Abstract P3-08-24: Mutational characterization of HER2-positive breast cancer

Background: Studies of mutational analysis have been widely reported in various global series of breast cancer. However, in the era of different phenotypes of breast cancer, these analyses should be more specific in order to find differences in each phenotype that could predict response to treatment. Particularly HER2 positive is a special subtype with different connotations that make the analysis of its genotype very interesting.

Methods: Cohorts of 47 consecutive samples of HER2 positive breast cancer, treated in our institution were analyzed. It was conducted a mutational study with NGS technique of the most common genes involved in breast cancer.

Results: 10 patients were metastatic at diagnostic, 17 with negative estrogen receptor expression, the median value of Ki67 was 45 (20-95) and the median initial tumor size was 33.5 mm (18-111). Inmunohistochemical expression of HER2 was +3 in 31 tumors and +2 in 15 with a median ratio by FISH of 3,2 (1,18-8,3). We also analyzed the expression of HER by PCR of mRNA in 35 samples with a median expression of 2,49 (0,26-33,15). 38 patients underwent surgical excision of the tumor with a pathologic complete response observed in 19.

We found a total of 38 significant mutations and the genes with more frequent mutations were MCPH1 (100%), HNF1 (98%), p53 (96%), somatic BRCA1 (62%), TSC1 (30%), PIK3CA (23%), ATM (21%), ALK (15%) and somatic BRCA2 (13%). Although the aim of the study was to find the most frequent mutations in this subtype, we have also analyzed possible correlations of those with pathological response or with more common variables, finding no significance in any of them.

Conclusions: In our series, we found a high percentage of mutations in MCPH1, HNF1 and p53 genes with almost 100% of mutations in p53 that are also limited in a very specific area. Also interesting is the 62% of mutations found in BRCA1 and 13% in BRCA2 that could allow more specific treatments in this subgroup. Although the study did not have the power to assess the predictive factor of these mutations, it is very suggestive that in the 7 patients with BRCA mutations, 6 achieved a complete pathological response.

Citation Format: Velasco Sánchez A, Gasol Cudos A, Morales S, Veas Rodriguez J, Serrate López A, Mele Olivé J, Canosa Morales C. Mutational characterization of HER2-positive breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-08-24.

Abstract P2-08-30: Vitamin D as a prognostic factor in triple negative early breast cancer

Background: Triple negative breast cancer is a special phenotype where the pathological complete response (pCR) remains the most important factor but only around a 40% of patients achieve this response. We analyze if the vitamin D receptors (VDR) could be a prognostic factor not related with the histological response.

Methods: A series of 160 patients with early or locally advanced triple negative breast cancer that received neoadjuvant chemotherapy were retrospectively reviewed from 2007 to 2017. Clinicopathological and vitamin D receptors analysis were correlated to pCR.

Results: Median age was 53, median tumor size 30mm, 48% had nodal involvement, and median ki67 expression was of 70%. Androgen receptor was expressed in 28% of tumors analyzed, EGFR in 89%, CK5/6 in 63%. VDR (cytoplasmatic and nuclear) expression was determined in 56 patients, finding in 45 (80%) an expression that was considered as high. We achieved a total of 73/160 pCR (45%) with a significant median disease free survival of 178 months (log rank p: 0,0001). In the univariate analysis, the initial tumoral size, initial nodal involvement and expression of VDR was significant; and in the mutivariate model the expression of VDR maintains the level of significance ( HR: 0,138 IC 95% 0,039-0,493 p:0,002).

Conclusions: The expression of VDR in the initial tumor before starting neoadjuvant chemotherapy is a strong predictor of recurrence independently of histological response with a median disease free survival of 149 months in patients with high expression versus 62 month. Furthermore, in patients without histological response, progression-free median survival is 86 months for patients with high expression versus 35 months.

Citation Format: Morales Murillo S, Gasol Cudos A, Veas Rodriguez J, Santacana M, Canosa Morales C, Mele Olivé J. Vitamin D as a prognostic factor in triple negative early breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-08-30.

[Tobacco brand-related headache]

INTRODUCTION

Tobacco smoking has been considered a risk factor for headache by some authors, while others disagree because of contradictory data.

PATIENTS AND RESULTS

We describe the clinical aspects of eleven patients (four men and seven women) who presented to us with tobacco brand-related headaches. Clinical history help us to discover that headache of each patient was directly related with certain cigarette brands smoking. The cigarette brands implicated were diverse and different for each patient. Headaches were migraine-like in seven cases, cluster-like in three, and non-specific in the other one. They disappeared after switching brand or stopping smoking.

CONCLUSIONS

In our patients, headaches were clearly related to smoking certain brands of cigarettes, which has never been reported before. This type of headache has characteristics that suggest that it could be a particular form of chemical odour intolerance, previously described. The number of possible responsible substances is large. More studies will be necessary in order to discover the mechanism leading patients to tobacco brand-related headache. It is important to ask our patients which cigarette brand they smoke, so it is possible to solve the problem.

Measles vaccination in Africa: by how much could routine coverage be improved?

Assuming that the level of Bacille Calmette Guerin (BCG) coverage gives a measure of access to immunisation services, it is possible to derive what fraction of infants are not immunised against measles due to under-utilisation of existing services (rather than unavailability of services). According to the most recent official statistics, the overall coverage for measles vaccine is 53% in Africa (10% lower than for BCG). This difference amounts to 3 million African children who will not be vaccinated against measles this year even though they probably have access to immunisation services.

When is a disease eradicable? 100 years of lessons learned

Since the 1915 launch of the first international eradication initiative targeting a human pathogen, much has been learned about the determinants of eradicability of an organism. The authors outline the first 4 eradication efforts, summarizing the lessons learned in terms of the 3 types of criteria for disease eradication programs: (1) biological and technical feasibility, (2) costs and benefits, and (3) societal and political considerations.

Wernicke's syndrome after bariatric surgery

Two young females with severe morbid obesity presented with Wernicke's syndrome after Roux-en-Y gastro-jejunum bypass had been performed. The first patient had recurrent vomiting and dyplopia two months post-surgery. Physical examination indicated bilateral ophthalmoparesia with conserved convergence and ataxia. The second patient had frequent vomiting episodes over the previous three months together with lower limb hypotonia, myoclonia and generalised tonicoclonic seizures on two occasions within one year of surgery. In both cases routine blood test, ion levels (sodium, potassium, calcium, phosphates), electroencephalogram and CT scan were normal. Thiamine therapy was instigated on the basis of clinical intuition and the first patient achieved complete remission within 24 hours while the second improved gradually in that two years later only mild lower limb hypotonia and a slight cognitive deficit remains. Erythrocyte transketolase activity determinations were abnormal on two separate occasions for this second patient. Vitamin B1 determinations were not available for the first patient. In conclusion, the restriction in energy intake and the persistent vomiting together with malabsorption induced by the surgical intervention could explain the vitamin deficiency causing Wernicke's encephalopathy. This indicates a need for close monitoring and systematic vitamin supplementation in those patients who undergo bariatric surgery.

Disease eradication as a public health strategy: a case study of poliomyelitis eradication

Disease eradication as a public health strategy was discussed at international meetings in 1997 and 1998. In this article, the ongoing poliomyelitis eradication initiative is examined using the criteria for evaluating candidate diseases for eradication proposed at these meetings, which covered costs and benefits, biological determinants of eradicability (technical feasibility) and societal and political considerations (operational feasibility). The benefits of poliomyelitis eradication are shown to include a substantial investment in health services delivery, the elimination of a major cause of disability, and far-reaching intangible effects, such as establishment of a "culture of prevention". The costs are found to be financial and finite, despite some disturbances to the delivery of other health services. The "technical" feasibility of poliomyelitis eradication is seen in the absence of a non-human reservoir and the presence of both an effective intervention and delivery strategy (oral poliovirus vaccine and national immunization days) and a sensitive and specific diagnostic tool (viral culture of specimens from acute flaccid paralysis cases). The certification of poliomyelitis eradication in the Americas in 1994 and interruption of endemic transmission in the Western Pacific since March 1997 confirm the operational feasibility of this goal. When the humanitarian, economic and consequent benefits of this initiative are measured against the costs, a strong argument is made for eradication as a valuable disease control strategy.

Measles elimination: progress and challenges

The accelerating progress in reducing measles incidence and mortality in many parts of the world has led to calls for its global eradication during the next 10-15 years. Three regions have established goals of elimination of indigenous transmission of measles. The strategy used in the Americas of a mass 'catchup' campaign of children 9 months to 15 years of age, high coverage through routine vaccination of infants, intensive surveillance and follow-up campaigns to prevent excessive build-up of susceptibles has had great success in reducing measles transmission close to zero. However, while these developments are impressive, much remains to be done to reduce measles-associated mortality in western and central Africa, where less than half of children are currently receiving measles vaccine and half a million children die from measles each year. The obstacles to global measles eradication are perceived to be predominantly political and financial. There are also technical questions, however. These include the refinement of measles elimination strategies in the light of recent outbreaks in the Americas; the implications of the HIV epidemic for measles elimination, issues around injection safety, and concerns about the possibility that secondary vaccine failures will contribute in sustaining transmission in highly vaccinated populations. The global priorities are to improve measles control in low income countries, increase awareness among industrialized countries of the importance of measles, and conduct studies to answer the technical questions about measles elimination strategies.

Current status of the global eradication of poliomyelitis

Substantial progress towards the global eradication of poliomyelitis by the year 2000 has been achieved since May 1988 when WHO Member States adopted this goal at the Forty-first World Health Assembly. Virtually all polio-endemic countries have begun to implement the WHO-recommended strategies to eradicate polio and it is expected that, by the end of 1997, all endemic countries in the world will have conducted full National Immunization Days (NID), providing supplemental oral polio vaccine (OPV) to nearly two-thirds of all children < 5 years. In contrast, although globally acute flaccid paralysis (AFP) surveillance was being conducted in 126 (86%) of 146 countries where polio is or recently was endemic, surveillance remains incomplete and untimely. A global network of polio laboratories, capable of detecting wild poliovirus when and where it occurs, has been developed. Furthermore, in countries where polio virus circulation has been limited to focal areas, and surveillance is adequate, mopping-up campaigns are being conducted to eliminate the final chains of transmission. The process for certification of polio eradication has been established in each WHO region as well as at the global level. The impact of the eradication initiative is evident, with an 88% decrease in the number of reported cases globally since 1988. In order to achieve the goal of eradication, the rapid development of complete and timely AFP surveillance and the continuation of effective NIDs constitute an urgent priority. This is of particular relevance in the remaining polio-endemic countries, especially in those that are affected by war or politically isolated and are important remaining reservoirs from where wild poliovirus continues to spread into bordering or even distant polio-free countries. External support will continue to be required by those countries and regions where the incidence of polio has reached low levels to ensure that final chains of poliovirus transmission are interrupted and to permit the eventual certification of eradication. The year 2000 objective for achieving poliomyelitis eradication remains a feasible target.

Disease eradication as a public health strategy: is measles next?

Following the failure of disease eradication efforts in the first half of this century, the success of smallpox eradication and the ongoing initiatives against poliomyelitis and dracunculiasis are re-establishing eradication as a viable disease control strategy. The perpetual benefits of eradication, together with the positive impact that such initiatives can have on health services in general, are changing the world's perception of these endeavours. Among the most obvious examples of this changing trend is the recent enthusiasm in both industrialized and developing countries for re-exploring the eradicability of measles. Increasingly, it appears that measles, the single leading cause of vaccine-preventable childhood morbidity and mortality worldwide, may be the next major organism targeted for global eradication.

Disease eradication and health systems development

This article provides a framework for the design of future eradication programmes so that the greatest benefit accrues to health systems development from the implementation of such programmes. The framework focuses on weak and fragile health systems and assumes that eradication leads to the cessation of the intervention required to eradicate the disease. Five major components of health systems are identified and key elements which are of particular relevance to eradication initiatives are defined. The dearth of documentation which can provide "lessons learned" in this area is illustrated with a brief review of the literature. Opportunities and threats, which can be addressed during the design of eradication programmes, are described and a number of recommendations are outlined. It is emphasized that this framework pertains to eradication programmes but may be useful in attempts to coordinate vertical and horizontal disease control activities for maximum mutual benefits.

The impact of immunization control activities on measles outbreaks in middle and low income countries

BACKGROUND

The World Health Organization recommended strategy for responding to measles outbreaks in developing countries does not promote the use of immunization campaigns due to their high cost, disruptive nature and limited impact. Given the substantial morbidity and mortality associated with such outbreaks, a literature review was conducted as a basis for re-evaluating this policy.

METHODS

Reports of supplementary immunization activities that were performed to control measles outbreaks in middle or low income countries were identified. The impact of the immunization activities on the course of each outbreak was evaluated by examining the data provided.

RESULTS

Of 66 reports detailing a measles outbreak in a middle or low income country, 17 described supplementary immunization activities which included seven 'non-selective' immunization campaigns, three 'selective' campaigns and one use of an early 2-dose schedule. Eight of the reports commented on the impact of the response, five of which reported a reduction in outbreak morbidity. Only one of the reports, from an isolated island outbreak, provided sufficient data to support a possible reduction in outbreak-associated morbidity.

CONCLUSIONS

There are limited data on the impact of measles outbreak immunization activities from developing countries. The available data do not support a change in the WHO recommended strategy for conducting a limited, if any, immunization response to such outbreaks. Immunization strategies which aim to prevent outbreaks may be more effective than campaigns to interrupt transmission of an outbreak which has already begun.

Epidemiologic study of Guillain-Barré syndrome in children <15 years of age in Latin America

In 1986, surveillance of acute flaccid paralysis (AFP) cases among children <15 years of age was implemented in Latin America as part of the initiative to eradicate poliomyelitis from the Western Hemisphere. Data on AFP, including Guillain-Barré syndrome (GBS), could be analyzed from a regional registry system and from specific GBS studies in seven countries. Between 1989 and 1991, 3112 cases of GBS were reported in Latin America, representing 52% of all nonpolio AFP cases. From the studies in seven countries, a total of 1527 GBS cases (49%) were studied, representing an overall annual incidence rate of 0.91/100,000 children <15 years old. Follow-up investigations showed a persistent muscular weakness at 60 days, 6 months, and 1 year after onset in 61%, 14%, and 10% of children, respectively. This study confirms that with the disappearance of polio, GBS arises as the most common cause of AFP.

National immunization days: experience in Latin America

Organization of national immunization days (NIDs) in all countries in Latin America in which polio was endemic has been one of the key elements that led to the interruption of the circulation of the wild poliovirus in 1991 from the Americas. National initiatives for control or elimination of measles using similar strategies have emerged from the successful organization of NIDs for polio eradication and lead the way to the eventual global eradication of this major killer of children. The major reasons for the success of polio eradication in the Americas were the commitment of national authorities, well-defined strategies, sustainable effort, and the participation of all sectors of society.

Eradication of wild poliovirus from the Americas: acute flaccid paralysis surveillance, 1988-1995

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.

Measles elimination in the Americas. Evolving strategies

The strategy currently used to control measles in most countries has been to immunize each successive birth cohort through the routine health services delivery system. While measles vaccine coverage has increased markedly, significant measles outbreaks have continued to recur. During the past 5 years, experience in the Americas suggests that measles transmission has been interrupted in a number of countries (Cuba, Chile, and countries in the English-speaking Caribbean and successfully controlled in all remaining countries. Since 1991 these countries have implemented one-time "catch-up" vaccination campaigns (conducted during a short period, usually 1 week to 1 month, and targeting all children 9 months through 14 years of age, regardless of previous vaccination status or measles disease history). These campaigns have been followed by improvements in routine vaccination services and in surveillance systems, so that the progress of the measles elimination efforts can be sustained and monitored. Follow-up mass vaccination campaigns for children younger than 5 years are planned to take place every 3 to 5 years.

Prevalence of dementia in a semi-rural population of Catalunya, Spain

This study was to investigate the prevalence of dementia in an aging population. A two-phase model was used to obtain information on the socio-demographic, medical and cognitive status of subjects over 65 years of age (n = 516), resident on December 31, 1990, within the general population (n = 3,457) of La Selva del Camp. A diagnostic protocol, following the criteria of DSM-III, was designed for application to all subjects. We diagnosed 64 subjects with dementia, which represented a prevalence of 14.9% of which 3.2% was classified as severe, 4.5% as moderate and 7.3% as slight. The prevalence by age and sex showed a large increase with age and a higher prevalence in females, although the latter was not statistically significant.

Risk of vaccine-associated paralytic poliomyelitis in Latin America, 1989-91

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.

Epidemiology and clinical characteristics of acute flaccid paralysis associated with non-polio enterovirus isolation: the experience in the Americas

The Pan American Health Organization adopted as a goal the interruption of transmission of wild poliovirus from the americas by 1990. Collection and processing of stool specimens from patients with acute flaccid paralysis (AFP) to identify wild poliovirus is critical for monitoring the success of the eradication programme. In the study described, cases of AFP in children less than 15 years of age reported in the Americas from 1989 to 1991 were evaluated to investigate the epidemiology of AFP associated with the isolation of non-polio enterovirus (NPEV), to characterize their clinical presentation, and to compare their clinical characteristics with those of AFP cases associated with the isolation of wild poliovirus (confirmed as poliomyelitis). The results show that the notification pattern for AFP associated with NPEV isolates is similar to that for all AFP cases. While AFP associated with NPEV isolates generally differs clinically from confirmed poliomyelitis, 2-21% of cases met one of three case definitions for poliomyelitis. Following the eradication of poliomyelitis, countries can therefore anticipate the continued reporting of cases of AFP that clinically mimic poliomyelitis but which are associated with NPEV. The study also confirms that NPEV circulation is common and that most isolates were from cases that did not resemble poliomyelitis. It is therefore questionable whether characterization of NPEV isolates is essential for global eradication of poliomyelitis and consequently whether allocation of resources for that purpose can be justified.

[Mini Mental State Examination: association of the score obtained with the age and degree of literacy in an aged population]

BACKGROUND

To differentiate dementia from the normal human decline scales may be used in an attempt to identity and quantify the cognitive damage which a subject may present. The Mini Mental State Examination (MMSE) is one of those. This study was performed to identify the relation of the responses between the MMSE and the sociodemographic variables of the subjects.

METHODS

The MMSE was applied as a tool to determine the presence of cognitive alterations in a prospective study of people over the age of 65 years from La Selva del Camp (Baix Camp, Catalonia, Spain). The population was differentiated according to the cut off point (24 points) with the relation of the score obtained by each subjects being studied with the sociodemographic variables of the same.

RESULTS

The mean score obtained in the test by the total population was: (mean +/- SD) 23.9 +/- 4.5 points; 24.6 +/- 4.9 in the males and 22.5 +/- 5.8 in the females. In the age group 65-74 years the mean score was 24.8 +/- 3.8; 23 +/- 4.6 in those from 75-80 years and 21.4 +/- 6 in the age group over 85 years. Sex was significantly associated (p = 0.0003), as were age (p = 0.0002) and the degree of alphabetization (p = 0.0000) with women obtaining a lower MMSE score than men, the most elderly was lower than that obtained by the younger and those of less alphabetization lower than those with education.

CONCLUSIONS

Although the MMSE is a good tool for the detection of cognitive alterations in a population, it must be kept in mind that the result of this test may be influenced by the age and education of the subject and should therefore not be used as an exclusive element in the diagnosis of dementia.

[Eradication of poliomyelitis from the American continent]

A strategy to eradicate poliomyelitis from America was developed in 1985 by the PAHO. The last case of poliomyelitis due to wild virus was detected in August 1991 in the Andean region of Peru. The main strategies used to eradicate polio are: 1) attainment of high immunization levels, 2) biannual National Vaccination Campaigns with OPV in all poliomyelitis infected countries, 3) organization in all America countries of effective surveillance of AFP, 4) setting up of a laboratory network for the isolation of the wild poliovirus from cases and contacts' stools samples and 5) the organization of a rapid response, to the occurrence of any new case with door to door vaccination (Mop-up). These strategies have been recommended by the WHO for Global Eradication of Poliomyelitis by the Year 2000. The next step in the Americas is to confirm the eradication of poliomyelitis. An ICPEC has been organized and the condition required to certify the eradication is the absence of cases of virologically confirmed indigenous poliomyelitis by a period of at least three years in the context of continued adequate surveillance. Four elements will be taken into consideration when confirming the eradication of poliomyelitis: 1) the surveillance of AFP, 2) the surveillance of wild poliovirus, 3) active searches for AFP cases in areas of risk, such as those areas with poor surveillance, or where there have been compatible cases, 4) documentation of mop-up operations in areas of risk.(ABSTRACT TRUNCATED AT 250 WORDS)

The desired field-performance characteristics of new improved vaccines for the developing world

Although the vaccination initiatives undertaken during the past decade are the cornerstones for protecting the world's children and helping to ensure their survival and development, the vaccines currently being employed may become obstacles for further disease reduction or eradication. Their characteristics complicate or increase the burden on health care infrastructures to maintain or expand vaccine delivery systems. This paper examines an experience with the vaccine technologies that currently are being used by immunization programs in developing countries, illustrating the field problems and obstacles associated with their use. It discusses the advantages and benefits that would accrue if new or improved, heat-stable, multi-antigen vaccines that require only one or two, preferably oral, doses were to become available.

Screening of cases of acute flaccid paralysis for poliomyelitis eradication: ways to improve specificity

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.

Eradication of poliomyelitis: progress in the Americas

In the span of 5 years since the eradication initiative was launched and only 3 years since external funds were made available, PAHO has been able to develop and implement a comprehensive program strategy for polio eradication that includes the following components: achievement and maintenance of high immunization levels (which include the supplemental strategies of national immunization days and mop-up operations); effective surveillance to detect all new cases; and a rapid response to the occurrence of new cases. Despite yearly increases in the number of cases of acute flaccid paralysis reported to the surveillance system, a decline in reported confirmed cases of polio has occurred since 1986 to record low levels in 1989. Cases in 1989 were reported from only 0.7% of the counties in the Americas. The occurrence of 24 wild-type virus isolates in 1989 were limited to only three geographic areas: northwestern Mexico; the northern Andean Region; and northeastern Brazil. At this writing the clock is ticking with only 3 months left to achieve the goal of interrupting transmission by the end of 1990. If the current level of effort is sustained and special efforts are directed at the remaining foci of infection, the eradication of the transmission of wild-type poliovirus from the Americas can be achieved. Continued external financial support will be critical if the effort is to succeed. The prospect of poliomyelitis eradication in the Americas led the 41st World Health Assembly of WHO to adopt a resolution in May, 1988, to eradicate the indigenous transmission of wild-type poliovirus from the world by the year 2000.(ABSTRACT TRUNCATED AT 250 WORDS)