Impacto poblacional a 10 años de la vacunación contra rotavirus en México / Population impact of rotavirus vaccination in Mexico after 10 years

Resumen: Objetivo: Evaluar el impacto de la vacunación contra rotavirus (RV) a 10 años de su universalización sobre la morbimortalidad por enfermedad diarreica aguda (EDA) en niños mexicanos menores de cinco años. Material y métodos: Se compararon las medianas anuales de casos nuevos, defunciones y hospitalizaciones por EDA del periodo pre y posuniversalización; se calcularon reducciones absolutas y relativas, considerando significativos valores de p<0.05. Resultados: La mortalidad, hospitalizaciones y casos nuevos por EDA en menores de cinco años disminuyeron 52.6, 46 y 15.5% respectivamente, en el periodo posuniversalización. Durante la temporada de RV las reducciones en la mortalidad, hospitalizaciones y casos nuevos fueron de 66.9, 64.7 y 28.7%, respectivamente. Conclusiones: A partir de la universalización de la vacuna de RV en México, se aprecian reducciones importantes y sostenidas en la mortalidad, hospitalizaciones e incidencia por EDA, con menor impacto en esta última. El mayor impacto se observa durante la temporada de RV.

Abstract: Objective: To evaluate the impact of rotavirus (RV) vaccination after 10 years of it´s universalization on morbidity and mortality from Acute Diarrheal Disease (ADD) in mexican children under five years of age. Materials and methods: Annual median numbers for ADD new cases, hospitalizations and deaths were compared between pre and post universalization periods; absolute and relative reductions were calculated, considering p<0.05 values as significant. Results: Mortality, hospitalizations and new cases from ADD in children under five decreased 52.6, 46, and 15.5% respectively, in the posuniversalization period. During rotavirus seasons, reduction in mortality, hospitalizations and new cases was 66.9, 64.7, and 28.7% respectively. Conclusions: As of the universal introduction of RV vaccination in Mexico, significant and sustained reductions are appreciated for mortality and hospitalizations from ADD, less so for incidence. A most prominent effect is observed during the winter season.

Zinc Supplementation and Fortification in Mexican Children.

BACKGROUND: Zinc is an essential micronutrient for human health. Approximately 1.4% of deaths worldwide are related to zinc deficiency. In Mexico, 33% of children younger than 5 years are zinc deficient. OBJECTIVE: To give an overview of zinc supplementation and fortification in children younger than 5 years through the analysis of current regulations in Mexico, the availability of these products, and the opinion of Mexican experts in this field. METHODS: We gave an overview of zinc supplementation and fortification strategies in the Mexican pediatric population by conducting a literature review of Mexican studies and national standards concerning zinc supplementation and fortification. Semistructured interviews were conducted with personnel from the main producers of zinc supplements and fortified products and from social assistance programs in Mexico. RESULTS: Zinc supplementation in Mexico has been associated with reduction in the duration and incidence of diarrhea. Through interviews with experts, we identified several barriers in achieving adequate zinc consumption such as problems in social assistance programs that distribute zinc-fortified foods, lack of specific dietary recommendations regarding the intake of zinc, lack of regulation of nonpatented zinc supplements, and inconsistencies in public health actions due to political and administrative changes. CONCLUSION: Despite current regulation and efforts made by social assistance programs, zinc deficiency continues to be a prevalent public health issue. Mexico requires an in-depth analysis of existing barriers and alternatives in order to reduce zinc deficiency.

[Population impact of rotavirus vaccination in Mexico after 10 years]. / Impacto poblacional a 10 años de la vacunación contra rotavirus en México.

OBJECTIVE: To evaluate the impact of rotavirus (RV) vaccination after 10 years of it´s universalization on morbidity and mortality from Acute Diarrheal Disease (ADD) in mexican children under five years of age. MATERIALS AND METHODS: Annual median numbers for ADD new cases, hospitalizations and deaths were compared between pre and post universalization periods; absolute and relative reductions were calculated, considering p<0.05 values as significant. RESULTS: Mortality, hospitalizations and new cases from ADD in children under five decreased 52.6, 46, and 15.5% respectively, in the posuniversalization period. During rotavirus seasons, reduction in mortality, hospitalizations and new cases was 66.9, 64.7, and 28.7% respectively. CONCLUSIONS: As of the universal introduction of RV vaccination in Mexico, significant and sustained reductions are appreciated for mortality and hospitalizations from ADD, less so for incidence. A most prominent effect is observed during the winter season.

OBJETIVO: Evaluar el impacto de la vacunación contra rotavirus (RV) a 10 años de su universalización sobre la morbimortalidad por enfermedad diarreica aguda (EDA) en niños mexicanos menores de cinco años. MATERIAL Y MÉTODOS: Se compararon las medianas anuales de casos nuevos, defunciones y hospitalizaciones por EDA del periodo pre y posuniversalización; se calcularon reducciones absolutas y relativas, considerando significativos valores de p<0.05. RESULTADOS: La mortalidad, hospitalizaciones y casos nuevos por EDA en menores de cinco años disminuyeron 52.6, 46 y 15.5% respectivamente, en el periodo posuniversalización. Durante la temporada de RV las reducciones en la mortalidad, hospitalizaciones y casos nuevos fueron de 66.9, 64.7 y 28.7%, respectivamente. CONCLUSIONES: A partir de la universaliza- ción de la vacuna de RV en México, se aprecian reducciones importantes y sostenidas en la mortalidad, hospitalizaciones e incidencia por EDA, con menor impacto en esta última. El mayor impacto se observa durante la temporada de RV.

Use of Internet Search Data to Monitor Rotavirus Vaccine Impact in the United States, United Kingdom, and Mexico.

BACKGROUND: Previous studies have found a strong correlation between internet search and public health surveillance data. Less is known about how search data respond to public health interventions, such as vaccination, and the consistency of responses in different countries. In this study, we aimed to study the correlation between internet searches for "rotavirus" and rotavirus disease activity in the United States, United Kingdom, and Mexico before and after introduction of rotavirus vaccine. METHODS: We compared time series of internet searches for "rotavirus" from Google Trends with rotavirus laboratory reports from the United States and United Kingdom and with hospitalizations for acute gastroenteritis in the United States and Mexico. Using time and location parameters, Google quantifies an internet query share (IQS) to measure the relative search volume for specific terms. We analyzed the correlation between IQS and laboratory and hospitalization data before and after national vaccine introductions. RESULTS: There was a strong positive correlation between the rotavirus IQS and laboratory reports in the United States (R2 = 0.79) and United Kingdom (R2 = 0.60) and between the rotavirus IQS and acute gastroenteritis hospitalizations in the United States (R2 = 0.87) and Mexico (R2 = 0.69) (P < .0001 for all correlations). The correlations were stronger in the prevaccine period than in the postvaccine period. After vaccine introduction, the mean rotavirus IQS decreased by 40% (95% confidence interval [CI], 25%-55%) in the United States and by 70% (95% CI, 55%-86%) in Mexico. In the United Kingdom, there was a loss of seasonal variation after vaccine introduction. CONCLUSIONS: Rotavirus internet search data trends mirrored national rotavirus laboratory trends in the United States and United Kingdom and gastroenteritis-hospitalization data in the United States and Mexico; lower correlations were found after rotavirus vaccine introduction.

Sustained Reduction of Childhood Diarrhea-Related Mortality and Hospitalizations in Mexico After Rotavirus Vaccine Universalization.

BACKGROUND: Mexico implemented routine childhood vaccination against rotavirus in 2007. We describe trends in hospitalization and deaths from diarrhea among children aged <5 years in Mexico before and 7 years after implementation of rotavirus vaccination. METHODS: We obtained data on deaths and hospitalizations from diarrhea, from January 2003 through December 2014, in Mexican children <5 years of age. We compared diarrhea-related mortality and hospitalizations in the postvaccine era with the prevaccine baseline from 2003 to 2006. RESULTS: Compared with the prevaccine baseline, we observed a 53% reduction (95% confidence interval [CI], 47%-58%) in diarrhea-related mortality and a 47% reduction (95% CI, 45%-48%) in diarrhea-related hospitalizations in postvaccine years, translating to 959 deaths and 5831 hospitalizations averted every year in Mexican children aged <5 years. Prevaccine peaks in diarrhea-related mortality and hospitalizations during the rotavirus season months were considerably diminished in postvaccine years, with greater declines observed during the rotavirus season compared with non-rotavirus season months. CONCLUSIONS: We document a substantial and sustained decline in diarrhea-related hospitalizations and deaths in Mexican children associated with implementation of rotavirus vaccination. These results highlight the public health benefits that could result in countries that adopt rotavirus vaccination into their national immunization programs.

Contribution of Mexico's Universal Immunization Program to the Fourth Millennium Development Goal.

OBJECTIVE: To identify and describe 1) progress achieved thus far in meeting the commitments of the Fourth Millennium Development Goal (MDG 4) in Mexico, mainly the contribution of the Universal Immunization Program (UIP) over the last 20 years, and 2) new opportunities for further reducing mortality among children under 5 years old. METHODS: An observational, descriptive, retrospective study was carried out to examine registered causes of death in children under 5 between 1990 and 2010. Indicators were built according to the recommendations of the United Nations. RESULTS: In 2010, deaths among children under 5 decreased 64.3% compared to the baseline (1990) figure. Of the total deaths of the children under 5, the neonatal period was the most affected (52.8%), followed by the 1 to 11 months (30.9%), and the 12 to 59 months (16.2%) groups. A 34% overall mortality reduction was observed after the universalization of immunization against influenza, rotavirus, and pneumococcus in children under 5. CONCLUSIONS: Despite a significant reduction in under-5 mortality in Mexico over the last 20 years, largely due to the successes of the UIP, several challenges remain, particularly in improving preventive and curative services during pre- and postnatal care.

Contribution of Mexico's Universal Immunization Program to the Fourth Millennium Development Goal / Contribución del Programa de Vacunación Universal de México al cuarto Objetivo de Desarrollo del Milenio

OBJECTIVE: To identify and describe 1) progress achieved thus far in meeting the commitments of the Fourth Millennium Development Goal (MDG 4) in Mexico, mainly the contribution of the Universal Immunization Program (UIP) over the last 20 years, and 2) new opportunities for further reducing mortality among children under 5 years old. METHODS: An observational, descriptive, retrospective study was carried out to examine registered causes of death in children under 5 between 1990 and 2010. Indicators were built according to the recommendations of the United Nations. RESULTS: In 2010, deaths among children under 5 decreased 64.3% compared to the baseline (1990) figure. Of the total deaths of the children under 5, the neonatal period was the most affected (52.8%), followed by the 1 to 11 months (30.9%), and the 12 to 59 months (16.2%) groups. A 34% overall mortality reduction was observed after the universalization of immunization against influenza, rotavirus, and pneumococcus in children under 5. CONCLUSIONS: Despite a significant reduction in under-5 mortality in Mexico over the last 20 years, largely due to the successes of the UIP, several challenges remain, particularly in improving preventive and curative services during pre- and postnatal care.

OBJETIVO: Determinar y describir 1) el progreso logrado hasta el momento en el cumplimiento de los compromisos del cuarto Objetivo de Desarrollo del Milenio en México, principalmente la contribución del Programa de Vacunación Universal (PVU) durante los 20 últimos años; y 2) las nuevas oportunidades para reducir aún más la mortalidad en niños menores de cinco años. MÉTODOS: Se llevó a cabo un estudio de observación, descriptivo y retrospectivo para analizar las causas registradas de muerte en niños menores de cinco años entre 1990 y el 2010. Se elaboraron indicadores según las recomendaciones de las Naciones Unidas. RESULTADOS: En el 2010, las defunciones en niños menores de cinco años se habían reducido en 64,3% en comparación con las cifras de referencia (1990). La mayor disminución de la mortalidad se observó en recién nacidos (52,8%), seguidos por los lactantes de 1 a 11 meses (30,9%) y los niños de 12 a 59 meses (16,2%). Se observó una reducción total de la mortalidad de 34% tras la universalización de la vacunación contra la gripe, el rotavirus y el neumococo en niños menores de cinco años. CONCLUSIONES: A pesar de una reducción significativa de la mortalidad en menores de cinco años en México durante los 20 últimos años, en gran parte debida a los éxitos del PVU, siguen existiendo diversos retos, en particular en cuanto a la mejora de los servicios preventivos y curativos durante la atención prenatal y posnatal.

Diarrhoea-related hospitalizations in children before and after implementation of monovalent rotavirus vaccination in Mexico.

OBJECTIVE: To assess, by socioeconomic setting, the effect of nationwide vaccination against species A rotavirus (RVA) on childhood diarrhoea-related hospitalizations in Mexico. METHODS: Data on children younger than 5 years who were hospitalized for diarrhoea in health ministry hospitals between 1 January 2003 and 31 December 2011 were collected from monthly discharge reports. Human development indexes were used to categorize the states where hospitals were located as having generally high, intermediate or low socioeconomic status. Annual rates of hospitalization for diarrhoea--per 10,000 hospitalizations for any cause--were calculated. Administrative data were used to estimate vaccine coverage. FINDINGS: In the states with high, intermediate and low socioeconomic status, coverage with a two-dose monovalent RVA vaccine--among children younger than 5 years--had reached 93%, 86% and 71%, respectively, by 2010. The corresponding median annual rates of hospitalization for diarrhoea--per 10,000 admissions--fell from 1001, 834 and 1033 in the "prevaccine" period of 2003-2006, to 597, 497 and 705 in the "postvaccine" period from 2008 to 2011, respectively. These decreases correspond to rate reductions of 40% (95% confidence interval, CI: 38-43), 41% (95% CI: 38-43) and 32% (95% CI: 29-34), respectively. Nationwide, RVA vaccination appeared to have averted approximately 16,500 hospitalizations for childhood diarrhoea in each year of the postvaccine period. CONCLUSION: Monovalent RVA vaccination has substantially reduced childhood diarrhoea-related hospitalizations for four continuous years in discretely different socioeconomic populations across Mexico.

Effect of rotavirus vaccine on diarrhea mortality in different socioeconomic regions of Mexico.

OBJECTIVE: In Mexico, declines in childhood diarrhea deaths have been documented during 2008-2010 after rotavirus vaccine introduction in 2007. Because of concerns about variation in rotavirus vaccine efficacy by socioeconomic status, we compared reductions in diarrhea mortality in the lesser developed southern region versus the more developed northern and central regions of Mexico. METHODS: We obtained data from national vital statistics on diarrhea deaths among children aged <5 years from 2002 through 2011. We compared region-specific diarrhea mortality before (2003-2006) and after (2009-2011) vaccine introduction. Regional vaccine coverage was estimated from administrative data, and socioeconomic status was assessed by using the Human Development Index. RESULTS: In northern, central, and southern Mexico, the 2007 Human Development Index was 0.84, 0.82, and 0.77, respectively, and by 2010 an estimated 99%, 84%, and 89% of children aged <12 months had completed rotavirus vaccination. Diarrhea mortality among children <5 years old declined from 8.3, 17.9, and 28.5 deaths per 100,000 children during 2003-2006 to 4.5, 8.1, and 16.2 in 2009-2011 in northern, central, and southern Mexico, respectively, corresponding to rate reductions of 45%, 55%, and 43%. No significant differences were observed in rate reductions between regions (P > .8). CONCLUSIONS: After introduction of rotavirus vaccination, marked and sustained declines in diarrhea deaths were seen among children in all regions of Mexico, including in the least developed southern region with the highest baseline diarrhea mortality. This finding indicates equitable vaccine delivery to children with varying risk of mortality and reaffirms the beneficial effects of rotavirus vaccination against fatal diarrheal disease.

Risk Factors Associated With Rotavirus Gastroenteritis During a Community Outbreak in Chiapas, Mexico During the Postvaccination Era.

BACKGROUND: In January 2010, surveillance detected a rotavirus gastroenteritis outbreak in Chiapas, Mexico. We aimed to identify risk and protective factors for developing rotavirus gastroenteritis of any severity among children in the epidemic setting. METHODS: A case-control study was conducted, comparing case patients (defined as children <36 months of age with acute gastroenteritis of any severity whose stool tested positive for rotavirus by enzyme immunoassay) with age- and municipality-matched controls. Information was obtained through face-to-face interviews on clinical outcome, demographics, breastfeeding history, rotavirus immunization status, and indicators of socioeconomic status. RESULTS: Eighty-five case patients and 170 controls were enrolled. Factors associated with lower risk of rotavirus gastroenteritis included current breastfeeding, owning a refrigerator, and being immunized with 1 or 2 doses of a live-attenuated monovalent rotavirus vaccine. History of previous diarrheal episodes and living with 7 or more people in the same household were associated with higher risk of developing rotavirus gastroenteritis. CONCLUSION: During this outbreak, dietary, socioeconomic, and environmental factors were independently associated with risk of developing rotavirus disease. Rotavirus vaccine also offered significant protection against rotavirus disease of any severity, emphasizing the value of vaccination as a simple and highly effective public health strategy for prevention of rotavirus illness.

[Diarrheal disease caused by rotavirus in epidemic outbreaks]. / Enfermedad diarreica por rotavirus en brotes epidémicos.

OBJECTIVE: Determine the epidemiological profile of outbreaks of acute diarrheal disease caused by rotavirus (RV) occurring in pediatric patients, based on a critical review of the literature published between 2000 and 2010. METHODS: A search was carried out for articles published from January 2000 to April 2010, collected by the Artemisa, EBSCO, Embase, Imbiomed, Lilacs, Ovid, PubMed, and Science Direct databases. In the studies that met the inclusion criteria, possible confounding factors were identified and risks of bias were attributed based on the number of items considered inadequate in each case. The epidemiological and microbiological characteristics of the outbreaks were described. RESULTS: The sample was comprised of only 14 (10.8%) of the 129 titles identified, which accounted for 91 092 reported cases of acute diarrhea. In 5 250 of these cases, a search for rotavirus was conducted, yielding 1 711 (32.5%) positive isolations. It was observed that the RV from Group A was the causative agent in 100% of the outbreaks, while genotype G9 was documented in 50% of the articles. CONCLUSIONS: Rotavirus, mainly serotype G9, was one of the principal agents responsible for outbreaks of acute diarrheal disease over the past decade. A careful outbreak study can contribute valuable information for RV disease control and prevention.

Enfermedad diarreica por rotavirus en brotes epidémicos / Diarrheal disease caused by rotavirus in epidemic outbreaks

OBJETIVO: Determinar el perfil epidemiológico de los brotes de enfermedad diarreica aguda por rotavirus (RV) ocurridos en pacientes pediátricos, mediante una revisión crítica de la literatura publicada entre 2000 y 2010. MÉTODOS: Se realizó una búsqueda de artículos publicados desde enero de 2000 hasta abril de 2010, recogidos por las bases de datos Artemisa, EBSCO, Embase, Imbiomed, Lilacs, Ovid, PubMed y Science Direct. En los estudios que cumplieron con los criterios de inclusión, se identificaron posibles factores de confusión y se atribuyeron riesgos de sesgo con base en el número de ítems considerados inadecuados en cada caso. Se describieron las características epidemiológicas y microbiológicas de los brotes. RESULTADOS: Solo 14 (10,8 por ciento) de los 129 títulos identificados formaron parte de la muestra, los cuales sumaron 91 092 casos de diarrea aguda notificados. En 5 250 de estos casos se realizó la búsqueda de RV, la cual arrojó 1 711 (32,5 por ciento) aislamientos positivos. Se observó que el RV del grupo A fue el agente causal en 100 por ciento de los brotes, mientras que el genotipo G9 fue documentado en 50 por ciento de los artículos. CONCLUSIONES: El RV, principalmente el serotipo G9, fue uno de los principales agentes responsables de los brotes de EDA en la última década. Un cuidadoso estudio de brote puede aportar información valiosa para el control y la prevención de la enfermedad por RV.

OBJECTIVE: Determine the epidemiological profile of outbreaks of acute diarrheal disease caused by rotavirus (RV) occurring in pediatric patients, based on a critical review of the literature published between 2000 and 2010. METHODS: A search was carried out for articles published from January 2000 to April 2010, collected by the Artemisa, EBSCO, Embase, Imbiomed, Lilacs, Ovid, PubMed, and Science Direct databases. In the studies that met the inclusion criteria, possible confounding factors were identified and risks of bias were attributed based on the number of items considered inadequate in each case. The epidemiological and microbiological characteristics of the outbreaks were described. RESULTS: The sample was comprised of only 14 (10.8 percent) of the 129 titles identified, which accounted for 91 092 reported cases of acute diarrhea. In 5 250 of these cases, a search for rotavirus was conducted, yielding 1 711 (32.5 percent) positive isolations. It was observed that the RV from Group A was the causative agent in 100 percent of the outbreaks, while genotype G9 was documented in 50 percent of the articles. CONCLUSIONS: Rotavirus, mainly serotype G9, was one of the principal agents responsible for outbreaks of acute diarrheal disease over the past decade. A careful outbreak study can contribute valuable information for RV disease control and prevention.

Enfermedad diarreica por rotavirus en brotes epidémicos / Diarrheal disease caused by rotavirus in epidemic outbreaks

Objetivo. Determinar el perfil epidemiológico de los brotes de enfermedad diarreica aguda por rotavirus (RV) ocurridos en pacientes pediátricos, mediante una revisión crítica de la literatura publicada entre 2000 y 2010. Métodos. Se realizó una búsqueda de artículos publicados desde enero de 2000 hasta abril de 2010, recogidos por las bases de datos Artemisa, EBSCO, Embase, Imbiomed, Lilacs, Ovid, PubMed y Science Direct. En los estudios que cumplieron con los criterios de inclusión, se identificaron posibles factores de confusión y se atribuyeron riesgos de sesgo con base en el número de ítems considerados inadecuados en cada caso. Se describieron las características epidemiológicas y microbiológicas de los brotes. Resultados. Solo 14 (10,8%) de los 129 títulos identificados formaron parte de la muestra, los cuales sumaron 91 092 casos de diarrea aguda notificados. En 5 250 de estos casos se realizó la búsqueda de RV, la cual arrojó 1 711 (32,5%) aislamientos positivos. Se observó que el RV del grupo A fue el agente causal en 100% de los brotes, mientras que el genotipo G9 fue documentado en 50% de los artículos. Conclusiones. El RV, principalmente el serotipo G9, fue uno de los principales agentes responsables de los brotes de EDA en la última década. Un cuidadoso estudio de brote puede aportar información valiosa para el control y la prevención de la enfermedad por RV.

Objective. Determine the epidemiological profile of outbreaks of acute diarrheal disease caused by rotavirus (RV) occurring in pediatric patients, based on a critical review of the literature published between 2000 and 2010. Methods. A search was carried out for articles published from January 2000 to April 2010, collected by the Artemisa, EBSCO, Embase, Imbiomed, Lilacs, Ovid, PubMed, and Science Direct databases. In the studies that met the inclusion criteria, possible confounding factors were identified and risks of bias were attributed based on the number of items considered inadequate in each case. The epidemiological and microbiological characteristics of the outbreaks were described. Results. The sample was comprised of only 14 (10.8%) of the 129 titles identified, which accounted for 91 092 reported cases of acute diarrhea. In 5 250 of these cases, a search for rotavirus was conducted, yielding 1 711 (32.5%) positive isolations. It was observed that the RV from Group A was the causative agent in 100% of the outbreaks, while genotype G9 was documented in 50% of the articles. Conclusions. Rotavirus, mainly serotype G9, was one of the principal agents responsible for outbreaks of acute diarrheal disease over the past decade. A careful outbreak study can contribute valuable information for RV disease control and prevention.