The Onchocerciasis Elimination Program for the Americas: a history of partnership.

The decision in 1987 by the pharmaceutical firm Merck & Co. to provide Mectizan (ivermectin) free of charge to river blindness control programs has challenged the international public health community to find effective ways to distribute the drug to rural populations most affected by onchocerciasis. In the Americas, PAHO responded to that challenge by calling for the elimination of all morbidity from onchocerciasis from the Region by the year 2007 through mass distribution of ivermectin. Since 1991, a multinational, multiagency partnership (consisting of PAHO, the endemic countries, nongovernmental development organizations, the Centers for Disease Control and Prevention in Atlanta, Georgia, as well as academic institutions and funding agencies) has developed the political, financial, and technical support needed to move toward the realization of that goal. This partnership is embodied in the Onchocerciasis Elimination Program for the Americas (OEPA), which is supported by the River Blindness Foundation (RBF) and now by the Carter Center. OEPA was conceived as a means of maintaining a regional initiative to eliminate what is otherwise a low priority disease. Since its inception in 1993, the OEPA has provided more than US$ 2 million in financial, managerial, and technical assistance to stimulate and/or support programs in Brazil, Colombia, Ecuador, Guatemala, Mexico, and Venezuela, so as to take full advantage of the Merck donation. Now halfway into a five-year, US$ 4 million grant provided through the Inter-American Development Bank, the OEPA's capacity to support the regional initiative is assured through 1999.

The onchocerciasis elimination program for the Americas: a history of partnership / Programa de Eliminación de la Oncocercosis para las Américas: historia de solidaridad

The decision in 1987 by the pharmaceutical firm Merck & Co. to provide Mectizan (ivermectin) free of charge to river blindness control programs has challenged the international public health community to find effective ways to distribute the drug to rural populations most affected by onchocerciasis. In the Americas, PAHO responded to that challenge by calling for the elimination of all morbidity from onchocerciasis from the Region by the year 2007 through mass distribution of ivermectin. Since 1991, a multinational, multiagency partnership (consisting of PAHO, the endemic countries, nongovernmental development organizations, the Centers for Disease Control and Prevention in Atlanta, Georgia, as well as academic institutions and funding agencies) has developed the political, financial, and technical support needed to move toward the realization of that goal. This partnership is embodied in the Onchocerciasis Elimination Program for the Americas (OEPA), which is supported by the River Blindness Foundation (RBF) and now by the Carter Center. OEPA was conceived as a means of maintaining a regional initiative to eliminate what is otherwise a low priority disease. Since its inception in 1993, the OEPA has provided more than US$2 million in financial, managerial, and technical assistance to stimulate and/or support programs in Brazil, Colombia, Ecuador, Guatemala, Mexico and Venezuela, so as to take full advantage of the Merck donation. Now halfway into a five-year, US$ 4 million grant provided through the Inter-American Development Bank, the OEPA's capacity to support the regional initiative is assured through 1999

La decisión tomada en 1987 por la Merck & Co., fabricante de productos farmacéuticos, de proveer Mectizan® (ivermectina) gratuitamente a los programas de control de la oncocercosis ha obligado a la comunidad sanitaria internacional a buscar formas de distribuir el medicamento a las poblaciones rurales que se ven más afectadas por la enfermedad. En las Américas, la OPS respondió al reto con un llamado a eliminar de la Región toda morbilidad por oncocercosis para el año 2007 mediante la distribución de ivermectina al público. Desde 1991, una alianza multinacional de diversas entidades (la OPS, países con oncocercosis endémica, agencias de desarrollo no gubernamentales, los Centros para el Control y la Prevención de Enfermedades en Atlanta, Georgia, instituciones académicas y agencias de financiamiento) ha generado el apoyo político, económico y técnico necesario para tratar de alcanzar esa meta. Esta alianza está representada por el Programa de Eliminación de la Oncocercosis en las Américas (OEPA), subvencionado por la Fundación Ceguera de los Ríos y actualmente por el Centro Carter. El OEPA se creó como iniciativa de alcance regional destinada a eliminar una enfermedad que no merece atención prioritaria. Desde su aparición en 1993, el OEPA ha aportado más de US$ 2 millones en ayuda económica, administrativa y técnica para fomentar y subvencionar programas en Brasil, Colombia, Ecuador, Guatemala, México y Venezuela, logrando así aprovechar al máximo la donación de la Merck & Co. Ahora que hemos llegado a la mitad de una subvención de 5 años y US$ 4 millones aportada por el Banco Interamericano de Desarrollo, se sabe que el OEPA tiene la capacidad para apoyar la iniciativa regional hasta fines de 1999

Risk for transfusion-transmitted infectious diseases in Central and South America.

We report the potential risk for an infectious disease through tainted transfusion in 10 countries of South and Central America in 1993 and in two countries of South America in 1994, as well as the cost of reagents as partial estimation of screening costs. Of the 12 countries included in the study, nine screened all donors for HIV; three screened all donors for hepatitis B virus (HBV); two screened all donors for Trypanosoma cruzi; none screened all donors for hepatitis C virus (HCV); and six screened some donors for syphilis. Estimates of the risk of acquiring HIV through blood transfusion were much lower than for acquiring HBV, HCV, or T. cruzi because of significantly higher screening and lower prevalence.rates for HIV. An index of infectious disease spread through blood transfusion was calculated for each country. The highest value was obtained for Bolivia (233 infections per 10,000 transfusions); in five other countries, it was 68 to 103 infections per 10,000. The risks were lower in Honduras (nine per 10,000), Ecuador (16 per 10,000), and Paraguay (19 per 10,000). While the real number of potentially infected units or infected persons is probably lower than our estimates because of false positives and already infected recipients, the data reinforce the need for an information system to assess the level of screening for infectious diseases in the blood supply. Since this information was collected, Chile, Colombia, Costa Rica, and Venezuela have made HCV screening mandatory; serologic testing for HCV has increased in those countries, as well as in El Salvador and Honduras. T. cruzi screening is now mandatory in Colombia, and the percentage of screened donors increased not only in Colombia, but also in Ecuador, El Salvador, and Paraguay. Laws to regulate blood transfusion practices have been enacted in Bolivia, Guatemala, and Peru. However, donor screening still needs to improve for one or more diseases in most countries.

Epidemic cholera in Latin America, 1991-1993: implications of case definitions used for public health surveillance.

This report presents the various cholera case definitions used by the affected countries of Latin America, shows the numbers of cholera cases and deaths attributable to cholera (as reported by Latin American countries to PAHO through 1993), and describes some regional trends in cholera incidence. The information about how cholera cases were defined was obtained from an October 1993 PAHO questionnaire. In all, 948429 cholera cases were reported to PAHO by affected Latin American countries from January 1991 through December 1993, the highest annual incidences being registered in Peru (1991 and 1992) and Guatemala (1993). The case-fatality rate over the three-year period, and also in 1993, was 0.8%. A general downward trend in the incidence of cholera was observed in most South American countries, while the incidence increased in most Central American countries. A good deal of variation was noted in the definitions used for reporting cholera cases, hospitalized cholera cases, and cholera-attributable deaths. Because of these variations, broad intercountry comparisons (including disease burden calculations and care quality assessments based on case-fatality rates) are difficult to make, and even reported trends within a single country need to be evaluated with care. The situation is likely to be complicated in the future by the arrival of V. cholerae O139 in Latin America, creating a need to distinguish between it and the prevailing O1 strain. For purposes of simplicity, wide acceptance, and broad dissemination of case data, the following definitions are recommended: Confirmed case of O1 cholera: laboratory-confirmed infection with toxigenic V. cholerae O1 in any person who has diarrhea. Confirmed case of O139 cholera: laboratory-confirmed infection with toxigenic V. cholerae O139 in any person who has diarrhea. Clinical case of cholera: acute watery diarrhea in a person over 5 years old who is seeking treatment. Death attributable to cholera: death within one week of the onset of diarrhea in a person with confirmed or clinically defined cholera. Hospitalized patient with cholera:a person who has confirmed or clinically defined cholera and who remains at least 12 hours in a health care facility for treatment of the disease.

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.

Antibodies to Plasmodium falciparum ring-infected erythrocyte surface antigen and P. falciparum and P. malariae circumsporozoite proteins: seasonal prevalence in Kenyan villages.

Two cross-sectional surveys of 954 persons in Asembo Bay and Got Nyabondo, western Kenya, were performed in August-September 1986, after long rains, and in February-March 1987, after a comparatively dry season. Serologic testing was performed using an ELISA with synthetic peptides representing repeat amino acid sequences of the Plasmodium falciparum ring-infected erythrocyte surface antigen (RESA), (EENV)5, (EENVEHDA)4, and (DDEHVEEPTVA)2 and repeat sequences (PNAN)5 and (NAAG)5 of the P. falciparum and P. malariae circumsporozoite proteins. In 1986, 45%, 73%, 72%, 85%, and 59% of the persons in Asembo Bay had antibodies to the respective peptides. In Got Nyabondo, the rates were 44%, 67%, 56%, 36%, and 41%, respectively. All positivity rates increased with age. When next determined in 1987, the positivity rates and levels of reactivity were generally unchanged in Asembo Bay, but were decreased in Got Nyabondo.

Low measles incidence: association with enforcement of school immunization laws.

Of 54 federal immunization project areas in the United States, 13 areas with low measles incidence rates in 1977 and 1978 and 10 with high measles incidence rates were compared for differences in surveillance systems, demography, vaccine utilization, school immunization laws, and immunity levels. There was no significant difference between the low incidence and high incidence group for any examined parameter of demographic characteristics, vaccine utilization, or surveillance systems. However, in the low incidence group, school immunization laws were found to be more comprehensive and more strictly enforced with a statewide policy of exclusion from school of noncompliant students. Furthermore, immunization levels were similar for two-year-olds in both groups but were significantly higher for school entrants in the low incidence group. In all public health efforts to control or eliminate measles, priority should be given to establishing and strictly enforcing comprehensive school immunization laws.

Live, attenuated influenza A/England/42/72 (H3N2) virus vaccine: a field trial.

Two doses of a live, attentuated influenza A/England/42/72 (H3N2) vaccine virus (inhibitor-insensitive Alice strain) were administered intranasally to 130 university students, and placebo was given to 134 students. Fourfold or greater rises in titer of hemagglutination-inhibiting antibody occurred in 68% of all vaccine recipients and in 88% of those with initial titers of less than 1:8; the geometric mean titer of hemagglutination-inhibiting antibody increased from 1:15 to 1:77. A 3.2-fold rise in titer of neuraminidase-inhibiting antibody occurred in 24% of the students. Side effects produced by administration of the vaccine include mild rhinitis and sore throat, which were found only during the first four days after administration of the first dose. Inhibitor-insensitive virus was shed only by three of 31 intensively studied vaccine recipients; these three subjects all had initial serum titers of hemagglutination-inhibiting antibody of less than 1:8. No transmission of vaccine virus to spouses was detected. During a 12-month interval after vaccination, the geometric mean titer of hemagglutination-inhibiting antibody in serum and the prevalence of antibody decreased minimally among the 47 vaccine recipients still available for study.