBJECTIVES: This study evaluated the impact of international coordination on polio eradication in Southeast Asia. METHODS: Active surveillance systems for acute flaccid paralysis were assessed. Analyses focused on surveillance proficiency and polio incidence. RESULTS: Ten countries coordinated activities. Importations occurred and were rapidly contained in China and Myanmar. Countries that have been free of indigenous polio transmission for at least 3 years include Sri Lanka, Indonesia, Myanmar, and Thailand. In the remaining endemic countries--India, Nepal, and Bangladesh--poliovirus transmission has been substantially reduced; however, these countries still harbor the world's largest polio reservoir. CONCLUSIONS: Unprecedented international coordination in Southeast Asia resulted in dramatic progress in polio eradication and serves as a paradigm for control of other infectious diseases such as malaria and tuberculosis. [ABSTRACT FROM AUTHOR]

No vaccine has been more effective in reducing disease burden, especially in preventing child deaths, than measles-containing vaccine. The return on investment makes measles-containing vaccine one of the most cost-effective public health measures available. Exhaustive reviews of biological, technical, economic and programmatic evidence have concluded that measles can and should be eradicated, and by including rubella antigen in measles-containing vaccine, congenital rubella syndrome will also be eradicated. All World Health Organisation Regions have pledged to achieve measles elimination. Unfortunately, not all countries and global partners have demonstrated an appropriate commitment to these laudable public health goals, and the negative impact of the COVID-19 pandemic on coverage rates has been profound. Unsurprisingly, large disruptive outbreaks are already occurring in many countries with a global epidemic curve ominously similar to that of 2018/2019 emerging. The Immunization Agenda 2030 will fail dismally unless measles and rubella eradication efforts are accelerated. Over half of all member states have been verified to have eliminated rubella and endemic rubella transmission has not been re-established in any country to date. In 2023, 84 countries and areas were verified to have sustained elimination of measles. However, without a global target, this success will be difficult to sustain. Now is the time for a global eradication goal and commitment by the World Health Assembly. Having a galvanising goal, with a shared call for action, will demand adequate resourcing from every country government and global partners. Greater coordination across countries and regions will be necessary. Measles, rubella and congenital rubella syndrome eradication should not remain just a technically feasible possibility but rather be completed to ensure that future generations of children do not live under the shadow of preventable childhood death and lifelong disability.

Each year in Latin America and the Caribbean, seasonal influenza is associated with an estimated 36,500 respiratory deaths and 400,000 hospitalizations. Since the 2009 influenza A(H1N1) pandemic, the Region has made significant advances in the prevention and control of seasonal influenza, including improved surveillance systems, burden estimates, and vaccination of at-risk groups. The Global Influenza Strategy 2019-2030 provides a framework to strengthen these advances. Against the backdrop of this new framework, the University of Colorado convened in October 2020 its Immunization Advisory Group of Experts to review and discuss current surveillance, prevention, and control strategies for seasonal influenza in Latin America and the Caribbean, also in the context of the COVID-19 pandemic. This review identified five areas for action and made recommendations specific to each area. The Region should continue its efforts to strengthen surveillance and impact evaluations. Existing data on disease burden, seasonality patterns, and vaccination effectiveness should be used to inform decision-making at the country level as well as advocacy efforts for programmatic resources. Regional and country strategic plans should be prepared and include specific targets for 2030. Existing investments in influenza prevention and control, including for immunization programs, should be optimized. Finally, regional partnerships, such as the regional networks for syndromic surveillance and vaccine effectiveness evaluation (SARInet and REVELAC-i), should continue to play a critical role in continuous learning and standardization by sharing experiences and best practices among countries.

Measles causes a substantial disease burden for all countries, while mortality is greatest in underserved, marginalized populations. Global measles eradication is feasible and the strategies critically rely upon well-functioning national immunisation programs and surveillance systems. All six regions of the World Health Organisation have adopted measles elimination targets. The Rule of Rescue and the principle of justice leave no ethical place for health programs, governments, global public health bodies or donors to hide if they impede efforts to eradicate measles globally by not taking all necessary actions to establish a global eradication target and committing the resources essential to achieve this goal., (© The Author(s) 2020. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene.)

The increasing geographical spread and disease incidence of arboviral infections are among the greatest public health concerns in the Americas. The region has observed an increasing trend in dengue incidence in the last decades, evolving from low to hyperendemicity. Yellow fever incidence has also intensified in this period, expanding from sylvatic-restricted activity to urban outbreaks. Chikungunya started spreading pandemically in 2005 at an unprecedented pace, reaching the Americas in 2013. The following year, Zika also emerged in the region with an explosive outbreak, carrying devastating congenital abnormalities and neurologic disorders and becoming one of the greatest global health crises in years. The inadequate arbovirus surveillance in the region and the lack of serologic tests to differentiate among viruses poses substantial challenges. The evidence for vector control interventions remains weak. Clinical management remains the mainstay of arboviral disease control. Currently, only yellow fever and dengue vaccines are licensed in the Americas, with several candidate vaccines in clinical trials. The Global Arbovirus Group of Experts provides in this article an overview of progress, challenges, and recommendations on arboviral prevention and control for countries of the Americas.

Opportunities for strengthening surveillance of meningococcal disease exist between and within countries in Latin America. In August of 2015, a workshop was convened in the city of São Paulo, Brazil, to address the following objectives: 1) to review meningococcal disease burden and vaccine use in Latin America; 2) to evaluate the effectiveness of current meningococcal surveillance practices in the region; 3) to identify challenges to meningococcal surveillance in the region; and 4) to outline steps for strengthening meningococcal surveillance and disease control in the region. Based on the workshop's discussions, recommendations for strengthening surveillance and controlling meningococcal disease in Latin America focus on improving: a) laboratory capabilities for diagnostic testing; b) communication regarding epidemiologic- and laboratory-based analyses; c) communication during outbreaks; d) monitoring of long-term disease outcomes; e) knowledge of vaccines against serogroup B disease; and f) criteria for defining and controlling meningococcal outbreaks. Overall, improving surveillance will help guide strategies for meningococcal disease prevention and control in Latin America., Competing Interests: Conflicts of interest. M.A.P. Sáfadi has received grants to support research projects and consultancy fees from vaccine manufacturers. M.T. Valenzuela has no conflicts or financial interests to declare. A.F. Carvalho has no conflicts or financial interests to declare. L.H. De Oliveira has no conflicts or financial interests to declare. D.M. Salisbury has provided paid consultancy services to vaccine manufacturers. J.K. Andrus has no conflicts or financial interests to declare.

Deployment of oral cholera vaccine (OCV) on the Island of Hispaniola has been considered since the emergence of the disease in October of 2010. At that time, emergency response focused on the time-tested measures of treatment to prevent deaths and sanitation to diminish transmission. Use of the limited amount of vaccine available in the global market was recommended for demonstration activities, which were carried out in 2012. As transmission continues, vaccination was recommended in Haiti as one component of a comprehensive initiative supported by an international coalition to eliminate cholera on the Island of Hispaniola. Leveraging its delivery to strengthen other cholera prevention measures and immunization services, a phased OCV introduction is pursued in accordance with global vaccine supply. Not mutually exclusive or sequential deployment options include routine immunization for children over the age of 1 year and campaigns in vulnerable metropolitan areas or rural areas with limited access to health services.

Governments have the authority and responsibility to ensure vaccination for all citizens. The development of vaccination legislation in Latin America and the Caribbean (LAC) parallels the emergence of sustainable, relatively autonomous, and effective national immunization programs. We reviewed vaccination legislation and related legal documents from LAC countries (excluding Canada, Puerto Rico, the United States, and the US Virgin Islands), and described and assessed vaccination legislation provisions. Twenty-seven of the 44 countries and territories in the Region have proposed or enacted vaccination legislation. Provisions vary substantially, but legal frameworks generally protect the sustainability of the immunization program, the individual's right to immunization, and the state's responsibility to provide it as a public good. Of the legislation from countries and territories included in the analysis, 44 per cent protects a budget line for vaccines, 96 per cent mandates immunization, 63 per cent declares immunization a public good, and 78 per cent explicitly defines the national vaccine schedule. We looked for associations between vaccination legislation in LAC and national immunization program performance and financing, and conclude with lessons for governments seeking to craft or enhance vaccination legislation.

New vaccines have been demonstrated to be effective in reducing morbidity and mortality, particularly in children, but come at increased costs to societies, governments, and their national immunization programs compared with other traditional childhood vaccines. Rational allocation of available resources requires systematic collection of the evidence base to decide whether to introduce a new vaccine, an important component of which is cost-effectiveness analysis. In this article, we develop in-depth case studies to examine the country experience of conducting cost-effectiveness analysis with the support of Pan American Health Organization ProVac Initiative and the implications of its process for decision making on new vaccine introduction in Latin America and the Caribbean. Key lessons regarding how cost-effectiveness analysis may be effectively used to inform evidence-based immunization policy are highlighted, drawing from the experience of Nicaragua and Paraguay. Based on the lessons identified, the vision going forward will focus on promoting the sustainability of multidisciplinary country teams while continuing to prioritize capacity development as an overarching guiding principle for preparing countries to face future new vaccine policy decisions., (Copyright © 2012 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.)

In 2003, the Pan American Health Organization (PAHO) adopted a resolution calling for rubella and congenital rubella syndrome (CRS) elimination in the Americas by the year 2010. To accomplish this goal, PAHO advanced a rubella and CRS elimination strategy including introduction of rubella-containing vaccines into routine vaccination programs accompanied by high immunization coverage, interruption of rubella transmission through mass vaccination of adolescents and adults, and strengthened surveillance for rubella and CRS. The rubella elimination strategies were aligned with the successful measles elimination strategies. By the end of 2009, all countries routinely vaccinated children against rubella, an estimated 450 million people had been vaccinated against measles and rubella in supplementary immunization activities, and rubella transmission had been interrupted. This article describes how the region eliminated rubella and CRS.

The Caribbean subregion was one of the first areas to successfully integrate measles and rubella surveillance, and it can serve as an example to other subregions on how to achieve similar success. The integrated surveillance system, established through strong political commitment by Caribbean countries, is coordinated by the Caribbean Epidemiology Centre (CAREC). The system, which became operational in January 2000, is designed to detect and investigate patients with fever and rash illness, and also test a blood specimen from each case investigated. During over 9 years of operation, 3733 cases were reported and investigated. Laboratory tests identified 2 imported cases of measles, 27 cases of rubella, 309 cases of dengue, and 260 cases of human herpesvirus 6 (HHV-6) infection. The lessons learned from the success of this integrated system indicate that the following factors are critical: strong political commitment, strong technical oversight from all levels within the health-care system, the use of proven tools or systems and technology for data collection and analysis, integration with other surveillance activities, continuing training, and continuing review and evaluation.

In the region of the Americas, goals for the elimination of endemic measles and rubella/congenital rubella syndrome (CRS) by the year 2000 and 2010, respectively were established. The successful implementation of measles elimination strategies in the region of the Americas resulted in the interruption of endemic measles transmission in 2002 and tremendous progress toward rubella and CRS elimination. In October 2007, the 27th Pan American Sanitary Conference adopted Resolution CSP27.R2 urging member states to begin documenting and verifying the interruption of endemic transmission of the measles and rubella viruses in the Americas. To ensure a standardized approach for the process of documentation and verification, the Pan American Health Organization/World Health Organization (PAHO/WHO) developed a regional plan of action to guide countries and their national commissions as they prepare and consolidate evidence of the interruption of endemic measles and rubella transmission. This article summarizes the plan of action including the essential criteria and components of the guidelines.

Background: Rubella during pregnancy can cause serious fetal abnormalities and death. Peru has had integrated measles/rubella surveillance since 2000 but did not implement congenital rubella syndrome (CRS) surveillance until 2004, in accordance with the Pan American Health Organization recommendations for rubella elimination. The article describes the experience from the CRS sentinel surveillance system in Peru., Methods: Peru has maintained a national sentinel surveillance system for reporting confirmed and suspected CRS cases since 2004. A surveillance protocol was implemented with standardized case definitions and instruments in the selected sentinel sites. Each sentinel site completes their case investigations and report forms and sends the reports to the Health Region Epidemiology Department, which forwards the data to the national Epidemiology Department. CRS surveillance data were analyzed for the period 2004-2007., Results: During the period 2004-2007, 16 health facilities, which are located in 9 of the 33 health regions, representing the 3 main geographical areas (coast, mountain, and jungle), were included as sentinel sites for the CRS surveillance. A total of 2061 suspected CRS cases were reported to the system. Of these, 11 were classified as CRS and 23 as congenital rubella infection. Factors significantly associated with rubella vertical transmission were: (1) in the mother, maternal history of rash during pregnancy (odds ratio [OR], 12.0; 95% confidence interval [CI], 3.8-37.8); (2) and in the infant, pigmentary retinopathy (OR, 18.4; 95% CI, 3.2-104.6), purpura (OR, 14.7; 95% CI, 2.8-78.3), and developmental delay (OR, 4.4; 95% CI, 1.75-11.1)., Conclusions: The surveillance system has been able to identify rubella vertical transmission, reinforcing the evidence that rubella was a public health problem in Peru. This system may serve as a platform to implement surveillance for other congenital infections in Peru.

One of the reasons the 1997 Technical Advisory Group on Vaccine-Preventable Diseases recommended acceleration of rubella and congenital rubella syndrome (CRS) prevention efforts was the fact that the enhanced measles surveillance system in the Americas found that 25% of reported measles cases were laboratory-confirmed rubella cases. Until 1997, the laboratory network primarily focused on measles diagnosis. Since 1999, due to the accelerated rubella control and CRS prevention strategy, laboratories have supported the regional measles, rubella, and CRS elimination goals. The measles-rubella laboratory network established in the Americas provides timely confirmation or rejection of suspected measles and rubella cases, and determination of the genotypic characteristics of circulating virus strains, critical information for the programs. A quality assurance process has ensured high-quality performance of procedures in the network. Challenges are occurring, but the measles-rubella laboratory network continues to adapt as the requirements of the program change, demonstrating the high quality of the laboratories in support of public health activities and elimination goals.

Background: The Region of the Americas set a goal of interrupting endemic measles virus transmission by the end of 2000. This decision was primarily based on rapid decreases in measles disease burden in pioneering countries that implemented Pan American Health Organization-recommended vaccination and surveillance strategies. Review of these strategies may inform measles elimination efforts in other regions., Methods: Results from the implementation of the measles elimination strategy in the Americas were compiled and analyzed over a 30-year period, which was divided into 4 phases: the early years of the Expanded Program on Immunization (1980-1986); the start-up phase for elimination (1987-1994); the elimination phase (1995-2002); and the postelimination phase (2003-2010). Factors that contributed to elimination and the challenges confronted during the postelimination phase are discussed., Results: An analysis of vaccination strategies over time highlights the transition from monovalent measles vaccine to the incorporation of measles-mumps-rubella vaccine administered in the routine program. Regional vaccination coverage increased during the period 1987-2010, sustained at ≥90% since 1998. Measles elimination efforts led to the implementation of 157 national vaccination campaigns, vaccinating a total of 440 million persons. Endemic measles virus transmission was interrupted in 2002. After elimination, measles importations and associated outbreaks occurred. Measles incidence has remained at <1 case per 1 million population since 2002., Conclusions: The success of measles elimination strategies in the Americas suggests that global measles eradication is attainable., (© The Author 2011. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved.)

Countries in the World Health Organization Region of the Americas successfully interrupted endemic measles virus transmission 8 years after setting a regional measles elimination goal and have sustained this achievement since 2002. The vast experience from the region clearly demonstrates that measles elimination can be accomplished and maintained over time. This brief report summarizes the lessons learned and the best practices that evolved in the Americas during 3 measles elimination phases (ie, preelimination, elimination, and postelimination phases), as well as the contribution of rubella elimination to strengthening and maintaining measles elimination. The effective measures that have been implemented and adapted by the countries of the Americas to eliminate endemic measles and rubella will serve as an example to other countries and regions embarking on this endeavor., (© The Author 2011. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved.)

Global nuclear proliferation, bioterrorism, and emerging infections have challenged national capacities to achieve and maintain global security. Over the last century, emerging infectious disease threats resulted in the development of the preliminary versions of the International Health Regulations (IHR) of the World Health Organization (WHO). The current HR(2005) contain major differences compared to earlier versions, including: substantial shifts from containment at the border to containment at the source of the event; shifts from a rather small disease list (smallpox, plague, cholera, and yellow fever) required to be reported, to all public health threats; and shifts from preset measures to tailored responses with more flexibility to deal with the local situations on the ground. The new IHR(2005) call for accountability. They also call for strengthened national capacity for surveillance and control; prevention, alert, and response to international public health emergencies beyond the traditional short list of required reporting; global partnership and collaboration; and human rights, obligations, accountability, and procedures of monitoring. Under these evolved regulations, as well as other measures, such as the Revolving Fund for vaccine procurement of the Pan American Health Organization (PAHO), global health security could be maintained in the response to urban yellow fever in Paraguay in 2008 and the influenza (H1N1) pandemic of 2009-2010.

The burden of rotavirus disease in the Latin American region has been poorly understood despite the promise of effective vaccines. We describe here the implementation and results of a rotavirus surveillance network in the Latin American and Caribbean region. From 2005 through 2007, stool specimens and epidemiologic information were gathered from children <5 years of age who were hospitalized for acute diarrhea (3 looser-than-normal stools within <24 h) lasting <14 days with use of a standardized generic protocol. Stool samples were tested for rotavirus, and a proportion of detected strains were typed. The proportion of samples positive for rotavirus was applied to World Health Organization diarrhea-related mortality estimates to calculate rotavirus-associated mortality. In 2007, the network comprised 54 sites in 11 countries. During 2006-2007, specimens were collected from 19,817 children; 8141 of these specimens were positive for rotavirus. The median percentage of positive specimens in the country was 31.5% (range, 24%-47%). The risk of death from rotavirus diarrhea by age 5 years was 1 of 2874. Strong rotavirus winter seasonality was apparent, even in tropical Central America. Globally common strains (P[8] G1, P[8] G9, and P[4] G2) accounted for >75% of strains, although unusual strains, including G12, were detected at low levels. As rotavirus vaccines continue to be introduced in Latin America, maintenance of surveillance will provide robust pre-introduction data and a platform for estimating vaccine effectiveness and other measures of impact.

Background: Seasonal influenza is a viral disease whose annual epidemics are estimated to cause three to five million cases of severe illness and 250,000 to 500,000 deaths worldwide. Vaccination is the main strategy for primary prevention., Methods: To assess the status of influenza vaccination in the Americas, influenza vaccination data reported to the Pan American Health Organization (PAHO) through 2008 were analyzed., Results: Thirty-five countries and territories administered influenza vaccine in their public health sector, compared to 13 countries in 2004. Targeted risk groups varied. Sixteen countries reported coverage among older adults, ranging from 21% to 100%; coverage data were not available for most countries and targeted populations. Some tropical countries used the Northern Hemisphere vaccine formulation and others used the Southern Hemisphere vaccine formulation. In 2008, approximately 166.3 million doses of seasonal influenza vaccine were purchased in the Americas; 30 of 35 countries procured their vaccine through PAHO's Revolving Fund., Conclusion: Since 2004 there has been rapid uptake of seasonal influenza vaccine in the Americas. Challenges to fully implement influenza vaccination remain, including difficulties measuring coverage rates, variable vaccine uptake, and limited surveillance and effectiveness data to guide decisions regarding vaccine formulation and timing, especially in tropical countries.

Rubella virus infection is typically diagnosed by the identification of rubella virus-specific immunoglobulin M (IgM) antibodies in serum, but approximately 50% of serum samples from rubella cases collected on the day of rash onset are negative for rubella virus-specific IgM. The ability to detect IgM in sera and oral fluids was compared with the ability to detect rubella virus RNA in oral fluids by reverse transcription-PCR (RT-PCR) by using paired samples taken within the first 4 days after rash onset from suspected rubella cases during an outbreak in Perú. Sera were tested for IgM by both indirect and capture enzyme immunoassays (EIAs), and oral fluids were tested for IgM by a capture EIA. Tests for IgM in serum were more sensitive for the confirmation of rubella than the test for IgM in oral fluid during the 4 days after rash onset. RT-PCR confirmed more suspected cases than serum IgM tests on days 1 and 2 after rash onset. The methods confirmed approximately the same number of cases on days 3 and 4 after rash onset. However, a few cases were detected by serum IgM tests but not by RT-PCR even on the day of rash onset. Nine RT-PCR-positive oral fluid specimens were shown to contain rubella virus sequences of genotype 1C. In summary, RT-PCR testing of oral fluid confirmed more rubella cases than IgM testing of either serum or oral fluid samples collected in the first 2 days after rash onset; the maximum number of confirmations of rubella cases was obtained by combining RT-PCR and serology testing.

In the Americas, the Pan American Health Organization supports strategies for the appropriate control and elimination of vaccine-preventable diseases, especially if the strategies are designed to reduce health inequities, strengthen the political commitment for immunization services, and promote the culture of prevention. In September 2003, the 44th Directing Council of the Pan American Health Organization adopted a goal to eliminate rubella and congenital rubella syndrome by 2010. One of the main objectives of this initiative is improving women's health, consistent with achieving the Millennium Development Goals. An important component of rubella elimination is conducting vaccination campaigns for men and women of childbearing age to reduce rapidly the number of people susceptible to rubella infection. From 1998 to 2002, the English-speaking Caribbean, Chile, Costa Rica, Brazil, and Honduras conducted mass rubella vaccination campaigns aimed at adults. Vaccination coverage reached > 95% in each country with an exception of the Caribbean, where the coverage was 80%.

Objective: Vaccine-associated paralytic poliomyelitis (VAPP) is a rare but serious consequence of the administration of oral polio vaccine (OPV). Intensified OPV administration has reduced wild poliovirus transmission in India but VAPP is becoming a matter of concern., Methods: We analysed acute flaccid paralysis (AFP) surveillance data in order to estimate the VAPP risk in this country. VAPP was defined as occurring in AFP cases with onset of paralysis in 1999, residual weakness 60 days after onset, and isolation of vaccine-related poliovirus. Recipient VAPP cases were a subset with onset of paralysis between 4 and 40 days after receipt of OPV., Findings: A total of 181 AFP cases met the case definition. The following estimates of VAPP risk were made: overall risk, 1 case per 4.1 to 4.6 million OPV doses administered; recipient risk,1 case per 12.2 million; first-dose recipient risk, 1 case per 2.8 million; and subsequent-dose recipient risk, 1 case per 13.9 million., Conclusion: On the basis of data from a highly sensitive surveillance system the estimated VAPP risk in India is evidently lower than that in other countries, notwithstanding the administration of multiple OPV doses to children in mass immunization campaigns.

Poliomyelitis surveillance in India previously involved the passive reporting of clinically suspected cases. The capacity for detecting the disease was limited because there was no surveillance of acute flaccid paralysis (AFP). In October 1997, 59 specially trained Surveillance Medical Officers were deployed throughout the country to establish active AFP surveillance; 11,533 units were created to report weekly on the occurrence of AFP cases at the district, state and national levels; timely case investigation and the collection of stool specimens from AFP cases was undertaken; linkages were made to support the polio laboratory network; and extensive training of government counterparts of the Surveillance Medical Officers was conducted. Data reported at the national level are analysed and distributed weekly. Annualized rates of non-polio AFP increased from 0.22 per 100,000 children aged under 15 years in 1997 to 1.39 per 100,000 in 1999. The proportion of cases with two adequate stools collected within two weeks of the onset of paralysis increased from 34% in 1997 to 68% in 1999. The number of polio cases associated with the isolation of wild poliovirus decreased from 211 in the first quarter of 1998 to 77 in the first quarter of 1999. Widespread transmission of wild poliovirus types 1 and 3 persists throughout the country; type 2 occurs only in Bihar and Uttar Pradesh. In order to achieve polio eradication in India during 2000, extra national immunization days and house-to-house mopping-up rounds should be organized.

In May 1985, the Pan American Health Organization proposed the goal of interruption of wild poliovirus transmission in the Western Hemisphere. An important component of the polio eradication strategy was conducting surveillance for cases of acute flaccid paralysis. Reported cases were thoroughly investigated, including the collection of stool samples for testing for the presence of wild poliovirus. The last patient with poliomyelitis due to wild poliovirus in the Americas had onset of paralysis on 23 August 1991 in Peru. Since then, >9000 cases of acute flaccid paralysis have been reported and thoroughly investigated; none has been confirmed as paralytic poliomyelitis due to wild poliovirus. On 29 September 1994, the International Commission for the Certification of Poliomyelitis Eradication declared the Americas to be polio-free.

In the South-East Asia Region (SEAR) of WHO, paralytic poliomyelitis has decreased from 25,711 cases in 1988 to 3304 cases in 1995, representing an 87% reduction. By 1995, in 6 of 10 member countries--India, Bangladesh, Myanmar, Nepal, Indonesia, and Democratic People's Republic of Korea--polio remained endemic. Two countries, Sri Lanka and Thailand, appear close to polio eradication, and 2, Bhutan and Maldives, reported no cases during 1989-1995. Although reported rates of acute flaccid paralysis and the percentage of cases virologically investigated are low in some countries, no isolates of wild poliovirus type 2 have been reported outside India since 1993. By the end of 1996, all 8 countries in which polio is endemic will have conducted national immunization days for polio eradication. The major challenge for polio eradication in SEAR will be strengthening surveillance, because national immunization days alone cannot eradicate polio.

A major factor influencing the success of poliomyelitis eradication in the Americas was the reliance on mass immunization campaigns with oral poliovirus vaccine (OPV). As global poliomyelitis eradication activities accelerate and campaign vaccine delivery strategies are applied elsewhere, it is critical to determine whether the risk of vaccine-associated paralytic poliomyelitis (VAPP) is altered when routine delivery strategies are supplemented with mass immunization campaigns. We analysed all 6043 cases of acute flaccid paralysis (AFP) reported in Latin America over the period 1989-91 in order to estimate the risk of VAPP. The overall risk was estimated to be one case per 1.5-2.2 million doses of OPV administered, compared with one case per 1.4 million doses administered in England and Wales (1985-91) and with one case per 2.5 million net doses distributed in the USA (1980-89). These data suggest that to eradicate poliomyelitis globally, strategies that rely on mass immunization campaigns to supplement routine delivery services, as recommended by WHO, do not appear to alter significantly the risk of VAPP.

The immunogenicity of trivalent oral poliovirus vaccine (TOPV), which is less effective in tropical than in temperate areas, may potentially be improved in several ways, including increasing the number of doses. Little information is available on TOPV when more than 6 doses are given. The situation in Cuba provides a unique opportunity to relate the seroprevalence of neutralizing antibodies to the dose of TOPV because Cuba has not reported culture-confirmed poliomyelitis since 1973 and TOPV is only administered in twice yearly 1-week mass immunization campaigns. Sera from 2000 children nationwide were studied for neutralizing antibody among children who received 0, 2, 4, 6 and 8 doses of TOPV. These doses were administered in the period 1989-91, when TOPV (from the USSR) was being used with 500,000, 200,000, and 300,000 median tissue-culture-infecting doses (TCID50) for types 1, 2 and 3, respectively--the 5:2:3 formulation. Seroprevalence of neutralizing antibody after two TOPV doses was 91.5% for type 1, 90.8% for type 2, and 45.9% for type 3. Seroprevalence of type-3 neutralizing antibody after 6 doses remained low (73.4%), but increased to 83.5% after 8 doses (P < 0.05). Although 16.5% of the children remained unprotected for type-3 infection even after 8 doses, mass campaign immunization strategies were sufficient to eradicate the transmission of wild poliovirus in Cuba. Because the seroprevalence of type-1 neutralizing antibody was high (91.5%) after two campaign doses, additional studies using different formulations are needed to determine whether simultaneous improvement in the type-3 response to two campaign doses can be achieved.

Cartagena, Colombia, was one of the last cities in the Americas known to have endemic poliomyelitis. After 3 cases were identified in 1991, two approaches for detecting continued silent transmission of wild polioviruses within a high-risk community were used: stool surveys of healthy children and virologic analysis of community sewage. Wild type 1 polioviruses were isolated from 8% of the children studied and from 21% of sewage samples. The proportions of wild polioviruses, vaccine-related polioviruses, and nonpolio enteric viruses were similar for both approaches. Wild poliovirus sequences were also amplified directly from processed sewage samples by the polymerase chain reaction using primer pairs specific for the indigenous type 1 genotype. The last reported cases associated with wild polioviruses in the Americas occurred in Colombia (8 April 1991) and Peru (23 August 1991). Direct sampling for wild polioviruses in high-risk communities can provide further evidence that eradication of the indigenous wild polioviruses has been achieved in the Americas.

Current levels of surveillance have contributed to substantial reductions in morbidity and mortality due to poliomyelitis in the Americas. Despite the success of the poliomyelitis eradication initiative, it has become critical that surveillance be intensified so that the absence of wild poliovirus circulation can be verified with confidence in countries not reporting confirmed cases of poliomyelitis. Cases of acute flaccid paralysis continue to be classified as compatible with poliomyelitis, because investigations of such patients do not provide sufficient information to rule out wild poliovirus as the cause of paralysis. At this stage of the eradication initiative, the presence of compatible cases in some countries in Latin America indicates a failure of the surveillance system. The greatest challenge for the eradication initiative may be correcting the remaining deficiencies of the existing surveillance system that hinder efforts to verify that wild poliovirus is no longer being transmitted in the Americas.

The Pan American Health Organization in 1985 adopted an initiative to eradicate poliomyelitis from the Western Hemisphere. In 1990, over 2000 cases of acute flaccid paralysis (AFP) were reported in this region, of which < 1% were determined to be caused by wild poliovirus. At present, the eradication programme uses AFP as the criterion for surveillance of children aged < 15 years; this is 100% sensitive, but not specific. To minimize unnecessary diagnostic investigations, we studied all 4333 cases of AFP reported to the programme during 1989 and 1990 in order to develop more efficient operational screening criteria for cases of AFP. Among children with AFP, the use of criteria such as age < 6 years and either presence of fever at the onset of paralysis or a < 4-day period for complete development of paralysis resulted in a sensitivity of 96% (95% C.I. 90-103%) and specificity of 49% (C.I. 47-52%). With criteria of age < 6 years and fever present at the onset of paralysis the sensitivity was 75% (C.I. 61-89%) and specificity was 73% (C.I. 71-75%). These results suggest that by screening young children with AFP who either had fever at the onset or showed a rapid progression of paralysis, the number of cases of AFP requiring investigation can be reduced by one half, with minimal compromise in the sensitivity of confirmed poliomyelitis case detection.

In January 1988, Oregon became the first state to require hospital-based reporting of attempted suicide (AS) in all adolescents less than 18 years old. From January to December 1988, 644 cases of AS were reported (annual rate of 214 per 100,000 population, ages 10 to 17 years). We compared these 644 cases of AS with all 137 Oregon adolescents less than 18 years old who committed suicide in Oregon during the 10-year-period 1979 through 1988, and found that the strongest predictor of outcome was method used.

To evaluate the utility of statewide laboratory Cryptosporidium surveillance, we screened stools from all 5,256 patients evaluated at local health departments for parasitic disease from January 1985 through June 1988. Fifty-seven patients (1.1 percent) were found to have Cryptosporidium. Seasonal peaks in positivity were observed in the spring, summer, and early autumn months. In children, younger age was associated with higher positivity rate of cryptosporidiosis. As a result of these surveillance efforts, Oregon's first known outbreak of cryptosporidiosis was detected and investigated during 1988. Twenty-five persons were infected, including children, parents, and staff associated with two day care centers. The cost of routine screening for Cryptosporidium was $1.13 per specimen in our laboratory, and we consider it useful.

We studied 977 newly incarcerated Oregon inmates to compare voluntary versus mandatory human immunodeficiency virus antibody (HIVAb) testing in the prison setting. All inmates were offered HIVAb counseling and testing. Blood drawn for routine syphilis serology from those who declined this offer was also tested for HIVAb after personal identifiers had been removed. Only 1.2 percent (12) prisoners were HIV positive. However, 62.5 percent (611) inmates were at risk for HIV infection by being an intravenous drug user, a male homosexual, or hepatitis B core antibody (HBcAb) positive. The ratio of at-risk, as yet uninfected inmates to those already HIV infected was 53 to 1. Two-thirds of all inmates including those at-risk chose to receive counseling and testing. In areas where most at-risk inmates are not yet infected, it may be more appropriate for HIV prevention activities in prison to focus on voluntary programs that emphasize education and counseling rather than mandatory programs that emphasize testing.